Help with drivers selection (Satori,vifa, Scanspeak)

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  • Vassilis-7-
    Junior Member
    • Jul 2020
    • 9

    Help with drivers selection (Satori,vifa, Scanspeak)

    Hi friends,

    When designing speakers, the biggest bite is with the choice of drivers. People who deal with this "every day" will be able to more or less imagine which speakers they play, but for a person like me it is an abstraction. I would like to ask you for help in choosing.

    First of all what I have and what I want to do.
    I already have speaker boxes, profesionally made and I want to use them.
    About 8inches(20cm) wide and 38inches(95cm) height
    One 6 inch woofer at 38liter(1.35 cf) and one 6 inch at 12liter(0.42 cf) seperated at their one volume and one 4 inch tweeter for each floorstander.
    I want to build a 2.5 way project with both the woofers SEALED, I listen mostly to metal and hard rock music.

    The drivers that I have concluded are:

    Dayton rs180 for the 0.5 woofer
    sb17cac for the 0.5 woofer or maybe for both woofers

    vifa ne180w for the extended woofer or both of the woofers
    satori mw16p for the extended woofer or both of the woofers

    Scanspeak d2608 (hds) or Satori tw29r or Satori tw29d or even the cheap sb29sdac for tweeter duties

    Sadly I've never heard any of those drivers, and here is where you guys step in, with your recommendations.

    I know that satori are highly rated, but I kinda feel that they are overhyped. My dealer recently tried the vifa/d2608(hds) combination at a 2way design and told my that I was better than mw16p/tw29r setup. He stated that the vifa/hds had much clearer/quicker bass and male voices where more pronounced, but who can trust a seller, right?
    Of course vifas are slightly cheaper (40 euros cheaper per pair in my region) and of course also the hds tweeter is cheaper and as always my coins are limited. 8)

    I've seen distortion measurements from all of those drivers, but sometimes the measurements dont say the truth (Sb17nbac measures great but very sterile and boring and one note bass). So I need some "real life"opinions.
    Last edited by Vassilis-7-; 11 July 2020, 11:04 Saturday.
  • tcpip
    Member
    • Oct 2005
    • 69

    #2
    I've designed and built many pairs of speakers, and I've used some of the drivers you've listed, but I'm quite at a loss what to write after reading your approach. We first choose the woofer or midbass driver, then model the box volume, then build the box. You seem to have built the box without any driver selection and (therefore) any box modelling.

    In that case, I guess the only reasonable (to me, I hasten to add) approach to selecting drivers now would be to use box modelling software, plug in the T/S parameters of each of your midbass drivers, and see which one gives you the low end response you like the most with the box volume your enclosure has.

    Don't worry about tweeter selection at this point. In my view, you have more fundamental issues to worry about in your project, and the Peerless HDS or a good Satori tweeter will both perform extremely well given the right crossover and final tuning.

    I've said this many times before, and I didn't think it needed repeating any more, but I feel
    • Driver selection has only about 5-10% of impact on final speaker performance,
    • Box design and more important, box construction, has perhaps 30-40% impact on final performance, and
    • Crossover design, construction and tuning has the remaining role


    And this is the sequence in which you should approach a new build too. Your approach has me confused. Hope others will be more useful.

    Sent from my moto g(8) plus using Tapatalk

    Comment

    • Vassilis-7-
      Junior Member
      • Jul 2020
      • 9

      #3
      Thanks for replying.
      Since I am going sealed, to be honest, I don't see much of a problem.
      I have enough volume to both of the boxes, the width is pretty standard for a 2.5 way with 6inchers and the box is very well made, and this is why I am planning to keep it the way it is.

      I don't want to debate on what you said, but drivers play more important role than 5-10%, I ve tried many different drivers on my car, pretty much without changing anything else and I heard a massive improvement. Also I've changed drivers to a dali concept speaker because of the damaged cone from the stock to seas and it was a serious step up without even looking at the crossover.

      Comment

      • tcpip
        Member
        • Oct 2005
        • 69

        #4
        Originally posted by Vassilis-7-
        I ve tried many different drivers on my car, pretty much without changing anything else and I heard a massive improvement...
        When someone believes he can replace speaker drivers in an existing system without touching the crossover, I know it's time for me to shut up. I wish you the best with your build.



