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Master Shit Fixer
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Good luck. Let us know how it goes.
 

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Discussion Starter · #42 ·
OK. Yet another update!

I received my two new harness today. The Metra harness with RCAs was correct but the other Kenwood harness wasn't so I have to return that one and I already ordered the "right" one. That was a mistake on my part. Anyway, for the hell of it I used the existing Kenwood harness, removed the connections to the old "car harness" and hooked up the new Metra one. The good news is the volume issue and static *buzz" is fixed! I can now lower the volume to a low level and no static. The bad news is the popping when I switch the radio out of standby mode is back to being loud again. I have a video of this below. Now, this could totally be the temporary twisted connections I had setup to see if this was gonna work but I doubt it. Sounds like a ground...just don't know where to check.

New Metra harness installed with old/existing Kenwood connector - New Metra Harness.MOV
 

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Discussion Starter · #43 ·
So, wanted to throw this out there for comments. I found Stu's initial post from many years ago for setting up an aftermarket stereo (like mine). Its much more involved and includes purchasing 3 harnesses which plug into the IH1 and IH2 ports. Do I need to do that? It seems like I have the volume and sound right, just need to fix the popping.
 

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Master Shit Fixer
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Its much more involved and includes purchasing 3 harnesses which plug into the IH1 and IH2 ports. Do I need to do that?
IH1 is a 10-pin connector furthest from the firewall. IH1 carries the front speaker wires. IH2 carries the rear speaker wires
I'd say no, you don't need to do that in your case. It sounds like you've already got connections to the front and rear speakers.

I don't know what your "popping" sound is caused by. I'll watch your video here in a little while, when people aren't coming into my office every 5 minutes.
 

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Discussion Starter · #45 · (Edited)
Sounds good @bitshftr.

I did do further testing just now. I hooked up Red, yellow, black and blue from the head unit harness to the Metra and plugged the Metra into the car. I did not connect the Blue/White wire which is "Amp Turn On". Headunit turned on and started playing playing music, no pop, but also no sound at all out of the speakers. The moment I connected the blue/white wires together (Head Unit to Metra) the speakers popped and sound came out of the speakers. This to me, confirms its a problem with the amp.

The fact that the head unit turned on without issue leads me to believe the ground coming from the harness is good. Perhaps the amp ground itself is bad? I'm not sure, but I would have thought the amp ground would end up passing through to the head unit. Maybe all of this is turning on some light bulbs for you all.

By the way, the reason I tested this is I figured if the power for the head unit is coming from the amp, then maybe the head unit doesn't have to tell the amp to turn on. Apparently, that is not the case. I learned something.
 

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Master Shit Fixer
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The fact that the head unit turned on without issue leads me to believe the ground coming from the harness is good. Perhaps the amp ground itself is bad? I'm not sure, but I would have thought the amp ground would end up passing through to the head unit.
The amp ground does not pass through to the head unit. The amp's ground is the brown wire attached to pin 4 of the amp's primary connector. Make sure it is actually grounded (at location "IF"...which the full wiring manual will show the location of). It wouldn't hurt to run the Metra black wire (ground) to the exact same grounding point. It also wouldn't hurt, as a test, to patch the radio's ground lug to the body of the amp (I'd use alligator clips to do this temporarily). Then see if you still have pop.
 

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Discussion Starter · #47 ·
@bitshftr Will do.

So I really thought I had it figured out today. I had the new Metra harness and the correct 22 pin Kenwood harness connected together. I also found some videos and guidance that the factory amp is looking for 5 volts from the amp turn on wire and newer aftermarket units are pushing 12. Many people say this is the cause of the popping noise. So, I bought a voltage reducer (not expensive) and hooked that up. Still made the damn popping noise. The black / ground wire in the picture below, from the voltage reducer I connected to chassis ground. At this point, I "think" everything is OK with the head unit and my focus is shifting to the amp. Pictures of the harness below

Completed harness with voltage reducer on the blue/white amp turn on wire - New Harness with voltage reducer.HEIC
New Metra going into car connector - New Metra into car connector.HEIC

One probably stupid question. Looking at the second link there I found it odd that the yellow and red wires don't line up from the car connector to the Metra harness. Is that normal. It looks like the yellow Metra wire connects to car turquoise and the Metra red connects to the car brown. Maybe thats normal...?
 

