Hi Dan,
I agree - room acoustics are very important.
Here is a copy of an article I wrote for an Audio magazine a while back on the Bryston Sound room.
Dear Ernie,
Thank you for featuring the Bryston and PMC music/testing room on your front cover in the last issue of the Inner Ear Report. I must say, I have had numerous calls asking to elaborate a little on the design and listening attributes of the room from a number of your readers – so here goes.
The room was designed to reduce, as much as possible, the standing wave and reflection problems which get in the way of assessing the quality of the audio component or recording with as little room interference as possible. Most rooms impose acoustical characteristics on the equipment which generally tend to swamp out the sonic differences between loudspeakers, preamps, poweramps, CD players etc. In other words, people end up listening to the equipment or the recording filtered through the room.
At Bryston and PMC a significant part of our design criteria is listening to our products as they progress through the various development stages. Things may look good on paper but when you actually listen to them in a neutral environment the subtle nuances that make for ‘great audio’ rather than good audio stand out like a sore thumb. I have always felt that one of the main benefits Bryston has as a company is that I get to participate in many live recordings in the field (because of our involvement in the Professional Studio market). The sound of real instruments in real space certainly educates you to focus on what sounds ‘real’ and what sounds ‘reproduced’ in an audio system.
The room itself is 20 x 25 feet with a 10 foot ceiling in the front sloping up to a 16 foot ceiling in the back – much like a concert hall. Construction is the same as many homes with 2x6 studs, fiberglass insulation and painted drywall. We wanted to keep the room similar in construction and materials so that it represented a relatively ‘normal’ environment in most of our customer’s homes. So, no special double walls, built in bass traps, resilient channels, false ceilings, rubber floats, etc to make the room irrelevant given the environments most people listen to music in.
The speakers are the PMC BB5 3-way Active Monitors which are used by most mastering facilities around the world to monitor music and movie sound tracks - Sony, DreamWorks, Universal, Stevie Wonder, Chick Correa just to name a few - in fact check out the Bryston/PMC Users List, at
www.brsyton.ca to see how significant an impact our equipment has made on the market place. They are an incredibly revealing speaker system so the sonic differences you hear when you move from one product design to another are extraordinarily obvious. An example of this is that some speaker systems impose a certain colouration or perspective on the music which makes all recordings sound similar. A good friend of mine has an excellent audio system but every recording he plays has an exaggerated depth to the sound field. With a high quality mastering speaker like the BB5’s if the recording contains depth you certainly hear it but if it doesn’t then you are certainly aware of that fact as well. I always relate it to photographs; if you look at a portrait taken with a quality camera you can pick out all the age lines and blemishes on the face of the person in the photograph, conversely if you look at a photo taken with an poor quality camera all of those subtle character traits meld into a seamless mass. It is the same with audio equipment - RESOLUTION of subtle detail makes the difference between good and great results.
The electronics, at the time the picture was taken, were two Bryston 7B ST’s driving the 15 inch Transmission-line woofers and two 4B ST’s driving the midrange and tweeters, crossed over with two 3-Way PMC Electronic Crossovers. They amplifiers have since been replaced with the new Bryston 4B and 7B SST Series. The front end is a Bryston BP25MC Preamplifer and the source (CD, Turntable) changes from time to time depending on what’s popular out there.
Acoustic treatment involved the use of TubeTraps to reduce corner standing waves, flutter echo and reverb time and varying depths of acoustical foam to damp out early reflections. I do not have enough space at this point to discuss in detail the acoustical goal for the room (would be glad to do a follow up article Ernie) but in short, the ear wants to detect the first arriving sound wave and then 10 to 15 milliseconds later the first reflection. Without this time lag between the first and later arriving sound waves the ear/brain can not distinguish what was the first sound and what was the second sound. This creates ‘blurring’ and you can not tell exactly where the sound is located. This obviously plays havoc with the imaging of the system. Early reflections at the listening location also produces severe dips in the frequency response (comb-filtering) as well. The later reflections (second, third etc.) you want in the room because they provide a sense of ‘space’ to the room. There is a lot more to it than this but it gets us started.
So if you look at the picture of the room on the front cover of the magazine the acoustical treatment you see is designed to accomplish the goal of allowing the listener to hear a great stereo image with a highly spacious sound field. This provides Bryston and PMC with an excellent tool to assess our equipment and allows for educated decisions as we develop products for our customers. Plus I get to sit in there for hours at a time just enjoying the experience.
The size of the soundstage is enormous with very specific images floating within the sound-field. People who have visited the room always comment on how natural instruments and voices sound. In fact, I had one reviewer from Japan who actually stood up and applauded after the demo session. What better tribute is there?
James Tanner
V/P Bryston Ltd.
