2-way to 3-way considerations?

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  • 4-iron
    Junior Member
    • Aug 2003
    • 13

    2-way to 3-way considerations?

    Hello...

    From a design point of view I can see the advantage of using an active crossover to 'voice' or dial in the low end of a 3-way system. But once you land on a preferred slope and crossover point, what considerations are there to 'translate' that back to a passive solution? Is it just a simple matter of adding a low pass filter to an existing 2-way? Or are all bets off when adding any other filtering components.

    Rather than trying to reinvent the wheel, I just want to improve on what I already have -- going from a proven MTM to WMTMW. This to add weight, greater dynamics to the low end and a good reason to build some new cabinets! Also to better match with the large sub -- which will cover the very lowest of frequencies.

    I appreciate your thoughts.

    Paul
  • ThomasW
    Moderator Emeritus
    • Aug 2000
    • 10934

    #2
    The down side of using passive components for any woofer or subwoofer is the loss of sound quality.

    This is due in part to the large inductors needed, and their effect on the damping factor of the power amp

    Also the raw component count doubles when going from a 2-way to a 3-way. And as we all know the fewer items in the signal path the better.

    Finally if high quality passive components are used they can frequently equal the cost of an active filter.

    But yes the implementation of the passive design is pretty much just copying what you created with the active filter.




    theAudioWorx
    Klone-Audio

    IB subwoofer FAQ page


    "Complicated equipment and light reflectors and various other items of hardware are enough, to my mind, to prevent the birdie from coming out." ...... Henri Cartier-Bresson

    Comment

    • intelonetwo
      Member
      • Jan 2003
      • 48

      #3
      From a design point of view I can see the advantage of using an active crossover to 'voice' or dial in the low end of a 3-way system.
      You are correct the active crossover will allow more options when trying to obtain the best sound in your room with your speakers, but not only in the low registers. The high end also benefits from being actively crossed over and/or actively amplified.

      I am currently bi-amping my system using a digital Eq. Many people have also used other digital xo's, and Eq's with some sort of room correction to obtain the best sound in a room with specific speakers.

      The Eq I am using (Behringer UltraCurve Pro DEQ 24/96) offers auto room Eq, and a Feedback Destroyer, all of which will taylor the sound of the speakers in a particular space. It has been a revealing experience to say the least.

      Another benefit of actively amplifying/crossing over your speakers is that you need less power to drive the speaker. Partly because of what ThomasW eluded to, passive components will suck power away from your amplifier as the signal is being passed through these components, thus leaving less power for the speakers as well as damaging the sound quality to a varyijng degree.




      MI-II-CENTS
      ______________
      The TailWind Generation I

      Comment

      • 4-iron
        Junior Member
        • Aug 2003
        • 13

        #4
        Hello...

        I know all too well of the extra cost of upper end crossover components. I purchased North Creek's Rhythm and Borealis info kit back when they were including the crossover schematics and such. Less than a month afterwards they changed their policy by lowering the price of the info kit, but choose not to include the schematics anymore. I was lucky when I got mine. They also decided to sell completed assemblies only - furthering the cost due to tech labor. Prior to that change, you could save by doing the soldering yourself - and for most of us that's part of the fun of DIY anyway, right?

        Anyway, I sat on this for a while and decided to go with AlphaCore 12 ga inductors, Mills resistors and Reliable MultiCap capacitors of varying degrees of boutiqueness in the critical areas. Solen caps for the larger sized shunt caps. My point is that I was able to pick and choose from a variety of high quality components and still save a substantial amount of money which funded other upgrades such as Cardas hookup wire and binding posts. The crossovers are nearly as costly as the drivers! So, I really don't want to retire them if I don't have to.

        This brings me to the new project and my reason for this thread. A North Creek Rhythm - Nova Rendition II hybrid. Nova uses the same SS drivers and crossover points as does North Creek for the MTM portion - 1.8 KHz - although from different topologies. Nova lists the crossover point for the woofer section at 100 Hz. So, I figured it was a natural to hit the workshop, add a couple of 8" SS 8555-01s and then do some serious voicing and such.



        I love the overall size of the Rendition (12.5" x 60" x 20.75") and although going with the larger 10" woofers looked very appealing initially, pragmatically it definitely wouldn't pass the SOF! Just too big of a footprint!

        So, from what I gather thus far I should start looking with earnest at the Marchand site for some ideas. Any other electronic crossover candidates I should be looking at?

        Also, any suggestions for slope? First order maybe?

        Thank you again for listening to my ramblings. As you can see, I'm getting kind of goofy just thinking about it!

        Paul

        Comment

        • intelonetwo
          Member
          • Jan 2003
          • 48

          #5
          You could look at the digital xo's made by dbx, behringer, and other notable companies. Althought the dbx is probably the most popular and flexible all in one unit.




          MI-II-CENTS
          ______________
          The TailWind Generation I

          Comment

          • ThomasW
            Moderator Emeritus
            • Aug 2000
            • 10934

            #6
            The proper way to design a XO is to measure the drivers in the baffles where they are going to be used. Don't trust the mfgr's specs, they don't represent your particular speaker.