        Sent from my moto g(8) plus using Tapatalk

        Comment

        • Vassilis-7-
          Junior Member
          • Jul 2020
          • 9

          #5
          This is not what I said but this in not the case, I will not debate on the how much the drivers matter. I obviously didn't came here to tell people to shut up nor change their minds, wanted some info from people who might have the kindness to share

          Comment

          • Bear
            Super Senior Member
            • Dec 2008
            • 1038

            #6
            Originally posted by Vassilis-7-
            This is not what I said but this in not the case, I will not debate on the how much the drivers matter. I obviously didn't came here to tell people to shut up nor change their minds, wanted some info from people who might have the kindness to share
            50L is a huge volume for a pair of 17 - 18cm woofers that will be in a sealed enclosure. I won't belabor the "you're doing it wrong" piece of advice, but. Drill some holes to join the two sub-enclosures. There's little point in pursuing the strategy of having separate volumes for a 2.5 way speaker. You also haven't mentioned budget, but since you are having the cabinets professionally made, I'll assume that you have some spending power.

            Your box width is more appropriate for 15cm drivers.
            Your box volume is more appropriate for 22/23cm drivers when sealed.
            You haven't posted a picture of the baffle to show whether you've already cut holes for drivers, so let's assume that step hasn't been done yet.

            So, a pair of vented SB17CACs in 50L tuned to 30Hz looks like a decent approach without relying on a subwoofer. If you want sealed, you'll want to transition to a subwoofer in the 60 - 80Hz, depending upon how much power you want to dump into them (and the corresponding SPL). Once you are crossing to a subwoofer in the 80Hz range or above, you can shrink the cabinet volume quite a bit.

            The MW16 are also well regarded drivers, thought a touch more expensive. They will have typical resonance issues in the 1.5kHz range, but you won't have to worry as much about handling the break-up node in the crossover. Speaking of crossover, the Rinjani design would be one that you could copy and then modify later once you've had more experience. If not, then building a crossover is your next step, and that is indeed where a lot of the work exists.
            Welcome to Rivendell, Mr. Anderson.

            Comment

            • Vassilis-7-
              Junior Member
              • Jul 2020
              • 9

              #7
              Thanks for replying!

              I don't have problem to join the sub-enclosures but I thought that having a separate sealed enclosure for the upper woofer would get me less excursion and probably "better" mids also that could be useful if I was about to use different lower woofer driver, which is under consideration.

              I will post pictures tomorrow, also I will double check the lower woofer volume, maybe I didn't measure it well. Even if I measure it well, what I had in mind is to fill some of the lower enclosure with sand or concrete or something.

              I want to go sealed in order to get some quick bass, I always liked the sealed box sound.

              I do have a subwoofer, a Peerless xls 10@40liter with passive radiator. Superb sub, I really like it, can go very low, fast and accurate.

              The rinjani drivers/crossover indeed are in my shortlist, but the layout of my boxes is very different (the placing of the drivers)
              The maximum coin that I could spend is for the satoris (mw16p and tw29r/d) but I would prefer to spend less. To be honest I've recently read at sb acoustics fan page and Jeff bagbys loudspeaker pad, respectful people whose opinions matter to me, that the sb17nrx is really close to the satori and I can get the sb17nrx for 1/3 of the satori price so this got to me and made me sceptical. Also is my dealer who insists that the vifa/hds(also cheaper combination) will do better than the satoris.

              Comment

              • lbstyling
                Member
                • Oct 2008
                • 80

                #8
                Originally posted by Vassilis-7-
                Thanks for replying!

                I don't have problem to join the sub-enclosures but I thought that having a separate sealed enclosure for the upper woofer would get me less excursion and probably "better" mids also that could be useful if I was about to use different lower woofer driver, which is under consideration.

                I want to go sealed in order to get some quick bass, I always liked the sealed box sound.

                I do have a subwoofer, a Peerless xls 10@40liter with passive radiator. Super sub, I really like it, can go very low, fast and accurate.
                I wouldn't even consider myself a novice, but from the general vibe I get from your comments, I get the impression you have some considerable hours under your belt in HiFi in general, but its primarily from reading and responding on forums, not 'the source'.

