# how to install a crossover for a subwoofer?



## djloui (Nov 10, 2014)

Hello everyone! I have a dual 15 inch PA speaker connected with my Behringer 3000 DSP amplifier. I really need to add some deep bass to this system. So i was thinking of building a subwoofer box for this pyle subwoofer. 

Since the amplfiier delivers full range audio can I use one of this? How should I use it?
http://www.amazon.com/FMOD-Crossover-Pair-Low-Pass/dp/B0006N41EM

http://www.amazon.com/gp/aw/d/B007J...&sr=8-1&pi=SX200_QL40&keywords=pyle+subwoofer


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## Kal Rubinson (Aug 3, 2006)

djloui said:


> Hello everyone! I have a dual 15 inch PA speaker connected with my Behringer 3000 DSP amplifier. I really need to add some deep bass to this system. So i was thinking of building a subwoofer box for this pyle subwoofer.
> 
> Since the amplfiier delivers full range audio can I use one of this? How should I use it?
> http://www.amazon.com/FMOD-Crossover-Pair-Low-Pass/dp/B0006N41EM
> ...


Your amp has only speaker level output, so this "crossover" will not work with it. (Also, it is not a crossover but simply a low pass filter.)

You can use a speaker level crossover (see: http://www.parts-express.com/cat/as...eca:matches(.,"P_Searchable","1")]&PortalID=1 ) as well as a level control for the sub in order to balance it with respect to the main speaker.


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## djloui (Nov 10, 2014)

Great thanks. Will this one work?
http://www.parts-express.com/parts-express-80-hz-low-pass-8-ohm-crossover--266-442


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## robbo266317 (Sep 22, 2008)

That one is suitable for 250 Watts as per their catalogue. So it depends on how hard you expect to drive it.


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## djloui (Nov 10, 2014)

robbo266317 said:


> That one is suitable for 250 Watts as per their catalogue. So it depends on how hard you expect to drive it.


Thanks. I will put like 600 RMS to this subwoofer. So should I buy two crossover or more since the crossover only handle 250 RMS?


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## Kal Rubinson (Aug 3, 2006)

djloui said:


> Thanks. I will put like 600 RMS to this subwoofer. So should I buy two crossover or more since the crossover only handle 250 RMS?


Not possible. First, this is an 8ohm filter and the sub is a 4ohm load so the frequency will not be as expected. Second, you cannot connect 2 of them in parallel.


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## djloui (Nov 10, 2014)

Kal Rubinson said:


> Not possible. First, this is an 8ohm filter and the sub is a 4ohm load so the frequency will not be as expected. Second, you cannot connect 2 of them in parallel.


Can i use it without a crossove? the amplifier delivers full-range audio and the subwoofer will receive good bass signal. Any suggestions?


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## Kal Rubinson (Aug 3, 2006)

djloui said:


> Can i use it without a crossove? the amplifier delivers full-range audio and the subwoofer will receive good bass signal. Any suggestions?


Sure you can. Nothing will break but it will sound like .............................................(something I can't post here).


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## djloui (Nov 10, 2014)

Kal Rubinson said:


> Sure you can. Nothing will break but it will sound like .............................................(something I can't post here).


I guess you meant that It will sound awful right? lol. I wanted to run the sub on one channel along with my other two pa speakers since I have my amplifier bridged which provides more power to my speakers. I have the ( Behringer 3000 DSP ). What would be better? Run the sub in one channel and set the crossover to low pass? And then use the other channel and power my two cabinet speakers. I have two 8 ohm cab speaker. ( one handle 1500 RMS and the other 350-500 ) If i wire them in parallel they will be receiving like 400 RMS each since the amplifier delivers 820 RMS at 4ohm? Should I wire the sub in one channel and the two cabs speaker in another channel?


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## Kal Rubinson (Aug 3, 2006)

djloui said:


> I guess you meant that It will sound awful right? lol. I wanted to run the sub on one channel along with my other two pa speakers since I have my amplifier bridged which provides more power to my speakers. I have the ( Behringer 3000 DSP ). What would be better? Run the sub in one channel and set the crossover to low pass? And then use the other channel and power my two cabinet speakers. I have two 8 ohm cab speaker. ( one handle 1500 RMS and the other 350-500 ) If i wire them in parallel they will be receiving like 400 RMS each since the amplifier delivers 820 RMS at 4ohm? Should I wire the sub in one channel and the two cabs speaker in another channel?


Can't help you with any of that stuff because it is beyond my ambit.


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## robbo266317 (Sep 22, 2008)

Kal Rubinson said:


> Not possible. First, this is an 8ohm filter and the sub is a 4ohm load so the frequency will not be as expected. Second, you cannot connect 2 of them in parallel.


I hadn't even noticed that Kal...

Crossover design is not a simple task and unless done properly will give very mixed results. And by very mixed I mean horrible.
You have to have components that can handle the power and work together to give the desired cutoffs.


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## MetropolisLake (Sep 22, 2014)

djloui said:


> I wanted to run the sub on one channel along with my other two pa speakers since I have my amplifier bridged which provides more power to my speakers. I have the ( Behringer 3000 DSP ). What would be better? Run the sub in one channel and set the crossover to low pass? And then use the other channel and power my two cabinet speakers.


What you need to do is buy a second amp. Run one amp on the highs in stereo and another amp to the sub(s). 




djloui said:


> I have two 8 ohm cab speaker. ( one handle 1500 RMS and the other 350-500 ) If i wire them in parallel they will be receiving like 400 RMS each since the amplifier delivers 820 RMS at 4ohm? Should I wire the sub in one channel and the two cabs speaker in another channel?


You don't need to be running a single amp channel into two different speakers.


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