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Positive Feedback ISSUE 40
november/december 2008


cathedral sound

Acoustic Panels

as reviewed by Francisco Duran






DALI Euphonia MS4.

Antique Sound Labs MG-SPM25DT monoblocks, Canary CA-301Mk-II amplifier, and Reference Line Preeminence lA passive and Canary CA-601Mk-II preamplifiers.

NAD T531 and Antique Electronic Supply CD-1 (temporary) CD players, and a Taddeo Digital Antidote Two.

Either JPS Superconductor+ and FX interconnects and a double run of JPS Ultraconductor speaker cables, or Analysis Plus interconnects and Oval 12 speaker cables, and Monarchy and various DIY AC cords.

Balanced Power Technologies BPT 4SE, Brick Wall Series Mode Surge Suppressor, Audio Prisim Quiet Lines and Noise Sniffer, Vibrapods, Black Diamond Racing Boards and cones, Final Labs Daruma-3II Isolation Bearings, various ferrite rings, Target rack, Yamaha KX-380 cassette deck, custom made wooden cable lifters by Mr. Clark senior, and all the NOS tubes I can afford!


It has literally been an audio roller coaster ride in regards to the contents of my system and the review of the Cathedral Sound Panels. It all started when I sold my Dali Euphonia speakers. The sale coincided with the arrival of the Cathedral Sound Panels that I requested for review from Robert Stein of Ultra Systems. This was bad timing on my part. My new pair of speakers, the Tonian Labs TL-D1's took a whole lot longer than anticipated to arrive. In the mean time I was using a $100 pair of speakers that barely held me off until the new ones arrived. The Cathedral panels hovered between hanging in my listening room and stacked on the floor of my home office. Then I still had to break the Tonians in as well as my new amp. The Chambers Brothers, The Pretenders and Pink Floyd were chiming in the back of my mind for months. The phrase time, time time, the avenger was haunting me as well as a few other rock songs about the slippage of time. I had to do this review!

After a rather lengthy time with speaker, amplifier break in, and component matching, a good assessment could finally be given to these compact little panels. What are they? If you haven't already read about them, I'll quote a bit and explain a little. “A small décor friendly means for reducing room acoustic problems, especially those associated with bass standing waves.” They are effective on bass response below 100Hz. But by cleaning up standing waves in that area, the midrange and frequencies above that also benefit. The panels are said to improve intelligibility in vocals and create a more spacious and detailed soundstage. I encourage readers to have a look at Ultra Systems unique and informative website. Besides the Cathedral panels, they have a whole assortment of cool and exciting products.

It has been hammered home to us that if we first get our rooms to sound right, everything else sonically falls into place. If your speakers aren't dealing with room nodes and suck outs, your system should initially perform better. Therefore whatever changes to said system in regards to cables or tweaks or gear, your system should be better able to showcase the quality of those changes instead of first fighting with the room. My new speakers are very revealing, much more so than my previous pair. Consequently inserting them into my system revealed a lot about associated equipment and listening room. It was obvious that some gear needed changing and my room definitely needed some acoustical help even though I do use a few acoustic panels and bass traps. With glass covered wall hangings and a double glass sliding door in my den, there were reflections galore and it needed taming.

Along come the Cathedral Sound Panels from Ultra Systems. Measuring just eleven by just a shade under sixteen inches, they definitely do not dominate a room. There are two ways to mount the panels. They can be hung either horizontally or vertically. They can be hung on one side of the wall or the other. That is on each corner directly behind each speaker or on the adjacent wall. One can use just two panels or four depending on the desired effect or the urgency of the room. The instructions are concise but informative. The panels come in several colors, I chose beige. They even come with small brass brads for hanging the panels.

Since I was sent four panels I mounted all four according to the measurements in the instructions. I opted for the horizontal placement. The choices in hanging are meant for experimenting in order to maximize the effectiveness of the panels. My panels were mounted on the wall directly behind the speakers and again on the wall directly behind my couch. I used many recordings in the evaluation of the panels as well as casual listening. But one recording in particular helped quite a bit in recognizing the panel's effects. The song, "Just Ahead" from Pat Coil's Just Ahead CD, it also happens to be on the Sheffield/XLO Test and Burn-in CD, was very useful. With its “punchy bass sound …natural openness …and… uncompressed dynamics,” it helped in fleshing out the bass and mid-bass qualities of my speakers.

