nttung1711

Hi all,

I have a 1995 LS400 with Lexus premium sound system. Last weekend I did replace stock head unit by a modern HU Pioneer AVH-X5600BHS and metra dash kit. I just want new feature on head unit so I keep stock amplifier and using preout amp from HU to feed the amplifier. Everything is done on dashboard section, no need to do any work under passenger seat and you can revert back stock head unit at anytime.

Below are what I did prepared at first try:











Well, it works, but too much noise and unstable connection. I decided to use wire hardness plug. Since I can't find correct aftermarket plug that fit in these connector, I decided de-solder the connectors from the old radio with blacked-out LCD (I have two of them) to source the connector .

I did solder all preout cable and HU wire hardness to connectors that was previously being de-soldered.




I'm using glue gun for holding all wires together



Here is the result:




Yeah it's works as expected. The only issue is I got small crack sound in around 20ms after push play/pause. Does not got these sound when switching tracks.

As you can see, metra kit have difference ABS plastic color and does not fit perfectly. For $13, you got what you're paid for. I believe beat-sonic kit is much better but it cost $125

Special thanks to all you guys here, especially from two below threads:
https://www.clublexus.com/forums/ls4...b-working.html
https://www.clublexus.com/forums/ls4...-diagrams.html

The wiring diagram is here:




There is another issue I got after installed new HU. Please you guys tell me where it's coming from and how to fix it?
Please listen to this sound track: https://soundcloud.com/trieudoahong/ls400-howling
There more pressure I put on gas pedal, the more howling sound I got, even when the car is being parked. It's really annoying and I can't live with it

Thank you all.

msweber97

Usually if you have a whistling sound coming from your speakers when accelerating you have some type of grounding issue, try running a new ground and see if that helps

nttung1711

I have that sound even when I turn off the radio (switch the audio source to off). I'm not sure if it's coming from the speaker or not. I'll check it tomorrow.

By the way I pick the ground from factory plug? Is it not good?

lexmoose

Glad my thread on the Nak help you, is the Pioneer working the same way with the EQ to control the sub level?

The noise could be picked up by your RCA, you should try shielded or twisted pair cable. If you look at the factory cable they are shielded after the connector. In my case I've cut in 2 an old set of Streetwire RCA giving me the 4 RCA ends I needed.

Also the SCOSCHE dash kit is a much better finish than the Metra (Much closer to the factory finish and fit perfectly)

nttung1711

Yes you're right. That sound coming from the speaker. When the car is not working (key in ACC position, there are no whistling sound.

Yes the sub work the same way as described in your thread.
Anyway how to confirm the noise/interfere coming from bad ground or RCA plug? About the dash kit, color is not really important to me, but a big gap do .

lexmoose

Wrap the RCA wires (all 4) in alu foil and ground one end, if it help you found your problem.

nttung1711

I wish I heard about SCOSCHE before then. They're selling on ebay as low as $16.

PureDrifter

iTrader: (10)

the interference is very possibly due to the CAT5/6 ethernet wiring you used to make your RCA plugs. It's completely unsuited to being used to carrying analog audio signal. I suggest replacing it with some actual speaker wire, preferably something shielded.

Otherwise good work, I'm interested in seeing if you can get this all going to 100%. The amp turn on was a major issue by previous guys who've attempted this iirc.

nttung1711

First 3 pictures just my first try. I got too much noise with it so I rework all my cables. Next two pictures are what in my car now.

timmy0tool

iTrader: (7)

wow been waiting for someone to tackle this! good job on taking the initiative.

now to try and fix the interference. did the newly reworked cables still give interference? i would try and run an independent ground which is fairly easy to do.

PureDrifter

iTrader: (10)

Try using a shield like lchouinard mentioned.

I would also triple check EVERY SINGLE wiring connection. If the hissing/sound is only coming from one side you may have miswired that side.

nttung1711

I've fixed it last weekend. First I did try wrap wires but it's does not works. After that I found out issue came from rca plug itself. 3 plugs of and the hissing sound came right after 4th cable being plugged in. Here is the latest version:




The SCOSCHE kit is much better than the metra one.



Honestly, the sub is working but seem does not strong enough. Not sure because of the sub is aging now or limitation inside the factory amplifier.

lexmoose

Good job!

For the sub output, it could simply be the colder temperature making the sub more stiff reducing its output. I know that's the issue with mine, when parked in the office garage the sub come back to life.

PureDrifter

iTrader: (10)

If you want to make sure the sub is actually working set the audio fade in the headunit to max front and max one side, and play something bassy. You should be able to feel it on the rear deck.

GH5T

is the stock Pioneer wiring the same in the 95 and the 98-00?