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Can you correct nulls with acoustic treatments.

I have Magnepan 1.6's. After hearing a musical clarity I really liked in a listening session at someone else's house, I broke down and bought a Rat Shack SPL meter and dowloaded some test files. I wanted to see if it was the acoustics or the type of speakers and system that made the difference.

A brief testing showed a 65 to 80 hz., 5 or 6 db. bump (the drywall bump?) that I had expected. What I didn't expect was 10 to 15 hz. wide nulls (-10,-15,even -20 db.) at several other frequencies.

I tried moving speaker positioning and the frequency of the nulls moved but the pattern was basically the same.

Acoustic treatment to tame + nodes seems intuitive. Can you treat nulls or is this a different problem?

Would really appreciate your thoughts.

Jim S.

stilljd

Showing 1 response by onhwy61

onhwy61's avatar
onhwy61
5,135 posts
 
the 1.6's probably average -7 or -8 db. from 80 hz. to 290 hz. (the range of this test CD is 10 hz. to 300 hz. in 1 hz. increments)....
FYI- The 1.6's are -15db. @ 35hz., -7db. @ 40hz. -3db. @ 47 .hz or so.

1 - don't measure in 1Hz increments. No speaker/room will measure smoothly at that level. Use either broad band noise or a slow moving sweep type signal to measure.

2 - Are you interpreting your measurements correctly? Rather than a broad dip from 80 to 290Hz, do you really have a boost in the 40 to 80Hz octave? If so, it's a fairly common problem that in relatively easily solved. How does the overall bass level compare to midrange (400 to 2000Hz) levels?
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