# pre n post bfd, svs pb12+



## moreira85 (Jul 10, 2008)

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Here are the results of the FR after adding the Behringer.
The blue line is the sub without BFD, the pink line is after I added the Behringer. I may make a few more adjustments, wanted to get your thoughts on this response. looks very good from 16hz to 50hz, any thoughts on the decible drop between 50 to 80hz? Is that normal? this test was done with the sub only, no mains.


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## brucek (Apr 11, 2006)

The drop in response in a sub will be as a result of the crossover you have selected in the bass management of your receiver (i.e. 80Hz).

Your response looks fine to me..

brucek


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## moreira85 (Jul 10, 2008)

great, thanks for response. Should I not worry about trying fix above 80HZ if I am crossed at 80Hz (for example the dip between 89-100hz?)
Anything esle I should try and tame here?
I have to throw out a huge thanks to the bfd guide that was very very useful.
I still dont have a grasp on bandwidth but i just played with it and started at a bw of 2 then 4 and gradually increased to use the best settings.


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## recruit (May 9, 2009)

your response is for the sub only so it will roll off quickly, the speakers should blend in at the crossover point and this all depends how good the room is and the acoustics in the room, ref to your graph that response looks good...you could run the test tone with the other speakers engaged and it will give you an idea of the response, also if you can use a test disc like AVIA it has good sweep tones which will also give you an idea how well the sub and speakers integrate with each other...

slight movement/positioning of the speakers can help in smoothing out integration with the speakers and sub..


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## moreira85 (Jul 10, 2008)

thanks, I have AVIA II and will try later to see how well they blend. If an adjustment is needed i should adjust the mains or positioning of mains since the sub response looks good? with the mains and sub should the freq response be a pretty flat line all the way across the Frequency range?

Last question, I used the test tones from 16 to 160 done in 1/6 octave, because i didnt test every singe frequency like 16, 17 18, 19,20,21,22,23 24 etc what are the chances there could be a dip or peak in between those range of say 16, 18, 20, 22, 25, 28, 31.5 etc.


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## recruit (May 9, 2009)

moreira85 said:


> thanks, I have AVIA II and will try later to see how well they blend. If an adjustment is needed i should adjust the mains or positioning of mains since the sub response looks good? with the mains and sub should the freq response be a pretty flat line all the way across the Frequency range?
> 
> Last question, I used the test tones from 16 to 160 done in 1/6 octave, because i didnt test every singe frequency like 16, 17 18, 19,20,21,22,23 24 etc what are the chances there could be a dip or peak in between those range of say 16, 18, 20, 22, 25, 28, 31.5 etc.


A dead flat response is not always the best sound it just depends, manufacturers of speakers and subs will always give an indication usually of the speakers response + or - 3db over a given freqency range, this is how we measure the performance but due to room acoustics as you well know there can be some nasty room modes which will cause distortion of the speakers response, ideally we should aim for a flattish response but dont get too hung up on it, your ears are the best measuring tool availible...

Dont worry about the 1/6th octave measurments as they are sufficient to get what you want done correctly...


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