I put in a JL 250 amp and JL 12w3 subwoofer in a box in my trunk. I think my system sounds very good now. Not too much bass to overpower the factory system, but enough to hit hard and sound good without upsetting the neighbors. I don't have Logic 7. I have the USA standard audio setup (called HiFi everywhere else around the world). This system actually has two pathetic subwoofers - one each underneath the driver and passenger seats. The standard USA audio system's bass is driven by a small puny amp in the back left of the trunk, while the head unit (MASK unit) in the dash powers every other speaker in the car. The head unit (MASK unit) sends a pre-amp level signal to the puny sub amp in the back left of the trunk, which then amplifies the signal and sends it to the subs underneath the front seats. I'm not sure if the pre-amp signal going to the factory sub amp is already crossed over to low frequencies by the MASK unit in the dash, or if that cross over occurs in the factory amp itself.

The route I took:

I used a line out converter to grab the bass frequencies from one of the two output channels of the factory sub amp and also to tapped into the remote turn on wire off the factory sub amp. I ran the power to the new amp straight off the battery. Nice and clean.

I decided to finally take some pictures and document to make this process to make this easier for everyone else. It took some time and some careful research to figure this stuff out. I put in the system myself - the work is not that difficult, once you know what's what. The hardest part was splicing into the wires with a knife without cutting them in two. Take a knife, carefully shave off some of the insulation, then twist your tap in wire to it, then tape it up. You can also use tap-in connectors, but I didn't have any on hand at the time and I wanted to make sure I got a good, solid connection. Later on, I can easily take out this whole system in a matter of minutes, and then tape up the wires I tapped into. No holes drilled. Nice and clean.
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thx the info

Looks neat! :thumbsup:

How was the sound?

ACRIBB, I can't thank you enough for the DIY with pics. I installed my first amp and sub today by using your instructions. It took me about 5 hours to do, mainly because I have never wired anything like this in my life. I'm running a JL Audio 12w6 in a sealed box measured to the specs on JL's website. I also used a Precision Power A600 2 channel amp using a Rockford Fosgate 4 guage wiring kit and Line Output Converter. I added one feature to the set-up...I included an On/Off switch on the remote wire so that I could turn the amp off from the cabin. Most of the newer amps have bass controllers but I was outta luck, so I added a simple switch for $3. As you said, the set-up is clean, no holes, nothing modified and it can be put back to stock within a few mintues. Hardest part was tapping into wires to get the LOC hooked up. You have to use a real sharp knife or razor for this.

I'm thinking about using the cigarette lighter for the remote wire when I get more time. Based on other posts, the amp will turn off once the key is out. Right now, the amp turns off a little after the key is removed, maybe 30 seconds. But it also turns on momentarily if you unlclock your doors or trunk. No biggie though.

The sub sounds awesome, no sound pollution, hits hard and precise.

nice write up

hey acribb thanks for the info...im trying to install a w3v3 and a jl 250/1 right now as i type this...i was just wondering what kind of line out converter did you use? i cant seem to make this work.. im thinking its my loc... pleasee helpp...

If you are installing the amp in the trunk of a 10 speaker setup, and using the hiring harness to the existing amp driving the under-seat woofers, you should not use a line converter, as the inputs to the stock rear sub amp are already line level. You should simply solder them into RCA phono plugs to connect to your new sun amp.

The diagram here might help:

http://forums.e60.net/index.php?showtopic=...mp;hl=subwoofer

how do you connect the line converter though to the amp for the stock system (10speaker i'm guessing)...couldn't really tell from the pics, great write up...thanks :twoup:

Anyone with Logic 7 install a system into their car? My amp and wiring is different from the write-up and their doesn't seem to be a remote wire going to my L7 amp. The remote wire is the only thing i'm missing.

Thanks for the great write up. I will be using this info in the near future.