Nasty standing wave...

[jonia]

Hello!

I have a standig wave somewhere around 50-60 Hz. Anyone have any idea how to solve this? I thought about buying some type of equalizer, but I am afraid this could ruin the sound quality....

Are there any good EQ's that could do the trick, and that aren't too expencive....?
Don't bother about the different curves, it is just some testing I did. The problem exists on all curves anyway...

[Brian]

You're a perfect candidate for a Behringer Feedback Destroyer DSP1124. It's a parametric eq that is used pretty often in HT's for eq'ing a sub. It will not degrade the sound quality.
This is assuming you are using a sub and that it is handling the frequencies where the problem is.
If you are not using a sub, then you wouldn't want to use the behringer on your mains which means you'd have to look at a better eq or adding bass traps to your room.
There's lot of information about them on some of the other HT forums (hometheaterforum.com for instance). Somewhere, there is also a pretty in depth tutorial for how to set them up and use them.
They're about $100-120 and well worth every penny.

[blownrx7]

Nasty standing wave - probably room interaction

Jonia,
First, try the cheapest, easiest thing: Move your speaker and /or subs around. If you are REAL LUCKY, you may only have to move them to at least move the (acoustic) hump away from your listening position.
Second, try the next cheapest thing, move your heavy furniture around to see if the spike can be absorbed.
In all probability, you will need some type of bass absorber (usually in the corners - ie bass traps), sometimes along entire walls (i.e. heavy curtains (yes, sometimes they DO WORK!) or acoustic panels.
If you are into DIY, check these out:
Acoustic panel and
http://www.angelfire.com/sports/RCcars/basstrap.htm

Also check out the discussion site hosted by Ethan Wimer of Real Traps http://www.musicplayer.com/cgi-bin/u...bb=forum&f=26& for some good discussion about room acoustics. He also has a DIY project that is almost as good as his commercial product at lower cost of course.
His commercial site (realtraps.com) is very helpful

The electronic alternative is to get a Behringer Feedback Destroyer (BFD) model 1124A - it is a very inexpensive unit (~$125) that is also be used for equalization. It is a digital equalizer and the thought is that it is NOT good for higher frequencies but is extremely good for low frequency (ie subwoofer territory). The BFD can apply a notch filter right on the hump!
Hope this helps

[Chris D]

Jonia- yes, what the others have said. Specifically with the BFD (Behringer) there is a LOT of information here on the Guide as to how to set one up and properly use it. As Brian said, you seem to be a prime candidate for it to help you. Search for "Behringer" here on the guide, and you'll even find a user's guide which one of our members has written that can help you out more than you're ever wished for.

[jonia]

Thank you for your replies!

I have decided to try out the Behringer DSP 8024. This is almost like the Feedback destroyer you mention, but it is better sounding according to the salesman. It costs a little more, but I don't have to break the bank to afford it. With this applied, I can use it on the sub if I want to, but the salesman also said that this unit is so good that I can use it on my mains too. This I will have to check out, I am sceptical to this... but I won't know before I try...

Thank you for your help!

Jon

[mikepinkerton]

i thought i'd read in several places that acoustic panels were useless for taking care of standing waves. I think Russ in (now defunct) SGHT was fairly adamant about that. Am I wrong?

-Mike

[Chris D]

Ummm... I think this is where semantics becomes important. Acoustic panels, both absorptive and reflective in nature, become important in dealing with soundwave REFLECTIONS off walls and objects in your theater.

[mikepinkerton]

Right, and a standing wave isn't a soundwave reflection, so acoustic panels won't help.

-Mike