Installed Amp & sub w/LOC

frdfandc · October 5, 2003

Well, I just installed my amp and sub via a LOC. All I have to say is the sound absolutely sucks big time. I had absolutely no bass, and all I could get was a little mid range and highs.

I guess my next step is to install one of these (clicky, clicky)

http://www.jpcustoms.com/store/customer/pr...&cat=307&page=1

If this doesn't work, then it will be time to install my pioneer head unit.

Anyone want a 2 channel LOC?????

Wingnut · October 5, 2003

I had no problems with my LOCs (I have two in there) bass output. I have 2 10s in back, MB Quart and Infiniti in the doors, all running off of a couple of Fosgate amps, and the stocker head unit. Sounds great.

Does your LOC have a little hole with a gain screw down inside? Most of them do, and you have to fiddle with it.

Also make sure that you have your sub wired in-phase, otherwise it is firing backwards, and will sound like a$$.

What kind of box/sub are you using? Is the airspace within spec tolerances of your sub?

frdfandc · October 6, 2003

I'm pretty sure its wired in-phase. The LOC I have has 2 small knobs on it. I played with them for approx 1 hr along with the amp. As far as the LOC wiring goes, it has 2 gray wires and 2 brown wires plus a black wire (ground). I wired the 2 gray wires up to the positive wires for the rear speakers and the 2 brown wires to the negative wires for the rear speakers. I do get sound out of the sub, but not nearly as loud as it should be.

Wingnut · October 6, 2003

What year is your truck? Do you have the factory Bose system?

vortec4800 · October 6, 2003

Make sure you tap into places that aren't attached to a crossover. I don't know what stereo you have and such, but a possible problem on another car is tapping into the rear speaker outputs for a subwoofer on a vehicle that has a stock subwoofer. The crossover is pulling out all the lows to the rear, and your sub isn't getting a signal below that level. I've installed a few systems using LOCs and it sounds great, double and triple check everything and you should be good. Its possible your amps are bad?

frdfandc · October 6, 2003

I have a 2003 Z71. And it does have the Bose system in it. I hooked the LOC directly to the rear speaker wires. I'm guessing its after the factory amplifier. My amp is ok. The truck does not have a factory subwoofer in it.

Wingnut · October 6, 2003

I have not yet torn into one of the Bose systems, so I'm not sure how they are wired....I'm thinking that they have their own amps in-line for each individual speaker...I don't know where I heard that, but if it's true, it would definately screw with the (now amplified) signal coming down the line.

If thats the way it works, it would be the typical un-upgradable Bose soup sandwich, and you would have to buy an adapter like the one that you found on JP Customs. That or replace the whole thing.

I know some of you like it.....But to me..... Bose

Especially for their home theater wannabe systems. You can just do so much more, for so much less money....Rant off.

Wingnut · October 6, 2003

Just an afterthought.

You might try tracing the speaker wires ALL the way to and from all their various destinations, and see if there are amps installed in-line. Double amping a speaker would probably produce some rather odd results.

rgardjr · October 6, 2003

Well, I just installed my amp and sub via a LOC. All I have to say is the sound absolutely sucks big time. I had absolutely no bass, and all I could get was a little mid range and highs.

I guess my next step is to install one of these (clicky, clicky)

http://www.jpcustoms.com/store/customer/pr...&cat=307&page=1

If this doesn't work, then it will be time to install my pioneer head unit.

Anyone want a 2 channel LOC?????

A have a couple of things for you. First off I'm pretty sure the PAC adapter isn't going to work for you. I have one in my truck '03 Sierra Denali and we tried to put one in my cousins '03 Silverado 1500HD with factory Bose and it didn't work. Unless something has changed from a couple of weeks ago when I talked to the PAC engineer that adapter works on the following vehicles:

Vehicle application: 2003 - Escalade (all), Trail Blazer LT, Trail Blazer LTZ, Envoy SLT, Sierra Denali, Yukon Denali, Hummer H2

PAC C2A-GM24

About your LOC. The factory Bose amp does some pretty serious crossing over/eqing. You'll want to tap the sub output coming out of the amp and not the rear speaker output. The Bose amp is in underneath the center console. That being said you're still going to have to put up with some of the same crossove/eqing from the sub out. There will be plenty of bass, but the Bose amp will start removing it at higher volumes. My cousin has done the same with his truck (LOC to Subs) and wasn't very happy with the results because of what the Bose amp does to the sound. The PAC adapter works great in my truck, but make sure you talk to someone at PAC to verify it'll work for you before you buy one.

frdfandc · October 6, 2003

Sounds like a boat load of work. I'll probably just end up replacing the head unit with the one I have.

Wingnut · October 6, 2003

Good call.

frdfandc · October 7, 2003

Thanks for the help guys.

rgardjr · October 7, 2003

Sounds like a boat load of work. I'll probably just end up replacing the head unit with the one I have.

That's exactly what my cousin ended up doing. He was pretty disappointed with the results of the LOC of the sub outputs. What he ran into was having to turn the bass up so it would be where he wanted it at higher volume and then it would absolutely overpower everything at lower volumes. Don't know if you have Onstar or not, but there are a couple of adapters you can use if you have Onstar and want to keep it or don't have Onstar and want to keep the factory chimes:

Keep Onstar Don't use Bose Amp OS-2 GM ONSTAR INTERFACE

No Onstar and keep chimes w/ C2R-GM24 GM Warning Chime & Radio Replacement Interface

I bought my PAC adapters from this place. Had the best price I could find on the adapters. Good luck with your install. I'm sure you'll be happier with you aftermarket deck.

frdfandc · October 8, 2003

Well, went to install the new headunit tonight. Got the dash kit and wiring harness adapter. got everything wired up except for the battery wire and the ign wire. I haven't been able to figure out what wire is for the ignition wire to the headunit. I know what wire is the battery wire (its hot all the time). Now according to the service manual (Haynes) its a dark green wire, but there are 2 dark green wires. I think this might have to go to an audio place. Nothing seems to match up.