                The problem is your product has been cut with baby powder.

                A video: You could watch and see where it takes you with your thought process on sealed sub sound when you put it in the general scheme of things - https://www.youtube.com/watch?v=SCWL-zusyqw&t=2014s

                And a book: https://www.amazon.co.uk/Loudspeaker.../dp/1882580338

                or two: https://www.amazon.co.uk/Loudspeaker.../dp/1882580338

                Please take this in the way it is meant. I hate reading.

                If I was directed to these sources, even if I disagree with most of what I read, I would say it would have saved me over 5000 hours. I kid you not. Most of what you read on forums for audio is half understood semi truths, even from many (perhaps even most!) in the profession.

                Considering the sheer amount of miss-information out there, just by reading/watching these, you would be in the top 5% (total guess?) of the population on the subject. Its the fastest way. By far.

                I will shut up now!

                Comment

                • Vassilis-7-
                  Junior Member
                  • Jul 2020
                  • 9

                  #9
                  Thanks lbstyling, I know this book, never read it (of course), but I know I have to.
                  Even if I read it, I guess I will have to buy drivers either way, so I guess I have to buy something that makes sense.
                  I do have some serious under my belt but automobile audio. A different animal as you know, much easier. You get a dsp, some good speakers/amps, some pods for placing the Tweeters some polyester panels for the midbass, some anti vibration sheets for the doors and you are there.

                  @bear indeed I've made a mistake, the lower woofer is a little less than 1cf. The number I calculated(1.35cf) is for the whole floorstander but I have to measure again for the precise volume. My bad.

                  Comment

                  • Bear
                    Super Senior Member
                    • Dec 2008
                    • 1038

                    #10
                    Originally posted by Vassilis-7-
                    Thanks for replying!

                    I don't have problem to join the sub-enclosures but I thought that having a separate sealed enclosure for the upper woofer would get me less excursion and probably "better" mids also that could be useful if I was about to use different lower woofer driver, which is under consideration.
                    Good theory, but, well, you blew past that opportunity when you executed the "ready fire aim" strategy. Troels Gravesen has some interesting options with asymmetric drivers in a 2.5 way, but the drivers he is using, and what I would recommend, would not fit into your baffle width. For example:



                    That would fit your desire to use SBA Satori drivers, but the cabinet width is an inch wider than what you've indicated is already built. Also, it uses vented drivers. If you were willing to ditch your existing cabinets, this would be a project to consider. Of course, if you are ditching your current cabinets, then the Rinjani's, to which I linked earlier, come with the cabinets in the standard kit from Madisound.

                    Here's a test of whether you need different enclosures for a 2.5 way:


                    Zaph did some really great, pragmatic work for quite a while before his interests went elsewhere. Given your enclosure volume and focus on rock music (dynamics over detail), you may want to look at one of Zaph's designs using his ZA14 driver. Specifically, I would point you to the 5.5t. It won't use any of the drivers you have mentioned, but the drivers it does use have a huge price/performance ratio -- especially if you are crossing to a subwoofer in the 80 - 120Hz range. Sealed, this design can be done in as little as 20L - 28L net, so you've got room to play (e.g., interior treatment). If you're willing to look at venting the enclosure, you're in the 40L net range.



                    I will post pictures tomorrow, also I will double check the lower woofer volume, maybe I didn't measure it well. Even if I measure it well, what I had in mind is to fill some of the lower enclosure with sand or concrete or something.

                    I want to go sealed in order to get some quick bass, I always liked the sealed box sound.

                    I do have a subwoofer, a Peerless xls 10@40liter with passive radiator. Superb sub, I really like it, can go very low, fast and accurate.

                    The rinjani drivers/crossover indeed are in my shortlist, but the layout of my boxes is very different (the placing of the drivers)
                    The maximum coin that I could spend is for the satoris (mw16p and tw29r/d) but I would prefer to spend less. To be honest I've recently read at sb acoustics fan page and Jeff bagbys loudspeaker pad, respectful people whose opinions matter to me, that the sb17nrx is really close to the satori and I can get the sb17nrx for 1/3 of the satori price so this got to me and made me sceptical. Also is my dealer who insists that the vifa/hds(also cheaper combination) will do better than the satoris.
                    There is no perfect speaker. Everything involves tradeoffs, even with unlimited budget. Let's take a look at some measurements (where you should have started this journey...):



                    Paper: https://hificompass.com/en/speakers/...s-sb17nrxc35-4
                    Aluminum: https://hificompass.com/en/speakers/...s-sb17nbac35-8
                    Satori: https://hificompass.com/en/speakers/...satori-mw16p-4

                    Yes, the impedance for the Al is different. That isn't material.