Let's start with all four panels at work at each corner of the room. The positive effects of these panels were readily apparent. The first thing I noticed was that the music became more focused. That is, the individual instruments sounded more solid and grounded in the soundstage. The soundstage became slightly more open and slightly spread out as compared to without the panels. The depth of the soundstage suddenly became more easily discernable. What was interesting was that now the soundstage “signature” of each recording was more easily recognizable. As far as bass was concerned, I used to use two corner traps from another company to aid in any lower frequency problems. It was funny but I always heard a persistent crackling sound mainly centered in the mid bass. Nothing I tried as far as speaker placement or component/wire change would alleviate it. That is before hanging the Cathedral Panels in my listening room and removing the bass traps. The little panels rendered bass noticeably more coherent. And the focus I mentioned earlier was evident through the whole frequency range. At least from 42Hz on up which is the lower most reach of my new Tonian Labs TL-D1 speakers. I did feel that the overall sound coming from my speakers was now slightly darker. The effects of the Cathedral Panels moves up from the bass to the upper frequencies and not only tamed a slight brightness there but also slightly changed the tonal balance a bit to the darker side.

I would like to mention here that I feel the Tonian Labs speakers were instrumental in helping me hear the qualities of the Cathedral Panels. The Tonian Labs TL-D1's are very revealing but musical, and have a very tonally correct nature to them. I would also like to mention that I may not have the most ideal room for a stereo set up, though on the surface it looks good. Its dimensions are 12X20 feet. I set up my system on one of the short walls because that is the most practical place to put it. A sliding door on one long wall and an opening on the other prevent use of one of the long walls. Wall hangings with glass panes and a 46 inch flat screen TV also add to negative effects of an ideal “listening” room.

Next I did a little experimenting. I took all of the panels out of the room and listened to some music. Immediately noticeable without the panels was a slightly looser, slightly congested bass. Amazingly the whole musical performance seemed to slow down. It was as if the dynamics had slowed down slightly. This was strange because this is another strong point of the Tonian speakers, that being dynamic speed. The top end, in particular the upper midrange to lower treble sounded a tad brighter and strangely, that part of the frequency spectrum had a little more “echo to its sound. Then I listened with just two panels hung in front of me. That is, two panels behind my speakers. Immediately the coherence was restored in the bass. Gone also was the distortion that plagued a non Cathedral paneled wall. The brightness was also tamed. I next repeated the experiment with two panels but this time on the wall directly behind my listening position. The same effects were noticed in regards to bass distortion and brightness. But this time inserting the panels behind me revealed a slightly warmer top end. Restoring the room once again to the four panel mode revealed that there was a thicker more dark quality. My preferred method for hanging the panels is with two of them hanging behind the listening seat. I feel this cleans up the bass region while taming a little brightness without rendering the room darker and thicker.

What all of this experimenting revealed was that first of all the Cathedral Sound panels definitely do work as advertised. And even in a slightly difficult room such as mine, satisfying results can be obtained. But as easy as these panels are to mount, you have to experiment. Will two panels be sufficient for you? Will four? There are many arguments in favor of these diminutive panels. They are unobtrusive, easy to install, decorator friendly and most of all they do their job effectively and with a noticeable positive impact on the music. One can rate their effectiveness as effective as a component or wire change. Yes there are many products on the market that address the problems of room correction. Many are just as effective as and even more so than the Cathedral Sound Panels. But I bet my listening chair that they are many times more expensive, cumbersome and more difficult to install than these gems. Oh yes, the Cathedral sound Panels have one more thing going for them, the upstanding Robert Stein and Ultra Systems. Francisco Duran

Cathedral Sound Panels
Retail: $179.95 a pair

Ultra Systems
web address: