Room Treatments

Kclone,
Nice system and expensive too! You really are only listening to a fraction of its capabilities because the room is the other 50% of what you're listening too, whether you realize or like it or not . . .

My room is the same dimensions as yours so for what it's worth look at my System pics to get an idea of what I've put where.

I would highly recommend you read Dr Floyd Toole's latest book as it's excellent at applying the physics and pyschoacoustics to stereo and surround sound / HT. Armed with some education you will be in a better position to critically evaluate manufacturer's products and other people's advise, mine included.

How much liberty do you have at hanging and adding room treatments or is there a significant other than will banish you from the bedroom at the first sight of treatments?

Not all reflections are created equally and the ones coming from the back and front walls are worst so I'd start there. Diffusion behind you adds listener envelopment and depending on your distance from the listening chair to the back wall will determine if 1D or 2D diffusion can be used and the max cell/well depth that it will diffuse down to. Also diffuse the side walls at and behind the listening position for further listening envelopment. The front & back walls should have bass absorption at the 25%, 50% and 75% points across the wall width at least. For mid/high frequencies for the front wall you can try absorption or diffusion for personal preferences.

Side walls will need some kind of treatment to deal with the slap/flutter echos and you can opt to experiment with absorption or diffusion to find what type of sound you like best. You can also use reflection which is what I'm in the process of redoing my room with using long boards hung horizontally but with the bottom angled upwards so that sounds hitting it are reflected upwards towards the ceiling where I have RPG Skyline diffusion to further attenuate the reflections.

As you can see there is much to this - throw in measurments of RT30/60, Frequcy Response Vs SPL levels, and others, then mix in personal preferences and you have thousands of permutations . . . I've learned a heck of a lot via studying and communicating with Dr Sean Olive, Prof Trevor Cox and experimentation within my own room moving diffusion and absorption here there and everywhere and measuring before/after effects.

Good luck.

Theaudiotweak - I agree that round and angled serfaces help keep the audio energy within the room and in the former case act as diffusion, minus the temporal affects. I've found the round hemi-cylindrical diffusers within my room a nice touch and effective at mid/high frequency diffusion over about a 120degree arc and bass trapping too. I'm in the current process of hangin long planks on the side walls (about 5 vertical feet worth) and pulling the bottom edge out from the wall so that sounds hitting it get reflected upwards to avoid 2 hard parallel surfaces.

I think the tray ceilings etc are a biproduct of retrofitting a typtical domestic room into a music/HT room and that every design has compromises and WAF too. I think what you speak of is for a net new room yet to be built. Having said that, there is still reason for some absorption at least for the low frequencies and likely mid/higher ones too so that the RT30/60 falls within the "right" range of values.

Kclone - you've been silent since Jan 7th - 10 days and counting . . . are you still following this thread? Any feedback on people's ideas?

Hi all - at the risk of self-promotion, I wanted to let you know that I got my side wall reflective baffles (i.e. horizontal oak planks) installed a little while back. Pictures of the room are in my "System."

The planks are 3/4" thick Oak and there are 3 rows per side wall: the top plank is 12" wide whereas the middle and bottom are both 24" wide. All are about 12 feet long. They are mounted using piano hinges on 2"*4" and I use doweling to push the bottom of the plank away from the wall to whatever angle I think sounds best. By changing the doweling length I have complete control over adjusting the angle from 0-90 degrees.

The bottom plank - which is at ear height - is at about 40 degrees (42 actually using trigonometry to calculate it) and reflects sound upwards to the ceiling where I have 12 RPG Skyline diffusers. The middle and top planks are at 30 and 20 degrees respectively, also reflecting sound upwards to the ceiling.

Besides looking cool IMHO, they are a welcome sonic addition to the tricked-out room. By splitting up the vertical space on the side wall across three planks, I can choose to listen to different amounts of 1st reflections at ear level compared to spots higher on the wall than ear level. I've found that with the bottom plank 'closed' - meaning, open a small angle (e.g. 10degrees) - that the plank actually absorbs bass and the sound becomes bass-shy and anemic sounding, but when the plank angle is increased to say 40-50 degrees the bass returns and sounds more natural and engaging.

I'm also playing around with putting a GIK Monster (that is a custom smaller sized unit) and GIK D1 diffuser on the bottom plank at the 1st reflection points to see what effect it has. The 40 degree angle does a good job of minimizing the 1st reflections upwards and over my head but doesn't do it 100% because when I add the Monster absorber the soundstage width gets a bit narrower and I can hear a few more musical details. (I suspect that with a larger angle of the bottom plank that there would be no sound difference between it and an absorbing panel at the 1st reflection point as in both cases early reflections don't make it to my ear as they're either reflected overhead or absorbed.) What the D1 diffuser does is make sure that more reflections come my way (when the QRD wells are oriented vertically so as to diffuse sound laterally). It sounds more live-sounding with more MF/HF energy sent to the ears.

I still have more experimenting to be done with the angles of the middle and upper planks before settling in on the perfect setup. But as an acoustical experiment it is doing an admiral job of reducing flutter echos down the length of the side walls and reducing MF comb filtering (which may or may not be a good or necessary thing). The built-in flexibility of varying reflective angles and adding optional absorption or diffusion at ear level makes for some fun experimentation. Any guesses on what will sound best?! ;-)

Hope this is of some help to the larger community.