                    Both paper drivers have a suckout at ~1.5kHz. That's pretty typical of paper. It's a surround resonance that's hard to get rid of. Also note that the NRX is a lot less smooth than the Satori, AND it still has a pretty decent break-up mode just a bit below 6kHz. That means that you will need to account for the breakup node in the crossover, and you will want to cross no higher than about 2kHz (the good news: Evgeniy's distortion plots don't show the breakup causing a rise in 3rd order at 2kHz).

                    Now compare that to the Satori. Since you're going to rock and roll with it, let's turn things up to 11 (really, 11.2v...). The second order harmonics are a bit elevated, but these are generally benign. There are some spikes in third order, but everything is below -40dB from about 150Hz and up. Setting aside the qualitative factors of the sound, that level of distortion would be hard to discern with most "mere mortal" gear. And that's at 102dB. This is stupidly loud unless you like being front row center with no ear plugs. If you do like sitting FRC with no hearing protection, then I'd recommend looking at Bose.

                    Now let's look at the SB17NBAC, the aluminum cone. It's got a sharper breakup node, but it's all the way to 7kHz. If you dial this one to 16 (this is where the impedance takes effect), then at that same 102dB, third order is below -45dB from 90Hz, and it is uniformly under -50dB from 200Hz and up. There's a reason that Revel featured these drivers (especially the "ceramic" version) in its mainstream speaker line.

                    All of that is mostly a tease, though. Your internal cabinet width will likely create masking/interference issues with each of these drivers (oh, yeah, part of the Satori's benefits is that the chassis design helps minimize rear wave interference). The 17cm drivers really need at least 6.5" of internal width, or you will start inducing some reflections and resonances that will be measurable. With standard 2/4" (18mm / 19mm) side walls and at least an 8" baffle width, these are possible, but you're definitely pushing it.

                    Let's take a look at what is probably a better fit:

                    The THD measurements at distance of 20 mm and voltage levels from 4 to 5.6 Volt were carried out with High Pass Filter "on" (4th order Butterworth type, 20 Hz cutoff, HPF4-20). The THD measurements at distance of 315 mm and voltage levels from 2 to 4 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 50 Hz cutoff, HPF2-50). The THD measurements at


                    I like the charcoal gray look of the NBAC versions, but many people prefer the sound of the CAC versions. Price-wise, they are similar, but the CAC will have a bit of a premium. The 15cm version isn't as sensitive as the 17cm version, and the sensitivity is a bit less. Also, the Xmax-limited SPL will be less because of physics (piston volume matters). However, a four pack of these will overcome the SPL limitations vs a pair of 17cm drivers, and they will likely fit into your cabinet.

                    Just be prepared to spend some coin on a reverse chamfering bit (~$100) no matter which driver set you choose. Here's a blog post from Zaph that includes practical examples of what chamfering does/doesn't do for speaker performance:



                    With that, I think I'll wish you the best!
                    Last edited by Bear; 12 July 2020, 16:53 Sunday. Reason: clarity
                    Welcome to Rivendell, Mr. Anderson.

                    Comment

                    • Vassilis-7-
                      Junior Member
                      • Jul 2020
                      • 9

                      #11
                      Thank you a lot for your time! You contributed to the mess that I have in my head in a very good way!. Sad to admit, but probably I will just have to follow a ready, proven design from a real designer.
                      Just out of curiosity, because I remember Jeff bagby at his kairos write up. Sealing a br box, will just change the f3. If I remember right, Jeff somewhere stated that kairos with sealed enclosure get some really sweet and fast bass, but a sub I necessity.
                      Anyways thanks everyone who contributed

                      Comment

                      • chrisn
                        Senior Member
                        • Sep 2007
                        • 166

                        #12
                        I don't know if its been answered, but are the baffles already cut for drivers? If they aren't, you could use 2 6-7" woofers in the lower part of the cabinet, and use the upper part for a mid and tweeter in a 3 way. More expensive, but two woofer might do better in that volume sealed.

