Can you correct nulls with acoustic treatments.

Did you take in to consideration the fact that the Radio Shack SPL meter is not acurate? There is a page that shows the corrected calibrations for that specific meter. So your room may not be as bad as you thought. I will try to find that info for you if you dont already have it.

Plato,
Thanks for the encouragement. I will work at it and see what I can learn.

Soundgravy,
No, I did not know the Rat Shack SPL meter was seriously inacurate. I will reread the thread (probably many times) and try to understand. Thanks for posting.

BTW- Do you guys miss Sean? (From the RS meter thread, and many others, that Soundgravy cited.) He really relished the technical and did a lot of work to solve problems. I notice he doesn't post as much as when I started following Agon threads.

Jim S.

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?

60 by 30 L
you could build a room in a room and get a great setup

that's a cavernous space to fill

Onhwy61,

Understand your first point. I am trying to look at trends over 20 to 30 hz. ranges. Started with the LF as it seems from previous threads that is where the largest gains for the effort come from.

I was thinking about your second point last night and wondering the same thing. Am I misusing or misunderstanding the info? The CD I am using for LF is from Real Traps. The CD has a white noise track to set a start level. I have assumed that start level would correspond to an SPL baseline and db. readings above that baseline level were bumps and below were nulls. That may be correct, but not necessarily so. If not correct, the data is valid (the amplitude swings are still there), but the description and amplitude I had assigned to null and bump are invalid.

Anyway, I should have done a little more prep work and broader data gathering before posting. I may have jumped the gun. Back to work on it.

Audiotomb,

Yeh, I wish I had 1800sq.ft. to play with. It is an odd shaped room that follows the contours of an irregular foundation. Because of the backwards L shape with a few extra zig-zags thrown in, the usable space is much smaller There are framed in steel support columns and beams. Also seperate rooms for laundry/storage, furnace/water heater and a bathroom with a Jacuzzi. Why the previous owners put the Jacuzzi in the basement is anybody's guess? Sounds a lot bigger than it is.

Thanks for your observations.
Jim S.