My Accuton project

[dsrviola]

This has been in the works for a very long time, but I'm finally listening to the pair. I'd like to put out a big thanks to Lou Coraggio for all of his help with the cabinets and Clayton Oxendine for his help with the crossover (which I've since modified.)

Drivers are C12-6, C89-13, and C95-6. The 7" drivers each have their own variovent. The 5" drivers are sealed. The tweeter to upper mid crossover is a series network at 5kHz. (How it sounds as good as it does crossed over that high is a wondrous mystery) The 5" drivers have no high pass network except for the cabinet, and the 7"s sneak in at about 300Hz. (Still tweaking this, but could happily live with where it's at right now.)

Past projects include using the C23, the C95 (running as a midrange driver), and SCC300 (a BRILLIANT driver IMHO.)

I had a brother of a friend (who's a cabinet maker) do the veneering, and an incredibly flakey car painter mess up.........errrr........I mean.....uh..... paint the front baffles. No, I didn't do these all by myself but I did plenty. I certainly stressed out about them!!!

Various parts of the building process can be found on my completely neglected My Space page:

http://tinyurl.com/l6gueq

[TacoD]

Can you elaborate on your driver choices? It looks like the compete speaker is tuned by ear?

[dsrviola]

I'm not sure I understand your question. What would you like me to elaborate on? I listed (using the older identification numbers) the model of each driver I used. I also don't understand why you would say "It looks like the compete (sic) speaker is tuned by ear?" I know Clayton used measuring equipment and did quite a bit of number crunching to come up with what he did. That's the joy ( 8O ?!?!?!? 8O ) of working with series crossovers.

Apologies for not being clear enough, nor understanding your inquiry.

[JonMarsh]

The Accuton C89 does pretty much die on it's own at 5 kHz, so the upper crossover frequency is a little surprising, unless you're just relying on what the driver does.



It sounds like you've had some fun and a lot of work; I know how that feels- any measurements of the completed system?

Some other system designs use the box high pass for the midrange; I believe that's what the Avalon Indra does; it saves money on crossover components, but in the case of the Indra, it results in a punishingly low impedance in the bass and midbass, typically under 3 ohms. Like your project, it has dual midwoofers. How did your impedance curve turn out? Do you have any measurements of the finished system? It would be interesting to see them.

~jon

[TacoD]

Clayton Oxendine for his help with the crossover (which I've since modified.)

I was only assuming that somebody else did the x-over, which was "modified" by you using your ears. Sorry it was not my intention to flame.

Apparently you want some feedback from others (also posting on other forums) and it look like you only expect compliments .

[dsrviola]

Hey Jon,

No measurements of the completed system yet. I don't know that Lou and I will be doing any outdoor measurements of the speakers since they're a bit unwieldy. We're definitely going to do some indoor measurements in situ. We need to do that to dial in the 7" drivers as well as integrate the subwoofer phase and level. If we run into too many room issues with that, we'll rethink getting the speakers outside.

As for the 5 kHz crossover: Clayton has his own ideas on crossover design and how speakers should sound. He and I have never met in person, nor have I heard anything that he's built. He has been considered by some to be.....how to put this?.....a bit of a series crossover guru. After some experiences with this type of crossover design, I've discovered that there are some aspects of it that I find intriguing and value as part of the listening experience. Anyway, I'm still very very surprised that the speakers sound so convincing in the crossover region. When he told me that's where the crossover point was, I was expecting to hear all the problems one associates with a crossover point that high. While the speaker may still measure with these expected artifacts, it's certainly not keeping me from enjoying the sound thus far.

I'm very surprised to hear the Indra does not use a high pass electrical crossover on the C79. Unless Avalon has the driver extensively modified, I don't see how it could possible survive the excursions (even in a very small box) and power. (shrug) Monitor Audio did a similar type of midrange loading in their Studio 50:

http://www.stereophile.com/floorloudspeakers/396monitor/

While the C79 is obviously a better dedicated midrange driver, it's not really the best candidate for a simple first order series crossover. The driver needs too much in the way of FR shaping that you can utilize in a parallel crossover.

