Three Way Evil Design Study

[Evil Twin]

Apologies for taking things OT for a moment, however hope springs to life when you say:



Maybe one of them a bit more affable to those of us with the same grand visions but slightly more austere budgets?

Something in the $2k range (drivers & xo’s) would be a sweet spot for many I would wager.

This is a very real possibility, as I have instructed Mr. Marsh to address a new version of the NeoD CC, having selected a new tweeter to evaluate and also directed crossover development using MY tried and true alignments, as demonstrated previously in the NatalieP and now in this new technological terror (terror from a fiscal viewpoint). Perhaps this will prove worthy of a custom cabinet effort, instead of the usual PE enclosures.

[Evil Twin]

Nearfield data for those curious

These plots were taken near field today, demonstrating the crossover + driver transfer function prior to baffle step, though not without other possible issues. There are two tweeter curves, one on axis (which likely generates some diffraction issues in the response from the microphone), and one about 40 degrees off axis, chosen for the fact that it generates a pleasing looking response curve in comparison to the first measurement, and one that appears more representative of the 2 meter measurements. Distances and relative SPL's were not particularly controlled; the intent was to document the crossover transfer functions.


Near field centered on one woofer; response is as expected given Fb of 38 Hz with a Q of about 0.56. Ideal room positioning should be set for boundary lift to start kicking in around 40-45 Hz.





Midrange near field, centered on driver




Near field for the tweeter, two measurement positions as noted.



Solid correlation exists with the LspCAD simulation, as should be the case.

[JonMarsh]

Listening to Cheryl Crowe Live in Central Park,

then Andreas Vollenweider "White Winds".



Hearing lots of things I've never heard before on these recordings, especially the second one. It features electric harp primarily, but has a lot of acoustic percussion and natural sound (weather kinds of things, water movement, other stuff. Never, ever, heard it so good. Scary. And this is the original 1990 CD, not the remastered version I've just recently heard about...

Oh, we've got the M51 NAD hooked up, along with my TASCAM CD transport.

And I've NEVER heard the top end of an Aragon 8008 of any persuasion sound this clean and transparent- I'd swear it was a different amplifier. So just maybe, those folks that think an 8008 is too bright and wiry or harsh just has a system that won't handle a flat top end? I don't expect the Clarity MR caps are hurting any, either. Or the Jantzen Superior Z on the midrange. Best not to dwell too much on those points- no need to start a cap war here!

[gbegland]

then Andreas Vollenweider "White Winds".

[ATTACH=CONFIG]21426[/ATTACH]
And this is the original 1990 CD, not the remastered version I've just recently heard about...

Ah yes, good disc. The $99 question on the remaster though is it actually better? You know, it's really a shame but as A/D conversion and DSP processing in general gets better, audio production standards continue to drop. So by now it becomes a choice of earlier CD releases with possibly questionable top end grain and that nasty "early digital" sound or newer, smoother transfers that are progressively more and more smashed from a dynamic range standpoint. If y'all haven't browsed the Dynamic Range Databass before, it can be rather eye opening just how bad compression and limiter use has become. Just as one example, see Michael Jacksons BAD. From vinyl to original CD release to 25th anniversary remaster and finally the "audiophile" 24 bit release. More and more squashed each generation. I was at Bruce Swediens(the original tracking and mixing engineer for basically ALL of Michaels albums) studio when the 25th anniversary reissues came out. Bruce played for me the 24bit master tape transfers, pre mastering. Just the raw mixes from the 80s. It was a revalation. Billy Jean jumped out of his monitors like being at a dance club. The mix had room to expand and breathe. A few weeks later I bought both Thriller and Bad, took them home was like WTF?!?! They had been smashed by the mastering engineer Bernie Grundman, who was also the original mastering engineer. He was forced by Sony to turn it up to compete with modern CDs. This is pretty common place over the last 10 years. Sooooo, don't trust the remasters until you check the database.

http://www.dr.loudness-war.info/index.php?search_artist=michael+jackson&search_album=bad

Public service announcement now over....please return to your normally scheduled programming.

Exciting for sure Jon hearing about your listening experiences tonight. Just think, once your high falutin' new DAC arrives and you get them in a better listening environment, things are only gonna get better.

