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Can you bridge a 4 channel amp and still power a sub?

Old Sep 20, 2007 | 10:08 PM
  #1  
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Can you bridge a 4 channel amp and still power a sub?

Recently I've been mulling over alternatives for my system. I've got a PPI 4 channel amp, focal separates up front and a MMats sub, DVC @ 4 ohms per coil.

I thought I read somewhere you could bridge to 2 channels, filtering the bass and running it to the sub. Is this possible with my system?
Old Sep 20, 2007 | 11:06 PM
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yes, you can bridge 2 channels to one coil and the other 2 channels to the other coil.
gains should be as close as possble and it should be a mono feed to all channels
Old Sep 21, 2007 | 05:11 PM
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I'm not sure if I adequately explained what I want to do. I want to run my separates AND my sub off of my amp, bridging it to 2 channels. It seems to me I would need a 3 way crossover after the amp to get it done.

If this is possible, is it superior to my present configuration ( 4 channels, 2 to front separates, 2 to the DVC sub), or is it just another way of getting to the same result.
Old Sep 21, 2007 | 05:25 PM
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to make sure, you want to bridge channels 1 and 2 to power one speaker, 3 and 4 to another, and have the sub running off of both? you're better off leaving it, or buying a seperate subwoofer amp.

to properly do what you want, you need to run everything in series, cutting back on the power. therefor you would actually be getting half the power you are right now.
Old Sep 21, 2007 | 06:33 PM
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West

Yes this can be done but it will necessitate you building a passive crossover network. You will also only be able to use one coil on the subwoofer. It is best to leave the amp running in 3 channel mode, channels 1&2 to the component speakers, channel 3 & 4 bridged to the sub (again only using one voice coil).
Old Sep 22, 2007 | 01:16 AM
  #6  
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Thanks for all of your input, I think I'll leave well enough alone and focus on getting sq HU, maybe some dynamat.
Old Sep 22, 2007 | 03:07 AM
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I'm not sure if yor confused or me but here it goes

Your 4 chan amp is bridgeable to 3 channels
the two unbridged channels will run your main staging speakers being your Focals
Your other two channels will be bridged to one channel to run your sub at 2ohms mono this is beyond the rated load of your apm but providing you supply the amp with enough current and airflow you will not have a problem.

the main channels running the focals will be using the high pass filter and the other channels will be lowpassed



periodically depending on how hard you run the system it will thermal out but if you use cooling fans it will help
Old Sep 23, 2007 | 01:02 AM
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i actualy ran a 1ohm load off my amp, bridged. (rated at 4 ohms). It went into protection as soon as I started cranking up the volume. But, it's still fine... I'm not sure if it goes into protection from heat, or if it's from too much current reaching the speaker output...

Anyways, if you're conservative on the amount of power you give your subs, you should be ok running it at 2ohms bridged.
Old Sep 23, 2007 | 02:00 PM
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Yeah, I think that may be a little risky for me. However, I'm presently running my 4 channel amp unbridged, with the 2 rear channels each connected to one VC of my DVC sub. It seems some are recommending bridging the rear 2 channels and running one coil. This would actually give me 300 watts instead of 75x2 at the sub, and sounds tempting, but is this acceptable for a DVC sub?
Old Sep 23, 2007 | 08:06 PM
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are all four channels bridge-able, 4 to 2, cuz you could run your comps from each channel, and parallel to your sub, but unless your running in mono, which wouldnt optimize your comps, then you'll be running stereo to your sub, not so good. But if you use 2 svc subs then it wont be too bad at all.
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