                        Comment

                        • Bear
                          Super Senior Member
                          • Dec 2008
                          • 1038

                          #13
                          Originally posted by Vassilis-7-
                          Just out of curiosity, because I remember Jeff bagby at his kairos write up. Sealing a br box, will just change the f3. If I remember right, Jeff somewhere stated that kairos with sealed enclosure get some really sweet and fast bass, but a sub I necessity.
                          Grab an enclosure modeling tool and check for yourself. I tend to use Unibox (Excel workbook with macros), others use Bassbox, etc. There are several available. In general, one issue that you will find is that "fast bass" is a point of contention. Some people look to Group Delay as a way to quantify it. Others will look to step response. There may be more camps out there.

                          If you look at Jeff's Helios design, you will see that a PR system can mimic a closed system for step response. Vented systems will generally have a much longer settle time, though the magnitude of the "wiggle" can be pretty minimal pretty quickly. Here's the rub:

                          The realized step response is going to depend upon the realized Qtc of the enclosure. If you want the minimum overshoot and fastest settle time, that's a Qtc of 0.707, and simply plugging a BR box won't get that for you. Play with some enclosure simulations, and you can see the tradeoffs. Whether they are audible to you or not is different, though (see above about quantifying "fast bass"). How your subwoofer fits into this equation is also an important consideration. In fact, you may want to look at the step response for your subwoofer system as a starting point....

                          Also note: for most modern music, there's reputedly not much information below 40Hz. Bear that in mind when looking at bass alignments.
                          Welcome to Rivendell, Mr. Anderson.

                          Comment

                          • Winter
                            Member
                            • Nov 2007
                            • 81

                            #14
                            Q < 0.5........Over damped...........No overshoot to rest position after a step input, extended settling time, tapered low frequency response
                            Q = 0.5........Critically damped......No overshoot to rest position after a step input, minimum settling time without overshoot
                            Q > 0.5........Under damped..........Overshoot to rest position after a step input
                            Q = 0.577.....Bessel Function.........Very slight overshoot to rest position after a step input, minimum settling time
                            Q = 0.71......Butterworth Function..Slight overshoot to rest position after a step input, lowest flat frequency response

                            Comment

                            • Dave Bullet
                              Senior Member
                              • Jul 2007
                              • 474

                              #15
                              Hey,

                              Did you ever build the SB16PFCR / SB29RDC 2.5 way I modeled? or have you decided to go for better drivers still?

                              Still using a subwoofer?

                              If so - then I would just model the lowest F3 out of the woofers chosen in the 35 Litre sealed volume... to be honest they will all probably be ~ Qtc 0.6 given they are only 6.5" drivers in a relatively large sealed volume.

                              The pre-existing cabinets are ported if I remember... so you could measure the length of the port, apply the 35L volume with Ts parameters and model in WinISD to find which driver combination works best without cabinet and port adjustment. This in my opinion is more important than choosing the best subjective sounding driver. Matching the volume is as nearly as important as matching the crossover, especially if you are retaining the port.

                              Comment

                              • Vassilis-7-
                                Junior Member
                                • Jul 2020
                                • 9

                                #16
                                Hi Dave, No I didn't build what you modeled, I decided to go for better drivers, although the pfc's sounded awesome.

                                I tried both ported and sealed at the oversized cab and I got much clearer bass in the sealed, and going low enough to smooth integrate with the sub.

                                I decided to go with sb17cac. Many people I respect at the diy community were talking about stellar performance on the cac speakers, some preffered them over satori -matter of personal taste of course- so I will give them a try. I also decided to try the cheaper sb29sdac. Of course they will not be as good as satori ,but where I buy from the price of the satori was 3 times the price of the sdcac which according to JB, has a world class performance.
                                And Last but not least, I bought a calibration mic something it had to be done long ago.

                                Comment

                                • fish fingers
                                  Senior Member
                                  • Apr 2015
                                  • 189

                                  #17
                                  SB17cac in sealed? What's the modelled f3? / f6?
                                  I've just starting a sealed 2.5way build

                                  Comment

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