Audio system problems help! Replacement Speakers + New Amp (1 Viewer)

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Without the wiring diagrams for an '06, I'm no help. My 99 diagrams aren't necessarily identical so I don't want to guess and lead you astray.

The phantom ground wire (the one to avoid once you bypass the factory amp) on my 99 was brown. I'm guessing that's the loose lead you see in your pics.

My apologies, I always assume everyone on here that's not me is an expert and knows everything without further reference.

Here is the information I pulled from the tlcfaq.com site that I believe is for a 2004 that seemed to match well with what I had:
1981950
1981951
1981953


The second image references the black wire (SGND???) I was curious about in my previous post, which I was wondering if it's likely tied in to the four speaker signal positives from the HU with the RCAs, and that it's okay that it is just hanging out like that?

The third image references the brown (GND...system ground???) wire I was curious about in my previous post, which would likely be the same as what you said is the phantom ground wire to avoid during a bypass, so I am now assuming it's fine left as is?
 
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suprarx7nut

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My apologies, I always assume everyone on here that's not me is an expert and knows everything without further reference.

Here is the information I pulled from the tlcfaq.com site that I believe is for a 2004 that seemed to match well with what I had:
View attachment 1981950View attachment 1981951View attachment 1981953

The second image references the black wire (SGND???) I was curious about in my previous post, which I was wondering if it's likely tied in to the four speaker signal positives from the HU with the RCAs, and that it's okay that it is just hanging out like that?

The third image references the brown (GND...system ground???) wire I was curious about in my previous post, which would likely be the same as what you said is the phantom ground wire to avoid during a bypass, so I am now assuming it's fine left as is?
Haha, no worries.

Ok, yeah so here's the problem as I see it. That OEM head unit does not expect that "SGND" to feed out to a normal amp. It expects to go to the OEM amp, which has a separate, non-ground ground. That's not a typo. The OEM setup (in the 99 and apparently in your 06) expects to have differing grounds for the audio system and the rest of the car. It works fine with all OEM stuff, but is hell once you swap either the head unit or amp. You replaced the factory amp and now that weird audio-only ground is trying to play with the normal ground that the new alpine amp wants to use and they don't always agree. The difference in the two grounds causes the hiss and hum. If you put a voltmeter on the signal ground and the "normal ground" or any groundpoint on the car, I bet you'll see voltage. You need to get rid of that voltage.

I haven't tried to fix it in your situation so I can't offer much help, except to say it may involve circuit changes within the head unit and an electrical engineer/expert car audio guru or similar to ensure it's done right. I'd avoid at all costs any kind of ground loop isolator. Those are invariably horrible for audio quality. They're a band-aid for cancer. Somewhere an audio enthusiast will be rolling in their grave if you pair up an $800 DSP with a ground loop isolator, haha.

If I think of anything else I'll chime back in.
 
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Read this post, I think it revealed an issue with trying to use low level inputs on the factory radio harness. I think people had better success connecting an aftermarket amp through the aftermarket and then going to the speakers from the aftermarket amp. I think it has to do with behind the amp being the usable signal
 
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My apologies, I always assume everyone on here that's not me is an expert and knows everything without further reference.

Here is the information I pulled from the tlcfaq.com site that I believe is for a 2004 that seemed to match well with what I had:
View attachment 1981950View attachment 1981951View attachment 1981953

The second image references the black wire (SGND???) I was curious about in my previous post, which I was wondering if it's likely tied in to the four speaker signal positives from the HU with the RCAs, and that it's okay that it is just hanging out like that?

The third image references the brown (GND...system ground???) wire I was curious about in my previous post, which would likely be the same as what you said is the phantom ground wire to avoid during a bypass, so I am now assuming it's fine left as is?

The speaker input wires share a signal ground wire in the oem amplifier - not sure why they did not connect the black wire to the signal ground in the rca harness. It looks like the rca harness they installed has a ground lead for all four channels and should be hooked up to the signal ground. This may be causing your interference. Also, is the main unit grounded properly - how did they do it?
 
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The speaker input wires share a signal ground wire in the oem amplifier - not sure why they did not connect the black wire to the signal ground in the rca harness. It looks like the rca harness they installed has a ground lead for all four channels and should be hooked up to the signal ground. This may be causing your interference. Also, is the main unit grounded properly - how did they do it?
1558272733475-png.1980652

1982564


As far as I know, the black cable may be somehow tied in to the RCAs somehow before the strand left hanging over OR that strand needs to get tied in somewhere...can you see the black cable going in with the signal wires in my photo (the WHITE, RED, PINK, YELLOW wires feeding the RCAs and then there is the BLACK one running with them...I was unsure if the black strand hanging beyond the RCAs is what's left of that, or should be tied in elsewhere?

