jgoldwood

Hello, everyone. Since I've had my 08 SS with the upgraded sound for the past month and a half or so I've been disappointed by the system's sound. I have since replaced the headunit with an Alpine INA-W900 and ordered all Alpine Type-R replacements for the speakers. As of right now, I'm in the middle of installing everything and was a little surprised when I switched out my first speaker - it still sounds bad. It sounds like the speakers are blown, or have a crackle to them. There is no way these new speakers should sound like that, nor is the headunit putting out a bad signal, so I'm at a loss. Has anyone else had this problem? I'm wondering if it has something to do with the d#mn GMOS-04 adapter. Any insight would be greatly appreciated! Thanks!

Jeremy

sick1

Hard for me to tell whats wrong without being there to see how you have it hooked up. Not sure what the GMOS-04 adapter is for, but if it's not installed between your head unit and speaker, then it should not affect the sound. Are you sure all your wires are properly connected? Have you adjusted the settings on your head unit?

jgoldwood

Hey man... thanks for the reply. The GMOS adapter is used to connect an aftermarket headunit up with the system that has a the upgraded sound package and OnStar. It is installed between the headunit and speakers, as it requires the aftermarket deck's RCA outs to be used for the speaker wires (no splicing of wires like I've always done in the past). HERE is the manual for that adapter - it's an odd one. I was wondering too, if it could simply be the generic amp that is used in the factory upgraded package? Something is definitely wrong, as it sounds absolutely awful still with the Type-Rs installed. Thanks again.

sick1

Try unhooking the GMOS and connect the wires directly to the speakers. If they sound much better you know the problem is with the Metra unit. Again, make sure your connections are good.

RFT

Are you connecting the speakers through the factory amps or do you have an aftermarket? Almost sounds like if you're running the factory amp, that the voltage out from the HU is too much for the amp.

I would try running wires from the HU's built in amp to the speaker and only using the adapter for power connections to the HU. It's been a while and I don't recall the mfg, but had heard of failure rates in the 25-30% range.

There was some discussions of it on this board as well. You may want to search and see if that matches your situation.

Rob

jgoldwood

Thanks for the reply. I did do a few searches, but could not come up with any material. I am still using the factory amp. I was looking at the PDX-5 but would still be using the stock wiring. Think that would clear it up? I can't imagine the INA-W900 would be too much for the stock amp - only 18 watts per channel. Thanks again.

RFT

I'm assuming since you're using the lan-04 you're using the RCA's from the Alpine to the factory amp through the adapter. If so, the voltage from the Alpine might be too much for the amp and might induce clipping very early. It is a totally different signal then the speaker level output.

If you hook up a speaker straight to the HU and it sounds great, it will narrow the problem down to the RCA lines. Since you apparently had the same problem with a prior aftermarket HU, that would seem to point it to the lan-04

From there, if possible, you could borrow an amp from a friend to verify that everything works if you bypass the adapter's RCA. I don't think the speaker wiring is the problem, so if you do get an aftermarket amp, you should be good if it passes the above test.

Rob

jgoldwood

Thanks again for the help - it's appreciated. I actually had tried asking that question before I installed everything, about how I should run the speakers with the GMOS, but did not get a clear response. Doing this, wouldn't I lose the warning chimes and door locks/turn signals and everything? I have also gotten a pop in the speakers after I do something such as pull the key out of the ignition after the car is off causing the warning dings to stop. It also does it when I lock the doors after the few warning tones go off. Thanks.

RFT

If you were to bypass the adapter's stereo functionality, yes you could lose warning chimes, etc. Some have an internal speaker for the chimes but don't know which one(s) did.

The hope is to identify if the adapter is the problem. If it is, you should be able to get a new one through warranty. That way you can just plug in a new one and off you go. The only way I know to do so is to bypass the adapter from the sound.

For the popping question - that sounds odd.. do you pull the key out as soon as you turn the car off or wait a couple seconds? If the former, try turning the car off and keep the key in the car for 10-15 seconds with the door closed. Then pull the key out and wait for 10-15 seconds before opening up the door.

As for installation, you'll get a lot of opinions on how to install. Myself, I bought the $15 harness, lost chimes and Onstar/XM. Ran new wire to the speakers and couldn't be happier.

Rob

jgoldwood

Thanks again. The pop happens anytime the car has a chime sound - locking the doors, keys in the ignition with the drivers door, etc. Honestly, I'm getting to the point where I too don't care if I lose the chimes and XM. The LAN-04 is terrible. Does the cheaper adapter work more like a normal adapter - you attach all of the speakers to the harnesses speaker cables instead of using the RCAs that the LAN-04 utilizes? Did you have the premium sound?