corner bass trap nonsense see below:
Mike
What Dennis is saying about modes is true. But the video misses the point that most of the acoustic problems we hear in our rooms are not modal! If a mode is the major problem that needs to be addressed, then yes, it might not be that effective to try to get after it with a corner placed trap.
Besides modal frequencies, there is a lot of sound that gets trapped in the front of the room, bouncing back and forth and muddying up the response at the listening position. Corner placed traps that can absorb some midbass while scattering/diffusing treble have proven highly effective. Adding more of them along the sidewalls is even better. Stacking them to the ceiling is generally going to give the best result.
How many TubeTraps are too many? Ultimately you ears have to decide, and there are definitely differences in preference, with some people preferring a much more controlled room than others. But generally we can look at the RT60 time of the room, and most people don’t want it much below 0.3 seconds in the midbass and lower midrange, with some rising in the bass and upper treble. If it continues to drop as the frequency goes up, that’s what most people are going to perceive as an overdamped sound. We can also look at clarity. A good room will typically have between 10 and 15 dB of clarity across the audible band. If it gets way up above 20 dB in the treble, that could also be a sign of too much treble absorption.
In some cases it’s even possible to get too much bass absorption such that the speaker’s in-room bass response starts to sag. I’ve heard reports of people loading enough TubeTraps into a room to get that to happen. That takes a LOT of big traps.