Originally Posted by Stealth3si
I've learned that bass traps are mainly designed to make the sound in the room smoother, that it does make a real acoustic difference, that is in terms of numbers, graphs, measurements, music production, sound mixing, etc. But since I only watch movies, I'm mainly interested in the audible differences it would produce from the main listening position for movies.
If I would notice a difference, describe to me what kind of sound I'd hear from the bass.
When I think of a residential listening room with problematical bass response I think of a number of different audible problems:
(1) The sound is out of balance, and the bass, mid bass, midrange and treble or some of them have incorrect balance. The music generally sounds thin, boomy, tinny, thick, forward, recessed, etc. Differences in the natural balance of recordings is overemphaized which may leave you with the sense that some recordings are strikingly good and others are very poor.
(2) Bass sounds seem to drone on, instead of having reasonable articulation. There is a loss of the sense of hearing different instruments and voices and instead there's just this boomy muddled hum. Vocals and instrumental solos get lost in the backup instruments. Dialog gets lost in environmental sounds.
(3) Sounds in certain parts of the bass region may be withdrawn or overemphasized. This is most noticeable when a musical scale or part of one is played on a bass instrument. Usually the musician plays the notes so that they are equally loud or follow some general progression of increasing or decreasing. Under damped resonances in the room are heard as the intensity of these notes rising and falling illogically, and some notes may even seem to disappear while others stand out excessively.
Can you give me an audible description of a smooth sound in a room?
The music and dialog is easy to listen to without straining to hear some sounds that are getting lost or having to ignore other sounds that are unnaturally loud.
Also, do they allow the subwoofer to blend in better with the speakers?
Yes, of course. They may also improve the consistency of the sound throughout more areas of the room instead of just a few tiny sweet spots.
If you listen to the Earl Geddes lecture I posted in the speakers and also the subwoofer forum earlier this week, he will somewhat bombastically say that bass traps don't work, and then sort of clarify himself by saying that they don't absorb bass but rather have their strongest effect in the upper bass and lower midrange regions. There is some truth in this because by cleaning up response above say 60 Hz, we can start really hearing what's going on at say, 30 Hz. The ear's sensitivity goes away as the frequencies go down and we need to clear away and better control what is happening at upper frequencies to really enjoy the deep bass sounds. Thing is that really good deep bass improves our perception of the entire frequency spectrum. Cleaning up the bass can make the treble sound better.