JBL P180.2 and 2 4ohm JLs

[Aaron407 10+ year member]

I have a JBL P180.2 (2 channel) amp that I'm pushing 2 jls with. The problem is, it puts out 360w rms bridged at 4 ohms, or 180w x2 rms 2 ohm stereo, but only 90w x2 at 4 ohms. Maybe it's common practice, but I'm still kind of a newbie, and I was thinking of trying the following:

-Tying the positive output terminal from each channel together, and tying the negative terminals from each channel together. It would basically be a stereo configuration, just with jumpers from positive to positive and negative to negative. This way, each channel would see a 2 ohm load. Each channel's output would be split between subs, but the full 180w x2 would be utilized (ie. each sub would get 90w from each channel). My question is, is it bad to push a sub with power from both channels without using the standard bridge configuration? I'd be running the amp to put out a mono signal, so it wouldn't be a different output on each channel. Would this configuration work properly?

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[Aaron407 10+ year member]

I guess a better question is, would the jbl internal bridge circuitry allow for this?

 

[Drum437 10+ year member]

that would probbaly Kill your subs or your amp, or just wouldnt work at all

 

[n2audio 5,000+ posts]

you would have one channel trying to drive the other. Most definitely fatal for the amp.

What allows two channels of an amp to be bridged is that one channel is inverted and operates 180 degrees offset from the other channel. While one pushes - the other pulls.

JBL's do really well on ebay. Before you destroy it you might try selling it and putting the money toward something that fits your needs a little better.

 

[Aaron407 10+ year member]

Yeah, I read a little more on a different website too and the P180.2 detects this configuration and doesn't draw any power from its power supply. Only displays a red light. Thanks for the advice anyway. I'll probably end up just buying another P180.2 for the other sub instead of risking blowing my amp. So another question is, how much rms power could be safely put into JL 12W0's? They're rated for 125w rms, but I've read that JL designs them by pushing them for 10 hours straight under twice that rms wattage.

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[n2audio 5,000+ posts]

Depends on how you plan to use them.

If you're porting them and want them to pound non-stop I wouldn't go much over what they're rated for. 150 - MAYBE 200.

If you're going to have them sealed and don't figure to be blasting it all the time I wouldn't hesitate to run them at 250.