Tweaks & Music Picks
by Art Tedeschi
Through years of system setup, the following rules have generally held true:
The wall behind the listening position should generally be absorptive (especially with dipoles). Reflections from the wall behind reach your ears quickly and react with the direct wave from the speakers.
The ceiling and floor should be of opposite reflectivity. If the ceiling is absorptive, the floor should be hard, and vice-versa. The typical drywall ceiling and carpeted floor work well together.
Think 'diffusely'. Arrange furniture, record racks, etc., in such a way as to break up reflections. I find that record shelves on each end of the back wall work well in this regard, and also serve to provide for #1 above.
Mix things up. A room should be neither too 'hard' nor too 'soft'. Utilize furniture intelligently and inventively. In an acoustically live room, you may wish to replace your stark listening chairs with an overstuffed sofa; or in a dead room, a picture on the wall may help brighten things up a bit (don't go overboard with this glass, though).
In small rooms, you must provide for some absorption for the first reflections off the side walls to the listener. These are potentially soundstage-killing reflections and must be dealt with as a high priority. An old trick is to sit in the listening position while an assistant moves a mirror along the side walls. When you can see the reflection of the speakers in the mirror, that's where you should provide for some absorption.
Many audio enthusiasts miss the importance of a high listening room ceiling. Try to avoid rooms with 7' ceilings or less, as those early reflections may seriously destroy any sense of air or space within the soundstage.
If you still can't get it done through 1-6 above, seriously consider the purchase of some room treatments. A good dealer will allow you to borrow some to try before you buy. For me, RoomTunes allowed me to shoehorn my SoundLabs into that 14' x 16' room and provide me with an excellent soundstage (I don't think I'd know what to do if a decent room would ever come along). A $300 - $500 investment in those devices can mean all the difference in the world (and could save thousands more on upgrades that can never improve the sound of that room).