Greg

[Steve Manning]

Listening to Cheryl Crowe Live in Central Park,

then Andreas Vollenweider "White Winds".

[ATTACH=CONFIG]21426[/ATTACH]

Hearing lots of things I've never heard before on these recordings, especially the second one. It features electric harp primarily, but has a lot of acoustic percussion and natural sound (weather kinds of things, water movement, other stuff. Never, ever, heard it so good. Scary. And this is the original 1990 CD, not the remastered version I've just recently heard about...

Oh, we've got the M51 NAD hooked up, along with my TASCAM CD transport.

And I've NEVER heard the top end of an Aragon 8008 of any persuasion sound this clean and transparent- I'd swear it was a different amplifier. So just maybe, those folks that think an 8008 is too bright and wiry or harsh just has a system that won't handle a flat top end? I don't expect the Clarity MR caps are hurting any, either. Or the Jantzen Superior Z on the midrange. Best not to dwell too much on those points- no need to start a cap war here!

Jon how are you liking the M51? That's on my if I had an extra $2K laying around (not likely) list.

[JonMarsh]

Jon how are you liking the M51? That's on my if I had an extra $2K laying around (not likely) list.

It's an excellent DAC, and Benchmark IMO in the $2K to $4K range, especially if you want balanced outputs and can use the preamp volume control function to replace your normal preamp in a system.

Highly recommended. Hopefully it will make it's way into the system area I originally bought it for, my bedroom HT/Music setup. With HDMI inputs/pass through you can connect a Blu-Ray player, extract 2 channel PCM, and pass on the video to your monitor.

If I had silly things like "component of the year" awards, it would be the 2012 component of the year, though technically I got mine a few days before the end of 2011.

[JonMarsh]

Ah yes, good disc. The $99 question on the remaster though is it actually better? You know, it's really a shame but as A/D conversion and DSP processing in general gets better, audio production standards continue to drop. So by now it becomes a choice of earlier CD releases with possibly questionable top end grain and that nasty "early digital" sound or newer, smoother transfers that are progressively more and more smashed from a dynamic range standpoint. If y'all haven't browsed the Dynamic Range Databass before, it can be rather eye opening just how bad compression and limiter use has become. Just as one example, see Michael Jacksons BAD. From vinyl to original CD release to 25th anniversary remaster and finally the "audiophile" 24 bit release. More and more squashed each generation. I was at Bruce Swediens(the original tracking and mixing engineer for basically ALL of Michaels albums) studio when the 25th anniversary reissues came out. Bruce played for me the 24bit master tape transfers, pre mastering. Just the raw mixes from the 80s. It was a revalation. Billy Jean jumped out of his monitors like being at a dance club. The mix had room to expand and breathe. A few weeks later I bought both Thriller and Bad, took them home was like WTF?!?! They had been smashed by the mastering engineer Bernie Grundman, who was also the original mastering engineer. He was forced by Sony to turn it up to compete with modern CDs. This is pretty common place over the last 10 years. Sooooo, don't trust the remasters until you check the database.

http://www.dr.loudness-war.info/index.php?search_artist=michael+jackson&search_album=bad

Public service announcement now over....please return to your normally scheduled programming.

Exciting for sure Jon hearing about your listening experiences tonight. Just think, once your high falutin' new DAC arrives and you get them in a better listening environment, things are only gonna get better.

Greg

So, so true- so I'll approach the newer remaster with some caution. A good example of the problem is the Stanley Clarke album "School Days", especially the title cut. The original vinyl was world class demo material, taped it to a half track Otari to use over and over again in the store. But the two CD versions of it, frankly suck! Only since the CD "Bass-Ic's" came out has their been a good digital version available, both the domestic and import versions. Import has a slight edge, in my opinion, maybe not worth the expense to most, unless you're a Stanley Clarke fan. And it's still not quite up to the original vinyl, but maybe 90% of the way there...

[JonMarsh]

Apologies for taking things OT for a moment, however hope springs to life when you say:



Maybe one of them a bit more affable to those of us with the same grand visions but slightly more austere budgets?

Something in the $2k range (drivers & xo’s) would be a sweet spot for many I would wager.

Though I wonder if it could be possible given the requisite count & quality of components?

