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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
plato
1,543 posts
 
The room dimensions and speaker positioning are going to dictate the peaks and dips more than anything. Such large nulls would be difficult to treat.

I suggest you move the speakers around the room if possible; maybe to the adjacent wall or even firing across a corner. If you can't achieve good results like that, then perhaps considering a different room (or headphones) would be warranted.

Happy Experimenting!
ngjockey
1,042 posts
 
Acoustic treatment can help but don't expect miracles. Good start, BTW.

These other frequencies can be harmonics or "half-harmonics" of the main frequencies. What I mean by the latter would be, for example, 100 and 150Hz. Start in the corners behind the speakers. If you want to try before you buy, hang blankets,towels, or futons pads and try the test again.
myraj
351 posts
 
You can't/it's difficult to correct for nulls/dips except with placement. The best placement will always have peaks and dips, except with perfect placement in a perfect room
All one can do is smooth out the peaks, With treatment, or with EQ. It difficult to impossible to correct for the nulls, unless you are using EQ with active crossovers.
Good luck!
audiooracle
387 posts
 

You have to understand the nature of nulls, meaning that a null is a depression in frequency response due to cancellation effects based on room interaction.

A null can not be tuned out by passive attenuation which is what room treatments can accomplish. You must redirect the energy by repositioning or by adding more bass energy to compensate for the null.
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