My Accuton project

[critofur]

Re: My Accuton project

Critofur, if you look at the pictures sometimes that helps you understand the words.

That's why I said "was" (past tense). Thanks

[xavier]

Re: My Accuton project

Well, after some input from others and some experiments on my own I've finally arrived at a final crossover for the speakers. The C79's are amazing transducers. I think they really do deserve their exalted reputation. I played with some 3rd order crossovers and some simpler ones as well. Surprisingly enough I ended up with something exceedingly simple. 2nd order electrical on woofers, 1st order electrical on the high and low pass for the mids (:eek::eek::eek and 2nd order electrical on the tweeter. A big BIG thank you to LouC for showing me just enough about LspCAD to get myself in trouble as well as giving me a starting place for the crossover.

I think I can finally get off the "high end audio" merry-go-round and just live with (and stop fussing over) what I've got. I'd also like to put out an invitation out to anyone in the area that's interested in hearing the set up.

Now on to other audio projects: the translam computer system, the

Newform R30/Usher HT mains and a revisit to my HT subwoofer.

Cheers

[ttan98]

Re: My Accuton project

Hi,

I heard the Accuton are very good drivers with excellent distortion profile, also they are expensive too, can you tell me the total costs of all the Accuton drivers for a pair of speaker(excluding the woofer) you are using?

Thanks

[xavier]

Re: My Accuton project

Per channel:

One C12: http://www.madisound.com/store/produ...oducts_id=8811

Two C79: http://www.madisound.com/store/produ...oducts_id=8797

Two C95 (old chassis): http://www.madisound.com/store/produ...oducts_id=8777

Sonic Craft has a sale on Accuton and other stuff right now:

http://www.soniccraft.com/specials.htm

[xavier]

Re: My Accuton project

Well, of COURSE I couldn't leave well enough alone. I'm just not a "well enough" kinda guy though. (sigh....and no comments from you, Lou)

I don't know how many times I've been told not to run the C95's sealed. Well, I finally got it through my thick head: they're now ported. Still getting some kind of port noise. I'm not certain it's turbulence (I've tried straws, stuffing, etc.), but it's not noticeable most of the time. Just when I play some of my electronica that has bass but next to nothing in the midrange/treble to cover up port noise. Kudos out to Curt Campbell for his article on port tuning: http://www.geocities.com/cc00541/Sealed_v_Vented.html and http://www.geocities.com/cc00541/group_delay.html. Big improvement in bass quality!

While playing around with "tuning" the crossover, it's interesting the little things that make a difference in sound. I found that while I could fill in that dip 4kHz, I either sacrificed a LOT of sensitivity, or I messed the sound up. I suspect too high a parts count in the latter situation. I did a version where the phase tracking was better between the tweeter and midrange, but the current version is more clear sounding and images better. This version also has more even vertical dispersion: I don't notice the vertical lobing issues that I did with the "better phase tracking" version.

Once I arrived at the current version, the sound seemed to have less noise. Don't ask. I don't get it. That's something for the psycho acoustics experts. The difference in the FR and phase between the different topologies I tried were small. One thing that was consistent was that the impulse response improved along with the improvements in topologies. I'm not saying that there's a correlation...just an observation. The C79 also seems to be very sensitive to the enclosure padding/stuffing. I could go from a warm/fuzzy sounding midband to something that was cold and sterile sounding with very little change in the type and amount of materials. FWIW I used 1" memory foam and wool felt (the same stuff I'm using around the tweeter) in the midrange enclosure and used memory foam/Blackhole in the woofer enclosures.

As for that HUGE hump at 150Hz....Lou and I figure it's a measurement anomaly. You certainly don't hear anything resembling that in the finished product.

I'll try to get some pictures with the current midrange drivers, as well as some shots of the current crossover board: something along the lines of a Reader's Digest Condensed version of the Nagra crossovers.

[xavier]

Re: My Accuton project

Figured out a way to fill in the dip at 4kHz with just a few minor changes to crossover.

[mgrabow]

Re: My Accuton project

I like the gray birds eye maple. Nice job...

[xavier]

Re: My Accuton project

As promised, <rolling eyes> an update on the resurrected/recycled system. Here are some photos of the current set up: http://www.flickr.com/photos/8626051...7627462556697/ The satellites were cut/salvaged from the large WMTMW arrays that I could no longer use. (Blew 2 of the woofers that turned out to be unobtanium)

Drivers:

http://www.accuton.de/media/datasheet/Datasheet%20C90-6-089%20disc.pdf

(the 13 ohm version of these)

http://www.accuton.de/drivers/detail.php?driver=4&matID=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.

[Face]

Re: My Accuton project

Very cool!

[evilskillit]

Re: My Accuton project

Awesome. Gratz on getting something that you might be happy enough to leave alone for a year or two. I've been watching your journey for ultimate sound for a while. Take a break and enjoy the music. :D

[xavier]

Re: My Accuton project

Thanks for the kind words. I'm definitely taking a break, evil. Working on inexpensive projects for friends for the foreseeable future. That, and helping LouC with his "to do" list. :D

[LouC]

Re: My Accuton project

If it ever cools down, and I get this chemo under control, the list is up to about 6 "big" projects, plus a ton of veneering and finishing. At this rate, it's gonna be November before we see sub 90 temps.

[50 watt head]

Re: My Accuton project

At this rate, it's gonna be November before we see sub 90 temps.

Yep, I've about had it with the heat already

[jcpahman77]

Re: My Accuton project

I hear ya, El Paso is cooler by maybe 5-10 degrees, but it's still not much better. Good luck with the work. If ya'll were closer I'd love to observe and learn, but gas just isn't cheap these days.

[xavier]

Re: My Accuton project

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.