            This measured data along with the driver's T/S parameters are then fed into a XO design program. LspCAD has a good one. Then the first XO is designed and built. A new set of measurements is taken and decisions are made depending on the results.

            Because it's so important I'll state this again; without actual in baffle testing, one can not make an optimal XO design. Using the mfgr's specs or randonly deciding on a topology is a recipe for disaster.

            XO topology decisions are based on using what's need to obtain optimal interaction between the drivers, the baffle and the room.

            Note that in baffle testing should be done with a quality calibrated mic and mic preamp, combined with a MLS software program. 1/3rd octave RTA's and or Radio Shack SPL meters aren't adequate to the task.




            theAudioWorx
            Klone-Audio

            IB subwoofer FAQ page


            "Complicated equipment and light reflectors and various other items of hardware are enough, to my mind, to prevent the birdie from coming out." ...... Henri Cartier-Bresson

            Comment

            • 4-iron
              Junior Member
              • Aug 2003
              • 13

              #7
              Well, I feel like I just went to the high school prom with a trophy date, only to find that she left for the evening with someone else! Put down the soldering gun, Paul - and slowly back away. :boohoo:

              I appreciate all your help. Notwithstanding, it seems a bit premature at this point to ask any further questions. My task now is to shelve this idea until such time I can afford the equipment and software you suggest. Sadly, from what I can tell, about a couple grand or so for quality product - (Clio, LMS, Leap, LspCAD, B&K, Sencore and the like).

              Now, back to the grind stone... :conveyer:
              Paul

              Comment

              • ThomasW
                Moderator Emeritus
                • Aug 2000
                • 10934

                #8
                Probably better to ask the 'how-to' question first, but don't dispare.....

                Here's the bottom line for test gear and software. If you have the bucks to pony up for high-end components you listed, these shouldn't break the bank. Note that this stuff will give you years of service.

                Behringer ECM-8000 mic $40
                Behringer Eurorack 604A $80
                LspCAD, includes XO design and JustMLS software $129
                Someone's low buck mic cable ~$15
                Someone's True RMS digital multimeter ~$70

                See it didn't hurt all that much to get back into the dance, did it?

                arty:




                theAudioWorx
                Klone-Audio

                IB subwoofer FAQ page


                "Complicated equipment and light reflectors and various other items of hardware are enough, to my mind, to prevent the birdie from coming out." ...... Henri Cartier-Bresson

                Comment

                • Dennis H
                  Ultra Senior Member
                  • Aug 2002
                  • 3791

                  #9
                  Yep, the trophy date just went to the bathroom and now she's back with love in her eyes. :LOL:

                  Comment

                  • 4-iron
                    Junior Member
                    • Aug 2003
                    • 13

                    #10
                    Excellent! Even a blind dog can find a bone once in a while! :eating: Clearly, your financial pill is much easier to swallow than mine. Thank you! ;x(

                    So, the quest is on. I should have all that was listed by next week's end. In the mean time, it's time to get back out into the workshop and build a pair of prototype cabinets for measurements. There's plenty of work to be done!

                    The saga continues... :dance:
                    Paul

                    Comment

                    • Hank
                      Super Senior Member
                      • Jul 2002
                      • 1345

                      #11
                      Wow, I didn't realize that software was so inexpensive. I've seen references to the quality software being several hundreds to over a thousand dollars. I assume the LSPCad in reference is a Light version, and I was under the impression that it wouldn't be everything needed to design a full-range speaker/crossover. What does the full/pro version get you? Also, I recently read the poop on the latest version of Soundeasy software and it seems excellent.

                      Comment

                      • JonMarsh
                        Mad Max Moderator
                        • Aug 2000
                        • 15272

                        #12
                        HI Hank,

                        The $129 version of LSPCAD really is a "standard" version, not a "lite" version, IMO. I've used both the Pro (an older rev), but currently just use the standard version. The Pro version includes filter emulation in the PC, using it's sound card, so in principle you can plug the outputs of your sound card into an amplifier and run a mult-channel emulation of your crossover filters. Takes a little bit of horsepower, but not that much.

                        The "Standard" version is quite complete as a development tool, with a full optimizer, the ability to save and store multiple network values and response sets in a single project file; it's really a very nice piece of software, and comes also with a free measurment program, "JustMLS", which would allow one with a Behringer mic and preamp to get started right away...
                        Having a full CLIO setup (as I do) is nicer, but you can get an awful lot done (if you know what you're doing, or willing to read and learn) with the standard version of LSP CAD. I have a Behringer ECM8000 and a dual channel MAudio mic preamp, with "deluxe" cables from Radio Shack, as a back up/comp to the HP preamp and B&K 1/2" condensor mic setup I usually use. As long as you use a mic cal file above 12 kHz, to compensate for the slight roll off of the Behringer, it gives great results (even without, as long as you understand what the mic is doing, for 90% of stuff it's fine).

