I wish that was generally true but, most often, it is not possible.
Why not?
Flat and fat.
If one wants an ideal impulse response, the only way in the real world you get there is dedicated construction and massive massive bass trapping first. Then finish the job with DSP and careful positioning.
Swarming the room with more bass doesn’t do anything to reduce reverb or room modes. It just drowns the problems in a sea of bass chaos so they are more or less equally spread throughout the room and frequency spectrum.
End result is sorta kinda flat response and reverb smeared out to about 300-500 milliseconds.
Of course if someone likes that….no arguing preferences.
Emphasis added: this is false. Here's why:
You cannot tell that a note exists until the entire waveform has past your ear. It usually takes a few iterations of the waveform to know what the note actually is. In the case of bass notes the waveforms are very long. 80Hz is 14 feet; 40Hz is 28 feet. In most rooms, the bass note has bounced off of every surface in the room before you can know what it actually is.
This means that bass is entirely reverberant. But it also means that the bass being reflected by the wall behind the listener can have the ability to cancel the incoming bass before you can even know what frequency it is. This phenomena is known as a
Standing Wave.
No amount of power can get rid of that kind of cancellation, which means that if you use DSP and bass traps to fix it, you'll have
immense power requirements made of your gear to no avail and bass traps will have to move dynamically about the room to fix the standing waves at various frequencies. Put another way,
if there is cancellation, the power you apply to fix it goes to infinity.
By adding subwoofers asymmetrically you can fix this problem without 'drowning in a sea of bass chaos'; keep in mind that bass is already 100% reverberant. You are correct that you don't get flat response. But you do get rid of the enormous peaks and valleys caused by the standing waves, with many more and much smaller peaks and valleys all over the room; evenly distributed. Since the peaks and valleys are so close to each other in frequency they are very hard to detect with the human ear.
It also turns out that its pretty easy to set the values for the subs by ear and get very close to correct. The trick to to make sure the subs do not reproduce anything above 80Hz that would cause them to attract attention to themselves.
Once you get the bass right, you'll find this is 95% or more of the problem with most rooms; the mids and highs calm down due to the fact that our ears have an internal tone control. If the bass is right, the ear places less emphasis on the mids and highs. So if standing waves are not fixed in the room, the DSP might get the mids and highs right but it
won't sound right to the ear.
Put another way, as I pointed out earlier on in this thread, do the Distributed Bass Array first, which usually takes care of 95% of your problems, then use the DSP and bass traps to do the other 5%. If you do it the other way around you are wasting your money as the effects will be minimal.