While Lou and I haven't done an impedance measurement, Clayton did with the drivers in his box (he built one for the design process), and while a little on the low side (I think he said 3.5), it was surprisingly flat and relatively easy from a phase standpoint. It's one reason I'm using a high current 250W amp. As much as I like tube amps, I know that any of the ones I could afford wouldn't be an ideal partner for this type of speaker.

TacoD,

Yes, the crossover was modified by ear. To make matters worse, I don't have an extensive stock of crossover components on hand. However, I lucked out and had something some inductors that were "in the ballpark" of what I was hoping for. I still hope to refine - using my ears as well as measurements - the modification I've since made to the crossover.

What I really wanted to do was just share my efforts with others of similar interests. Isn't that what these forums are for? I'm certainly not naive enough to think that posting ANYTHING on a forum such as this or others is going to get me nothing but compliments. However, I'm also not here to get affirmation of my project from others. I built these speakers for MY listening enjoyment. I'm not trying to promote a product or a design philosophy. Just posting in the interest of sharing with the DIY community.

Cheers

[TacoD]

I am surely impressed with the project and I also appreciate the sharing of it. There are not that many people doing such large systems. My experience with loudspeakers is that its very hard to tune by ear.

Not having the proper parts can be very frustrating. Somehow I always need different values than the ones I've got on the shelf .

[relder]

Lookin' good Joeseph, bring 'em to the next AZ DIY event (whenever that may be) so I can hear 'em!

Rob

[Rick Craig]

This has been in the works for a very long time, but I'm finally listening to the pair. I'd like to put out a big thanks to Lou Coraggio for all of his help with the cabinets and Clayton Oxendine for his help with the crossover (which I've since modified.)

Drivers are C12-6, C89-13, and C95-6. The 7" drivers each have their own variovent. The 5" drivers are sealed. The tweeter to upper mid crossover is a series network at 5kHz. (How it sounds as good as it does crossed over that high is a wondrous mystery) The 5" drivers have no high pass network except for the cabinet, and the 7"s sneak in at about 300Hz. (Still tweaking this, but could happily live with where it's at right now.)

Past projects include using the C23, the C95 (running as a midrange driver), and SCC300 (a BRILLIANT driver IMHO.)

I had a brother of a friend (who's a cabinet maker) do the veneering, and an incredibly flakey car painter mess up.........errrr........I mean.....uh..... paint the front baffles. No, I didn't do these all by myself but I did plenty. I certainly stressed out about them!!!

Various parts of the building process can be found on my completely neglected My Space page:

http://tinyurl.com/l6gueq

Is Clayton still around? It's been about nine years since I've seen him. At that time he was living here in North Carolina.

[chrismercurio]

Clayton

I haven't read that name since Madisound had a good BBS. 9 years ago sounds right.

[dsrviola]

Rob,

You're welcome to come by anytime, as is anyone else who happens to be in the area. Don't know about lugging these beasts to a DIY, but who knows... Besides, what I'm hearing here is the system, not just the speakers.

Rick,

Yes, Clayton is still around....and kicking too! He's still in NC as well. You should look him up and harass him. It'd be good for him :T

[dsrviola]

Posted this over on the PE Board. Here it is again for those who don't make it over there:

As promised, <rolling eyes> an update on the resurrected/recycled system. Here are some photos of the current set up: http://tinyurl.com/3fts36n

The satellites were cut/salvaged from the large WMTMW arrays that I could no longer use. (Blew 2 of the 7" woofers that are now unobtanium)

Drivers:
http://tinyurl.com/3gxysl6 (the 13 ohm version of these)

http://tinyurl.com/3ug5vrr

http://tinyurl.com/3wo5qrm each powered by a BASH 300.

The crossover is 3rd order electrical on tweeter and 2nd order electrical on the woofers. There are two outputs coming from the very modified Oppos: one is buffered and is full range for the subs, the other has a simple high pass (a super primo fairy dust/snake oil .1 uf V-Cap) set at 80 Hz for the Pass amp that powers the satellites. Installing this high pass capacitor allowed me to remove the huge 10uf caps on the input section of the Pass amp. These were built to "hold me over" till I can make another attempt at a project utilizing the C79 midrange again. <What? The piggy bank is empty?!?!?!>

Kudos to LouC for all his help and dlr for his documentation on diffraction reducing felt.

