RMAF Pictures

FredT300B · « **on:** 23 Oct 2006, 08:38 pm »

Mostly of non mainstream manufacturers' products

http://fredt300b.smugmug.com/gallery/2040368/1/104741473

JoshK · « **Reply #1 on:** 23 Oct 2006, 09:07 pm »

Excellent photos. Would love to hear your comments on the sound of, in particular, the emerald physics speakers, and the Audio Kinesis speakers (which aren't on their website). I couldn't find anything on the web about these two.

FredT300B · « **Reply #2 on:** 23 Oct 2006, 10:13 pm »

Quote from: JoshK on 23 Oct 2006, 09:07 pm

Would love to hear your comments on the sound of, in particular, the emerald physics speakers, and the Audio Kinesis speakers (which aren't on their website).

The Emerald Physics speakers aren't my cup of tea. They sounded very good, and the DSP produced a sound that's absent the peaks and dips I hear with many other OB dipoles, but the 6K price plus the six channel amplification requimement leaves me cold. They also have a low WAF and will occupy lots or real estate in your listening room.

The Audio Kinesis speakers sounded very much like the other Eminence based speakers I've heard, including Pi Speakers and the Tyler Acoustics speakers at the fest. The waveguide may be a better choice than the horns used on most other high sensitivity speakers. I could live with these. Emerald Physics literature doesn't mention a web site, and the Audio Kinesis site hasn't been updated to include their latest products, but their forum is at the link below.

http://audioroundtable.com/AudioKinesis/

JoshK · « **Reply #3 on:** 23 Oct 2006, 11:50 pm »

Thanks! I am solely DIY, but the design concepts I am borrowing/using. So I am curious how people like the sound of the commercial units. Did the EP only turn you off because of hte price/amp'ing/waf or did you not like the sound? I couldn't tell from your post.

I am working on a waveguide loaded CD, + JBL 10" mid + 2 x 15" Hi-eff woofer design. I am also doing a dipole design. The DEQX I own (not cheap) allows for such flexibility of system(s). But I am also going in somewhat blind, knowing I can always scrap it if it doesn't turn out. Yes, I have invested a lot but most everything can be used or sold, except for time which I count towards hobby time.

FredT300B · « **Reply #4 on:** 24 Oct 2006, 12:54 am »

Quote from: JoshK on 23 Oct 2006, 11:50 pm

Thanks! I am solely DIY, but the design concepts I am borrowing/using. So I am curious how people like the sound of the commercial units. Did the EP only turn you off because of hte price/amp'ing/waf or did you not like the sound? I couldn't tell from your post.

I really did like the sound, but I was so turned off by four large towers plus tri amplification that I didn't listen very carefully. If I wanted a high end dipole I would be more inclined to go with the far more attractive Orions. So it's really a matter of aesthetic taste, and others might find them attractive in a form-follows-funcition way. My other passion/hobby is antique collecting, and my wife and I don't want speakers that will detract from the antiques.

http://fredt300b.smugmug.com/gallery/132888

Duke · « **Reply #5 on:** 24 Oct 2006, 07:24 am »

Hi FredT,

Thanks for posting pictures of my speakers & my wife!

A couple of minor corrections, if I may...

My speakers are about 92 dB efficient, not 96 dB. Also, we don't have a retail storefront - had one briefly, but it burned to the ground last December. Finally, I don't use Eminience drivers - wish I could have, as they're a lot less expensive than what I ended up using.

Sorry about the out-of-date website, JoshK. I have been unable to contact my web designer by e-mail or phone, and I've prepaid a substantial amount of service with him but at this point don't know what's going on. Now that the show is past I'll have a little more free time and will work on getting it updated. In the meantime, I'd be glad to take a shot at any questions you may have either by e-mail or phone 208-852-2610, or shoot me an e-mail with your number and a good time to call). Don't worry I'll leave my dealer hat off and put my DIY hat on.

Cheers,

Duke

FredT300B · « **Reply #6 on:** 24 Oct 2006, 06:51 pm »

Duke, thanks for the correction. I changed the caption to reflect the 92dB sensitivity. What were the output tubes in the amp in Lori's room? My picture doesn't do it justice, but that was some gorgeous finishing on that amp.

Duke · « **Reply #7 on:** 24 Oct 2006, 08:55 pm »

Hi FredT,

The tube was indeed what's commonly called a "50", though I think the full name is "UX-250 power triode". In this application, the tube puts out five watts per channel. My understanding is that they haven't been made in decades, until just now - the Chinese have made an initial batch that is close to the best of the NOS tubes in sound quality, and these tubes were from that initial batch.

The amplifier is designed and built by Richard Gray (yes, that Richard Gray). The chassis is the work of craftsman Nick Ferber. Most of the chassis is figured cherry, and the transformer covers are wenge. If you're familiar with Cain & Cain speakers, Nick is sort of a Terry Cain of amplifier chassis work. I didn't show you the rear or underside of the amp, but the same level of artisanship shows up there too.