I'm assuming the BROWN cable with the arrows in my photo there is the system ground that is grounding the new system? As I mentioned before, all this audio stuff (and electrical in general) is fairly foreign to me, so I'm not sure what's properly needed in theses scenarios.
 
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Read this post, I think it revealed an issue with trying to use low level inputs on the factory radio harness. I think people had better success connecting an aftermarket amp through the aftermarket and then going to the speakers from the aftermarket amp. I think it has to do with behind the amp being the usable signal

I do wish they would've left the factory amp in place and bypassed for simplicity sake, especially now that there are several wires not being used that must serve some kind purpose. My MFD touch-screen beep is barely audible now, and I also can't figure out if I can address that somehow. Do I need to tie the GREEN "BEEP" wire in somewhere. I wonder if it's worth reinstalling the factory amp and bypassing?

Surely others have had good success with factory HU + New Speakers + New Amp though?
 
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suprarx7nut

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This may help to understand the grounds.

In aftermarket equipment, there is 1 ground. Ground is ground is ground.

In the Toyota system, there are 3 grounds. Not all the same.
1. Chassis ground
2. Head unit to amp ground
3. Speaker low level (signal) ground

This is the problem you're facing. The aftermarket amp can only work off one ground. No way around that I'm aware of.

The OEM head unit must use it's own speaker low level ground (which is NOT chassis ground) in your low level signal. No way around that.

You can't use that low-level ground to power your new amp.

Now we're stuck.

I think your best course might be to re-install the factory amp and use the high level outputs from that factory amp as inputs to your dsp amp. Hopefully the DSP amp is ok with that high level (-) signal coming out of the factory amp. We know it is NOT ok with the low level signal. This option would leave you with unused RCAs on that Metra harness and that's ok.

The shop would need to go back and re-connect all their bypass work, which is a bummer. When I did my bypass, I specifically avoided any cutting of wires and used a connector with the same terminal type to make it all reversible if needed.

**Edit: Oh, and that black with white wire appears to be the amp shield ground. It should be connected to the head unit SGRN or chassis ground. I'd try both and see if either magically solves the problem. I suspect it won't, but it's definitely worth a shot.
https://pdf.crutchfieldonline.com/ImageBank/v20170313094500/Manuals/120/120708113.PDF

I do wish they would've left the factory amp in place and bypassed for simplicity sake, especially now that there are several wires not being used that mus serve some kind purpose. My MFD touch-screen beep is barely audible now, and I also can't figure out if I can address that somehow. Do I need to tie the GREEN "BEEP" wire in somewhere. I wonder if it's worth reinstalling the factory amp and bypassing?

Surely others have had good success with factory HU + New Speakers + New Amp though?

Some people have said it worked, but I suspect those people all have some sort of ground loop isolator or are just OK with (or don't notice) the ground noise buzz and hum. For a high quality setup, I don't see how you could use the OEM Toyota head unit with a normal aftermarket amp. Same goes for the OEM amp with aftermarket head unit. The Toyota design its own little eco-system of grounds and I've never seen an aftermarket amp setup to handle that sort of integration.
 
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1558272733475-png.1980652

View attachment 1982564

As far as I know, the black cable may be somehow tied in to the RCAs somehow before the strand left hanging over OR that strand needs to get tied in somewhere...can you see the black cable going in with the signal wires in my photo (the WHITE, RED, PINK, YELLOW wires feeding the RCAs and then there is the BLACK one running with them...I was unsure if the black strand hanging beyond the RCAs is what's left of that, or should be tied in elsewhere?

I'm assuming the BROWN cable with the arrows in my photo there is the system ground that is grounding the new system? As I mentioned before, all this audio stuff (and electrical in general) is fairly foreign to me, so I'm not sure what's properly needed in theses scenarios.

Is the black signal ground from the factory harness connected to the harness on the alpine amplifier? If that is the case, then it should probably be connected to the black wire coming from the rca cables. That is...assuming that black wire is tied to all four positive channels.

Apparently, the oem amplifier shares a common signal ground between all four positive channels. I am not sure the Alpine is doing it the same way, but the installers basically copied the oem setup if the common speaker ground is connected to the main amp harness. I have a feeling that the positive channels have to have the separate ground at each rca input like most aftermarket amplifiers. So, if the black rca cable wire is connected to all four channels, then it will be a simple wire splice to test it out. If not, you can purchase four sets of rca cables and splice all negative wires into the common ground wire.

