Publisher Profile

Experiencing the Sound Lab Ultimate 990PX electrostatic loudspeaker system

By: |

Spotlight Framed

What kind of speaker will you choose if you could afford anything and you had a dedicated listening room with a twenty feet ceiling?

What kind of music would you play in the system you choose and in such vast venue?

Not many of us have the privilege of tackling such tacky issues, so imagine my reaction when Sound Lab of Salt Lake City came to my home to pick up the reviewed pair of Ultimate 545 and showed me a picture of a couple standing next to a pair of nine feet tall Sound Lab speakers that he just delivered sixty miles away prior to visiting me.

The speakers were the Sound Lab Ultimate 990PX, delivered to a Dr. Chen. I suggested an introduction, it was made, and Dr. Chen agreed to a visit.

Dimension of music room:

LxWxH = 22x18x20 ft
Front wall and 2 windows of music room:(WxH)=6/7/6 x20 ft
Distance of speaker to the front wall: 100 inches
Distance between midpoint of two speakers: 10ft


Speakers: Sound Lab U990PX
Source: EMM Lab TSD 1 CD transport and DAC2
Amplification: D’Agostino Momentum preamp, D’Agostino Progression monoblock amplifiers
Cables: Kimber Kable KCAG interconnect Or Kimber Kable Hero, AudioQuest Dragon or Kimber 8TC speaker cables


Dr. Roger West offers the following regarding Dr. Chen’s U-990PX:

“The first digit (9) of “990” represents a 9 feet tall speaker.  The last two digits (90) indicates that it has 90 degree dispersion.  The “PX” suffix represents our most recent panel design without the bass-focus technology.  If Dr. Chen’s panels had “bass-focus” they would be of our latest technology, which we now refer to as the Ultimate 990 minus the PX suffix.”

For the readers’ info, I took delivery of a pair of the company’s Majestic 645 in August this year. The Review of which is in progress.

The Sound Lab designs are akin to the Pass Laboratories design philosophy, in that all their products have the same level of resolution and tonal vividness, but the bigger ones are for bigger rooms and more demanding dynamic scaling requirements. Dr. Chen’s U-990PX is Sound Lab’s largest and most capable product supposedly in delivery of the most realistic dynamic scaling in a large space.

Then Chen mansion was in a secluded, gated valley community surrounded by rolling hills on all sides. A complete golf course adorned a central patch of land, surrounded by scenic drive routes.

The Ultimate 990PX were originally an earlier model, sent back to the Sound Lab factory in Salt Lake City for retrofitting, hence the PX limitation. A new pair of the Ultimate 990 costs $55,000 the pair. Still, Dr. Chen’s 990PX was positively huge. Each curved panel was 40 inches wide!

Dr. Chen enjoyed listening to chamber or solo music performances predominantly, for he felt the Sound Lab were among the very few designs in the world capable of producing the full body and spectrum of instruments, be it a piano or triangle. I presented my demo CD full of orchestral, synthesizer, heavy metal and what-have-you rambunctious music, including a sound field recording titled, “Night at the airport,” and was asked very cordially by a baffled Dr. Chen if I’d considered just enjoying the most natural and realistic presentation of the sound of solo instruments. Retrospectively, now that I have had months of experience with the Majestic 645 in my system, I think Dr. Chen was not amiss in the pursuit of music his way, via the Sound Lab. He is probably among the most hard cored of us all.


To be featured in the Dagogo Spotlight Column:

Email your system detail and a picture of it to for consideration. Sorry, we can only consider submissions from the San Francisco Bay Area at this time.

All Spotlight submissions will be acknowledged.


  • (Page 1 of 1)

3 Responses to Experiencing the Sound Lab Ultimate 990PX electrostatic loudspeaker system

  1. john vogt says:

    So I take it that you did not get to play the CD you brought along? That aside, how did the system sound with the material Dr. Chen chose to play?


    • John,

      Thank you for your readership and inquiry.

      On how the system sounded, as an invited guest, I was there to share with the readership what Dr. Chen put together, and perhaps sample the sound of his system. I wasn’t focusing on critiquing.

      That said, I did play my demo CD as described, and the experience led me to pursue a larger pair of Sound Lab panels for my own use, culminating in the Majestic 645.

  2. Marc Silver says:

    The Old Ultimate was my favourite loudspeaker ever.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Popups Powered By :