static noise????

steve-o · 07-16-2006, 02:22 PM

So i just got an eclipse deck, with sirius radio. i got it all hooked up, works great, but a get static noise, like if you have the volume cranked right up. when its on cd its not to bad, but on sat radio, you can notice it alot more. i checked all the wiring, it it looks fine, so i was thinking it was the monsoon amp. Anyways, i was just wonder if anyone has had issues with the monsoon amp creating a lot of noise on the line??

viciousmalibu · 07-16-2006, 02:29 PM

are you running your rca's down the same side as your power? and is your ground sanded well? lemme know

steve-o · 07-17-2006, 08:10 AM

well the noise is coming through the speakers, which as all factory. i understand where your coming from if it was aftermarket amp and speakers, but its not, just stock amp and speakers.

mikegett · 07-17-2006, 10:14 PM

You are correct on the first assumption. The monsoon amp gets a signal from your radio that states how to set the gain. It has to do with the feature that lets the radio increase volume as your increase speed. When the factory HU is removed, the amp simply goes to full gain and introduces a preamp hiss. Does anyone still have the monsoon pinout? The old links are now dead thanks to the hacking job. I would have to look at the connector pinout to find the signal. I don't believe the amp uses any digital signal, so it is most likely looking for 12 volts on off to set the gain. Possibly a stepped voltage, but I doubt it. I no longer have a alero, but I could probably step you through a quick check that may remedy the hiss if we can get that pinout. Later, Mike G.

steve-o · 07-18-2006, 08:54 AM

this is the best i can getcha

steve-o · 07-18-2006, 09:22 AM

got this off the GAGT site

Pin Wire Color Function
E1 LT GRN Right Front Speaker Output (+)
E2 TAN Left Front Speaker Output (+)
E3 GRY Left Front Speaker Output (-)
E4 LT BLU Right Rear Speaker Output (-)
E5 DK BLU Right Rear Speaker Output (+)
E6 BRN Left Rear Speaker Output (+)
E7 YEL Left Rear Speaker Output (-)
E8 BLK Ground
E9 BLK Ground
E10 DK GRN Antenna Relay Coil Supply Voltage
E11 ORN Battery Positive Voltage
E11 ORN Battery Positive Voltage
E13 BLK Left Front Tweeter Speaker Output (+)
E14 YEL Left Front Tweeter Speaker Output (-)
E15 DK BLU Left Front Midrange Speaker Output (+)
E16 LT BLU Left Front Midrange Speaker Output (-)
F1 DK GRN Right Front Speaker Output (-)
F2 LT GRN Right Front Speaker Tweeter Output (+)
F3 PPL Right Front Speaker Tweeter Output (-)
F4 PPL Left Rear Tweeter Speaker Output (-)
F5 RED Left Rear Tweeter Speaker Output (+)
F6 DK GRN Right Front Midrange Speaker Output (-)
F7 ORN Right Front Midrange Speaker Output (+)
F8 PPL Gain Control Signal
F9 -- Not Used
F10 YEL Right Rear Tweeter Speaker Output (-)
F11 WHT Right Rear Tweeter Speaker Output (+)
F12 -- Not Used
F13 LT BLU/BLK Right Subwoofer Speaker Output (-)
F14 DK GRN Right Subwoofer Speaker Output (+)
F15 DK BLU/WHT Left Subwoofer Speaker Outlet (+)
F16 LT GRN/BLK Left Subwoofer Speaker Outlet (-)

mikegett · 07-18-2006, 08:59 PM

Unfortunately, it won't be as simple as getting a 12 volt signal to lower the gain. The PPL gain control signal does not come from the HU. It comes from the CAN network into the HU and then out to the F8 amplifier input. I can't read the small print, but the first page shows it as a purple line. Possibly B6? Most likely, this is a RS232 serial connection. The bad news is that RS232's communicate both ways. Remove one, and they both stop functioning. This is why you loose the amp turn on when the HU is removed. The CAN stops sending the signal to the amp. The good news is that it may still be possible to mimick the signal. If you can locate the PPL line comming into the HU (I think it is B6), you can test it out. Just remove the PPL line coming into the HU and connect it to the PPL line (F8 on the amp). You are looking to see if the CAN will send the signal even though the OEM HU is removed. If the hiss went away, then your good. If not, then you may still have a option. I believe the PPL line is being recieved by the HU. The HU then outputs the desired range deepending on the driving conditions. If the HU wasn't altering the signal, then the CAN would simply send it straight to the amp like the amp turn on. Unless, the amp turn on may be seperate from the HU due to trim level options. In this case, the PPL signal may simply pass through the HU and all gain variations are performed at the CAN. If the later is true, then a Peripheral module may allow the CAN to send the signal to the amp with a aftermarket HU. I would first try connecting the two signals with your afermarket HU. You may get lucky. If it doesn't work, then plug your OEM HU back in, with the two PPL signals routed around the OEM HU. If the amp gain functions correctly, then the Peripheral module should work great. The Peripheral would also allow you to have retained power and all warning lights again. The downside is that the module costs about 100 dollars on sounddomain. Good luck, and keep me informed. You've actualy made me miss the alero. Mike Gettinger.

steve-o · 07-18-2006, 09:21 PM

intresting, i will try that. what really sucks is that i already put my stock HU in my moms cavalier, so i'm hoping the first idea works.