Well, this is something I've been thinking about, how to do this and capture some of the best parts of what this configuration does.

well, let's just say I have a plan for a Mini-Me proof of concept, and have selected a likely driver complement that looks pretty promising. I'm really focussing on high bang for the buck drivers with the right acoustical properties to do what is needed in this same configuration, but smaller- think about 12" wide instead of 15", and 50" tall instead of 62". And I think I may be able to save enough on the driver cost to put in some of the good stuff in the crossover filters; not just the same topology, but high grade components, too.

Overall will keep a similar concept- sealed bottom end, double woofers in series, a very flat and smooth midrange driver, and a tweeter with the right dispersion characteristics.




Note similarities in upper range dispersion



High sensitivity with smooth response in upper crossover region (2500 Hz)

I may be able to modify an M8ta cabinet for the bass section in a proof of concept exploration- we'll see. The idea is to use selected high grade caps still in the midrange and treble- Jantzen Superior Z. Though I'd prefer to go dual 10" woofers, finding the right drivers with regards to parameters is tough- I have them - Aurasound NS10-513-4a, but those are hard to source, and with dual 8's using the RS225-4, we should be in fair shape and save money for the crossover components. Network has to be very similar to what I built for the big project- that's the trouble with trying to do a good 3 way on a budget- too often compromises are made in the crossover.

Now, let's see, I could do a hack job on my M8ta cabinets and cut off the front panels to create some "bass bins"... do one for 8" woofers, one for 10" woofers, maybe test the Arum Cantus AC-250SW as well as the NS10's... geez, GF is going to kill me!

[5th element]

You may also want to consider the SB17MFC35-4 from SB as the midrange, ever so slightly less sensitive but with a well controlled cone giving a reasonably smooth response.

http://www.madisoundspeakerstore.com/approx-6-7-woofers-sb-acoustics/sb-acoustics-sb17mfc35-4-6-poly-cone-woofer/





Zaph has measured the 8 ohm unit and it basically has class leading HD for the price too and it's cheaper than the scan.



Whether or not this saving would be countered by requiring a slightly more complex crossover I am not sure. In my experience a controlled rising top end typically only requires a more aggressive low pass and as you'd be using a 3rd order network anyway that should have the required flexibility to get the curve to hit the desired target.

The Scan does look nice, but looking at Zaph's measurements of it's smaller brother, that also includes the shorting ring, if the motor trend remains, it's clear that the SB has the Scan pipped in absolute terms.



The only question could perhaps be small resonances in the 800-1500kHz region so typical of soft cones, but these seem almost unavoidable.

[JonMarsh]

Actually, what with finding the Arum Cantus AC-250 on sale at PE, current tentative driver budget for the Mini-Me is now $710, for the pair, leaving the rest for crossovers and what not. What not can quickly get out of control if you aren't careful, you know.... :W

[JonMarsh]

You may also want to consider the SB17MFC35-4 from SB as the midrange, ever so slightly less sensitive but with a well controlled cone giving a reasonably smooth response.

http://www.madisoundspeakerstore.com/approx-6-7-woofers-sb-acoustics/sb-acoustics-sb17mfc35-4-6-poly-cone-woofer/

Zaph has measured the 8 ohm unit and it basically has class leading HD for the price too and it's cheaper than the scan.



Whether or not this saving would be countered by requiring a slightly more complex crossover I am not sure. In my experience a controlled rising top end typically only requires a more aggressive low pass and as you'd be using a 3rd order network anyway that should have the required flexibility to get the curve to hit the desired target.

The Scan does look nice, but looking at Zaph's measurements of it's smaller brother, that also includes the shorting ring, if the motor trend remains, it's clear that the SB has the Scan pipped in absolute terms.



The only question could perhaps be small resonances in the 800-1500kHz region so typical of soft cones, but these seem almost unavoidable.

Very good suggestion, and moved to the top of the list! It certainly looks quite workable...

[tf1216]

I contacted Monacor about a couple of their drivers. They are about $100 a pop. They appear to be worthy for consideration.

http://www.monacor.de/index.php?id=128&artikelid=8815&L=1

http://www.monacor.de/index.php?id=128&L=1&artikelid=8816

[wkhanna]

This is a very real possibility.......... Perhaps this will prove worthy of a custom cabinet effort, instead of the usual PE enclosures.