Are those dedicated rca cables for lo/hi input? If they just cut regular rca's and put heat shrink on, then that could be an issue. If you cut rca's, they have shielding material (fiber) that cannot be repaired. There are cables specialized for this (Amazon product). Additionally, all of your butt connections should have heat shrink to decrease interference, and the unused, cut wires coming from the head unit should have caps.
 
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Some people have said it worked, but I suspect those people all have some sort of ground loop isolator or are just OK with (or don't notice) the ground noise buzz and hum. For a high quality setup, I don't see how you could use the OEM Toyota head unit with a normal aftermarket amp. Same goes for the OEM amp with aftermarket head unit. The Toyota design its own little eco-system of grounds and I've never seen an aftermarket amp setup to handle that sort of integration.

I have been running my oem amp with the naviav head unit for quite some time. It actually sounds pretty good with my setup and the sound is super clean. That said, I am installing the 6-channel JL audio to run the system and do it some justice. The interesting thing is that all of the functions on my head unit work without the oem amp connected. It has been out of my LX for the last couple of weeks - the only issue is the antenna acting erratically. This makes sense because it is tied into the wiring.

All of the stuff I suggested in my previous post will be done on my install. I am curious to see what the heck is going on with the grounding setup.
 
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suprarx7nut

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I have been running my oem amp with the naviav head unit for quite some time. It actually sounds pretty good with my setup and the sound is super clean. That said, I am installing the 6-channel JL audio to run the system and do it some justice. The interesting thing is that all of the functions on my head unit work without the oem amp connected. It has been out of my LX for the last couple of weeks - the only issue is the antenna acting erratically. This makes sense because it is tied into the wiring.

All of the stuff I suggested in my previous post will be done on my install. I am curious to see what the heck is going on with the grounding setup.

Interesting, I wonder if that head unit mirrored the Toyota method and kept the frame of the head unit separate from the wired ground. Since it's a Toyota specific head unit, I suppose that's not inconceivable. I'd love to hear how it turns out with that new amp!
 
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So this is likely the one conversation where folks chiming in with Lexus May be confusing the solution. If the amps aren’t the same and radio manufacturers aren’t the same it’s likely a different scenario. That said let’s clarify...

The factory radio signal that is usable is out the factory amp which is why guys with actual 2003-2007 Landcruisers (not lx’s) have kept the factory amp in. That dsp and other factory integration units are expensive and worth it because in most circumstances they convert and sum low level factory inputs. In the case of the factory lc radio...those inputs are not usable separate from
The factory amp.

This thread got long. My frustration with the audio shop is that the OP is now Exhausting his hours chasing bad audio that he paid for and his stereo shop should have known when they heard his radio. The fact that they put 25watts per Chanel on two ohm components is the first head scratcher.

This is a prime problem with many audio shops they take your money and when they see your back it’s game over and now your problem.
 
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Is the black signal ground from the factory harness connected to the harness on the alpine amplifier? If that is the case, then it should probably be connected to the black wire coming from the rca cables. That is...assuming that black wire is tied to all four positive channels.

Apparently, the oem amplifier shares a common signal ground between all four positive channels. I am not sure the Alpine is doing it the same way, but the installers basically copied the oem setup if the common speaker ground is connected to the main amp harness. I have a feeling that the positive channels have to have the separate ground at each rca input like most aftermarket amplifiers. So, if the black rca cable wire is connected to all four channels, then it will be a simple wire splice to test it out. If not, you can purchase four sets of rca cables and splice all negative wires into the common ground wire.

Are those dedicated rca cables for lo/hi input?

I believe the black signal ground from the factory harness is connected to the signal positives.

I have no clue regarding what type of RCAs they are, that’s beyond my current knowledge level.

The factory radio signal that is usable is out the factory amp which is why guys with actual 2003-2007 Landcruisers (not lx’s) have kept the factory amp in. That dsp and other factory integration units are expensive and worth it because in most circumstances they convert and sum low level factory inputs. In the case of the factory lc radio...those inputs are not usable separate from the factory amp.

This thread got long. My frustration with the audio shop is that the OP is now Exhausting his hours chasing bad audio that he paid for and his stereo shop should have known when they heard his radio. The fact that they put 25watts per Chanel on two ohm components is the first head scratcher.

This is a prime problem with many audio shops they take your money and when they see your back it’s game over and now your problem.

I’m hearing that some of the issue may be due to trying to drive the amp from the HU low level outs? Reinstalling the OEM amp, and then using it somehow to a new amp may be the key it seems if I’m understanding this right. This may also explain why I have to turn the volume levels up much louder than prior to the amp install just to hear. We may also try a more powerful amp with a lower input sensitivity threshold if that makes sense.

