Stereo hiss after aftermarket install (1 Viewer)

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I recently installed an Alpine ilx-w650 in my 2000 Toyota land cruiser. I chose to not bypass my factory amp. I have a minor but annoying hissing noise that comes from the stereo which is more noticeable at low volume. I have read all over the forms but can't find a solution. It is not picking up anything from the alternator because even when the engine is shut off and I am just running off battery I still get this noise. I believe the solution is either finding new ground, RCA filter, or a ferrite core electric filter. I am not sure what will fix this and I am wondering if any of you guys have had this problem and have any advice. Thanks!
 
Bypass factory amp.

RCA filters don't work. I wasted money on that.
Good luck finding a new ground, since amp and head unit are part of same circuit.
If you are using factory amp the floating ground will cause the buzzing/hissing even when alternator is not running.
Never tried the electric filter though.
 
Probably not what you want to hear, but ....

We've cycled through a number of headunits (five I believe) in my son's 2000 TLC, all running through the factory amplifier. Most have worked just fine, except for one, that exhibited the constant "hiss" at a fixed volume. We fiddled with all sorts of "fixes" that didn't resolve the issue, and considered bypassing the amplifier, but ended up swapping out the headunit, which resolved our issue.
 
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If you are confident in your wiring connections and the ground, I'd rig up a temporary amp bypass and see if that does the trick.

I just installed this same H/U today in my daughter's Rav4 (no factory amps, no alpine power duo). The sound quality was excellent and it had no trouble sufficiently powering factory speakers. Crutchfield's wiring notes were a little off, but otherwise no complaints.

I also used a "MicroBypass Parking Brake Override Bypass for Alpine", a Raayoo camera, and a flushmount USB cable from Amazon. They also work well.
 
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Bypass factory amp.

RCA filters don't work. I wasted money on that.
Good luck finding a new ground, since amp and head unit are part of same circuit.
If you are using factory amp the floating ground will cause the buzzing/hissing even when alternator is not running.
Never tried the electric filter though.
Thanks for your response. I do have a question though, why do you think finding a new ground will be difficult? Is it not as simple as just finding metal to ground it to.
 
If you are confident in your wiring connections and the ground, I'd rig up a temporary amp bypass and see if that does the trick.

I just installed this same H/U today in my daughter's Rav4 (no factory amps, no alpine power duo). The sound quality was excellent and it had no trouble sufficiently powering factory speakers. Crutchfield's wiring notes were a little off, but otherwise no complaints.

I also used a "MicroBypass Parking Brake Override Bypass for Alpine", a Raayoo camera, and a flushmount USB cable from Amazon. They also work well.
I think I might end up just doing the bypass. I did not want to lose the sub but honestly it’s not like I’m loosing much with the stock sub. I also used that parking brake bypass saved me a hassle. Thanks for the input!
 
Probably not what you want to hear, but ....

We've cycled through a number of headunits (five I believe) in my son's 2000 TLC, all running through the factory amplifier. Most have worked just fine, except for one, that exhibited the constant "hiss" at a fixed volume. We fiddled with all sorts of "fixes" that didn't resolve the issue, and considered bypassing the amplifier, but ended up swapping out the headunit, which resolved our issue.
When you guys hookup your head units do you use the metra 70-8113 and the pre amp outputs? Thanks
 
If you are not going to use the factory amp and power the speakers through the OEM wiring via the power from the head unit, you'll need an amp bypass kit. This does not involve any RCA connections.
 
When you guys hookup your head units do you use the metra 70-8113 and the pre amp outputs? Thanks

Yes, we've generally used the Metra 70-8113 (or its equivalent) with the pre-amp outputs of the head unit.
 
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Have the same thing with my JoyingAuto 7" universal Android headunit. Looking through all the threads with stock amp, there are a couple guys that have been able to get around it while still using the factory amp, sourcing a new ground near the amp seems to be the one that sticks out in my mind.

But in my mind if you are going to the lengths of trying to do this and hunt down the ground loop hiss, why not just resolve it all together with a new amp that will produce more power for your better speakers? If you plan to keep everything else stock minus the headunit, then that is a different story. But for most of us the speakers are starting to give up the ghost and thus a full system replacement is warranted. Not to mention that the stock amp is rather anemic seeing as it is something like 170w total for all 5 channels (doors plus sub), if that is correct you are looking at a MAX RMS of about 34w per channel.
 
Yes, we've generally used the Metra 70-0113 (or its equivalent) with the pre-amp outputs of the head unit.
you mean the 70-8113 right?

For my 98 I used the 70-8112 which I believe covers to 99.
 
When I bypassed my amp, I just installed a cheapo $20 single channel sub amp to drive the factory sub and put it in the same spot under the passenger seat. It works quite well, I think. It just gives a little more bass depth to music, but not at all like a real sub setup of course.
 
For posterity, here's what's going on:

The factory amp and head unit has a completely independent ground loop from the vehicle ground. This is unusual in the audio world and almost all aftermarket amps and head units are NOT meant to work in that sort of system. The OEM head unit uses ONLY this isolated, floating ground and isolates itself from factory ground (AKA, the metal frame it mounts to). Almost ALL aftermarket head units from any manufacturer use the FRAME of the head unit to help ground itself. This is not a problem you can resolve easily. No ground loop isolator will work without also destroying audio quality. No filter will work without also destroying audio quality.

When you plug in an aftermarket head unit the head unit is trying to use frame ground on the negative low level signals. This signal then hits the amp, which is prepared for it's special isolated ground. There's now a voltage difference that is not related to the audio signal. This is your hiss.

There seem to be some years or some head units that are less affected, but nearly ALL 100 series will suffer from this.

When installing an aftermarket head unit, always count on bypassing the factory amp and count on losing the factory sub unless you add back a new amp.

More details:
 
Now that you have an aftermarket headunit just get an aftermarket amp. It’s more complicated on an lx since they have three way fronts. Since you have an lc and it’s 2 way component speaker in Front doors, coaxials in rear doors, and sub... a semi competent 5 channel will be a solid upgrade and eliminate the frustration of a hiss.
 
For posterity, here's what's going on:

The factory amp and head unit has a completely independent ground loop from the vehicle ground. This is unusual in the audio world and almost all aftermarket amps and head units are NOT meant to work in that sort of system. The OEM head unit uses ONLY this isolated, floating ground and isolates itself from factory ground (AKA, the metal frame it mounts to). Almost ALL aftermarket head units from any manufacturer use the FRAME of the head unit to help ground itself. This is not a problem you can resolve easily. No ground loop isolator will work without also destroying audio quality. No filter will work without also destroying audio quality.

When you plug in an aftermarket head unit the head unit is trying to use frame ground on the negative low level signals. This signal then hits the amp, which is prepared for it's special isolated ground. There's now a voltage difference that is not related to the audio signal. This is your hiss.

There seem to be some years or some head units that are less affected, but nearly ALL 100 series will suffer from this.

When installing an aftermarket head unit, always count on bypassing the factory amp and count on losing the factory sub unless you add back a new amp.

More details:


You are really putting out some high quality content. Thanks for taking the time to do so!
 
For what its worth on my last 2000 LC I tried the install myself with wire harness from crutchfield and got the hum. I tried several things but I suck with electrical so returned the head unit. I then had best buy install the same exact head unit and they fixed whatever hum there was, not sure exactly what he did.
 

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