                        Regards,

                        Jon




                        Earth First!
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                        the AudioWorx
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                        Comment

                        • Hank
                          Super Senior Member
                          • Jul 2002
                          • 1345

                          #13
                          Thanks Jon. I've just read more user comments re Soundeasy and the new version is tempting. I do remember your recommending the Behringer mic and preamp (analog meters do have a certain nostalgic appeal, don't they?), and I do respect your and Thomas' advice.
                          Also, glad to read that you're using Dee-Lux RS cables for accurate readings :roll:
                          Sent your resume to Austin yet?

                          Comment

                          • ThomasW
                            Moderator Emeritus
                            • Aug 2000
                            • 10934

                            #14
                            SoundEasy???

                            Jusy say no to dongles :blowup:




                            theAudioWorx
                            Klone-Audio

                            IB subwoofer FAQ page


                            "Complicated equipment and light reflectors and various other items of hardware are enough, to my mind, to prevent the birdie from coming out." ...... Henri Cartier-Bresson

                            Comment

                            • JonMarsh
                              Mad Max Moderator
                              • Aug 2000
                              • 15272

                              #15
                              Also, glad to read that you're using Dee-Lux RS cables for accurate readings
                              Well, I'll know I'm really doing well when I can afford Ayre Signature series balanced interconnects for my Mic preamp! Hey, I even use a premium Rat Shack phone plug cable for the connect between the preamp and CLIO system input! No expense spared!

                              And did I mention I buy the Euroblock power connectors at RS for the crossover board interface wiring?

                              Hey, I'm a RS guy through and through, when they have the appropriate technology at the appropriate price. Their 8 ohm 20 watt non-inductive resistors aren't bad, either.

                              And they had an orange 75 ohm digital audio cable that looked like the connectors were made by Monster, which has the lowest TDR I've ever measured on an RCA based digital audio cable under $100. Too bad it's so butt ugly, with the dayglo orange jacket.

                              Well, haven't sent that resume out, our Austin office is just a memory design group; I wouldn't really fit in there.... :B


                              ~Jon




                              Earth First!
                              _______________________________
                              We'll screw up the other planets later....
                              the AudioWorx
                              Natalie P
                              M8ta
                              Modula Neo DCC
                              Modula MT XE
                              Modula Xtreme
                              Isiris
                              Wavecor Ardent

                              SMJ
                              Minerva Monitor
                              Calliope
                              Ardent D

                              In Development...
                              Isiris Mk II updates- in final test stage!
                              Obi-Wan
                              Saint-Saëns Symphonique/AKA SMJ-40
                              Modula PWB
                              Calliope CC Supreme
                              Natalie P Ultra
                              Natalie P Supreme
                              Janus BP1 Sub


                              Resistance is not futile, it is Volts divided by Amperes...
                              Just ask Mr. Ohm....

                              Comment

                              • Eduardo
                                Moderator emeritus
                                • Jun 2002
                                • 1258

                                #16
                                Hey - I use the RS Orange Coax Cable. I liked the Orange color. Helps me identify DVD audio cable. It only cost $15 (open package). :T




                                http://home.nc.rr.com/ejimenez

                                Comment

                                • Hank
                                  Super Senior Member
                                  • Jul 2002
                                  • 1345

                                  #17
                                  Jusy say no to dongles
                                  Uh-oh, there may be one of Thomas' hidden messages in there. Okay, what's wrong with Soundeasy? Out with it.

                                  Jon, I'm 56 and made my first significant RS purchase at about age 17, buying an H.H. Scott integrated tube amp kit, the LK-48B, which I still have and plan to refurb. Some say those Scott amps were so well engineered that they sound as good as the new megabuck botique tube amps.

                                  Another tip: RS sells so many batteries, theirs are usually the freshest in town.

                                  If I wouldn't be embarrassed as a fool, I'd tell you guys about last evening in the garage when I had my dust collector turned on and was holding the 4" dia hose in front of the table saw blade doing a tad of front baffle tweaking. Turned off the saw and came a wee bit too close to my cordless phone with the DC hose......SUCK! WHOOSH! POP! CRACK! RATTLE! click...click...whirr...
                                  I peeked in the transparent window of the DC bag and there amongst the MDF dust was my former cordless phone in all its component glory. It was meant to be - the phone was going downhill and earlier yesterday I said to myself: "Self, we need to check out a new cordless phone at Costco (or RS?).
                                  Don't tell anybody that story - I would be embarrassed. ops:
                                  I think I'll go to a meeting now...

                                  -Dilbert

                                  Comment

                                  • ThomasW
                                    Moderator Emeritus
                                    • Aug 2000
                                    • 10934

                                    #18
                                    Uh-oh, there may be one of Thomas' hidden messages in there. Okay, what's wrong with Soundeasy? Out with it
                                    Hidden messages who, me???

                                    For SoundEasy to run one must use a hardware 'dongle' that attaches to the printer port. Forget or lose your 'dongle' and the software won't run.

                                    Jon used SE for several versions, then abandoned it a couple of rev levels ago.

                                    Does that tell you something?

