[AzRiz]

Hi guys

I installed a JL XD600/6 amp over the weekend and used Technic's harness for the connection. The car is a 2010 E92 330d with HiFi system.

All went well, the amp works and the music plays well.

The only problem is that I hear the speakers make an instantaneous crackle noise when I start the engine. It doesn't stay, it just happens once quickly. The few times that it doesn't happen, my iDrive screen goes black for a few seconds and then re-appears. This has never happened before until after this install.

I have checked and re-checked my connections, the positive is connected to the top-left terminal on the battery's fuse box (because my fuse box didn't have any populated slots available) with a 50-amp inline fuse. The ground is connected to the ground connection where the factory harness also grounds to just above the factory amp location, and is connected flat and solid.

I am using the recommended settings on amp of: no gains on channels 1+2, 3+4 ... 9'o'clock gain on channels 5+6 ... 200Hz cutoffs on all channels with channels 1-4 being high-pass and 5+6 being low-pass. Switched to 4-channel amp mode. All speakers are the factory speakers.

Factors that I have concluded:

• Crackle only happens once upon engine start, no issues after this instance
• This issue has only started since the new amp has been installed
• Unplugging harness from new amp and plugging back into the factory amp stops the crackle issue
• Removing RCAs from JL amp removes the crackle noise (quite obvious, but worth a check)
• I'm quite certain the crackle comes from all 4 corners because removing the RCAs for front inputs makes the crackle audible from the rear speaker very obviously (wasn't so obvious before as the crackle noise from the front is louder and dominates)
• The green light on the amp flashes a few times upon its own startup and then stays on as a solid light after this (I hope that's normal?)

Any help or advice would be appreciated!

Thanks
Az

[Technic]

Your battery is about to go dead. The XD install just made it obvious and forceful.

Originally Posted by AzRiz

Hi guys

I installed a JL XD600/6 amp over the weekend and used Technic's harness for the connection. The car is a 2010 E92 330d with HiFi system.

All went well, the amp works and the music plays well.

The only problem is that I hear the speakers make an instantaneous crackle noise when I start the engine. It doesn't stay, it just happens once quickly. The few times that it doesn't happen, my iDrive screen goes black for a few seconds and then re-appears. This has never happened before until after this install.

I have checked and re-checked my connections, the positive is connected to the top-left terminal on the battery's fuse box (because my fuse box didn't have any populated slots available) with a 50-amp inline fuse. The ground is connected to the ground connection where the factory harness also grounds to just above the factory amp location, and is connected flat and solid.

I am using the recommended settings on amp of: no gains on channels 1+2, 3+4 ... 9'o'clock gain on channels 5+6 ... 200Hz cutoffs on all channels with channels 1-4 being high-pass and 5+6 being low-pass. Switched to 4-channel amp mode. All speakers are the factory speakers.

Factors that I have concluded:

• Crackle only happens once upon engine start, no issues after this instance
• This issue has only started since the new amp has been installed
• Unplugging harness from new amp and plugging back into the factory amp stops the crackle issue
• Removing RCAs from JL amp removes the crackle noise (quite obvious, but worth a check)
• I'm quite certain the crackle comes from all 4 corners because removing the RCAs for front inputs makes the crackle audible from the rear speaker very obviously (wasn't so obvious before as the crackle noise from the front is louder and dominates)
• The green light on the amp flashes a few times upon its own startup and then stays on as a solid light after this (I hope that's normal?)

Any help or advice would be appreciated!

Thanks
Az

[AzRiz]

Thanks for your input Technic. I had a bad feeling it was the battery because the car is over 4 years old now and probably on the factory battery. Also, I started the car many times on the day of the install without taking it on a good drive so maybe it became drained in an already-weak state. I drove it 30 miles to work today so will see how it behaves on the way home and again tomorrow morning.

Some fellow members said that it might be because of the choice of grounding location which probably isn't doing a good job, so I'll have a look into that also.

