Aaaaaah, the fun of havin' slam dancing fests in a listening room. It's just one of the cool byproducts of acoustically re-engineering some rooms. The way a room effects what we hear from the output of our speakers can have quite a large effect! Pretty please DO NOT underestimate the effect a room can have. Now i wouldn't under ANY circumstances put a pair of Wilson X-1's in a 8 by 8 foot room. On the other hand, i personally wouldn't put a pair of small bookshelf speakers in a 20 by 40 foot room either. Would a Stadium be good acoustically for a small jazz band? Would a small club be good acoustically for a complete orchestra? By properly mating appropriately sized speakers in a room, you have taken the first step towards musical nirvana. But then we have the room...
If your a "lucky dog", you've got a dedicated room of good proportions where you can do ANYTHING you so desire. If you want 100 Lava lamps in there, so be it. Now maybe "i" wouldn't want 100 Lava lamps, though i WOULD like to acoustically re-engineer the room in the hopes of gaining better music/movie/sound reproduction. This article will not cover ALL the aspects of this. Nor is it to be considered 100% complete in any way, shape, or form. Like the engineers who renovated Carnegie Hall, even folks who are considered to know what they're doin' can MESS THINGS UP (and what a pity too). So we gots a room. Let's hope it has good dimensions and one with matched sides (perfectly "mirror imaged" from one half to the other). The best rooms, to my ears, seem to be those that have 8 or 10 foot ceilings with dimensions in the ratio of 3 : 4.5 (i.e. 12 by 18).
Ok, so we have this room and found our speakers. Where ARE we gonna place them? Should we get a sound pressure level meter and find the place where the speakers measure the "flattest" throughout the frequency range? Perhaps. Should we find the "null" point in the room where the speakers interact the lest with the present, non treated room, room boundaries? Perhaps. Should we put on a set of headphones and drink large quantities or our favorite beverage? Hmmmm... Well, my humble opinion is to place the speakers where they reproduce music/movies/sound the best to your ears AT THIS POINT. Then listen.
Now comes the fun part! Go to your local store and find some of that cheap and cheesy bed foam egg crate stuff. Get LOTS of it!!! At least get enough to totally cover the walls to the right, left, and behind the speakers. If you're as nutty as i am (uh oh), get an extra one for putting on the ceiling too! Now here comes the tricky part. Cover the walls to the right, left, and behind the speakers. As for that ceiling tile, it should be placed at the axis directly in front of the speakers and extend outward towards the listening position.
Listen. Listen for the changes and take away and/or move the tiles about. Cut a tile in half if need be (though by cutting it you have just voided your returning for cashola privileges). What worked for me is to leave the bottom most part of the back wall behind the speakers uncovered. Also, make sure your foam tiles cover the side wall in front of the speakers. Ya' know, the place where the first reflection point lies or there abouts. Listen. With a bit of experimentation you may wind up with some awesome sound OR you may wind up with the room too dead and lifeless. Wash, lather, rinse, repeat. If all else fails, relax, drink your favorite beverage, and return the foam tiles and get your hard earned cashola back. And if it DOES work out, then can a few of my closest buds stop by for a slam dancin' fest??? Just wonderin'.