allanc45

Just a link to another thread running. Seriously, I think most of you will find this informative and helpful, especially if you are thinking of modifying your stereo (new amps, subs, speakers, etc.), but keeping the stock Head Unit. Comments/Flames welcome!

http://216.177.40.14/forum/showthrea...threadid=19495

AllanC

Brewboy

Very nice work Allan. Why are you on your third amp? Where and how did you bypass the Bose EQ? Did you tap into R&L out from HU to EQ but leave the connection between them? What color are the wires you are using to bypass the EQ? Can you describe the grounding scheme between the HU and EQ and such per your diagrams? I'm wondering about ground loops between everything, especially when adding a LOC. With only one common between L and R we've got an unbalanced system so I'm thinking how to avoid a ground loop between the equipment and RCA's. I'm ready to install my LOC tomorrow. Talk about just in time. One more Q, what's the easiest way to get behind the HU to install LOC?
thanks

ghost31711

i'm keeping the stock headunit and adding a audio control HPX, i guess i'll have to bypass the EQ and hook the front left and right speaker wires to the HPX (it accepts speaker line input) so i would need front speaker wires to be putting out full-range as oppsed to HP or LP, please enlighten me ASAP, thank you so much

allanc45

Brewboy/Ghost,

If I'm lucky, I'll finish my install tomorrow. The Infinity Kappas are going away in favor of a Focal component system.

I'm on my third amp because...(semi-long story made short)...I originally bought an Alpine V12 amp, returned that because of the awful treble coming from the Bose EQ, got a Sony with a built-in 5-band EQ, but that didn't correct it enough (5 bands would never be able to counteract that Bose POS), so I got mad enough and returned that Sony, figured out the EQ bypass, and bought last year's Sony ES 4x75 amp (the huge one that was originally ~$600). Btw, this latest amp is UH-mazing. Took it apart, the components are definately in the range of audiophile/recording studio monitor amps.

Brew:

I bypassed the EQ by sending the L/R EQ-outs right back to the EQ-ins on the HU. Now this makes the signal go through the stock HU amps, which forces me to use LOCs to knock down the power, plus it hurts the sound quality a tiny bit, cuz that HU amp is nowhere near the quality of the Sony ES. But I did that instead of tapping right off the line-level EQ-outs simply because I wanted to keep fader controls. If I change my mind in the future, it's a piece of cake - just remove the LOCs, and take the EQ-out signal, then Y-cable that signal to the front/rear Sony amp inputs.

Now about the grounding....the good news is, all the components themselves have power grounds (HU, Bose EQ, Sony amp, etc..) which never get lifted, so you won't get engine/alternator noise. The BAD news, *and this just might be MY situation*, is that somewhere during this project I picked up a slight noise that is coming the CD motor of the HU. How do I know? Cuz you hear this sound when the player is switching tracks and such. Bummer, but it's incredibly low (inaudible with the engine running at idle while parked), so I probably won't mess with it.

When I'm done, I'm going to post some small pics of my installation progression, including the wiring diagrams I got from my dealer. I have to repeat how thankful I am they gave them to me without any kind of fuss. Those diagrams have been invaluable - I recommend you copy mine when I post them, or better yet, get them yourselves from your dealer.

AllanC

Brewboy

Allen,
Have you tried using the EQ-out L&R from the HU directly to your amp? Can I assume this would be a low-level(preamp)signal? Do you know the wire colors for these wires. Not too sure I like the idea of sharing a common between L&R but willing to try it. I'm only interested in the fronts, so two channels will work for me. Couldn't you run this same preamp signal thru an aftermarket EQ/preamp to add fader control if you wanted to separately amp your rears and get rid of your LOC at same time?

djsteve

Did you confirm that the line-level signals going in and out of the Bose EQ follow the volume control? In otherwords, are you sure they are not a static level that is attenuated further down the line (by the volume control) before being fed to the internal amps? If not, then you would have a bigger problem that just not being able to fade front-rear, you would be at full volume all the time without an external control

Looking forward to the schematics and photos - they will be very helpful! Thanks!!!

allanc45

Brew,

>Have you tried using the EQ-out L&R from the HU directly to your amp? Can I assume this would be a low-level(preamp)signal?

Not yet, but I may try that in the future. And yes, it is line (preamp) level.

>Do you know the wire colors for these wires?

Yep. There are 2 wiring harnesses going into the back of the HU. The smaller, black harness has the EQ ins/outs. 12 pins altogether. You need to connect pins 1 (white) and 3 (orange) together, and pins 7 (Red) and 9 (Blue/Green) together. 1/7 are the sends to the EQ, 3/9 are the returns. Doing this bypass still leaves the Sum-out going to the Bose EQ, so it can send that signal to the sub amp behind the rear seat.

>Couldn't you run this same preamp signal thru an aftermarket EQ/preamp to add fader control if you wanted to separately amp your rears and get rid of your LOC at same time?

Yep, but I am trying to keep this simple , without extra pieces all over the place. I would only venture down that road if necessary, and I don't see that happening. At most, I may cut out the Bose EQ entirely, get a small passive/active sub crossover, fed by either the front or rear stereo preamp signals going to my amp in the trunk.


Djsteve,

>Did you confirm that the line-level signals going in and out of the Bose EQ follow the volume control?

I didn't confirm it, but I know that its level is controlled by the main volume knob. Why? Because the sub gets its signal from these outputs as well, and if it were fixed power, the sub would always be on full blast!

I was planning on finishing tonight, just mounted the new Focal tweeters in the sail panels. But alas, my XTC foam baffles for the door speakers didn't arrive today, and I'm flying out for the rest of the week. I'll finish early next week and post those pics and diagrams.

Allanc

Btw, I noticed tonight for the first time....if you look on the inside of the OUTER door panels, each door has a big chunk of Dynamat in there....LOL....I'm adding more myself