I guess with the car probably having the factory battery fitted (says BMW on it, by Banner) it's a good time to change it anyway, as preventative maintenance. I had best give them a call to ask the spec of the required battery.

[Technic]

The fact that the iDrive unit flickers upon start up means that something is not right with the battery itself. The alternator apparently is fine as the flickering is no longer present while the engine is running. By the way, the iDrive flickering is the cause of the speakers crackle -the XD amp turns on/off/on during the flickering.

The OEM ground point on the left fender is also fine, so only the positive battery post connection could be an issue. However, it will be an issue even if the engine is running if the connection is poor. But it is not.

Therefore we go back to a battery in its last days of service.

[AzRiz]

Originally Posted by Technic

The fact that the iDrive unit flickers upon start up means that something is not right with the battery itself. The alternator apparently is fine as the flickering is no longer present while the engine is running. By the way, the iDrive flickering is the cause of the speakers crackle -the XD amp turns on/off/on during the flickering.

The OEM ground point on the left fender is also fine, so only the positive battery post connection could be an issue. However, it will be an issue even if the engine is running if the connection is poor. But it is not.

Therefore we go back to a battery in its last days of service.

Makes total sense, thank you for your advice. It's strange how I haven't had any warnings come up about it, I would have hoped the system would tell me that the battery voltage is too low or something.

I had best get it changed soon, might even have to disconnect the amp and stick to the OEM Hifi amp until battery is changed as next Friday is the earliest chance that I have of getting it done.

Thanks again

[AzRiz]

Originally Posted by Technic

The fact that the iDrive unit flickers upon start up means that something is not right with the battery itself. The alternator apparently is fine as the flickering is no longer present while the engine is running. By the way, the iDrive flickering is the cause of the speakers crackle -the XD amp turns on/off/on during the flickering.

The OEM ground point on the left fender is also fine, so only the positive battery post connection could be an issue. However, it will be an issue even if the engine is running if the connection is poor. But it is not.

Therefore we go back to a battery in its last days of service.

Oh, but one thing to note, is that EITHER the screen goes black OR the speakers crackle. I don't think both issues have occurred at the same time. Just for the info of future readers, whether this info makes a difference to the solution or not.

[ctuna]

You could try putting full charge on it.

[AzRiz]

So the iDrive screen has stopped blacking out, but the speakers still crackle when engine is started. I'm guessing that the battery has regained enough health to not kill the screen but is still killing the JL amp when it is required to start the engine? Would I be right in thinking this Technic ?

I'll be doing a voltage check on the battery on Saturday and seeing if I can get some info on its health via the BMwhat setup that I ordered yesterday.

I'm booked in for a transmission service on the 6th of Feb and have told them that I'll probably be bringing a battery to be swapped over to as well.

[Technic]

Just to confirm: the 12V cable is connected directly to the battery + post, correct?

Originally Posted by AzRiz

So the iDrive screen has stopped blacking out, but the speakers still crackle when engine is started. I'm guessing that the battery has regained enough health to not kill the screen but is still killing the JL amp when it is required to start the engine? Would I be right in thinking this Technic ?

I'll be doing a voltage check on the battery on Saturday and seeing if I can get some info on its health via the BMwhat setup that I ordered yesterday.

I'm booked in for a transmission service on the 6th of Feb and have told them that I'll probably be bringing a battery to be swapped over to as well.

[AzRiz]

Originally Posted by Technic

Just to confirm: the 12V cable is connected directly to the battery + post, correct?

Yes it is connected to the battery's positive post on the top-left covered terminal.

[AzRiz]

Update:

Had the battery replaced and the problem is fixed. Thanks for the pointer, Technic

[Technic]

Originally Posted by AzRiz

Update:

Had the battery replaced and the problem is fixed. Thanks for the pointer, Technic

Glad that you are set... eventually that battery was going to leave you stranded.