                                    BTW, the 'phone' story is TOO funny......TGFC (thank goodness for Costco) :righton:




                                    theAudioWorx
                                    Klone-Audio

                                    IB subwoofer FAQ page


                                    "Complicated equipment and light reflectors and various other items of hardware are enough, to my mind, to prevent the birdie from coming out." ...... Henri Cartier-Bresson

                                    Comment

                                    • JonMarsh
                                      Mad Max Moderator
                                      • Aug 2000
                                      • 15272

                                      #19
                                      Well, Hank, that's why I don't have a dust collection system... I know my limitations and the kinds of things I'm likely to do under some circumstances...

                                      BTW, how'd the meeting go?




                                      Earth First!
                                      _______________________________
                                      We'll screw up the other planets later....
                                      the AudioWorx
                                      Natalie P
                                      M8ta
                                      Modula Neo DCC
                                      Modula MT XE
                                      Modula Xtreme
                                      Isiris
                                      Wavecor Ardent

                                      SMJ
                                      Minerva Monitor
                                      Calliope
                                      Ardent D

                                      In Development...
                                      Isiris Mk II updates- in final test stage!
                                      Obi-Wan
                                      Saint-Saëns Symphonique/AKA SMJ-40
                                      Modula PWB
                                      Calliope CC Supreme
                                      Natalie P Ultra
                                      Natalie P Supreme
                                      Janus BP1 Sub


                                      Resistance is not futile, it is Volts divided by Amperes...
                                      Just ask Mr. Ohm....

                                      Comment

                                      • Hank
                                        Super Senior Member
                                        • Jul 2002
                                        • 1345

                                        #20
                                        I hate it when I misplace my dongle. :spin:
                                        Seriously, you guys wouldn't take a fresh, objective look at Soundeasy?

                                        Hey, cut me some slack - that's the only item I've unwittingly sucked into the DC, and as I said it was meant to be. Also, hooray for refurbished items on Ubid. The impeller blades on my dust collector were unscathed - heavy duty. I love my dust collector. Talk about value and rated top-performing, I bought a Penn State DC2-5.

                                        Meeting? Another thrilling, action-packed corporate meeting. I think tomorrow will be particularly unproductive: meetings most of the day. Some days you're just unlucky. :conveyer:

                                        Comment

                                        • JonMarsh
                                          Mad Max Moderator
                                          • Aug 2000
                                          • 15272

                                          #21
                                          I think tomorrow will be particularly unproductive: meetings most of the day. Some days you're just unlucky.
                                          That's why I'm a "lab rat" - helps keep me out of unproductive meetings! I don't even have a cubicle... :banana:

                                          Bohdan has done a lot of great development with the last two updates to Soundeasy, but I guess there are two factors at work here. One, I hate dongles, already have way too many of them. I have an old version of Soundeasy that won't even run anymore because the dongle driver won't work under XP or WIN2K. I do have 98SE on one PC, but it's the audio test PC; these days the most common place I get to work on crossover design is on the train to and from work; if I was tied to only running my crossover development stuff on the same box as the test hardware, that would be a major pain in the @ss.

                                          Number two issue is mental bandwidth, and available time for learning new programs, or new ways of doing things. Right now, LSPCAD is working well for me, and gives good support for the level of "what if?" and juggling alternate configurations that I like to do. I have a modest library of designs in it, plus custome designs I've whipped up for others; that wouldn't be transferrable. So, I'd have to have a compelling reason to switch; right now, I'd rather invest the time it would take, and the money, in other things. If I had more time and money available, it might be another matter. Many things in my life have to work this way- for example, there are other CAD programs for drawing that might be superior to good old AutoCAD 2000 which I currently use, but would the cost and learning curve make it worthwhile? I dunno. If I had the bucks, at this point I probably would go for AutoCAD 2004, but that is a $2500 upgrade, not to be taken lightly. Used to be AutoCAD just cost $2500 outright, at one time! $2500 is a nice CD player or preamp; or one heck of a saw; since I can get AutoCAD 2000 to pretty much do everything I need, an incremental upgrade that's fast and prettier is a tough sell at that price. At least AutoCAD and Protel, my main CAD systems, don't have dongles!

                                          ~Jon




                                          Earth First!
                                          _______________________________
                                          We'll screw up the other planets later....
                                          the AudioWorx
                                          Natalie P
                                          M8ta
                                          Modula Neo DCC
                                          Modula MT XE
                                          Modula Xtreme
                                          Isiris
                                          Wavecor Ardent

                                          SMJ
                                          Minerva Monitor
                                          Calliope
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                                          In Development...
                                          Isiris Mk II updates- in final test stage!
                                          Obi-Wan
                                          Saint-Saëns Symphonique/AKA SMJ-40
                                          Modula PWB
                                          Calliope CC Supreme
                                          Natalie P Ultra
                                          Natalie P Supreme
                                          Janus BP1 Sub


                                          Resistance is not futile, it is Volts divided by Amperes...
                                          Just ask Mr. Ohm....

