• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

AEOM-GM24 rear audio control warning

KeenAV

SM 2006
Full Member
Joined
Aug 21, 2004
Messages
34
Location
Bartlesville, OK
2004 and Bose 6 disc.  Added PAC AOEM-GM24 to interface to 4 channel amp and new speakers.  I read the little piece of paper that came with the adapter that said that there is no way for PAC to keep the rear speakers from playing when someone activates the rear seat audio controls.  I thought, no problem, I'll just fade to the front and those in the back on the headphones would be fine.  I like having a fade control on the head unit, so I hooked patchcords to all 4 outputs on the adapter and hooked them to the amp.

Wrong.

Everthing works fine with normal stereo listening, but last night I thought I'd turn on the rear seat audio to see how bad the issue was.  The normal head unit output was on like two notches on the volume, the two knobs on the RSA control were all the way counterclockwise --- AND A NOISE ERUPTED FROM MY REAR SPEAKERS THAT WAS LOUD ENOUGH TO MAKE MY EARS RING FOR A COUPLE MINUTES AFTERWARD (I am not exagerating).  It was audio signal, but distorted and boosted to the moon.  Killing the power on the RSA stopped it, and (knock on wood) my brand new Alpines seem to be okay, but it certainly could have blown those speakers.

I guess it's mono output from the AOEM-GM24 and good-bye fader.  I can't have someone hitting that by accident while I'm driving.  Might scare me off the road and blow my speakers.  (btw, I might have had the headphones plugged in, but I honestly can't remember.  seems like I would have had to.  I might experiment, but this time I'll have the amp levels all the way down.)

I welcome replies with work-arounds or similar experiences.  I've only seen one other post where this was experienced, but they had the rear outs hooked to the sub amp, not a rear stereo channel like mine.  I'm sorry, but PAC needs a better warning message.  :8:
 
Here's the OEM diagram; perhaps you can compare it to the wiring changes of your adapter.

Refer to reply #15. Sometimes the link doesn't go to the proper position of the posts.
 
I think I learned something new I didn't know back a year ago:

http://www.logjamelectronics.com/pacaoemgm24.html

It says here that when the AOEM-GM24 is installed that its rear outputs will play whatever is commanded from the Rear Seat Audio if the RSA becomes enabled (as if that were a feature).  OH!!!  So the way it works is that the RSA sends an "on" signal through the data bus to the head unit and that changes the usual rear audio output (the one the PAC is intercepting) into one tailored only for the RSA's use.  I guess it also mutes the rear speaker amp on this command?  I must of had my rear patch cable hooked into the 4 channel amp when I turned on the RSA that one time and the amp didn't like the change in the level much.
 
KeenAV said:
2004 and Bose 6 disc.? Added PAC AOEM-GM24 to interface to 4 channel amp and new speakers.? I read the little piece of paper that came with the adapter that said that there is no way for PAC to keep the rear speakers from playing when someone activates the rear seat audio controls.? I thought, no problem, I'll just fade to the front and those in the back on the headphones would be fine.? I like having a fade control on the head unit, so I hooked patchcords to all 4 outputs on the adapter and hooked them to the amp.

Wrong.

Everthing works fine with normal stereo listening, but last night I thought I'd turn on the rear seat audio to see how bad the issue was.? The normal head unit output was on like two notches on the volume, the two knobs on the RSA control were all the way counterclockwise --- AND A NOISE ERUPTED FROM MY REAR SPEAKERS THAT WAS LOUD ENOUGH TO MAKE MY EARS RING FOR A COUPLE MINUTES AFTERWARD (I am not exagerating).? It was audio signal, but distorted and boosted to the moon.? Killing the power on the RSA stopped it, and (knock on wood) my brand new Alpines seem to be okay, but it certainly could have blown those speakers.

I guess it's mono output from the AOEM-GM24 and good-bye fader.? I can't have someone hitting that by accident while I'm driving.? Might scare me off the road and blow my speakers.? (btw, I might have had the headphones plugged in, but I honestly can't remember.? seems like I would have had to.? I might experiment, but this time I'll have the amp levels all the way down.)

I welcome replies with work-arounds or similar experiences.? I've only seen one other post where this was experienced, but they had the rear outs hooked to the sub amp, not a rear stereo channel like mine.? I'm sorry, but PAC needs a better warning message.? :8:

Is there ever a work around on this?? ?

While I was figuring out my remote start problem and given up, I decided to check this RSA function (yes after 3 years of owning the AV I just decided to use this now).? ?When I turn the RSA on , I almost had a heart attack...? I never heard my subwoofer that loud before? :eek:

I was shaking and confused trying to figure out how to turn it off...?

For now, I just moved it to the front speaker RCA out connection.? I was planning on using all four RCA out in the future (next month adding more speaker/amp), but now I'm not so sure.

 
This is such an informative thread... particularly about the role that the RSA plays by sending a signal over the Class 2 bus to the head unit to modify the rear out channels for a second audio source. 

It sounds like if hooking up a sub to only the rear channels in order to avoid the LOUD chimes from the front channels, one then also must prepare for a SUPER LOUD tone should the RSA button get pressed.

Are the experiences in this thread consistent with your experience, MS03?
 