Well gents (and ladies if applicable)...I certainly appreciate the time and help you’ve put into this. I was hoping for a single straightforward answer to get the existing components to work, but alas I’ll be heading back to the pros to hopefully get this resolved, because as Pucker5 has said I’ve spent more time than I’d prefer trying to solve this! But I really appreciate the advice from all.

I’ll try and update this thread once I get back to good/great to hopefully help others who may end up in such a situation.

ONE MORE QUESTION (make that two) though that I’m hoping someone may be able to provide some additional insight on:
  • I’ve noticed the volume of the MFD touchscreen beep being lower, coupled with an apparent slowing of the MFD to respond or taking several pushes of an onscreen button to function (seems slower and less responsive) in addition to what seems to be a slight decrease in the power of the A/C flow through the vents since this was installed...any idea if/how this could be related to the prior factory amp connections? They all function, but seem “off”.
  • AND FINALLY, probably completely unrelated, but when I got under the seat, I noticed this red cable in the photo below just under the front left corner of the passenger seat that was not plugged into anything and was just hanging out. This appears unrelated to all of the stereo wires, so was just curious if anyone knows what it is off the top of their head?
1983158
 
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So since the factory system was designed with an amp they made the factory radio with basically no level input that would Be completed with the amp. I don’t think any other low voltage “factory integration” amps will work either as it’s not a traditional low voltage signal. If you’re keeping the stock radio, you will probably get pretty solid results from reconnecting that factory amp and hook up a stronger 5 channel amp.
 
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This being a 2006 Toyota LC and assuming that the speaker level outputs on the OEM amp were used to feed the aftermarket amp, would it help to homerun a ground wire to a specific location to tie into the appropriate ground? Should the aftermarket amp connect to the Head unit to amp ground or the Speaker low level (signal) ground?
 
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My system is finally back and better than before. I went to another local audio shop to get their opinion because the first shop couldn't seem to give me a proper honest opinion that the sound just wasn't that great.

We opted for:
-Reinstall factory amp (per my request)
-Amplifier: JL Audio XD700/5v2 700W 5-Channel
-Subwoofer: JL Audio 8" MicroSub+
-Maintain Infinity Kappa speakers for now to see how they do with new setup.

Results:
-Sound volume is restored. I don't need the factory head unit cranked just to get normal sound.
-General sound is much better. I may consider different speakers in the future, but for now we're back to at least factory or better quality.
-Bass is plenty for my needs. Can get some bump if desired, but glad to have some depth back.
-MFD beep is back to audible (was very low volume after last install/removal of factory amp).
-MFD responsiveness seems normal, and before seemed slower and less responsive. Not sure how that could tie in at all, but it seemed different after previous install and back to normal with this install.

Thanks for all the help along the way and hopefully this can help others in the future.
 

TDJ

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Not to revive the old thread, but I am curious if you have any tips to get the 62ix to fit in the rear without cutting the door card?
 
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Not to revive the old thread, but I am curious if you have any tips to get the 62ix to fit in the rear without cutting the door card?
The internal mounting diameter is only 5.125. Make wood mounting plates the same size as the plastic ones with 5.25 inner diameter hole
1609092148306.jpeg
 

ramangain

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Not to revive the old thread, but I am curious if you have any tips to get the 62ix to fit in the rear without cutting the door card?
I do believe a 1/2" spacer, or maybe a 1" spacer (though doubt it), can be directly attached to the metal door skin at two points if oriented properly. Since the rears should act as rear fill only, the concern of not sealing the woofer cone front to back is minimal for sound quality purposes.

This is exactly what I did when replacing the rears on my 01LX with the ML audio (crap) speakers.
 
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Yeah mine were 1” and overkill but I did it because I used mdf and it was an easier cut. Knowing better now About Landcruiser doors and moisture I would use 1/2 to 3/4 and use a real wood. In the process of making new ones for my front doors. The rings front and back were the same. Also poly come divers would be my choice over any paper cone driver in these doors
 
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I installed my sound system back in March and I had the same dilemma on whether or not I should remove the factory radio. It was a huge headache because I realized that the factory radio, head unit, and navigation are all tied together in grounds. I ended up dropping the project and left factory radio in place and just used the wires exiting the factory radio into a LOC then to an aftermarket amp.

The only thing I can really say I can't stand is the hissing sound the speakers have when you turn on the head unit. Did you have this issue? or rather do you hear this now with your factory amp back in place? OP

Here was my original thread if you want to take a look.

2005 Toyota LC Audio System Upgrade
 

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