Speakers crackling after new HU install

[nc_co]

So i've done a dozen head unit installs in my life with no issues. This time I'm not sure what happened. I had the Audi Symphony radio and changed it for a cheap ebay Lanzar unit. The unit itself was pretty terrible, but the wiring part of it went flawlessly. I got tired of the cheap unit being unable to perform adequately (bluetooth, aux in, antenna reception was all horrible) so I purchased a Pioneer unit (Clicky click). It was all seemingly straight forward as usual, wired everything up, tested it, put it in the dash.
Unfortunately for me, I didn't realize when testing it, that if the volume is turned up past a certain level, the speakers start crackling . This wasn't an issue with the cheap Lanzar unit, and this time I even soldered the entire harness together using heat shrink and the whole nine yards. Where as last time, I didn't. Solder's were clean and I used a 60/40 Rosin Core solder.

My thoughts are:

a. The pioneer head unit is producing too much power in conjunction with the stock amp.?

b. Bad ground? (I only have one ground coming from the head unit, the one that was used with the old Lanzar. It was never relocated, just wires cut and resoldered from the old unit to the new one. No reason for it to not be okay.)

c. Speakers are too weak for the head unit?


If anyone could shed some light on the situation I would appreciate it!!!!

[texasboy21]

Not sure on the exact issue here, but I do know Audi advises against solder and recommends butt connectors for wiring repair.

[kmarei]

Does the new unit have 4volt pre outs?
Some amps distort with that much signal gain

[POPO]

I have a new pioneer app radio and I get the same thing when I have the volume up over 24 or 25. It sucks because I never had an issue with the stock unit. I even used the enfig harnesses so I know there is no grounding issues. Hopefully someone can chime in with a solution.

[nc_co]

texasboy21
Not sure on the exact issue here, but I do know Audi advises against solder and recommends butt connectors for wiring repair.

That's interesting to hear. Solder is a form of welding and is used in the worlds super-computers. I wonder why they would recommend NOT soldering. Hm. I think its a ploy by Audi. They want you to use the butt connectors so they eventually fall apart, forcing you to bring the car into your nearest local dealership for diagnosis and repair . Or not, idk. But thanks for the info!

kmarei
Does the new unit have 4volt pre outs?
Some amps distort with that much signal gain

This particular head unit has a max preout of 2.0V. Max power at 50w x 4.

POPO
I have a new pioneer app radio and I get the same thing when I have the volume up over 24 or 25. It sucks because I never had an issue with the stock unit. I even used the enfig harnesses so I know there is no grounding issues. Hopefully someone can chime in with a solution.

Likewise. Somewhere around there, depending on what song or station I'm listening to, it start to crackle. Sometimes its around 31, sometimes its around 25-26. I hope this gets figured out.

The weirdest thing is that sometimes I can turn it up to 40-45 with no problems. I'll then turn it down (before I switch to the next station) as I expect extreme crackliness to obliterate my ears. I switch to a different station and, yep, its crackling. Switch back to the station that was clean, and it still is. wtf?
Side note, Bluetooth music streaming also creates the crackle effect.. If you have any ideas, throw em at me!

[nc_co]

UPDATE: I have possibly solved my issue. In a nutshell, I was partially right about the speakers not handling the HU power.

I sat in the car bringing the stereo up to a slight crackling point. I went under the Audio menu and started messing around.

Bass Boost: OFF (Was enabled initially, probably the issue )
Loud: OFF
Bass: 0 or -1 (Was up at 3)
Equalizer: Custom: Made the frequencies flat and low.

Tested it with those settings and could not create the crackling effect! I then started raising the output of equalizer frequencies to a nice crisp, clear level. Audio quality is great with clear highs and clean lows (even turned up to a very loud 48). I'm just glad it wasn't a grounding or wiring issue. I only tested this in my car for 10 minutes at a standstill. I'll drive it today to see if I get the crackling while taking corners, pot holes, speed bumps, etc. Just to be sure there isn't a loose wire bouncing around in there. (I can't imagine it is)

[l0uietheking]

nice, i think i need to do this mine is kind of crackling as well

[nc_co]

Well even still, I can't just turn my radio up to wherever I want. It still seems to be crackling. Continuous power on this HU is 22w x 4, 14w x 4 (RMS), I can't imagine that's too much for the stock speakers?

[nc_co]

Can anyone chime in?

[K04-B6]

I had the same issue with mine, Swapped in the Pioneer 4500Bt Hu and speakers where crackling at high volume.. I thought the HU was to powerful for the stock amp so I intalled a seperate amp with a 10 inch sub and havent had the issue since. So the speakers are still runing off the stock amp and then I have a second amp for just the sub and never had an issue!

[Timtheguru]

Audi bose speakers are 2ohm, what ohm output does the HU have? If you're going directly to the amp (which outputs 2ohm) from the HU then you need to find out if that's 2ohms as well.

[james612]

make sure you dont have a bad wiring connection, ive had this happen before and 1 of the wires was not connected to the speaker correctly and was causing crackling. simple fix.

[nc_co]

I have the Audi Symphony system, I'm not sure if that translates to speaker type at all. But that being said, the HU puts out at 4 ohms. Though, the old aftermarket unit I had in previously was also a 4 ohm HU and I didn't have these problems. This new pioneer might be outputting more than the old one though. I also should note I have a sub in the trunk with its own amp. The sub operates perfectly at all levels. Heres the details for my HU.

