The problem is that the room has a dimension and bass waves will
reinforce at certain frequencies and cancel in others. So unless your
bass traps are actively able to move about the room as the bass notes
change they will have little effect. DSP doesn’t work because it tries
to make your amplifier put out more power at one frequency and less at
another. But when you are dealing with a standing wave you might be able
to kill a bit of bass bloat at one frequency but you can put as much
power as you want into the bass nulls and the waveforms will still
cancel. So its only slightly more effect than bass traps.
If
you really want to deal with this problem, the elegant way to do it is
to use a distributed bass array which can break up standing waves,
resulting in evenly distributed bass throughout the room. Do do this,
you take advantage of the simple fact that below about 80Hz in all but
the largest rooms, the ear cannot detect where the bass is coming from
so you can run the bass in mono. But it is important that the subs do
not reproduce anything above 80Hz; in this way they will not attract
attention to themselves. You’ll need at least four subs to do this
right. They need to be asymmetrically placed in the room and therefore
do not have to be aligned with your Harbeths. One sub system called the
Swarm (
www.audiokinesis.com)
is also the most well-known sub designed for this purpose. To minimize
their size they are designed go directly against the wall and take
advantage of the room boundary effect, to go flat to 20Hz.
This is basic physics- in almost any room there will be standing waves. I've seen audiophiles fight them for decades- only to find out that by using a DBA that suddenly all is well. If you want an elegant and effective way to solve this issue, this is how its done.