I do believe I felt quite the positive ripple current is the Force as I read this response.

Either that, or repercussions from the two-day old piece of cold pepperoni pizza I grabbed out of the fridge for breakfast this morning?

[Leadfinger]

Hello Jon,

I see you mentioned the Aurum Cantus AC-250SW on sale at PE. Apparently a lot of them being shipped out are defective. The suspension is hard as a rock and the TS parameters are so far off they are completely unusable. PE is aware of this problem, so if anyone has some they recently purchased be sure and test them asap. Too bad, they are a beautiful design and very well made woofer...db

[JonMarsh]

Hello Jon,

I see you mentioned the Aurum Cantus AC-250SW on sale at PE. Apparently a lot of them being shipped out are defective. The suspension is hard as a rock and the TS parameters are so far off they are completely unusable. PE is aware of this problem, so if anyone has some they recently purchased be sure and test them asap. Too bad, they are a beautiful design and very well made woofer...db

well, that is a TOTAL drag, but thanks very much for the heads up! Haven't ordered any, may still, but this does raise flags.

I hope PE isn't just using the sale to achieve field quality control by testing by customers instead of themselves!

Actually, reviewing parameters and searching in Subwoofers besides woofers, it's possible the RSS265HF-4 might work out fine; has the right Qts parameter, ~12mm of Xmax, and if it's really 84db for 1Watt (not 2.83VRMS), then 2.8VRMS sensitivity should be 87 dB, which puts it in the ball park- price being OK, and consistency pretty good. And I even think I have one or two around...

OTOH, the RS315HF-4 might work even better... except then we don't have a Mini-Me system, other than budget. It would be a full size budget downsized Isiris. Isiris MM? Well, it could be designed both ways- and built to your preference, with crossover adjustments.

Gotta check dimensions on those RS315HF and see if they can drop in the Isiris cabs for testing...

could build another top module just to test the new mid and tweeter candidates... for the crossover to really work out well, they must be 90 dB or more drivers.

[JonMarsh]

Looks good! Are you planning to listen to these speakers before finishing the cabinets? Chances are you will not take these apart anymore

You don't know the half of it...

I've been just using the one connected for crossover tests for background listening today while working, and I can't count the number of times something has caught my ear and I've stopped and looked up and done a "Holy sh*t!" It's more like having half of an electrostatic headphone sitting in the living room, but with weight in the bottom end...

I'm definitely finding my motivation for getting going on finishing increasing! I'll have to do that, or I'll have two unfinished speakers I'll be listening to for who knows how long...

[JonMarsh]

You may also want to consider the SB17MFC35-4 from SB as the midrange, ever so slightly less sensitive but with a well controlled cone giving a reasonably smooth response.

http://www.madisoundspeakerstore.com/approx-6-7-woofers-sb-acoustics/sb-acoustics-sb17mfc35-4-6-poly-cone-woofer/

Zaph has measured the 8 ohm unit and it basically has class leading HD for the price too and it's cheaper than the scan.



Whether or not this saving would be countered by requiring a slightly more complex crossover I am not sure. In my experience a controlled rising top end typically only requires a more aggressive low pass and as you'd be using a 3rd order network anyway that should have the required flexibility to get the curve to hit the desired target.

The Scan does look nice, but looking at Zaph's measurements of it's smaller brother, that also includes the shorting ring, if the motor trend remains, it's clear that the SB has the Scan pipped in absolute terms.



The only question could perhaps be small resonances in the 800-1500kHz region so typical of soft cones, but these seem almost unavoidable.

Thinking about this a little further, and realizing this will likely be more a Maxi-Me than a Mini-Me, and remembering the adage to "love the one you're with", I shouldn't forget the NE-180's I've got on hand- might be fairly suitable for the midrange, given bandwidth, sensitivity, and HD.





Plus, no out of pocket on the mid now.

[PMazz]

Jon, if it helps, I'll volunteer to build boxes or "flatpacks" and ship them to you. I've been on the receiving end of your work and would gladly give some back.