The sound? Best I've had in my room. Not the most resolved I've ever had (those C79's I had in the BIG project, not to mention the C12 tweeter are clearly superior in that regard,) but certainly the most coherent and speaks-with-one-voice quality I've ever had the pleasure of owning. The 12" subs pictured on each side are not in use. The 10" Daytons obviously don't go down as far, but they're easily the best woofing (except for my fox terriers) I've EVER had. (I never had a chance to get the tuning right on the 7" accutons.) Having powered woofers is the biznitchal! Makes balancing the system SO much easier.

Regarding the measurements: Raw drivers were measured in the box and used to come up with the pictured simulations. The measurements were taken with a much different felt surrounding the tweeter than what's pictured. I haven't taken measurements with the current felt. While I'm uncertain that measurements would show a difference, my ears are certainly hearing one.

[Generic George]

Posted this over on the PE Board. Here it is again for those who don't make it over there:

As promised, <rolling eyes> an update on the resurrected/recycled system. Here are some photos of the current set up:

Images not available

The satellites were cut/salvaged from the large WMTMW arrays that I could no longer use. (Blew 2 of the 7" woofers that are now unobtanium)

Drivers:

http://www.accuton.de/media/datashee...089%20disc.pdf

(the 13 ohm version of these)

http://www.accuton.de/drivers/detail...atID=4&appID=1

http://www.parts-express.com/pe/show...number=295-460 each powered by a BASH 300.

The crossover is 3rd order electrical on tweeter and 2nd order electrical on the woofers. There are two outputs coming from the very modified Oppos: one is buffered and is full range for the subs, the other has a simple high pass (a super primo fairy dust/snake oil .1 uf V-Cap) set at 80 Hz for the Pass amp that powers the satellites. Installing this high pass capacitor allowed me to remove the huge 10uf caps on the input section of the Pass amp. These were built to "hold me over" till I can make another attempt at a project utilizing the C79 midrange again. <What? The piggy bank is empty?!?!?!>

Kudos to LouC for all his help and dlr for his documentation on diffraction reducing felt.

The sound? Best I've had in my room. Not the most resolved I've ever had (those C79's I had in the BIG project, not to mention the C12 tweeter are clearly superior in that regard,) but certainly the most coherent and speaks-with-one-voice quality I've ever had the pleasure of owning. The 12" subs pictured on each side are not in use. The 10" Daytons obviously don't go down as far, but they're easily the best woofing (except for my fox terriers) I've EVER had. (I never had a chance to get the tuning right on the 7" accutons.) Having powered woofers is the biznitchal! Makes balancing the system SO much easier.

Regarding the measurements: Raw drivers were measured in the box and used to come up with the pictured simulations. The measurements were taken with a much different felt surrounding the tweeter than what's pictured. I haven't taken measurements with the current felt. While I'm uncertain that measurements would show a difference, my ears are certainly hearing one.

None of your links seem to work. Looks like they got trimmed or edited by the board software.

Question. There are "E" versions of the accuton drivers that you list. I believe the main difference is lower distortion. Do you think that they are sufficiently close that you could substitute them. They aren't much more expensive (relatively speaking) than the base models.

I do find your design interesting. I am kicking around some possibilities for some "ultimate" speakers.

[dsrviola]

I changed the links. They seem to be working now.

From what I can tell, there are no "E" versions of the drivers that I'm using. Unfortunately, the midrange driver (technically, it's a mid/bass driver) has been discontinued. It's the 13 ohm version of the midrange driver used in the Talon Firebird.

In my original project, the four 7" C95's that I was using were the original version. I blew two of them in one channel because of faulty protection circuit in the system. (DC got sent to one channel and shattered the 7" drivers) I tried to find a couple of replacement drivers and finally came across somebody who was using them in a small production run of speakers. It turns out that at one point the vendor switched from the older version to the newer version without telling him. When I got the drivers they were much different than the drivers I was using. I wasn't about to replace ALL four woofers when I only blew two hence my going in a completely different direction from the original project.