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Discussion Starter · #48 · (Edited)
I just did a ton of searching though SupraForums, Youtube, and other sites to help me understand and fix this stupid popping noise. Many of these posts say that the popping is due to the headunit and amp coming on at the same time so there is a power surge. They solve this by installing a time delay OR a relay and switch. Most of these would delay the amp turning on after the headunit powers up. This actually makes sense. However, I believe I've actually tried this already. I hooked up my two harness but left the blue/white wires unhooked. I powered up the head unit and started a track on my CD and the headunit was playing but obviously no sound. I then touched the blue/white wires together (well after the headunit was on) and it still popped. I kinda think this rules out the fix that seemed to work for everyone else...?

UPDATE: I manually tested the delay and the voltage reducer. Even if I unplug the blue/white wire coming from the voltage reducer to the car harness (disconnects amp turn on), power up the headunit, select an input, see it play a CD and THEN connect those wires (simulating a delay), it still pops. OK....I'm going to the amp now.
 

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1987 MA71 R154 Pearl White, Blue Velour
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Man you are being thorough! (y) I wish I had something to add but I'm fresh out of ideas other than seeing if there is a way to bypass the factory amp.
 

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Discussion Starter · #50 ·
@Dumeinao Thanks man. I really appreciate all the help that you and @bitshftr have given me. I'm fairly positive that this thread as gone on long enough that nobody is looking anymore but regardless, my battle continues.

Today I got at the amp and took it out. If I disconnect the speaker out connector, then turn on the head unit and select an audio source I (of course) don't get the pop because I'm not getting anything with it unplugged. So, if I just had a switch to enable all the speaker outs AFTER the amp turned on I'd be all set but...that solution....is absolutely ridiculous. I checked the power and ground coming into the amp and they seem to be OK so I'm stuck again. I'm at the point where a replacement 5 channel amp (with cross over for the woofer) may be in my future.

If you want a laugh, feel free to watch my video. I talked about how there was no pop after plugging in the speaker harness like that was a freakin surprise. At that point the amp was already on so of course there wouldn't be a pop. lol

 

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1987 MA71 R154 Pearl White, Blue Velour
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Also too, refer back to my 87 design for ideas. Basically my rear 2 channels are sub only. 10" Punch. The alpine 4 channel amp provides the power, with the rear being set to low pass and adjusted. I also have a bass knob that I can use to fine tune a song if its subbing too much.

The front channels are also hi passed on the amp, with the 2 piece Fosgates in the doors also having their own crossover.

Other than that, the Alpine also handles the step down of the speaker power coming from the factory head unit.

If you can make THAT work, you're golden..

Amp https://www.amazon.com/gp/product/B00BLQA9BM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Knob: https://www.amazon.com/gp/product/B07484YZZG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Two subs: https://www.amazon.com/gp/product/B004UFHX4W/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Some of these: https://www.amazon.com/gp/product/B00G352P2C/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Doors: https://www.amazon.com/gp/product/B00WTMYLBG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1


Basically Head unit all 4 channels go to Alipine. At that point I ran all new wires back up front from the amp to connect with factory speaker wiring.

I extended the rear speaker wiring from the pods to where I could plug them into my sub box. I thought I might need heavier gauge wire to the subs, but honestly it sounds just fine with the original wires and less trouble.

Let me know what you find.
 

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Discussion Starter · #52 ·
My plan as of a few minutes ago was to "Office Space" the factory amp and route the 4 speakers from the back of the head unit, out the harness wires (speaker level) and directly into the existing speaker harnesses. Basically removing the factory amp IH1 and IH2 connectors completely. Then I was going to get a small amp and run RCA from the head unit down to the amp and run the factory sub off of that. That was the idea.

Your setup sounds awesome. Really nice and I like the bass knob idea. Now that you've given me a suggestion, I have questions:

So I was already thinking of buying an amp and the Alpine one you mentioned here looks perfect. Where does the knob connect to the amp? I didn't see an input in the pictures.

Did you remove your factory rear speakers completely? If so, your basically running bass out of the subs and the "hi's" in the front, yes? Sorry if I butchered that.

Did you do a custom install of the two sub woofers in the trunk? I have a targa so I want to make sure I have room for that.

Lastly, did you use the existing wire harnesses (IH1, IH2, IH3 and R6) with your Alpine amp? I'm assuming that comes with a wire harness of its own that you just had to modify to fit with what pops out of the factory amp area? Hopefully that made sense...
 

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1987 MA71 R154 Pearl White, Blue Velour
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Ok, so...

First off, MK3, so i don't have an IH1, 2 or 3 to the best of my knowledge. I basically used the electrical manual for the 87T that I have to identify all the speaker wires. Keep in mind, in 87, the amp was built into the head unit.