[JonMarsh]

That's a great offer, Pete! I've got some calculations to do, but I can probably use one of the existing cabs to test the woofers- now, a new top module out of MDF will be needed, and I could send you detailed plans for the piece parts, and I could finish off the front panels and assemble (front panel process flow started with a rectangular piece, which is then routed for driver holes, back bevelled ,etc. Let me put some plans together this weekend and shoot them off to you and see what you think! That would be a big help to get a budget "open source" project off the ground quickly.

I'm also going to check this weekend if I have cutting LBL cutting boards around the right size for laminating up a bamboo front panel. I still think a stiff launch panel for the mid/tweeter is a good thing.


I've identified an area where I think I still need some adjustment to the crossover, very lower mid and total top to bottom balance, but it's very close overall, and the definition and resolution of each section is clearly the best thing I've ever done. I wonder how much of that we can bring down to a more reasonable price class? It's an exciting thought.

[5th element]

Thinking about this a little further, and realizing this will likely be more a Maxi-Me than a Mini-Me, and remembering the adage to "love the one you're with", I shouldn't forget the NE-180's I've got on hand- might be fairly suitable for the midrange, given bandwidth, sensitivity, and HD.

Plus, no out of pocket on the mid now.

I was going to say the same thing, but figured the Vifa might be out due to it's relatively high cost. There's always the 4 ohm Satori, but then that is pushing the budget, nice driver though!



I think the NE180 would be a safe bet for almost all who are interested, my only slight worry is availability, is it odd that it's been removed from Mad's part inventory? Still you can always go to PE.

The little SEAS tweeter is a no brainer and will no doubt be around for years to come as will the Dayton reference subs I think. Considering that this alternate version would mainly be aimed at giving diyers something cheaper, but still high performance, to build, I'd figure that driver availability would be a rather significant concern.

[JonMarsh]

I was going to say the same thing, but figured the Vifa might be out due to it's relatively high cost. There's always the 4 ohm Satori, but then that is pushing the budget, nice driver though!



I think the NE180 would be a safe bet for almost all who are interested, my only slight worry is availability, is it odd that it's been removed from Mad's part inventory? Still you can always go to PE.

The little SEAS tweeter is a no brainer and will no doubt be around for years to come as will the Dayton reference subs I think. Considering that this alternate version would mainly be aimed at giving diyers something cheaper, but still high performance, to build, I'd figure that driver availability would be a rather significant concern.

Yes, you hit the nail on the head with that comment- don't want any un-obtainium drivers for this effort. Got enough of those in the current version!

I figure the mid is pretty critical, as well the bottom end- I looked at all kinds of drivers, trying to find a nice 10", but not really much luck. The RS315HF just makes a lot more sense if it models correctly- should get around to that kind of analysis by this weekend. The other ironic thing is, I'm not concerned about how it models as a sub, but as a woofer! My past measurements show going to 300 shouldn't be an issue.

For "premium" 3 way, my preference is a woofer with 10-12 mm of xmax and reasonable sensitivity (86-87dB), and from my experience with the Isiris so far, I like how stacking 2 four ohm drivers works out as far as impedance control and net system impedance after applying the crossover and dealing with mid and woofer overlap (which usually drops the impedance a bit. The total system sensitivity won't look great on paper, but in the real world it will be fine the typical range of solid state amps, say 50-200W/ch. It still makes a fair bit of noise with 2.83 VRMS on the input sweep! The RS315HF has only moderate sensitivity, but I'm guessing (before analyzing) that two will work fine in this cabinet, given that the HF's cone mass is about 200g, compared with the NS12's 130G. With Erse iron core inductors, insertion loss should be minimal.

[5th element]

The current range of subs from a number of manufactures have stepped up the ante from what was available 10-15 years ago. The peerless xls nomex are good till 300Hz with a steep filter and that's only limited by a cone resonance rather than the motor. Then you've got the newer alu coned xls in various formats and the similar designs in the Scan Discovery line up. SEAS too have decent representation with their ROY subs, of which you have experience with, all which should work over a more extended range and at a variety of price points.

I think for EU members though, that the Scan/Peerless/SEAS products are easier to obtain than the Dayton series, if that's a consideration.

[Hdale85]

Still you can always go to PE.

I think we should boycott them until they advertise with us again :B

[dlneubec]

Yes, you hit the nail on the head with that comment- don't want any un-obtainium drivers for this effort. Got enough of those in the current version!

