New Car Stereo Problem

[DONP1217]

I added an XM Commander for satellite radio. It uses a wired FM modulator to connect to my stock head unit. Next I added four Pioneer 6x8 4 way speakers rated at 50 RMS or 240 watt peak. Finally I added an Audiobahn A4004T 50w x 4 amplifier. I kept my stock head unit because I like it. I also kept the stock 6.5 inch subwoofer and sub amplifier.

It sounds great now but my problem is that I can hear what sounds like white noise or a hiss or buzz when the car is turned on and the stereo is played at low volumes. I don’t hear this noise with the car off. The noise does not increase when I rev up the engine. It does not increase when I turn up the volume. It is just a constant noise.

I had Circuit City install the XM Commander. There were no problems with it. They installed it on Saturday morning.

On Monday morning I installed the Pioneer speakers. There were no problems. I did not have any noises etc. I used Metra harnesses to tap into my factory harnesses.

On Monday afternoon I had Circuit City installed the Audiobahn amp. Besides the noise it sounds really good. The amp is mounted against the back wall of my trunk behind the spare tire and next to the factory sub woofer. I do not know where the amp is grounded and I do not know what they set the levels to.

Any ideas as to what is making the noise and how to fix it?

[lgetz]

From what you describe it sounds like a problem a client had when I worked sales for an auto sound store. He was a Mexican national w/ an MG 75 (nice looking and driving car) and we installed 6.5 PCE MB Quart Component sets front and rear a 10" sub and a 4ch amp. and a mono amp. He was happy but returned because there was noise as you described in your post. We troubleshooted it under warranty and even swaped amps and replaced the hi/lo convertors. Did not help. The problem was with the stock radio. Like yourself he liked the looks of the stock unit and besides he lives across the border in Reynosa and theft risk is a consideration. My advice would be switch to a stereo like an Alpine 9811 with built in RCA outputs and crossover. It's relatively inexpensive looks nice but you would lose the changer if you have it. Hope this helps.

[03SILVERSTREAK]

If I may-have the tech: that did the installation check for possible ground loops. Its possible that the power amp is not properly grounded or grounded at a point thats not a proper ground. I installed a pioneer power amp and bolted it against the wall behind the rear seat and placed the ground wire about 9-12 inches were I mounted the amp. I also made sure that there was no paint under the ground wire mounting location. my 0.2 cents...

[rookie1]

If I may-have the tech: that did the installation check for possible ground loops. Its possible that the power amp is not properly grounded or grounded at a point thats not a proper ground. I installed a pioneer power amp and bolted it against the wall behind the rear seat and placed the ground wire about 9-12 inches were I mounted the amp. I also made sure that there was no paint under the ground wire mounting location. my 0.2 cents...
Is it a hiss like white noise or a whine? A whine suggests a ground loop but that would typically vary with revs. A hiss would indicate something else. Did you connect your amp using the speaker level inputs? if so, using these will eliminate the noise:
http://www.crutchfield.com/cgi-bin/S-5kIv36LD9np/ProdView.asp?s=0&c=11&g=721&I=101PL2&o=m&a=0&cc=01&avf=N

connecting high end components to what are essentially low end OEM components can be tricky in this regard, the signal to noise ratio in most OEM units is usually awful and the added components reveal this weakness. Don't despair it is fixable with tweaking and patience. I've used the factory head units in combination with aftermarket amps and subs in all my cars.

Good Luck!

[martyo]

Is it a hiss like white noise or a whine? A whine suggests a ground loop but that would typically vary with revs. A hiss would indicate something else. Did you connect your amp using the speaker level inputs? if so, using these will eliminate the noise:
http://www.crutchfield.com/cgi-bin/S-5kIv36LD9np/ProdView.asp?s=0&c=11&g=721&I=101PL2&o=m&a=0&cc=01&avf=N


I agree with Rookie.

I would make the follow suggestion in running down the this problem. Run a ground lead directly from the battery to each component. To make this easy, you can run the ground leads outside of the car first as a test. Often times hisses and whines are from bad grounds. If this elimintaes the problem, then you can take the time to properly run a ground lead internal to the car.

Be sure to let us know how you make out.

[DONP1217]

It is a hiss like white noise.

[rookie1]

It is a hiss like white noise.
Then if you didn't use line level converters like in the link I gave you, buy them and it will eliminate the noise. If you haven't used them b4, there's nothing to hooking them up. Simply connect the speaker leads from the head unit to the converter then connect the converter to the amps rca jacks via a couple rca cables. You will need 2, one for the front and one for the back.

[DONP1217]

Thanks, I will give it a shot.

I guess my other option is to buy a new head unit with an XM tuner.


Then if you didn't use line level converters like in the link I gave you, buy them and it will eliminate the noise. If you haven't used them b4, there's nothing to hooking them up. Simply connect the speaker leads from the head unit to the converter then connect the converter to the amps rca jacks via a couple rca cables. You will need 2, one for the front and one for the back.

[rookie1]

Thanks, I will give it a shot.

I guess my other option is to buy a new head unit with an XM tuner.
It will work and they're nothing to install. Crutchfield isn't the only place that has them, any car stereo store and some Circuit city and best buy stores have them also.

[joflewbyu2]

all i know is that the cd playing after new speakers (Kenwood kfc-6808c 6x8 3 ways all around and new kenwood 6.75" tornado sub) is plenty loud. it is a lot louder and clearer than fm stereo..

