[Brian Cheney]

A 13x17x9' hotel room is not a good venue for high quality sound reproduction.  Bass modes in particular can be fierce, and pop up close to corners and walls. There are strong primary modes at 33Hz, 43Hz, and 63Hz, and the entrance foyer (6ft x 7ft) made that listening position extremely boomy and echoey as well.  While there were no exhibits on either side, a very loud demo was going on directly across the hall, and we had to keep our door open, as did the neighbor, which led to dueling bleedthroughs.  Not what you'd order from a wish list.

And yet, our system (Esoteric or Oppo 83SE transports, W4S DAC2 or NuForce DAC 9, Ampzilla Ambrosia preamp, modded DCX xover/controller, four Ampzilla 2000II monoblocks, Wywires interconnects and speaker cable, VMPS RM30 Series II speakers without subwoofer) made for the best overall reproduced musical presentation I have ever heard in 34 years of doing high end audio.  I will spend some time examining why in this thread, and attendees who can confirm my opinions are welcome to post to it.

[pardales]

Sounds like magic....in a good way.   

[JLM]

At the 2009 AKFest (with rooms roughly the same size), the only rooms that I thought sounded good were transmission line speakers, Quad 989s, or Hawthorne open baffles.

[John Casler]

Since this is the first year for THE Show at this venue, I think they will learn from the results.

It seems that they "staggered" the rooms, so the you didn't have "side by side" neighbors, but didn't think about having "across the hall" neighbors.

All they need do next year is adjust the stagger so that the room across the hall is a non-demo room.

That should solve 90% of the competing sound from your across the hall neighbor.

Strangely enough, that very issue was posted about in the Stereophile SHOW report of VMPS, so it shows what an issue it was.

Stereophile SHOW report

[Hugh]

Agreed 100%.

Since this is the first year for THE Show at this venue, I think they will learn from the results.

It seems that they "staggered" the rooms, so the you didn't have "side by side" neighbors, but didn't think about having "across the hall" neighbors.

All they need do next year is adjust the stagger so that the room across the hall is a non-demo room.
That should solve 90% of the competing sound from your across the hall neighbor.

Strangely enough, that very issue was posted about in the Stereophile SHOW report of VMPS, so it shows what an issue it was.

Stereophile SHOW report

[Brian Cheney]

THE SHOW had supplied us with 10 chairs, a large upholstered chair, a 6ft table, and a small end table.  I decided on short wall placement of the speakers and subwoofer, pulling both well into the room with considerable toe-in to define the center seats as the "sweet spot". 

This being a consumer show, I did not want to turn the environment into an anechoic chamber.  I had brought four 4ft square sheets of 3" Sonex, which we attached to the short wall behind the speakers and hid with curtains.  Two portable 48"H x 10"W Roomtunes (sheets of foil-backed R19 fiberglass suspended on a frame) were placed on the side wall at the first reflection point--these proved a little touchy, but we found good spots for them.  I had planned to bring at least two ASC 15" dia corner traps for bass control, but decided not to, as most consumers find these ugly and intimidating.  Given the room's bass-heavy proclivities, this was a mistake we won't make again.The 6ft wooden table was turned into an equipment rack, as was the end table, both covered with black drapes.


Thanks to the Audience people, we had a splendid Adept Response AR6 line conditioner and a second BPT conditioner, which we ran on separate lines.  Initially after setup we found a dead channel, which turned out to be a wiring error.  RM30 owner russtafarian was most helpful in the setup and had a portable Iphone RTA, with which he identified an additional room mode in the 200Hz region.  Using the DCX's 7 bands of parametric EQ  I cut 63Hz (floor-to-ceiling mode) by over 6dB and  176Hz about 2dB.  This was all the room correction necessary to make the center seats free of bass problems.  The side-firing PR's of the Series II radiated towards the side wall for a broad presentation, and I tuned the PR's with some putty pinching during setup.  Thanks to the flexibility of the modded DCX I could run the mid treble about 2dB hotter than in my home soundroom, which helped address the bass problems and gave sparkle to the trebles and presence to the mids.  We were ready for some sound checks, and in record time.

