configuring jl 300/4 amp for bi amping

Hi everyone,

I have a JL 300/4 amp, and just went out yesterday and picked up a set of JL XR 5.25 components for the doors in my car. This amp puts out a rated 75 watts X 4 channels, or it can be bridged. I have a couple of questions, because the amp and speaker documentation has confused me:

I am not going to be using rear speakers, at least not at this time. I would like to take full advantage of the power of the amp and have it just power the components in the doors (mid-bass and tweeter in each door). If I configure this amp to run into two channels, will that put 150 watts into each channel? If so, how do I wire the amp and speakers to achieve this?

Iknow I will need to setup the outboard crossovers for bi-amping as well, and maybe some other settings on the amp, but this thing is so configurable that I'm not sure which combinatino of settings will give me the desired result. Any help would be appreciated. Thanks!

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2004 BMW 325ci.
Alpine CDA-9885
JL 300/4 and 250/1
JL XR 5.25 comps
Infinity Kappa Perfect 12

Inside your crossover box, (or possibly on the terminal strip) there will be two jumpers, right next to each other, marked bi-wire and standard (default). Move BOTH of those jumpers to the bi-wire position, nad now you will just PRETEND that it is two crossovers ('cause really, it is...) in one box. Follow the instructions in your OWNER'S MANUAL, page 3... BOTTOM picture. Easy. Hell, JL even put the wiring diagram ON THE COVER, so you can't lose it, even if you lose the manual.

As far as settings on the amp? None, save setting your gains for the appropriate levels of each driver.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Thanks...I did study the manual, and think I have a good idea how it's done, but I've never done it this way before. Will that put 150 watts into the two channels?

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2004 BMW 325ci.
Alpine CDA-9885
JL 300/4 and 250/1
JL XR 5.25 comps
Infinity Kappa Perfect 12

A potential 150 watts, yes. The tweeter channels will make (and consume) FAR less than 75 watts - probably on the order of 10 watts.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Thanks, I'm on my out to the garage now to wire everything up....I'll post again if I encounter any issues. Thanks for the help!

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2004 BMW 325ci.
Alpine CDA-9885
JL 300/4 and 250/1
JL XR 5.25 comps
Infinity Kappa Perfect 12

Ok, I do have a question. What RCA's do I plug into the amp? I have two sets of RCA's from my head unit...one for front channel and one for rear channel. I would think I would only use the front channel RCA's, but the manual says something about using a "Y" connector to give a mono signal for each channel. I don't really understand what it's talking about.

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2004 BMW 325ci.
Alpine CDA-9885
JL 300/4 and 250/1
JL XR 5.25 comps
Infinity Kappa Perfect 12

Either way... If you want to be able to adjust your tweeter/mid levels from the driver's seat, use all 4 RCA outouts from the deck. Otherwise, use the Y adapter.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."