I figure the mid is pretty critical, as well the bottom end- I looked at all kinds of drivers, trying to find a nice 10", but not really much luck. The RS315HF just makes a lot more sense if it models correctly- should get around to that kind of analysis by this weekend. The other ironic thing is, I'm not concerned about how it models as a sub, but as a woofer! My past measurements show going to 300 shouldn't be an issue.

For "premium" 3 way, my preference is a woofer with 10-12 mm of xmax and reasonable sensitivity (86-87dB), and from my experience with the Isiris so far, I like how stacking 2 four ohm drivers works out as far as impedance control and net system impedance after applying the crossover and dealing with mid and woofer overlap (which usually drops the impedance a bit. The total system sensitivity won't look great on paper, but in the real world it will be fine the typical range of solid state amps, say 50-200W/ch. It still makes a fair bit of noise with 2.83 VRMS on the input sweep! The RS315HF has only moderate sensitivity, but I'm guessing (before analyzing) that two will work fine in this cabinet, given that the HF's cone mass is about 200g, compared with the NS12's 130G. With Erse iron core inductors, insertion loss should be minimal.

How about the new Dayton Ultimax Series, either the 10 or 12. I believe the 10 is at around 86.5 and the 12 at 87.7 or so. They are little more expensive than the RSS HF series, but seem to go a little lower in a sealed box, have more xmax (19mm) and better looking response. The breakup is a little less severe given the paper/glass fiber cones.

http://www.parts-express.com/pe/showdetl.cfm?partnumber=295-510

[Hdale85]

Don't forget they are like 100x sexier as well Don't pretend that doesn't matter to some extent! haha.

[dlneubec]

Don't forget they are like 100x sexier as well Don't pretend that doesn't matter to some extent! haha.

Agreed! That alone makes them worth a few more $'s.

[Hdale85]

Very much in agreement, they look amazing. Actually thinking about using them in my car build....

[JonMarsh]

How about the new Dayton Ultimax Series, either the 10 or 12. I believe the 10 is at around 86.5 and the 12 at 87.7 or so. They are little more expensive than the RSS HF series, but seem to go a little lower in a sealed box, have more xmax (19mm) and better looking response. The breakup is a little less severe given the paper/glass fiber cones.
http://www.parts-express.com/pe/show...number=295-510

Now, those definitely are subs- I have one of the 10" which I'm doing a build for GF's HT, with a Hypex plate amp. My current feeling is that the RS315 will be a better fit as a woofer. Of course, IF I find out otherwise, I'll come back here and say "You told me so!" (the Qts on the 12" version is a bit on the high side for what I want, 0.59, and they don't spec MMS. Ideally, I'm looking for an Aurasound replacement. Thanks for making suggestions, though!

[dlneubec]

I'd love to see some measurements of the Ultimax. The thing about the RSS HF series, and I've used the RSS265HF in two projects, is that the breakup is really nasty and audible. Play some music through them full range, for example, compared to something like the TC1000's I used in my Echelon's. Night and day difference in unfiltered, raw sound quality. I thnk the RSS series has a secondary dust cap resonance that really stands out. I would assume the Aura's would perform more like the TC1000's in terms of raw sound quality, though I can't say I ever listened to my NS10's full range. I once compared the RSS265HF with the TC1000 and the RS225 full range. The TC1000 was easuly much better than the other two to my ears and it was not subtle. That said, I'm sure you can handle their breakup in the XO when crossing at 300hz.

Of course, you could always dump the 2 driver concept and go with a single AE Lambda TD12H. There would be little reason for 2 of them, since they have a sensivity in the 93-94db range, plus a 14mm Xmax. Of course, you would want to go ported with them to get into the upper 30's and they don't need a big box, either. Hard to beat the TD12H in my book. I'm surprised you haven't used them in something already, Jon.

[JonMarsh]

Well, I've had these Aurasounds quite some time, and only now just got a project built for them. They have some pretty special characteristics, including steadily falling midrange distortion up to 1 kHz due to the under hung motor design, and the first breakup at ~2.3 kHz. I still have four of the NS10's, too!

I'm sure the Lambda's are great for some configurations, but with a Qts of 0.24 they're not for a sealed system unless you can make provision for active EQ. Actually, that one is designed more as a pro midbass driver, from the specs and Lambda's copy.

