# Input conversion?



## atledreier (Mar 2, 2007)

Hello!

I am about to start using a 'pro' amp for my DIY subs. Up until now I've used an SVS PB12+/2, which have single ended inputs. My pre also have single-end output. The new pro amp (EP2500) have balanced (XLR) inputs. Will the BFD accept single ended input and output balanced? I realize of course I won't get the full benefit of a balanced setup, but it would save me a new cable converter.

Also, while I'm on the subject. Is it better to have the long run balanced XLR from the BFD to the amp, or have them close and run long speaker cables? I'd imagine the XLR to be better screened than the speaker cable, but the speaker cable is higher level...


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## tonyjover (Feb 1, 2008)

atledreier said:


> Is it better to have the long run balanced XLR from the BFD to the amp, or have them close and run long speaker cables? I'd imagine the XLR to be better screened than the speaker cable, but the speaker cable is higher level...


Hi,

Long XLRs over long speaker cables every time. Voltage levels, and hence current, and hence voltage drop are all miniscule in signal cables; the opposite is true for speaker runs. Always keep your speaker runs as short as possible.

As for your other question, there's nothing particularly bad about going unbalanced to balanced, just ensure that the cables are correctly wired - many aren't. See this thread.

Regards,
Tony


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## atledreier (Mar 2, 2007)

Thanks alot! Bummer though, XLR cables are pretty pricey...


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

Maverick,

How long of a cable run are we talking about? Tony is technically correct, and that’s the way you see things done in a pro-audio installation. But in a home theater the cable runs are rarely long enough to make a difference. For instance, the speaker wire runs for my subs and front mains are over 30 ft., which would not be considered long in a pro-audio installation.

There’s another issue you won’t see addressed much that I feel is important as well. As you note, long balanced cables aren’t cheap, so the urge will be there to get the cheapest ones you can find. Wouldn’t want to see you do that. As an experienced cable builder I’ve cut open plenty of them, and I can assure you, you don’t want that junk in your system. Equally as bad as the poor build quality of the cables is the cheesy off-brand XLR connectors they use. 

Bottom line, I’d rather see you use decent-quality shorter cables in your equipment rack, with Switchcraft or Neutrik XLRs, with a long speaker cable run, than cheap balanced cables with “correct” short speaker cables.

Regards,
Wayne


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## atledreier (Mar 2, 2007)

we're talking runs of about 10m (30'). I have my BFD in the same rack as my pre. So I was hoping to run balanced from the BFD to the amp in the adjacent room, then speaker cable back to the subs. I'll have to experiment with positioning first and see what cable length I end up with. I've read that many have problems with hum in their BFD. I have no such issues. Might I introduce hum with a balanced run in the loop?


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## brucek (Apr 11, 2006)

> Will the BFD accept single ended input and output balanced?


Yes...........


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## atledreier (Mar 2, 2007)

ok, thanks!


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

Balanced signal runs don’t introduce hum. If you get it, the source is elsewhere.

Regards,
Wayne


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