                                          Comment

                                          • Dennis H
                                            Ultra Senior Member
                                            • Aug 2002
                                            • 3791

                                            #22
                                            AutoCAD 2000
                                            Man, that's ultramodern by my standards! For drawing house plans, I'm still running the DOS version of Release 12 with the ArchT add-on. Don't need no steenking Weendows. :banana:

                                            Comment

                                            • ThomasW
                                              Moderator Emeritus
                                              • Aug 2000
                                              • 10934

                                              #23
                                              Dennis

                                              Don't worry 'retro' is in vogue now......... :yeah:

                                              Hank

                                              What we (Jon and I) can't say on a public forum, is "on general principles" that we don't like any product that JohnK (Mr "Transient Perfect XO") hypes... :smackbutt:




                                              theAudioWorx
                                              Klone-Audio

                                              IB subwoofer FAQ page


                                              "Complicated equipment and light reflectors and various other items of hardware are enough, to my mind, to prevent the birdie from coming out." ...... Henri Cartier-Bresson

                                              Comment

                                              • Hank
                                                Super Senior Member
                                                • Jul 2002
                                                • 1345

                                                #24
                                                Jon, the learning curve will be long and steep for me, no matter which product I eventually buy, so your reason for sticking with LSPCAD doesn't apply to me. I will heavily weight you Poohba's advice for sure though.

                                                Thomas, I'm not familiar with JohnK and his transient-perfect crossover designs (got a nice ring though). I'm trying to be objective here. If Osama liked BMW's, that would not be reason for me to not consider buying one.

                                                Thanks for the advice, Poohbah's. It appears LSPCAD has staunch supporters, and it IS less expensive than Soundeasy, so it may be in the lead. Is there an updated version on the horizon?

                                                Comment

                                                • JonMarsh
                                                  Mad Max Moderator
                                                  • Aug 2000
                                                  • 15272

                                                  #25
                                                  If Osama liked BMW's, that would not be reason for me to not consider buying one.
                                                  You gotta understand, Hank, that ThomsW is not above a little chain pulling now and then, and besides funnin' us here on the HT Guide board, his favorite targets tend to be those which could be perceived at times as a bit holier than thou with regards to their technical opinions, even when up against folks like Sigfried Linkwitz. I don't think JohnK has even heard an Orion; some day he ought to try it. (I have, just for the record (see No. Cal DIY coverage))- I would award it the some kind of title for "Best DIY Design", excpet that Sigfried is no more a DIY amateur than I'm Osama Bin Laden.

                                                  SoundEasy has undergone a tremendous amount of eveloution in the last 18 months, with a lot of useful feedback being taken from many users.

                                                  Ingemar has been working on a totally revamped version of LSPCAD (may even result in a bit of a learning curve for me!), but he's not talking publicly about how that's progressing, just dropping hints occasionally in email.

                                                  You can download a brochure, and see a feature comparison for standard vs. Pro at his site.

                                                  One thing that might be helpful for you starting out is that the filter development system has two main modes , simple, and advanced; the former does a lot of the work for you, including setting up the network topology for the crossover function you specify (3rd order Butterworth, 4th order L-R, whatever), while the advanced mode allows you to create pretty much any ladder network configuration you want- lot's of opportunities for customization, or digging yourself a really deep hole!




                                                  I realize that for you, starting from scratch, there's probably not much difference in the learning curve, and I can't comment specifically on how hard or easy the newer versions of Soundeasy are. I was just trying to relate to you why I haven't gone out and jumped on the latest piece of software from him.

                                                  I'd suggest going to both sites, downloading the available info, and see what appeals to you.

                                                  BTW, I also like the ability to export specific windows as well as screens, and printing options; I really didn't like what the older version of Soundeasy didn't do (next to nothing; had to use Print Screen a lot) for graphical output. I'm sure that's much improved, now.

                                                  Best regards,

                                                  Jon




                                                  Earth First!
                                                  _______________________________
                                                  We'll screw up the other planets later....
                                                  the AudioWorx
                                                  Natalie P
                                                  M8ta
                                                  Modula Neo DCC
                                                  Modula MT XE
                                                  Modula Xtreme
                                                  Isiris
                                                  Wavecor Ardent

                                                  SMJ
                                                  Minerva Monitor
                                                  Calliope
                                                  Ardent D

                                                  In Development...
                                                  Isiris Mk II updates- in final test stage!
                                                  Obi-Wan
                                                  Saint-Saëns Symphonique/AKA SMJ-40
                                                  Modula PWB
                                                  Calliope CC Supreme
                                                  Natalie P Ultra
                                                  Natalie P Supreme
                                                  Janus BP1 Sub


                                                  Resistance is not futile, it is Volts divided by Amperes...
                                                  Just ask Mr. Ohm....

                                                  Comment

                                                  • Hank
                                                    Super Senior Member
                                                    • Jul 2002
                                                    • 1345

                                                    #26
                                                    ThomsW is not above a little chain pulling now and then, and besides funnin' us here on the HT Guide board, his favorite targets tend to be those which could be perceived at times as a bit holier than thou with regards to their technical opinions, even when up against folks like Sigfried Linkwitz.
                                                    Nooo...I hadn't noticed :roll:
                                                    Yes, I think I noticed a tad of that friction with the designer from the South of France :argue:
                                                    Anyway, thanks for your patient input - I will take heed.
                                                    Lunch is over; gotta call our Japanese buds in CA now. Reality reaches up and bites me in the butt.