I agree dealing with the cone breakup takes a little work; same issue with using the RS180's in the NatalieP's.

Something in between the TD12X and the Dipole 12 would be closer to what I need. BTW, double 12's has other benefits, including improved floor bounce and distribution of boundary effects.

[JonMarsh]

After a few days of listening, my conclusion is that from about 400-500 Hz and up, they're great, but there is a problem/dip somewhere in the lower midrange that impacts fundamentals on some female vocals (just in a specific range) and some piano. After getting out my Tom Terrific thinking cap, I refined my measured data, revisited the crossover, and between some tweaks to the LF and a BSC circuit on the midrange, and a slight lift in Mid and tweeter levels, think I have it pretty close to sorted... on paper. Will implement this weekend and know for sure, hopefully. It's very close, I think...

[gbegland]

Very nice. I'm liking the slight downward slope. Good for the long haul. Smooth smooth smooth.

Greg

[JonMarsh]

Very nice. I'm liking the slight downward slope. Good for the long haul. Smooth smooth smooth.

Greg

That's what I hope. After a lot of experimentation in the last year with listening tests, this is probably going to be the "AudioWorx" house curve for current and upcoming projects. It's sloped like that now, but because the upper range dispersion is so wide and uniform, the power response doesn't sound at all soft or lacking in the presence or top range.

I'm going to need to finish these updates, and test in a larger room (GF's family room), but I just have a feeling about this. Who know, maybe we can get these to the Northern CA DIY in April. Have inductors on hand for test for L7, and high DCR Jantzen AWG18 parts already shipped; more resistors just arrived from Madisound, so we're on a roll of sorts. SB Acoustics tweeters and more resistors ordered today, too!

Lee Ritenour Smoke'n'Mirrors on for background music while working... really nice.

[benchtester]

..... Who know, maybe we can get these to the Northern CA DIY in April....

I will be going to NCDIY with a camper-shelled mini-pickup. If you need help with lifting and/or more cargo space; I can swing by.

[JonMarsh]

I will be going to NCDIY with a camper-shelled mini-pickup. If you need help with lifting and/or more cargo space; I can swing by.

That's something to keep in mind- could make a real difference!

[JonMarsh]

For Loggins and Messina fans, this remastered best of release which sent Jim Messina back to the original analog source tapes is the real deal, in my opinion. Just got in today...




Very clean sounding A/D conversion, much better than the earlier CD's I have, and this translates to better top to bottom clarity. Dynamics are fine to my ears, so in the event you should be a bit of a fan, too, you've been notified! :B

Unfortunately, work-work dominated the weekend, so no updates to report... hopefully next weekend will be different! Covering for an engineer on "mandatory' vacation with an urgent assignment... but he's back today.

[lhwidget]

For Loggins and Messina fans, this remastered best of release which sent Jim Messina back to the original analog source tapes is the real deal, in my opinion. Just got in today...




Very clean sounding A/D conversion, much better than the earlier CD's I have, and this translates to better top to bottom clarity. Dynamics are fine to my ears, so in the event you should be a bit of a fan, too, you've been notified! :B

Unfortunately, work-work dominated the weekend, so no updates to report... hopefully next weekend will be different! Covering for an engineer on "mandatory' vacation with an urgent assignment... but he's back today.

I seem to notice this on quite a few of my old favorites:
Paul Simon: Graceland (and probably everything else), just sounds great
Joni Mitchell: Clouds - just ok, by Mingus, great, really sounding detailed with good dynamic range
CSNY: most of the old ones are pretty good
Elton John: Tumbleweed Connection, wow, what he did back then still impress me (there's some tubas (I think) on My Father's Gun that amaze me)...
Jethro Tull: All over the map, some of their albums sound like they were recorded on an 8-track (cartridge, not RtR) in a small bathroom, and others sound wonderful

Seems like lots of popular stuff was recorded with great fidelity in the 1970s and the engineering talent just didn't carry over to digitally mastered recordings.

[JonMarsh]

Seems like lots of popular stuff was recorded with great fidelity in the 1970s and the engineering talent just didn't carry over to digitally mastered recordings.