That particular amplifier is not for sale and won't be until they sell off my estate (and probably not even then). Nick made that chassis especially for me. It's the most beautiful piece of woodwork I have ever owned. If I still lived in New Orleans, I'd have Nick build the speaker cabinets for me, or at least the top-of-the-line-ones.

Duke

G.ear · « **Reply #8 on:** 25 Oct 2006, 07:12 pm »

Hey JoshK,

FWIW, I was rather taken by the Emerald Physics "Nemesis" loudspeaker system sonically (was glad to see FredT330B liked them sonically as well). I, too, am somewhat disinclined with all the amplification needed (I was told 8 channels, not 6), but if you're into multi-channel amps, it doesn't become cost prohibitive. The samples at the show were strictly prototypes, so the final cosmetics are TBD.

This system exhibited a very high standard in terms of clarity, depth of soundstage, detail, bass reproduction, and dynamics (rated as 100 db efficient), though I found it appealing more to the brain than the heart. I attribute this to the amplification, but it could have just as easily been due to the extreme level of neutrality afforded by an ultra linear frequency response resulting from DSP. Clayton claimed that the speakers were flat within 1/4 db from 100 Hz to 20 KHz. From a subjective perspective, when seated nearfield, I felt the upper midrange was just a bit more energetic and brighter than my personal preferences. However, when standing or seated further away, my perception of being moderately bright was removed. Unlike the Orion, there isn't a sense of some additional warmth. Of course, given that the system is DSP controlled, one could pretty much program in whatever response primed their pump.

Among the show-goers that I spoke with, the Emerald Physics speaker was the most frequently mentioned as their favorite at the show. Robert Harley of TAS fame indicated to my traveling companion that he felt it was one of the best if not "the best" at the show. People were impressed enough that, despite this being just a prototype from a brand new company, they were placing orders and giving deposits for the first production units. Very impressive for and upstart.

Dean

jhm731 · « **Reply #9 on:** 25 Oct 2006, 09:18 pm »

Quote from: G.ear on 25 Oct 2006, 07:12 pm

Hey JoshK,

FWIW, I was rather taken by the Emerald Physics "Nemesis" loudspeaker system sonically (was glad to see FredT330B liked them sonically as well). I, too, am somewhat disinclined with all the amplification needed (I was told 8 channels, not 6), but if you're into multi-channel amps, it doesn't become cost prohibitive. The samples at the show were strictly prototypes, so the final cosmetics are TBD.

This system exhibited a very high standard in terms of clarity, depth of soundstage, detail, bass reproduction, and dynamics (rated as 100 db efficient), though I found it appealing more to the brain than the heart. I attribute this to the amplification, but it could have just as easily been due to the extreme level of neutrality afforded by an ultra linear frequency response resulting from DSP. Clayton claimed that the speakers were flat within 1/4 db from 100 Hz to 20 KHz. From a subjective perspective, when seated nearfield, I felt the upper midrange was just a bit more energetic and brighter than my personal preferences. However, when standing or seated further away, my perception of being moderately bright was removed. Unlike the Orion, there isn't a sense of some additional warmth. Of course, given that the system is DSP controlled, one could pretty much program in whatever response primed their pump.

Among the show-goers that I spoke with, the Emerald Physics speaker was the most frequently mentioned as their favorite at the show. Robert Harley of TAS fame indicated to my traveling companion that he felt it was one of the best if not "the best" at the show. People were impressed enough that, despite this being just a prototype from a brand new company, they were placing orders and giving deposits for the first production units. Very impressive for and upstart.

Dean

See:

http://www.avguide.com/news/2006/10/22/rocky-mountain-audio-fest-emerald-physics-dsp-based-loudspeaker/

PaulFolbrecht · « **Reply #10 on:** 25 Oct 2006, 09:35 pm »

I was also very impressed by the AudioKineses speakers, especially the ones in the AtmaSphere room (which was the cheaper of the two). That was an extremely good-sounding and reasonably-priced setup.

DeadFish · « **Reply #11 on:** 25 Oct 2006, 11:41 pm »

Hey Fred, great pictures!!

You also showed me a lot that I inadvertantly missed, durnit! (can I get a 'do-over' over here?)

Good job!

DeadFish

Duke · « **Reply #12 on:** 26 Oct 2006, 01:06 am »

Thank you very much for putting in a good word for me, Paul!

I didn't get by the Emerald Physics room, as I was showing in two rooms and flying solo in one of them. Their design looks very, very interesting to me. Anyone who was in both rooms, I have a question for you: Were we using the same waveguide as Emerald Physics? Just eyeballing the photos it looks to me like it's the same.

I sure enjoyed meeting some of the people from AudioCircle at the show. Ya'll are a great group.

Duke (aka "AudioKinesis")

JDUBS · « **Reply #13 on:** 26 Oct 2006, 03:53 am »

Duke

Let's here more about your new speakers! They look really great...wish I knew about them before my recent speaker purchase (which I haven't received yet).

