Can you correct nulls with acoustic treatments.

Thank you all for your responses. I was hoping to see 7 or 8 posts saying that's easy, diffusion. But I posted to leverage your experience before purchasing and it has already paid off.

Did a little more testing and review of the data. Found some hope in speaker placement and an interesting (and depressing) overall trend.

The room is a 60' long X 30' wide irregularly (almost a backward L) shaped finished basement. There is a "stadium" wall 9' wide at a 45 degree angle in one corner. That is where the system is set up, shooting out into the long part of the room. The only wall parallel or perpendicular to the speakers is the angled "stadium" wall. I think this contributes to the lack of boomy nodes.

The really serious nulls (-20 db.) are very location dependant. Move your head (or the meter) a foot or two and they change. Common sense seems to say that you would never be able to eliminate all the 2, 3, 4 hz. wide strong cancellations at a single position.

I moved the 1.6's straight back 5 inches and most of the nulls improved 4 or 5 db. I don't know if I like how it sounds as much (soundstage), but I may have to move my listening position to correspond to speaker movements. Classic chasing your tail.

The disturbing overall trend is.... 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). That seems like a lot. A quick review of old Stereophile freq. response graphs shows the speakers fairly flat from 50 hz. to the crossover @ 600 hz.

Care to venture an opinion of the trend?

FYI- The 1.6's are -15db. @ 35hz., -7db. @ 40hz. -3db. @ 47 .hz or so. Didn't change a lick with speaker movement or starting SPL.

Jim S.

"New speakers may be far cheaper - or may do nothing to correct the problem".

How would changing speakers change the room acoustics?
bob

Either acoustic treatment such as tube traps or electronic EQ can help. Neither is easy to do but both are worth it

Again, THANK YOU ALL for taking the time to post your thoughts, even as I was typing the extra information above. I would have posted more at first but didn't want to complicate what may have been a simple situation.

You have provided a multitude of great places to start.

And the measuring will not be... the be all, end all. I was just very impressed with the clarity in our friends heavily treated, dedicated room and was hoping to add a little bit of that to my system. It may be that I can't get there with the components I have, but, any room improvements will be in place as I move on.

Will update as I try your suggestions.

Jim S.

The worst room I ever heard had one 8' diagonal wall in the rear corner. It had two 300Hz nodes just in front and to the side of the listening position that were painful, even with music. I helped him get some materials for DIY tube and panel traps and that helped quite a bit, except aesthetically.

You might have to completely rearrange the room with the speakers on the long or short wall. The good news is you have lots of room to deal with and, apparently, bass is not the problem. It's easier to deal with higher frequencies.