Yes sir, that's why the pac unit is attached to the headunit. Once the power goes back to the amp it does interface with the RSA before it goes to the AMP.

The RSA is before the AMP for the rear channels. If someone uses the RSA the rear speakers are cut off
 
One of the old threads with the www. in it

http://chevyavalanchefanclub.com/cafcna/index.php/topic,44768.msg705172.html#msg705172
 
If you intend to use the RSA and use an amplifier you HAVE to pull your RCA's from the back side of the RSA...

I tried to use the output of the sub channels to my high level input and it was very distorted and didn't work well. I figured it was a good idea because I was replacing the factory sub... Not so much...

The only bad thing about pulling your subwoofer from the back side of the RSA is that you lose the sub if someone is using the RSA... Your other choice is to just pull the subwoofer from the front right speaker because it is only the front left speaker that has the chime in it from what I have read.

Rodney
 
You could just bypass the RSA, but it's still sound like crap
 
BTW low blow sperry taught me a bunch about the bose system he even walked me though how to install a LUX Bose in my AV
 
MS03 2500 said:
Once the power goes back to the amp it does interface with the RSA before it goes to the AMP.

What did you mean by "power"?  Did you mean the left and right rear channel circuits that GM labels "low level audio signal"?  Or did you mean something else by "power"?

MS03 2500 said:
The RSA is before the AMP for the rear channels.

This seems to support my guess that you meant rear low level audio signal.  But since you said power, and power in a vehicle to me means 12v power supply, I just wanted to your confirmation so that I could clear the hurdles of my own preconceptions!


O I C  (after looking at the diagram sperry posted years ago, that you very kindly reposted above.)   Thanks MSO3!
 
redheadedrod said:
If you intend to use the RSA and use an amplifier you HAVE to pull your RCA's from the back side of the RSA...

I don't understand what you mean here?



redheadedrod said:
I tried to use the output of the sub channels to my high level input and it was very distorted and didn't work well. I figured it was a good idea because I was replacing the factory sub... Not so much...

So you spliced into the high level speaker output lines between the factory Bose amp and the factory subwoofer?

Which voice coil did you splice into, left, right, or both? 

If both, then did you combine the two voice coil splices (total of 4 wires) back into just two wires, summing the left and right voice coils, in order to feed the inputs of your aftermarket  mono block amp?   Or was your aftermarket amp a two channel amp, where you directed each voice coil of the factory subwoofer into a separate channel, and then bridged the channels to power your aftermarket subwoofer?

After all this reading about "OMFGLOUD" chimes and "ears ringing for two days afterward" RSA pings, I was starting to think about buying a high level input amp, and just splicing into the high level factory subwoofer speaker wires... which would avoid any issues with RSA and chimes, since the only time the aftermarket sub would be sounding off is when the factory sub was sounding off.

I wanted to avoid that at first, because I assumed that Bose amp pre filters the frequencies that get sent to the Bose subwoofer... both at the high end (which is fine) AND at the low end, since the factory sub is only 5.25".  This would deprive the aftermarket amp and sub of any frequency below 60HZ I imagine.  That's why I originally wanted line level outs.  But I also want fail safe operation.  I don't want the vehicle to only be operable by people who know what special button to push so they don't get their ears blown out.  I also want to retain all the original factory features.

redheadedrod said:
The only bad thing about pulling your subwoofer from the back side of the RSA is that you lose the sub if someone is using the RSA...

Case in point.


redheadedrod said:
Your other choice is to just pull the subwoofer from the front right speaker because it is only the front left speaker that has the chime in it from what I have read.


Interesting idea... front right only.  I would be delighted to do that, since subwoofers are not really directional.  However, if I'm listening to a book on tape, and there is a dialogue between two people, and the recorder mixed the audio in stereo to create the effect of say, the man on the left and the woman on the right... wouldn't I only hear the tenor of the man's voice, and not the bass, if the only input to the aftermarket sub amp came from the right channel?
 
Yes RSA takes low level output of radio... Rear channels... If the RSA is not being used it just passes the signal to the amplifier...

So RSA only deals with low level sound... When it is active the back channels are not used on the amplifier and you don't get sound out of the rear speakers. This means you want to tie into the low level signal for the rear channels between the amp and the RSA.

I have read that the BOSE amlifier crosses over for the subwoofer but I am not sure it does. My subwoofer amp has both high and low inputs.. Problem is the amplified feed from the subs (BOTH channels) are too high for the amplifier to take into its high level input and the low level outputs from the head unit are too high for the RCA inputs. Currently using the low level outputs into the high level inputs on the amp and they are too low... So I need to use a PAC adapter to feed the low level audio into the sub amps RCA input. I am not sure if the BOSE amp does actually cross over because I had to use the crossover in my amp or I was getting what appeared to be full range when I tried pulling off the subwoofer outputs because I was getting pretty high frequencies through the subs.

My amp is a 2x250 amp that can be mono or stereo. I let it do all the work on its own.

As far as the LUX radio system. It is apparent they use different head units. I was under the apparent false assumption that they used the same units. The Lux amp does get controlled by the Databus and it receives low level audio from the head unit as per the OEM drawings.. I will mention again, when I say "Assume" or "I believe" I am saying just that and welcome correction...
 
Back
Top