                                                    Comment

                                                    • Dennis H
                                                      Ultra Senior Member
                                                      • Aug 2002
                                                      • 3791

                                                      #27
                                                      Jon, I'm in the same boat as Hank - I'd have to learn something from scratch. I have a question about the 'working style' of the two programs.

                                                      I've read through Ingemar's Ugly Duckling tutorial and something strikes me as a bit odd. He designs an active filter and then uses that transfer function as the target for the electrical output of a passive filter. But for that to work, he has to flatten the impedance perfectly so that takes a whole bunch more components. It doesn't seem like that would be the way to design the most elegant (low parts count) crossover. One filter stage may be 'doing something' and the next may be 'undoing it again.' Soundeasy lets you work with passive components from the beginning and calculates the real interaction between the XO and the driver. I'm wondering if that might let you design a more elegant (there's that word again) XO or if it would just let you dig yourself a deeper hole?

                                                      Edit: as an aside, shouldn't Ingemar have put the impedance flattening networks on the drivers before he measured them? They will probably change the amplitude and phase response which in turn will change the required electrical transfer function of the filters.

                                                      Comment

                                                      • JonMarsh
                                                        Mad Max Moderator
                                                        • Aug 2000
                                                        • 15272

                                                        #28
                                                        Hi Dennis,

                                                        I think that using Ingemar's article about the Ugly Duckling as a "first tutorial" could be more than a bit confusing for someone that wan't really pretty well grounded in EE basics. The short tutorial is a little better, but better still is the actual crossover manual.

                                                        LspCAD, even in it's earlier versions, gave a lot of flexibility, including the ability to combine active and passive network configurations, and move back and forth between the two. That's not what I would call "entry level" technique. For a reasonable discussion of crossover optimization basics, the third part of the M8a article which I wrote for AudioXpress touches on some important points, especially for the case of pure passive crossovers. But still, it's not a step by step tutorial.

                                                        The good thing about the Ugly duckling tutorial is that he does touch on some of the more difficult topics in a fairly useful way, including the effects of room interaction, modeling this effect, baffle step effects, and diffraction effects. But some of this is reall only relevant if you're trying to model the whole speaker, cabinet, and room interface, and need to for the purpose of your crossover design. That's not always necessary; a lot of the issues can get taken care of best simply by intelligent room placement; and measuring what you actually have from the speaker, as opposed to trying to simulate it also. A crossover can't adequately compensate in many cases for bad speaker positioning (see part one of my AudioXpress article).

                                                        Some other points in your questions bear addressing. The zobel networks are necessary to flatten impedance with a PASSIVE crossover network, not with an active- you don't need to flatten it unless you're running a tube amp with a high output impedance. The problem is that the varying impedance (for example, LF tweeter resonance) interacts with the frequency varying impedance of the network filter, and produces a response unexpected from what the filter would do into a resistive load- that can mean just a gradual slope deviation from the expected response, or with a driver LF impedance peak, a big bump in the response. This is why it's hard to create passive filters for dynamic drivers in the lower frequency ranges, such as a passive sub crossover at 100-125 Hz. It can be done, but there the big variations in the driver impedance are very near the network corner frequencies.
                                                        With an active crossover with good amps with low output impedance, there isn't any impedance interaction with the driver- the amplifier just delivers a consistent output voltage, and the current depends on the load.

                                                        Doing a passive crossover with LSPCAD is not that different from any of the other programs, at it's fundamentals. Basically, you're going to make amplitude and impedance measurements of the drivers, and import that data into your project. Then, you have to use your best judgement about what crossover frequencies and filter slopes you need to use, based on the capabilities of the driver and staying within there comfortable range- i.e, not too low for tweeters and mids to provoke distortion due to excursion limits, not to high for woofers and mid woofers to get into cone breakup modes. You setup the target transfer functions for the "acoustical" response of the filter, then optimize the combination of the measured driver response and the simulated filter response to hit that target.

                                                        Both frequency response and impedance curves give the designer a lot of clues- again, not to be a broken record, but my article for AudioXpress is not just how to build these specific speakers, but a lot of material re the philosphy and reasoning behind some straight forward methods. As ThomasW put it after reading the first draft, it's as much a tutorial about DIY speaker design and construction, as it is about building this specific set.

                                                        Well, dinner's ready, gotta run. Hope this helps a little.

                                                        Regards,

                                                        Jon




                                                        Earth First!
                                                        _______________________________
                                                        We'll screw up the other planets later....
                                                        the AudioWorx
                                                        Natalie P
                                                        M8ta
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                                                        Modula Xtreme
                                                        Isiris
                                                        Wavecor Ardent

                                                        SMJ
                                                        Minerva Monitor
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                                                        In Development...
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                                                        Resistance is not futile, it is Volts divided by Amperes...
                                                        Just ask Mr. Ohm....