[Brian Cheney]

Just before starting with the critical listening on setup day, I decided to install some vibration control devices called Black Ravioli, which Clark Johnsen had introduced to my home system a few weeks ago.  These are hard feet placed under all gear (except speakers) were particularly effective improving the sound of CD transports and DAC's.  It took a few minutes to do this, but the before and after differences were substantial..

I devoted two EQ bands of the DCX to speaker correction.  I reduced the 1 to 3kHz level by about 3dB (centered around 2.16 kHz) to remove a built-in presence peak the designer of the panels must have thought desirable.  I also used a sharp cut of 4.1dB at 12.0kHz where the panel has its HF breakup mode.  For the rest of the setup time I toggled between different mid/treble vs bass levels, and tweaking the room mode cuts at 63Hz and 175Hz.  Without this flexibility we would not have achieved the results we got, which were spectacular. I did not see such measures taken in other exhibits, and I think they suffered considerably because of it.

[Conradicles]

Good job Brian. At the Axpona show in Atlanta I recently attended, most all of the rooms suffered. Nice to see somebody take the time and have the desire to get that fixed.

[Brian Cheney]

I think the lesson to be learned here is that any difficult room (very small, very large, untreated, ceiling higher than 10ft, etc) requires room correction.  While we had much more damping than any other room I visited, it was not by itself enough to do the job.  The qualities of the modded DCX were necessary, and no one could claim this was not a high end piece, providing the best of sounds top to bottom.

It became apparent after a few hours of opening day (very well attended, as on all three Show days) that we had an exceptional system set up, better in many ways than any in my experience, and not just at shows. 

Highs were simply amazing: extended, perfectly defined in space, lifelike, not harsh or etched in the least.  Percussion sounded hard, strings soft (for lack of a better term--there was no edginess whatsoever).  The female VP of a large, famous audio company told me these were the best highs she had ever heard, and I was flattered.  Mids were smooth and very present, with fat vocals and piano, each note and voice practically in your lap.  And yet, there was no overemphasis, and backup instruments and vocals stayed in perfect proportion with solos.

For a speaker with two active 6.5" and one 10" PR, the bass was outstanding.  I played the 26Hz bass drum in the Telarc Holst Suite no 1 "March", and it was reproduced in ideal fashion without doubling or distortion.

Visitors reported many rooms refused to play customer cuts, and for good
reason: many excited the room problems and sounded bad.  We took on all comers, had a huge variety of mostly ordinary CD's, and aced nearly every one of them. Complements came non-stop from attendees, critics, and even fellow exhibitors.  Of course the perfect dispersion from the speaker's Constant Directivity Waveguides contributed mightily to the overall high quality presentation.

[OzarkTom]

After going to the CES show about 22 times over the years, I gave up on how good a system should sound, given those hotel room restrictions. The hotel's power grid alone has to be taxed to death during a show like that. In Chicago at those old hotels, there were always some floor going out on the power.

It sure is nice to see that classic name Ampzilla and James Bongiorno still producing products.

Congradulations Brian, not everyone can do a job that well in those conditions.

[Brian Cheney]

Thanks.  I'll give you examples of a job done well, vs a job done poorly, at the Newport show.

Fritz Speakers produced some very good sound from a small pair of 6" 2ways playing vinyl through Modwright gear and Wywires cabling.  "Buena Vista Social Club" had good balance, transparency, and soundstaging.  I spied two large corner traps, so there was some damping available for the bass.

On the other hand, the Show's most expensive exhibit ($360K for speakers and electronics) disappointed.  Lowbass was lacking (probably turned down to avoid room problems), trebles actually stabbed the ear, and I noticed a gray pall over the (rather two-dimensional) sound due (I suspect) to multiple, highly audible diaphragm resonances and breakup modes.  This was not a good showcase for our industry.  The presenters seemed happy with it, tho.

[Housteau]

That modded DCX is a wonderful tool.  I can't imagine even attempting setting up a new system without that flexibility, especially now that I have been living with mine for several years now and know full well what it can do.