Dedicated listening room design

Streetdaddy - if you have GIK D1s laying around then sure go ahead and place them at your side wall 1st reflection points to see if it makes it 'less dead' sounding. If you don't have them, then try a sheet of plywood angled so that lateral reflections are sent upwards to the ceiling or sent behind you to preserve the mid/high freq energy.

Summitav - I would agree with you that any indirect reflection is a corruption (e.g. temporal or spectral) of the original direct signal, so as such, may be labeled a distortion. If your mindset and taste is for purity of sound reproduction then you ought to consider listening through headphones. Even in a well damped room such as you enjoy you cannot absorb the low bass frequencies unless it's a huge room where the first modal frequency is below auditory threshold levels. So even an absorbent domestic room will only be absorbent across a limited set of frequencies skewing the reflections you wish to absorb fully. Reflections at glancing angles won't be absorbed so yet again indirect reflections persist.

I like to think in terms of limiting the bad sonic effects of a room while leveraging the positive sonic effects. Get the room working for you not against you, so to speak. Hence the suggestion that not all reflections are bad and those that are should be absorbed or diffused and those that are good should be left alone.

Like I mentioned previously, sonics are as personal as your taste in music. There is no one right way.

For my tastes I don't want to listen to either reproduced or live music in an acoustically dead room.

Hi Soix, There is NO ARGUMENT with taste and or preference. I prefer to use the term "acoustically neutral" rather than DEAD since what I am referring to is hearing the original sonic information without the distortion of reflections. I should also make the distinction that this DOES NOT apply to LIVE VENUE performances where natural reflections become part of the actual performance, and not distortions.

Theaters are different because you've got multiple surround speakers creating reflections and ambiance you'd normally hear naturally in a lightly or untreated room. To each his own as usual.

Again there is NO disputing personal preferences, but in two channel reproduction overlaying "your" rooms echos and decay times on top of the original venue's same will not produce accuracy. That said, again it is often not the goal of the user to be accurate. In fact most often is is produce a "prefered" sonic.

As far as HT (which is what i thought you were looking for) my main thrust was to know that Acoustic Isolation, (of the room) and Acoustic Treatment for accurate sound, are two distinct and different goals.

In my case, I am far more forgiving of Acoustical Accuracy in a HT since virtually ALL of the sound heard in films is manufactured in post production sound studios. Foley, voice dubbing, musical scores, and sound effects are all less critical to me than attempting to recreate a LIVE recoreded musical event in my space, without allowing my space to intrude upon it with its own sound stamp.

Good luck with your project.

IMHO, HT demands a room with lower reverb time as a lot of ambient info is accounted for in the surround tracts. Lower reverb time allows for improved speech clarity for HT dialog. Many acousticians shoot for an RT60 of 0.3sec in mod sized room.

In two channel music playback especially classical music, slightly higher reverb time improves the body or "sonority" of playback. Many acousticians shoot for RT60 of 0.35 to 0.4s in the mod sized room. Sure enough, acoustically dead room with maximal damping similar to an anechoic chamber would allow most insight into the recording. This is why many master studio/control room has RT60 of 0.25sec. The playback would not sound particular spacious and the speakers would have a tough time disappearing (very high ratio of direct sound vs indirect sound). These are the very qualities which many audiogoners strive for.

Most people in this hobby are not just after how a recording is made. I would think most wanted to create a musical involving experience which strikes a balance betw sonority and adequately low reverb.. Diffusors are great tools to cut down on slap echos without killing reverb. so clarity is maintained without sacrifizing sonority.

The theoretical ideal of an anechoic chamber is not easy or practical in most home situation. The midrange and highs can be easily absorbed but bass in most moderate sized room would be subject to many boundary effect which includes both boost and cancellations. Just look at the speaker measurements from stereophile where some efforts are spent to create pseudoanechoic measurement. Yet they differs significantly from same speakers measured by soundstage done in NRC. There is certainly the phenomena of acceptable bass rise (in reverb) but one need to experiment to see how much bass rise is desirable.

In tuning my room, I have got the RT60 to 0.25 to 0.28 and the detail, microdynamics and image specificity are very good. However, most listeners that come thru dislike the experience and feels the music is not flush out, harmonics are stunted, etc.

A lot of room tuning requires experimentation and learning. Not only learning about room acoustics but also about your own listening preference/priorities. I would choose an acoustician that is flexible to your needs, provide continuous supervision during construction and repeated experimentation after the initial phase is complete. There are many factors that mathematical modeling cannot predict.

After learning how to do the room measurements, you should learn how the measurements translate into what you are hearing. Then you can pick your compromised when faced with two opposing issues. At the end of consultations/contructions/reconstructions and there are areas of dissatifaction. Don't let measurements or consultants convince you that this is the sound you want. Continue to experiment and learn about psychoacoustics.

Regardless of expense or effort, I doubt there is a "perfect room". You may not even like an objectively perfect room. What you need is the right room for your enjoyment.

Good luck

Six,
It has been about 3 months since you posted your thread. Care to give us an update on where your construction project stands and the acoustical treatment decisions you've made?

Hi Kevin. Sorry I haven't posted back, but I've had the french drains installed, and the heat pipes replaced/moved so now I'm having the permanent generator insatalled which involves running elecrical and gas lines before putting up walls.

I got Toole's (and other's) book and they all have been very helpful. By the way, I'm very much onboard with diffusion in certain applications since that "live" type sound is exactly what I'm looking for. I'm working with and getting estimates from contractors to see what they're able to do, and I'll certainly report back once the walls are up. What I do know is that I'm incorporating all of the feedback I got from this site (and the books recommended) and it was incredibly helpful in intracting with contractors as it seems most of them are not really familiar with the kinds of things we audiophiles are looking for. Anyway, Happy Holidays to all.