[hdwrench]

Is it a hiss like white noise or a whine? A whine suggests a ground loop but that would typically vary with revs. A hiss would indicate something else. Did you connect your amp using the speaker level inputs? if so, using these will eliminate the noise:
http://www.crutchfield.com/cgi-bin/S-5kIv36LD9np/ProdView.asp?s=0&c=11&g=721&I=101PL2&o=m&a=0&cc=01&avf=N

connecting high end components to what are essentially low end OEM components can be tricky in this regard, the signal to noise ratio in most OEM units is usually awful and the added components reveal this weakness. Don't despair it is fixable with tweaking and patience. I've used the factory head units in combination with aftermarket amps and subs in all my cars.

Good Luck!
i had 4 infinity speakers and a rockford 4ch amp installed today with line out converters and i have the hiss... they told me id have it unless i replaced the head unit?

[rookie1]

This is a tough problem to eliminate completely. Understand that the hiss was always present just not reproduced by our OEM speakers due to their limited range.
So, it is important that high quality line level converters are used when adding amplifiers. Assuming that they used high quality converters the next thing we have to look at is the gain settings on the amplifier. Sometimes the gain is set too high and will cause the hiss to be overly amplified along with the rest of the signal.
The easiest way to check this is to find some program material you are familiar with and sit in the vehicle and steadily increase the volume till you reach what you perceive to be the maximum volume level. This is level at which you start to hear slight distortion. At this point take note of the volume setting on the head unit, if it is not near maximum then the gain on the amplifier is adjusted to high and lowering it slightly will help alot. It may take some tweaking but this can be accomplished without too much trouble.

Now, understand that hiss is component related and whines, alternator noise, and any noise being reproduced the speakers that varies with rpms is related to faulty ground or poor shielding between signal cables and power/ground wires. That being said even if the problem is purely component related one thing I found that might help(it helped in my MM) is to ground the amplifer to the factory ground wire in the subwoofer harness.
Out of phase speakers will also cause the perception of more hiss due to slight delays in the signal reproduction. The test for this is easy, listening to the front speakers only adjust the balance to each side and determine if the low frequencies are more prominent when you are listening to the one channel or if they are more powerful when listening to both channels. If more powerful when listening to one channel the speakers are out of phase and correcting this will help. Repeat the procedure with the rear speakers.

Good luck and I hope this helps.

[Donny Carlson]

I added an XM Commander for satellite radio. It uses a wired FM modulator to connect to my stock head unit.
I recommend you replace the FM modulator with a Blitzsafe XM commander interface. This interface is plug and play, connecting between the data cable of the CD Changer and the changer itself. It can also be installed under the dash and plug into the data cable port on the head unit if your dont have a CD changer, or even if you do, it can be installed between the data cable and the head unit if you prefer under dash installation instead of trunk installation.
It provides a power connection and RCA connectors for the XM Commander.
This will provide you with the best possible audio quality, AND my unit does not have the hiss or whine that you describe.


----- Original Message -----
From: Donald Carlson (donnysan@bellsouth.net)
To: blitzsafe@blitzsafe.com (blitzsafe@blitzsafe.com)
Sent: Saturday, April 10, 2004 2:42 AM
Subject: Product that will work in my car
<!-- Converted from text/plain format -->I have a 2003 Mercury Marauder. Want I want to do is hook up an XM
Commander to work with the OEM CD changer. Your application guide says
"nothing yet." Do you have anything that will work with my car and allow me to use both the XMCDR and the OEM changer?

Thanks

Donald Carlson
Birmingham, AL
________________________

FORD/XM DMX CMD V.3B will work for you.

Thanks,
Christian Rodriguez
BlitzSafe Technical Support
techsupport@blitzsafe.com (techsupport@blitzsafe.com)
201-569-5000 800-597-SAFE
Fax: 201-569-5042






The Blitzsafe was ordered from http://www.logjamelectronics.com/
price was $107.45 shipped.

[hdwrench]

This is a tough problem to eliminate completely. Understand that the hiss was always present just not reproduced by our OEM speakers due to their limited range.
So, it is important that high quality line level converters are used when adding amplifiers. Assuming that they used high quality converters the next thing we have to look at is the gain settings on the amplifier. Sometimes the gain is set too high and will cause the hiss to be overly amplified along with the rest of the signal.
The easiest way to check this is to find some program material you are familiar with and sit in the vehicle and steadily increase the volume till you reach what you perceive to be the maximum volume level. This is level at which you start to hear slight distortion. At this point take note of the volume setting on the head unit, if it is not near maximum then the gain on the amplifier is adjusted to high and lowering it slightly will help alot. It may take some tweaking but this can be accomplished without too much trouble.

Now, understand that hiss is component related and whines, alternator noise, and any noise being reproduced the speakers that varies with rpms is related to faulty ground or poor shielding between signal cables and power/ground wires. That being said even if the problem is purely component related one thing I found that might help(it helped in my MM) is to ground the amplifer to the factory ground wire in the subwoofer harness.
Out of phase speakers will also cause the perception of more hiss due to slight delays in the signal reproduction. The test for this is easy, listening to the front speakers only adjust the balance to each side and determine if the low frequencies are more prominent when you are listening to the one channel or if they are more powerful when listening to both channels. If more powerful when listening to one channel the speakers are out of phase and correcting this will help. Repeat the procedure with the rear speakers.

Good luck and I hope this helps.
i hope they put in high quality line outs since i paid 25$ each for them. the system sounds pretty good but in order to not hear the hiss you have to listen to it at 50% or maybe even more volume...

i guess now i need a new head unit to get rid of the hiss, a new sub because the upraded speakers overpower the stock one, and a new amp for the sub(s). ...if id known it was gonna be this much of a PITA and $$, maybe i could have lived with crappy stock sound system.