The bass knob just has a plug-in to the amp. Basically you use minimal adjustment to keep some songs from drowning in bass, or to pump up the bass a bit on other songs. I used velcro and just stuck it to my trans tunnel, right in front of my seat to my right. I put it down low a bit so its really inconspicuous.

The factory rear speaker boxes are there, but the speakers themselves are out. The connector for mine is on the outside of the box, so I disconnected it and spliced wires to run to the subs.

I don't have a targa so space wasn't an issue for me. I simply bought a dual ported 10" sub box from the same tint/stereo shop that did my X5.

In your case, you could probably have a simple lower profile box built that would accommodate the roof. You might possibly have 2 separate lower profile places to put subs. Heck, 8" might work for you as well. In any event, even in the 80s we recognized that nobody was in our rear seats 99% of the time listening to the radio, so a sub rear and mid high front makes much more sense.

Honestly mine sounds very good considering its all coming off a 30+ year head unit and also running Bluetooth through RF to play music.
 

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1987 MA71 R154 Pearl White, Blue Velour
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Also, I did all my work last summer during lockdowns. My overriding focus was keeping the car as stock as possible, and spending only what was necessary for a good outcome. I could easily have put a top of the line unit it and spent quite a bit.

That said, I really tried hard to hide everything. I didn't cut door panels, and only made a custom bracket to mount the tweeters up in the triangle of the mirrors (where modern cars have them).

I then realized this is just a fun car and I don't need my trunk for anything. At that point I abandoned trying to make the non standard rear speaker boxes sound good and just went late 80s old school and got a ported box that would fit under my cargo cover.

The biggest challenge for me was I used 91-92 6.5 speaker mounts in the doors that made it difficult to hide them behind the 87 door grills.

The 91-92 has larger and lower grills, so I may be missing some sound, but I wasn't going to cut door panels in 2021.

(y) :D
 

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Discussion Starter · #55 ·
Ah yes. Forgot you had an MK3....my bad.

All great info and thank you. I think I'm going to march forward with my plan and see how it turns out. I really like the Alpine amp you have and the bass knob so once the harness's arrive I'll purchase the amp and get to work.

I do wish I was able to figure out what the issue I have is. The only thing I didn't try is purchasing ground loop isolators. Oh well. New equipment it is!
 

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Discussion Starter · #56 ·
OK, I have new harness coming in today and my plan is to bypass the amp completely right now which means I'm also losing the subwoofer temporarily. Most of the wiring to do this makes sense as I no longer will be shooting audio down to the amp area. That being said, where am I to get power for the head unit as this initially came through the amp and the R6 connector? I suppose I could leave the amp there and just is it for HU power but that seems a bit silly. Are any of the other wires in the IH1 or IH2 harness hot?
 

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Master Shit Fixer
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where am I to get power for the head unit as this initially came through the amp and the R6 connector? I suppose I could leave the amp there and just is it for HU power but that seems a bit silly. Are any of the other wires in the IH1 or IH2 harness hot?
Yes, gray wire, pin #3 at the amp...this is accessory power (red radio wire). Extend it up to the radio cave. Also, pins #6 and #2 on the same connector (both are blue/yellow wires) are battery power (yellow radio wire). Use these wires from the harness side, and you can still remove the amp completely.
 

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My plan as of a few minutes ago was to "Office Space" the factory amp...
I get that reference! Video it if you do. But, you'll have to add the appropriate background music to the video ("Still" by the Geto Boys).
 

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1987 MA71 R154 Pearl White, Blue Velour
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@TTSupra You're welcome. Also, don't feel bad about being defeated by OEM audio. I messed around a bunch with stereos and stuff when I was a kid. I do network engineering now. In my career I have learned to embrace greenfield clean installs, vs trying to rework or remanufacture either OEM or Previous Owner Modded OEM systems.

Sometimes the best answer is to start from scratch. No harm in that :D
 

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Discussion Starter · #60 ·
@Dumeinao @bitshftr Thank you both so much for your countless responses to be never ending questions.

So, my plan worked! I used the new IH2 and IH3 female harnesses combined with the new Kenwood and Metra harness to get everything working. At this point I'm still using the factory amp for power to the HU and...I'm still using it to power the subwoofer and feeding it from the RCAs on the Metra. The "pop" when the head unit turns on is almost inaudible through the subwoofer so I'm good with that. Also, the sound quality coming from the speaker level input on the HU is better than what I was getting out of the amp so all good there too.

@Dumeinao my next step is to replace the factory amp completely and then run power as you recommended. I'll save that for another day...but not too far out. Also, I'm in IT as well so I totally get where you're coming from. Never a bad thing to start over and do it right.
 
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