Fading the speakers to the Front, it seems the crackling is non existent. With the volume unchanged, I fade back to center and the crackling appears in the rear doors.

My next thought is to bypass the stock amp for the rear speakers as it seems the HU is powering the front just fine, it should power the rears just fine as well. If needed, I could even disconnect the stock rear deck sub to keep from drawing too much power from the HU. Whether its loud enough for me or not, without the crackling I'll be happy enough until I get new component speakers and an amp to power them.

I'm searching right now, but does anyone know the best way to go about this without running new wires? Theoretically, I should be able to tap into/disconnect the speaker wire going from the HU to the stock Amp and run it directly to the speaker. Where and How to go about this are the questions. Does the wiring from the HU run under the carpet into the trunk, then back out from the trunk and through the doors?

[nc_co]

In my search I've learned a few things:

Both Bose and Non-Bose systems have an Amp.
Non-Bose Audi Symphony HU (4 ohms) has low output to the rears (because of the stock amp), but normal output to the front.
Non-Bose speakers are all 4 ohm with an amp powering the rear speakers.
Bose speakers are 2 ohm with an amp powering both front and rear speakers.

Which means:
The pioneer HU is not putting out low voltage to the rears, causing the amp to amplify the already powerful enough signal.
Cutting the HU->Amp rear speaker wires and Amp->speakers wires and mating them together (bypassing the amp) will produce the right impedance and hopefully enough power to the speakers.

To sum up:
If you get an aftermarket HU, it most likely will not have a lower output on the rear speakers. Head Units are designed to power all the speakers independently. Unfortunately, the A4 radio harness is not set up for that. The A4 radio harness attached to the car, is directly wired to the amp, and from the amp it goes to the rear speakers. So with an aftermarket HU, it takes what is already enough power, amplifies it to more than it needs, and creates a clipping effect of the sound waves as they grow beyond the speakers threshold. (crackling)

At the stock amp, I'm going to try to cut the speaker wires from the HU --> Amp (should be White, White, Violet, and Yellow) and mate them to the R/L speaker wires coming out of the amp running from Amp --> Speaker (should be Brown/Black, Red/Green, Brown/Red, Blue/Green)

We'll see what happens, wish me luck. Or stop me if I should be stopped!! lol

[Timtheguru]

Put a resistor or crossover on the rear speaker outputs from the HU to the amp that would reduce the voltage to the correct amount. Otherwise, do you have pre-outs on the HU? You could wire those to the rear input of the amp.

[nc_co]

my preouts go to my woofer amp so the harness is mated together as usual. I'd rather not rip the HU out of the dash again so I think I'm just going to do what I said above, bypass the amp. It's just not needed anymore.

[Timtheguru]

HU removal is easy, other thing you could do is T or Y off from the Pre-outs to the amp input.

[nc_co]

If I did that, the rear door speakers would be controlled by the HU subwoofer output controls, and I dont really want that. I'd like to be able to fade and balance appropriately. Thanks for the idea though!

[Timtheguru]

Not if you split before the subwoofer amp, I'm saying still at the head unit. :)

[nc_co]

Well I bypassed the amp and I'm still getting some crackling at high volumes. I don't know the stock symphony speaker ratings, but I'm just going to assume new speakers will be better either way. Heck, they're stock 11 year old speakers, time for an upgrade. I'll get speakers that I'm positive can handle the HU output. If replacing the speakers doesn't solve the issue, I'm going wire diving. It would have to be a bad ground or something if that were the case.

I'm looking at These or These. I'm leaning on the first set though. I've always enjoyed my experience with alpine stuff. I'm gonna order this in a few hours so if you have an opinion on either of these let me know!

[MikeDVNT]

Hey.

I know this is a really old thread, but I came across it while looking for answers to a bizarre riddle. And hopefully I can provide a solution to this problem, should anyone else come looking.

Here's the story.

I got an old A4 B5 avant, with an aftermarket head unit installed. I had no idea about the partial amping or any of that junk - I just went about my normal business of installing my own head unit and sub etc.

After installing the HU, I also had the same issue as the OP, where the front speakers - mainly the tweeters - were popping and crackling once I hit a certain volume. I assumed that I would have to go to the hassle of replacing the speakers etc, but in the process of investigating the issue, I noticed that the front and rear output was switched. I just used the ISO loom from my old car, and it would appear that Audis have the front and rear wired the other way round to my old car. So, I swapped the wires around in the ISO connector, and hey presto, I can crank my rig to almost uncomfortable volumes without and cracking or popping at all.

Even though my problem was solved, I still wanted to know why that had solved it, which is what lead me here. AFAIK, the partial amp system in my car means that the rear speaker outs get summed and then sent to the amp to power the factory sub and rear door speakers, and then the front outputs just go directly to the front speakers. However, the front and rear output from the head unit should be the same, so regardless of what happens after the HU output, surely the end result should be the same whether they are the right way around or not??? I feel I might be missing something here!!!

I know this is a pretty dead thread, so I'm not expecting any answers any time soon, but if anyone is able to clear this up for me, I'd really appreciate it.

Also, hopefully my solution will help anyone else in the same predicament. Check that front and rear are wired the right way around, if not, swap them over.

Cheers all.