# BFD on HGS-18 Velodyne. Let's run through the setup



## fastline (May 7, 2010)

I am looking for maybe pick one up to try out. Hopefully I just keep it unless there is some reason I would have to have the SMS-1. My HGS can play reasonably down to about 15hz. I know my response is far from linear. I have noticed that the back of the BFD looks to only have XLRs or 1/4" jacks, how do we get around that? 

Also just curious if there are integration concerns in a system? I read where I may have problems at very low frequencies? 

I guess just wanting to make sure this is the right approach before jumping in. I already know I NEED to EQ. I also know my pocket will is not going to fork over the coin for the Audyssey either.


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## Wayne A. Pflughaupt (Apr 13, 2006)

> I have noticed that the back of the BFD looks to only have XLRs or 1/4" jacks, how do we get around that?


There’s no “get around.” You have to use one or the other. Most people use the 1/4” jacks, as cables with RCAs on one end and 1/4” on the other are easier to find, and cheaper. Some people just get some 1/4” to RCA adapters and just use regular RCA cables from there.




> Also just curious if there are integration concerns in a system? I read where I may have problems at very low frequencies?


Nope, no such problem. Some people occasionally have an issue with not being able to set a filter with a center frequency lower than 20 Hz, but that’s rare.

Regards,
Wayne


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## fastline (May 7, 2010)

Would there be any benefit to using the SMS over the behringer piece? 

Also, can you better explain the situation around 20hz?  I guess I still do not understand what the problem even is. Might make more sense if I owned one though.


Also was curious about the 2496 model and if it had anything that is more desirable?


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## Wayne A. Pflughaupt (Apr 13, 2006)

> Would there be any benefit to using the SMS over the behringer piece?


 The SMS has it’s own built-in measurement system, so you don’t have to use something like REW. Probably less technically challenging, but it comes at a price.



> Also, can you better explain the situation around 20hz? I guess I still do not understand what the problem even is. Might make more sense if I owned one though.


 The BFD being a parametric equalizer has 60 available frequency stops per octave. These frequency stops are what is selected when you want to use a filter to boost or cut response. The lowest frequency that can be set on the BFD is 20 Hz. However, a filter will affect response on both sides of its center frequency. So in the rare event that you needed to accomplish some equalization below 20 Hz, a wide filter would “reach” lower. 

Have you loaded REW? If so, you can open the EQ panel and play with filters, and REW will show you on the screen what affect they would have.

The 2496 offers no real benefit that I'm aware of. Supposedly its noise specs are better, but that's pretty much irrelevant for equalizing subwoofers. The BFD's noise specs are grossly inaccurate, to the point of being an out-and-out lie, so I don't put much stock in the 2496's specs either.

Regards,
Wayne


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## fastline (May 7, 2010)

Well, I just loaded REW and clicking around a bit. I would guess that setting up a sub could be done just with the meter and EQ for no more than needs to be done. 

I would not try to use it in the whole system. I am not sure if it would induce noise or not but I am switching the the Elite SC series receiver soon and will take advantage of their auto tuning for starters and go from there. 

I still want to play around the REW software a bit I think.


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## Wayne A. Pflughaupt (Apr 13, 2006)

> I would not try to use it in the whole system. I am not sure if it would induce noise or not


If you're talking about using the BFD or 2496 full range, no you wouldn't want to do that. The BFD for sure will introduce audible noise. For full-range equalization, a better quality equalizer is required.

Regards,
Wayne


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