Not to a lot of the first releases... you've got to keep in mind, there's been a lot of advance in digital equipment over the last 30 some years since CD's were originally introduced- not just to the home equipment, but to the available professional equipment for A/D and mastering.

[technodanvan]

Every time I see this thread pop up I read "three way evil design study".

I probably need to work on my reading.

[JonMarsh]

Nah, you're just about as averagely dyslexic as the rest of us!

Maybe someone should have titled it differently to begin with! :W

[technodanvan]

Maybe someone should have titled it differently to begin with! :W

I would never question the dark lord!

[Evil Twin]

I would never question the dark lord!

It is fully possible that your dyslexic transposed title is an improvement... perhaps I can convince the moderator to adjust the thread title slightly...

[JonMarsh]

Update on LF-Mid crossover



This is a follow up to my LspCAD data on a proposed modification to the LF to mid crossover, based on what I was hearing, and going back and redoing and filtering some measurement data.

This will seem a bit OCD to some, so for those of you, "these aren't the data graphs you're looking for, move along now..." :B

I decided to measure both nearfield and at 1 meter on axis, and look at the original response and my proposed modifications, and compare individually for the LF and Mid, and then jointly- thought this might be more useful than just looking at the axial response net at 1 meter. This proved to be quite helpful, as there are clues in the individual response curves that give understanding (to me) for what I hear in the power response which is not well represented in the 1 meter on axis response- another reason I rely on this less and less.


This is the near field LF response, original (blue) and modified (maroon). The modified LF circuit adds 82 uF to the 125uF original C1.



This tightens up the roll off, and the near field shows the corner frequency pulled in and 250 Hz down a bit more than the original- this actually tightens up the phase transition and should result in a better phase match through the crossover region with the adjusted mid.


This is the one meter LF response, original green, modified (red):



This shows some of the room effects along with the increased roll off rate, and the slight tip up coming from baffle step transition near the crossover point; this reaches a better net acoustical point than the original curve.


This is the near field (six inches) midrange response, original (maroon) and modified (red):



The effect of 2.2mH and 4 ohms connected in series, paralleled with the 8 ohm input attenuation resistor is quite apparent; this is needed for baffle step compensation.

The one meter response is shown next for the original filter design (blue) and the modified version (green); as expected. This compensates better for baffle step effects.




This is an overlay of the summed LF and Midrange at 1 meter, original (green) and modified (maroon).



Now, this is probably the LEAST informative measurement- yes, the modified maroon curve for the total 1 meter on axis is a bit flatter, but the sonic difference is more apparent in the power response in room, after listening. What seems to be happening here is that at 1 meter on axis the old network was not summing in correct phase, and I believe this would show up more with more off axis (including vertical) measurements. I think there is less interference summing between the drivers off axis than with the original network, and the improved lower midrange output makes a big difference in many midrange instrumental fundamentals and voice, and in area's that don't show up so much in the on axis measurement- say, in the 300-500 Hz area, by my ear.



this is the total response at 1 meter, same measurement point, for the modified LF and Mid networks, with the tweeter added in:



There's a buch more material I'd like to listen to, but quick checks on two albums have convinced me that this is either "it" or very, very close.

Now, this plot above for the complete system would suggest a soft top end and a slight presence dip. BUT, they don't sound this way at all in this room, even with some Real Traps on the walls. I figure that with the very good off axis response of the system, the net power response is giving them the presence that the curve above could suggest that they lack. Curious, and interesting, to say the least.

Should be pulling drivers out and starting the detailed finishing steps this weekend, and finalizing the BOM.

I'll do a measurement at 30 degrees, too, and add that in this weekend.

[JonMarsh]

Last additional reference plot for now: 0 degrees and 30 degrees, 1 meter

I think this comes as close as I can hope for, for now, to my original planned voicing target- and I like what I hear.






It may not be obvious, but this does fit more or less with my revised target concept, based on Linkwitz's studies with Don Barringer and his Version 2 curve.

[ColoradoTom]

Jon,

Any feel for how well these are performing at moderate to high levels...... for us inquiring headbangers!! Also, my subs sounded good with my Geddes Abbeys, but sounded great with my SoundLab M1's. Initially setup the M1's to begin the process of putting them up for sale. Now I'm not so sure!! So many toys... so little time.

Tom