Axiom Home Page Forums General Discussion Home Theater BFD - Anybody care to inform me...

Apparently this little jewel of an electronic device must be worth it's weight in gold upon reading about and seeing all of these graphs concerning the new 800.

Pardon my ignorance but how exactly does this component work, how is it connected and what specific model are you guys referring to? In principal is it like an 'automatic' equalizer?

Is it Behringer or Berringer? I've seen both while searching.

The BFD was intended , as the name implies, to eliminate mics feedback on PA sound systems. It does that by , first finding the offending freq range and then modifying the gain. Feedbacks usually are a very small/narrow area of the freq spectrum. The BFD can zoom in and only affect that offending freq area; that way the overall freq spectrum (sound) doesn't vary significantly.
So , essentially it is a parametric equalizer.

EDIT: I've never used or played with one. That was more or less the answer an sound engineer gave me 15 years ago when I asked him what the BFD was.

Hey Rick - It's Behringer. I'd go loiter around at http://www.hometheatershack.com. That's where the Room EQ Wizard (REW) software resides, as well as kind folks who will dispense the knowledge you seek.

Thanks Tom, I'll get over there and check that out.

My curiosity has been piqued since reading the threads here on the boards.

Edit ... Thanks to you also for the explanation Jaime!

Sucks, doesn't it?

No doubt Tom, just whenever you think all is quiet along the western front.

The BFD is actually quite cheap for the fun and tweakability it offers. I am contemplating putting one on my B-day present list or this years Christmas list as well as a mic to go with it to get better full range readings. What am I getting myself into.

FWIW, I am not finding the BFD to have as much effect as I was led to believe by things I had read.

I had a huge and broad peak at 52Hz: +14db. I thought by eliminating it, I would eliminate some of the boom from my sub and hear a dramatic difference. Surprisingly I heard no obvious difference in music. When switching the filter on and off, the main thing I noticed was that the kick drums got a little louder and quieter.

On HT I used the LOTR Bridge of Khazad Dum scene. Here, because there is so much more bass energy, I could hear a bit more of a difference, but it was quite subtle; sort of like comparing the M22/M60/M80. The LFE for the bridge breaking up and stone crashing into stone sounded a little more well defined and less boomy.

I shouldn't be surprised. Boom and muddyness in bass is caused by the reflection back and forth of frequencies in the room and EQ does not really change this much.

It is also difficult/impossible to EQ a null, because it is caused by cancellation.

Or, maybe I just have tin ears.

Edit: The current model is the DSP1120, I picked up a DSP1100 used. I don't think there is much difference between the two.

Having a sucky room might have something to do with that also

One trick I've found is if you have a null that you can't fix by relocating the sub, you can turn the gain up on the sub and then use the BFD to drop all surrounding frequencies down to the level of the null. This works for me because I need nowhere near the full level of power the EP800 (or 600) provides, so I'm still at < 50% and managed to cut out 1 or 2 nulls that I couldn't get rid of otherwise.

Jason