                                                        Comment

                                                        • Dennis H
                                                          Ultra Senior Member
                                                          • Aug 2002
                                                          • 3791

                                                          #29
                                                          Big reply deleted. They more I type the more I confuse myself. :LOL:

                                                          Anyway, as always...... :amen:

                                                          Comment

                                                          • Davey
                                                            Senior Member
                                                            • Jan 2003
                                                            • 355

                                                            #30
                                                            The new version of SoundEasy is very powerful, but it still pails in user-friendliness compared with LspCAD. If a person is just starting out and looking for the best/easiest program it's a no-brainer IMHO. I'd get LspCAD Standard edition.

                                                            Cheers,

                                                            Davey.

                                                            Comment

                                                            • ThomasW
                                                              Moderator Emeritus
                                                              • Aug 2000
                                                              • 10934

                                                              #31
                                                              Hank, Dennis, et al,

                                                              If I was a speaker design noob here's what I'd do.......

                                                              Grap LspCAD standard
                                                              Grab the last 3 issues of AudioXpress (Sept/Oct/Nov)

                                                              Ask Jon to sent via email his LspCAD files for the final version of the M8a-MKIV. (Actually for greater convenience we could probably get him to upload them to a server now that the entire article has been published)

                                                              As previously stated Jon's article is virtually a treatise on loudspeaker design. So armed with the article and the LspCAD files, one could 'reverse' engineer the M8a design. This would allow a person to see the how and why of this particular design, with an accompanying narration from the designer. Then questions could be ask and answered in a new thread.

                                                              This approach should go a long way toward helping person create their own speakers, using similar design concepts.

                                                              And (inside joke time now) no they don't design speakers this way in the 'south' of France. :banana:




                                                              theAudioWorx
                                                              Klone-Audio

                                                              IB subwoofer FAQ page


                                                              "Complicated equipment and light reflectors and various other items of hardware are enough, to my mind, to prevent the birdie from coming out." ...... Henri Cartier-Bresson

                                                              Comment

                                                              • Brian Bunge
                                                                Super Senior Member
                                                                • Nov 2001
                                                                • 1389

                                                                #32
                                                                Thomas,

                                                                Is the Nov. issue out already? I must have waited too late to send in my renewal check! I better hit the newstands!

                                                                Comment

                                                                • ThomasW
                                                                  Moderator Emeritus
                                                                  • Aug 2000
                                                                  • 10934

                                                                  #33
                                                                  Brain

                                                                  My Nov issue arrived mid week.




                                                                  theAudioWorx
                                                                  Klone-Audio

                                                                  IB subwoofer FAQ page


                                                                  "Complicated equipment and light reflectors and various other items of hardware are enough, to my mind, to prevent the birdie from coming out." ...... Henri Cartier-Bresson

                                                                  Comment

                                                                  • Dennis H
                                                                    Ultra Senior Member
                                                                    • Aug 2002
                                                                    • 3791

                                                                    #34
                                                                    Thanks for the replies guys. Just to be clear, I understand the basics of designing a speaker using either active or passive crossovers (maybe just enough to be dangerous :LOL: ). My misunderstanding was about how LspCAD works but I think I've got a bit more of a handle on it now.

                                                                    At a glance, I still think Ingemar's XO looks kludgy (5 coils on a midrange?) but maybe it really is optimum.

                                                                    I'd love to read Jon's articles but I don't have access to them so I'll just pick up whatever crumbs of wisdom I can here and there until I can get my hands on them.

                                                                    :amen:

                                                                    Comment

                                                                    • 4-iron
                                                                      Junior Member
                                                                      • Aug 2003
                                                                      • 13

                                                                      #35
                                                                      I've seen SoundEasy advertised at OrcaDesign.com, but having no experience with any of the offerings available out there, I thought it would be just as easy to go down the laundry list of items Thomas enumerated above and go from there. My thinking is to learn from those whom have gone before -- and then venture out. :amen: And realistically, the $129.00 asking price is more than a bargain for LsdCAD if there's any truth in advertising.

                                                                      And that was a great story, Hank. I can't say I've lost a phone to the dust collector, but I can relate -- watching my son suck up his mom's cheap digital camera last year! Very close to the way you described your phone loss! :uhoh:

                                                                      Now, back to the workshop and the smell of fresh cut lumber!

                                                                      Paul

                                                                      Comment

                                                                      • Mark K
                                                                        Senior Member
                                                                        • Feb 2002
                                                                        • 388

                                                                        #36
                                                                        My 2 cents.

                                                                        I've got both the standard version of LspCAD and SE version 8. They both work well to do straightforward 2 and 3 ways. LspCAD is cheaper and Ingmar has provided updates for free, so far. I agree with Davey that LspCAD has a gentler learning curve, but that the current version of SE has a broader range of features and flexibility.

                                                                        I learned LspCAD first and am currently still doing my projects in it. However, I'm working hard to figure out SE and think that it has some nifty advantages. Version 8 is certainly slicker than my previous version, 6, and works well under w2k.

