HK rear speaker deck rattle?

codestar · 03-13-2020, 10:39 AM

Hi all,

I've noticed the speakers on the rear deck rattle quite a bit while playing mid-high volume music. I've spent time tuning the sound through the idrive and also turned off EQ through apple music so that it's neutral and controlled by the vehicle. I have a buddy with a 340i (also with the HK system) and his does the same.

Does anyone know the cause or potential fix? Cheaper vehicles I've owned in the past allowed much easier access to the rear speakers but our vehicles have a multitude of cladding both above and below the deck.

Thanks!

psyki · 03-13-2020, 03:03 PM

Quote:

Originally Posted by codestar

Hi all,

I've noticed the speakers on the rear deck rattle quite a bit while playing mid-high volume music. I've spent time tuning the sound through the idrive and also turned off EQ through apple music so that it's neutral and controlled by the vehicle. I have a buddy with a 340i (also with the HK system) and his does the same.

Does anyone know the cause or potential fix? Cheaper vehicles I've owned in the past allowed much easier access to the rear speakers but our vehicles have a multitude of cladding both above and below the deck.

Thanks!

I get this occasionally after I added a sub to my trunk, I haven't tried to address it yet but I read somewhere that the middle brake light can be one of the culprits.

Billfitz · 03-13-2020, 03:27 PM

Finding rattles is easy with the right tool, in this case a sine wave generator, which you can download to PCs and as apps for iPad/android. You need to get your device playing through the system via Bluetooth or the auxiliary input, then use the iDrive radio controls to pan to the rear speakers only. Sweep up through the frequencies starting at 100Hz. When you get to a frequency that's causing a sympathetic vibration it should be easy to feel where it's coming from. Testing for what's rattling in response to a sub you'd start at 100Hz and sweep down.

codestar · 03-13-2020, 03:51 PM

Quote:

Originally Posted by Billfitz

Finding rattles is easy with the right tool, in this case a sine wave generator, which you can download to PCs and as apps for iPad/android. You need to get your device playing through the system via Bluetooth or the auxiliary input, then use the iDrive radio controls to pan to the rear speakers only. Sweep up through the frequencies starting at 100Hz. When you get to a frequency that's causing a sympathetic vibration it should be easy to feel where it's coming from. Testing for what's rattling in response to a sub you'd start at 100Hz and sweep down.

Great idea! Embarrassing that I didn't think of that already being an electrical engineer

03-13-2020, 10:39 AM	#1
codestar Second Lieutenant 181 Rep 252 Posts Drives: 2017 Model S P100D Join Date: Feb 2019 Location: Vancouver iTrader: (0) Garage List 2014 435i xdrive [0.00]	HK rear speaker deck rattle? Hi all, I've noticed the speakers on the rear deck rattle quite a bit while playing mid-high volume music. I've spent time tuning the sound through the idrive and also turned off EQ through apple music so that it's neutral and controlled by the vehicle. I have a buddy with a 340i (also with the HK system) and his does the same. Does anyone know the cause or potential fix? Cheaper vehicles I've owned in the past allowed much easier access to the rear speakers but our vehicles have a multitude of cladding both above and below the deck. Thanks!
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03-13-2020, 03:27 PM	#3
Billfitz Lieutenant General 8256 Rep 16,101 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	Finding rattles is easy with the right tool, in this case a sine wave generator, which you can download to PCs and as apps for iPad/android. You need to get your device playing through the system via Bluetooth or the auxiliary input, then use the iDrive radio controls to pan to the rear speakers only. Sweep up through the frequencies starting at 100Hz. When you get to a frequency that's causing a sympathetic vibration it should be easy to feel where it's coming from. Testing for what's rattling in response to a sub you'd start at 100Hz and sweep down.
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