Posted by Dave Rat on December 10, 2003 at 12:36:56:
In Reply to: EQ to Boost or Reduce posted by rodman on December 08, 2003 at 19:32:08:
: I'm working on a sound system in a skating rink, and I've heard that when it comes to the system eq, it's better to Cut eq frequencies instead of boosting them, however this system sounds real flat especially when the DJ's spin vinyl. Would it be Ok to slightly boost (+3 or 4 db) a few frequencies on the EQ to make this system sound better. FYI all speakers have been repaired and are working at this time.
When dealing with monitors or situations when feedback is an issue, cutting frequencies seems to be a much better choice than boosting. I have not seen actual documentation but my experience is that boosted eq frequencies, especially narrow band like a 1/3 octave, tend to be more "resonant" when boosted. This translates to where they seem to be less stable and more likely to feedback.
The other issue with boosting has to do with running out of headroom. Most people have no concept of how much cut or boost the cumulative effect of multiple 1/3 octave bands has on a system. The amount of cut or boost quickly becomes a major issue when more than 6 or 8 bands are used on a 1/3 octave.
When cutting, and then adding the "make up" gain just translates into increased noise which is usually not a big deal. When boosting, it is easy to run out of headroom and run into clipping which is a much less desirable situation.
So, when in doubt, it is safer to cut. Boosting select frequencies is not a problem and is often the correct solution to system EQ.
Like with everything, just don't over do it!
Dave Rat