The Stormbringers look especially nice!

-Jim

PaulFolbrecht · « **Reply #14 on:** 26 Oct 2006, 04:38 am »

Let me say I few more words about the Stormbringer/AtmaSphere combo.

1st of all, it sounded like SET to me. I don't know if this was the OTL or the speakers or both, but I would have sworn this was a SET setup if I hadn't know otherwise. This does not happen often.

Sound was very extended and very PURE (the SET thing). VERY sweet-sounding and listenable. In fact, the audio note room later reminded me of this room... I am not kidding. (We're talking about over a 10x difference in price here, all-up.)

Bass was excellent. I think I was told they went down only to the mid 30s (I could be wrong) - sounded lower than that.

If I'd been in the market for speakers, I would have been very interested. I'd forgotten to take notes in this room and thus almost forgot about it. I should've included it in my 'top rooms' in the thread I started.

Duke · « **Reply #15 on:** 26 Oct 2006, 05:24 am »

Jim -

I'm not sure how appropriate it would be for me to launch into what could be construed as a "promotional" post explaining what I think are the cool features of my speakers.

A few weeks ago I e-mailed theBorg and asked what I'd have to do to get my own board in the "Audio Manufacturers" section. I was told:

".... at the moment the policy is that you have to be known and accepted by the community first. Please use the marketplace to introduce yourself and discuss your product."

I introduced myself and my speakers in this post: http://www.audiocircle.com/index.php?topic=32287.0

Maybe the time has come that I'm "known and accepted" enough to get my own manufacturer's board. I'll ask again, and if I'm not accepted then I'll post a reply to your inquiry over on "Marketplace", and come back here and post a link to that reply.

Paul, thanks for the encouragement! I must admit that I stole an idea from Audio Note - namely, using a rear ported enclosure with the port tuned fairly low and positioned to take advantage of boundary reinforcement. That being said, I think at least equal credit should go to Ralph Karsten of Atma-Sphere. I think his amps helped my speakers to sound better than they should have.

Duke

Russell Dawkins · « **Reply #16 on:** 26 Oct 2006, 06:39 am »

How were the bass drivers wired in the Emerald Physics subs? I am presuming they were all wired in the same polarity, that is that all the cones moved out at the same time. I don't understand the reasoning behind this if true. Can someone enlighten me?

Duke · « **Reply #17 on:** 26 Oct 2006, 06:47 am »

Russell,

I didn't see the Emerald Physic subs, but having played around with back-to-back dipole woofers I think I can guess how they're wired.

All of the woofer cones move towards the listener in unison, and all of them move away in unison. This means the leads are reversed on the backwards-facing rear drivers.

The net effect is comparable to having all four woofers on the same baffle, but it takes up less space (or at least it takes up space in a somewhat easier-to-manage package).

Very intelligent design, imho.

Duke

Duke · « **Reply #18 on:** 26 Oct 2006, 07:03 pm »

Reply to JDUBS/Jim:

Apparently it's okay for me to answer your question here after all.

"Let's here more about your new speakers!"

Both designs are quite similar in approach: A constant-directivity waveguide-loaded compression driver, a prosound woofer, crossover where the woofer's radiation pattern has narrowed to match the waveguide's, and rear-ported reflex enclosure.

I use a 10" diameter 90-degree pattern waveguide, a 10" woofer in the floorstander, and a 12" woofer in the stand-mount. Why the bigger woofer in the smaller speaker? Because it's targeting a price point, and I couldn't find a suitably priced 8" or 10" prosound woofer that had good bass. The 10" woofer in the big ones is quite expensive, and 10" is the ideal size for this application.

My intention is to first of all get the reverberant field to have essentially the same spectral balance as the first-arrival sound, hence the CD waveguide. Second, I want to avoid thermal compression so I'm using prosound drivers. Third, they both have an especially tube-friendly impedance curve. These are the main ways my speakers differ from most of their competition.

The port length is user-adjustable, so that if the speakers are placed close to room boundaries the reinforcement can be used to extend the bass a bit deeper. I stole the idea of boundary reinforcement of the port's output from AudioNote.

The two models have slightly different voicing. The stand-mounted Stormbringer is voiced a bit on the warmish side, and the floorstanding Jazz Modules are closer to neutral. Interestingly, among people who listened to both, preference is split roughly 50-50. So while I could tweak the voicing of either speaker, I'll probably leave them like they are.

These speakers are my own design, though in many areas I draw heavily on the work of Dr. Earl Geddes. I'll answer questions about most aspects of the design, but won't give away details about the crossover.

Later today if I have time I'll post a couple of ads in Marketplace, wherein I'll give specs and so forth.

Duke

JDUBS · « **Reply #19 on:** 27 Oct 2006, 01:25 am »

Good stuff, Duke! I saw your ad on Audiogon and it was very helpfull.

-Jim