Cliff8928 · 07-19-2006, 12:34 PM

Our cars don't have CAN, you're probably thinking of Class-2. That Gain Control signal wire goes from pin F8 on the Amp to pin B6 on the radio and is a purple colored wire. There doesn't seem to be any Class-2 integration into the amplifier, I've only seen that with the lux (Audiopilot) system on the trucks.

cavaliers60 · 07-19-2006, 04:14 PM

umm if you are running your volume way up, you are putting a lot of current through your speakers which is creating that static noise you are getting... sooo, you might have to turn that volume down a little too.. just be careful not to run too much power to the speakers... obviously they will blow. I'm guilty of that being a soundboard operator... lol

steve-o · 07-19-2006, 08:22 PM

alright, i fiqured it out... the factory amp does not like to work with anything other then the factory HU. Aftermarket HU put out a stronger signal then factory, which the monsoon amp picks up and amplifies.

with the gain control signal, it actually comes from the amp to the HU, found this out by grounding out the wire from the HU side,which caused the vol to go down, but when i grounded out the wire form the amp side, nothing.

So what i did is removed the monsoon amp from the picture all together, put caps on the tweaters, and just wired everthing up right to the deck. hiss is gone, and sounds better then it did with the amp.

steve-o · 07-19-2006, 08:24 PM

Quote:

Originally Posted by cavaliers60

umm if you are running your volume way up, you are putting a lot of current through your speakers which is creating that static noise you are getting... sooo, you might have to turn that volume down a little too.. just be careful not to run too much power to the speakers... obviously they will blow. I'm guilty of that being a soundboard operator... lol

nope, i was getting a hiss at vol 2 (deck goes to 80), you could hear the hiss over the music.

mikegett · 07-19-2006, 11:41 PM

Quote:

Originally Posted by steve-o

alright, i fiqured it out... the factory amp does not like to work with anything other then the factory HU. Aftermarket HU put out a stronger signal then factory, which the monsoon amp picks up and amplifies.

with the gain control signal, it actually comes from the amp to the HU, found this out by grounding out the wire from the HU side,which caused the vol to go down, but when i grounded out the wire form the amp side, nothing.

So what i did is removed the monsoon amp from the picture all together, put caps on the tweaters, and just wired everthing up right to the deck. hiss is gone, and sounds better then it did with the amp.

Now that pisses me off. I can't believe I looked over that. Your schematic even illustrates the signal direction as it passes through the fuse block. It sounds as though the amp is simply looking for ground. Probably a switched ground in the HU. You could probably simpy ground the wire to chasis and lower the gain with your aftermarket HU. Cavalier60, as he stated turning down the volume won't help in this case. The amp requires some signal to set gain levels. This means that even at 1 volt, the amp would be inducing noise into the line (preamp hiss). The higher the gain the more sensitive the amp becomes. At full gains, they can easily see noise at milliamp levels.
Cliff8928, your right that the alero does not have the Canbus system. That utilizes the full ethernet high speed, mid speed, and low speed. However, the class 11 databus does use the same protocol and operates via a bi-directional serial. For this reason, the automotive industry refers to the class and Canbus as CAN systems. We use the same computers, same protocols, and same commands to program both HU's. The new GM 250 (seen in nearly all 2007 GM's) are identical HU's with one exception. The firmware. They even both have analog and digital output capability.

steve-o · 07-20-2006, 01:45 PM

Well like i said, if i grounded the gain control on the amp side, it did nothing, but when i grounded it on the HU said, vol went down, and it was the same effect as if i would connect the wire back togeter. So this being said, makes me think that amp is actually turning down the HU.

Almost all aftermarket HUs would put out more then enough power to power the factory speakers without the amp, so i say the best thing to do would just remove the amp right from the picture.

But I want to thank you mike for all your help, and also everyone eles.

mikegett · 07-20-2006, 03:19 PM

I agree with the amp sending the signal to the HU. I was upset with myself for not seeing that in the schematic. What I wandered was if the static was still there when the volme went down. I don't have the alero any more, but you made me pretty curious.

Cliff8928 · 07-21-2006, 03:22 AM

Quote:

Originally Posted by steve-o

Almost all aftermarket HUs would put out more then enough power to power the factory speakers without the amp, so i say the best thing to do would just remove the amp right from the picture.

Well, most speakers, but i don't think i would want to connect those particular ones right to the head-unit. The amp has 8 output channels and none of the speakers have "normal" resistance values as far as i know.

steve-o · 07-21-2006, 02:20 PM

yeah, thats what i said. but the guy at the stereo shop said it wouldn't matter because i put caps on the tweaters. so we'll see if the deck blows up or not, and if it does i'll be taking it right back to them.

mikegett · 07-21-2006, 06:22 PM

The only one you will have to be carefull with is the 6x9. The midrange and woofer are 4 and 2 ohms. If you wire them in parallel it will be 1.3 ohms. The HU can handle a 2 ohm load but no lower. The front speakers are prewired at the midrange and will either be 4 or 2 ohm deepending on the year. My 2003 was a 2 ohm resistance on the front stage. You probably didn't need the cap on your fronts. My front had a cap inline at the woofer to restrict the low from going to the tweets. Your rear 6x9 would be the one needing the cap since the amps dsp took care of all frequencies to the midrange and tweeter.