# BFD Filter Setting Help



## Ciscokid (Jan 1, 2007)

Hi,
I just received my BFD 1124 have it all up and running.I tried moving my sub everywhere in my room and this is about as good as it gets. I have some major room modes that I will have to deal with. My question is how should I go about figuring out where to apply the filters. Looking at my graph where should I set the target before finding peaks. My crossover is 80hz. Should I set the target to 75 and try to bring down from 20hz to 40hz with the BFD? I clicked the find peaks and REW wants to assign 7 filters. Does that seem correct? Finally being a newbe and all, I would like to know if I am setting my filters correct. It seems everytime I set them they end up getting reset some how. Let me kind of walk through the process I am using to set my filters. I use the jog wheel to select channel 1 then make sure PA is selected for filter mode. Both Engine lights are on ( not sure if this matters.) Then I set the frequency, fine octave, BW, and gain. Once I do that then I hit the save button and repeat the sequence for the remaining channels. When i hit the save button do I then move the jog wheel to the channel I would like to save it to? When I finished setting all 7 channels I moved the jog wheel until the display had two dashes and that seemed to have erased every thing I did. What am I doing wrong? Thank you for any help you can provide me.


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## lsiberian (Mar 24, 2009)

Ciscokid said:


> Hi,
> I just received my BFD 1124 have it all up and running.I tried moving my sub everywhere in my room and this is about as good as it gets. I have some major room modes that I will have to deal with. My question is how should I go about figuring out where to apply the filters. Looking at my graph where should I set the target before finding peaks. My crossover is 80hz. Should I set the target to 75 and try to bring down from 20hz to 40hz with the BFD? I clicked the find peaks and REW wants to assign 7 filters. Does that seem correct? Finally being a newbe and all, I would like to know if I am setting my filters correct. It seems everytime I set them they end up getting reset some how. Let me kind of walk through the process I am using to set my filters. I use the jog wheel to select channel 1 then make sure PA is selected for filter mode. Both Engine lights are on ( not sure if this matters.) Then I set the frequency, fine octave, BW, and gain. Once I do that then I hit the save button and repeat the sequence for the remaining channels. When i hit the save button do I then move the jog wheel to the channel I would like to save it to? When I finished setting all 7 channels I moved the jog wheel until the display had two dashes and that seemed to have erased every thing I did. What am I doing wrong? Thank you for any help you can provide me.



Sounds like you are missing something on the filter entry. I've not used a BFD, but have you tried the manual for help. Usually this kind of thing is a brain freeze of some kind.


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## Ciscokid (Jan 1, 2007)

Ok,
Finally after scouring the archives I finally figured out how to operate everything. Once I take a sweep as shown in my earlier post, I would then set my target level and find peaks. Correct? It gave me 7 filters to apply. I applied the filters but it looks nothing like what REW predicted. I have a 8dB drop at 22.1 hz and also an issue between the 70-80hz region. Is this something I should be worried about. One thing I have read is that you should not apply to many filters. I have also read you should not apply boost. I was looking at boosting the 2 areas of concern. Any thoughts on This?

Frankie


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## glaufman (Nov 25, 2007)

WRT boosting low areas, it kind of depends. Sometimes boosting a low area results in no or little improvement in the FR. This is a case where you don't want to use the boost, all it's doing is eating into your headroom. As for too many filters, and not liking the response of the filters REW suggests, experiment. Start by applying REWs filter to the worst area, and play with the settings ot optimize it. Then add the next filter and optimize that. If they're close, you may have to go back and play with the first one again as well. You're not looking to get an absolutely flat response, that would be too many filters. At some point you'll see a curve that looks and sounds fairly good, with a good improvement over the original. At that point you want to take a deep breath and listen for a while and decide if it's really worth going further. If you optimize a filter and don't hear a difference, don't bother with additional filters.


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