Where to start with room acoustics

Don't fear that you have to buy lots of truly ugly hardware to properly dampen a room, either. My 14x24-30x8 with lots of openings still sounds quite properly "dead" because of wall-to-wall, stuffed sofa (L) and big chair (R), each topped with a propped pillow at the reflection points AT WILL if the recording demands it! Cross-beamed ceilings break up these reflections well, but the biggest factor is that I sit in a smallish 7.5' nearfield triangle 8' out from the front (back...you know) wall, creating a stage with phenomenal depth precision, despite the 7' Steinway back there. Learning to pull my listening chair forward one extra foot closer (it sits in a double-doorway to a 6x10 library behind it), was the only tweak that room-mode analysis provided. I was doing that anyway when I noticed that if I leaned forward a lot the stage blossomed perfectly. Starting with a smallish nearfield triangle in a deadened room certainly works, as the first-arrivals predominate, and you get a good feel for your speakers. You can then widen and lengthen the triangle as the room boundaries, aethetics and preference combine. Lots of folks start at the 1/3 points, too. Damping sidewalls just right obviously has a great effect, but the bigger surprise for me was the huge stage depth provided by having 8' behind the speaker plane for trios and quartets to inhabit. I often "see" pianists sitting AT MY PIANO, with the standup on one side, cymbals on the other. On great orchestral/choral stuff it seems the front bushes and yard are the stage! So don't feel you have to really sweat this out and use the WHOLE room's geometry at first, getting all the modes nulled and all surfaces treated. Start small, then spread out, tweaking as the triangle grows.... Worked for me. Have fun.

LEDE is treated on the side of the system leaving the rest of the room live. Very common among very knowledgeable people as in recording studios or the best audio setups. There's lots of information on it. As far as bass is concerned the largest problem is of course corners but tube traps are necessary to tame bass, foam alone won't do it. The traps may be set in different areas of the room depending of course on your room. Check out Jon Risch's DIY site. Lots of good info there including how to make your own bass traps for alot less money and they work great. Good luck. You'll be glad you treated your room. Unless it is a very dead room I'd try some treatment behind the system.

Warnerwh,we must have the same room.Live end ,dead end.Jon Risches tube traps...I made a whole bunch of acoustic panels and my rear wall is covered with homemade sky line diffusers.They are blue until the weather warms up and I can paint them out side.The only problem with two ch. audio is using a parametric to rid bass modes.Subs are sooooo much easier to work with.And Home theater with one sub is a sinch.All this is great advice.

i have a dedicated room similar size to yours..

what type of speakers do you have ( dynamic, planar, dipole)etc...

do you want to put the speakers on the short wall or the long wall.

what other obstacles or oblect do you have in the room.

mike

I have been there, and have just finished my dedicated home theater/listening room and ran into every question you will, so take this advice: bass, bass, bass.

After everything that's been read and researched your treatments can easily be summed up by these statements:

1) Treat ALL corners for bass as this is where it builds up. Most rooms have the same frequency problems in this area so a carte blanche-type absorption will most likely work best. I personally used Auralex LENRDs stacked 4-high to the ceiling (I have 9' foot ceilings), so you would actually have less gap in your 8.5 foot-high room. Other options are available, however: www.realtraps.com I would also recommend checking out these sites: www.recording.org and www.auralex.com

2) once you have a general idea of where speakers will go creat an RFZ area, or a "reflection free zone." Determine first order order reflections by having someone place a mirror at speaker/driver level and have them drag it along the wall while you sit in your listening position. Whenever you can see the speaker from your listening position, treat that area accordingly. I recommend acoustic foam because of its application simplicity; however, some audiophile gurus say foam creates an environment that's 'less' natural. Finding the first order points go for ALL speakers, even if you're only running a 2-channel system.

For home theaters, diffusors on the ceilings and back wall (even for 2-channel systems) increases spaciousness so treat accordingly.

Going to realtraps.com, auralex.com and recording.org will take you EVERYWHERE you need to go. From DIY absorbers/diffusors to real-time, real-world application, the answers are here.

sig