                                                                        Neither one comes with Crossover design for dummies and I've seen more than a couple get frustrated and sell their copy used. Fwiw, John K has written tutorials for both LspCAD and SE, though he's partial to SE. Regardless of whether you like him, his site is very helpful and he's done alot for the diy community. He's taken down his tutorials, feeling they are obsolete, but is working on a new one, for SE at least, and you can find his tutorial on LspCAD if you hunt around.

                                                                        I think that Thomas' idea of using Jon's files is a good one. I, for one think Jon should just spend a couple weekends making a powerpoint presentation/tutorial as he seems to have so little to do these days :P

                                                                        Both have measurement packages. I haven't looked at the one for LspCAD, but have checked out the one with SE and it actually is quite full featured-mls/sine/waterfall/rta.

                                                                        Anyway, both work well and you really won't be disappointed whichever you chose. Remember though, the programs are quite stupid, in a way, and you can really get some garbage ciruits/results if you're not sure about what you're doing. As long as you think figuring it out is half the fun, then you'll be fine.
                                                                        www.audioheuristics.org

                                                                        Comment

                                                                        • ThomasW
                                                                          Moderator Emeritus
                                                                          • Aug 2000
                                                                          • 10934

                                                                          #37
                                                                          HERE's a link to the LspCAD users group. There, people can communicate directly with Imgemar himself, and with other LspCAD users.




                                                                          theAudioWorx
                                                                          Klone-Audio

                                                                          IB subwoofer FAQ page


                                                                          "Complicated equipment and light reflectors and various other items of hardware are enough, to my mind, to prevent the birdie from coming out." ...... Henri Cartier-Bresson

                                                                          Comment

                                                                          • JonMarsh
                                                                            Mad Max Moderator
                                                                            • Aug 2000
                                                                            • 15272

                                                                            #38
                                                                            Mark makes a lot of good points- I should have remembered JohnK's tutorials, but I've never read them myself- from what I've heard from others, you should check them out.

                                                                            And Mark, I'll get right to work on that PowerPoint tutorial, I don't know why I've been putting it off so long. Hmmm, where's my to-do list for this weekend. Uh-oh. How come the first six things are Infineon related? Geez, lately I never seem to get beyond item 4 on the weekend to-do lists, either. :cry: Maybe that explains it...

                                                                            (I'm even going to be gone on business in Europe during part of the "mandatory shutdown" week for Thanksgiving this year... :? )

                                                                            And no, there's no veneer on those hard to build cabinets of mine, yet. :boohoo:


                                                                            ~Jon




                                                                            Earth First!
                                                                            _______________________________
                                                                            We'll screw up the other planets later....
                                                                            the AudioWorx
                                                                            Natalie P
                                                                            M8ta
                                                                            Modula Neo DCC
                                                                            Modula MT XE
                                                                            Modula Xtreme
                                                                            Isiris
                                                                            Wavecor Ardent

                                                                            SMJ
                                                                            Minerva Monitor
                                                                            Calliope
                                                                            Ardent D

                                                                            In Development...
                                                                            Isiris Mk II updates- in final test stage!
                                                                            Obi-Wan
                                                                            Saint-Saëns Symphonique/AKA SMJ-40
                                                                            Modula PWB
                                                                            Calliope CC Supreme
                                                                            Natalie P Ultra
                                                                            Natalie P Supreme
                                                                            Janus BP1 Sub


                                                                            Resistance is not futile, it is Volts divided by Amperes...
                                                                            Just ask Mr. Ohm....

                                                                            Comment

                                                                            • Hank
                                                                              Super Senior Member
                                                                              • Jul 2002
                                                                              • 1345

                                                                              #39
                                                                              Uh-oh. How come the first six things are Infineon related?
                                                                              Because your priorities need reordering, poohbah.

                                                                              Comment

                                                                              • JonMarsh
                                                                                Mad Max Moderator
                                                                                • Aug 2000
                                                                                • 15272

                                                                                #40
                                                                                You've got me pegged dead to rights, what's worse is that I only made it through items 1 and 2, and that took until 6:30 PM Sunday...

                                                                                Geeez louieez...


                                                                                ~Jon




                                                                                Earth First!
                                                                                _______________________________
                                                                                We'll screw up the other planets later....
                                                                                the AudioWorx
                                                                                Natalie P
                                                                                M8ta
                                                                                Modula Neo DCC
                                                                                Modula MT XE
                                                                                Modula Xtreme
                                                                                Isiris
                                                                                Wavecor Ardent

                                                                                SMJ
                                                                                Minerva Monitor
                                                                                Calliope
                                                                                Ardent D

                                                                                In Development...
                                                                                Isiris Mk II updates- in final test stage!
                                                                                Obi-Wan
                                                                                Saint-Saëns Symphonique/AKA SMJ-40
                                                                                Modula PWB
                                                                                Calliope CC Supreme
                                                                                Natalie P Ultra
                                                                                Natalie P Supreme
                                                                                Janus BP1 Sub


                                                                                Resistance is not futile, it is Volts divided by Amperes...
                                                                                Just ask Mr. Ohm....

                                                                                Comment

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