[BMWTurbo]

Hey all

2016 m235i with Harmon Kardon system. Car is two months old completely stock.

Got into my car today like normal. No bass from radio at all. Tried iPhone, fm, and XM...nothing. Tried adjusting bass and treble... Nothing. Any thoughts or recommendations?

Thanks
Ryan

[BMWZ4]

Failed bass? Yep, oldie but a goodie. There's a thread on this. Always comes back.

[Grentz]

Let the car turn fully off and turn it back on again. It will come back.

Annoying but well documented that it happens. I have noticed it when it is really hot outside.

Note that just quickly turning the car on/off does not necessarily fix it. You need to let the iDrive/AMP go into sleep mode which takes a few minutes after the car is turned off.

[BMWTurbo]

Originally Posted by Grentz

Let the car turn fully off and turn it back on again. It will come back.

Annoying but well documented that it happens. I have noticed it when it is really hot outside.

Note that just quickly turning the car on/off does not necessarily fix it. You need to let the iDrive/AMP go into sleep mode which takes a few minutes after the car is turned off.

As you posted. A quick on off didn't fix it. Turned off again ate lunch and came back fifteen minutes later.... And it's on. This is terrible. The amp was off all night and it couldn't power up from a dead start from being off...

[LiuC]

I just had same thing happen to me no bass in car, turned it off and gonna wait right now.... not sure if it's gonna come back on...

[BMWZ4]

It'll come back on. Your dealer won't be able to fix this either. Best I can figure is that the amp "overheats" or clips and you lose the bass temporarily. You can't just turn the car off/on, it has to sit although I can't say how long.

I can, more often than not, recreate it by simply cranking the volume and pushing the bass toggle in idrive all the way to the top - playback in this manner for roughly an hour and voila!....bass shuts off.

[Hudmammas]

Had this problem many times including the logic 7 HK system from the 3 series . It's not due to overheat .! Even from cold start , the woofer was silence . Came back on after the car was switched off ( sleep mode ) anyway after a total rebuild of the audio system minus the headunit, this problem never ever came back.! Conclusion .......oem amplifier is the problem . Cya

[BMWZ4]

Originally Posted by Hudmammas

Had this problem many times including the logic 7 HK system from the 3 series . It's not due to overheat .! Even from cold start , the woofer was silence . Came back on after the car was switched off ( sleep mode ) anyway after a total rebuild of the audio system minus the headunit, this problem never ever came back.! Conclusion .......oem amplifier is the problem . Cya

OK overheat isn't the right word, but the amp gets overworked and the bass drops off. I can recreate it nearly every time. Telling the dealer about it will only get the amp replaced...and the cycle starts over again as I don't believe the amp has changed.

As for how long it takes to get the bass back...it definitely doesn't come back on after an on/off cycle. It needs to sit for at least a half hour...on my "tests" anyway

[Hudmammas]

Originally Posted by BMWZ4

OK overheat isn't the right word, but the amp gets overworked and the bass drops off. I can recreate it nearly every time. Telling the dealer about it will only get the amp replaced...and the cycle starts over again as I don't believe the amp has changed.

As for how long it takes to get the bass back...it definitely doesn't come back on after an on/off cycle. It needs to sit for at least a half hour...on my "tests" anyway

Hi . If in your case the amp gets overworked , it must get overheated. Is your cabin ventilation set to recycle .? If not , try to set it to constant air intake , and set the ventilation fan a little higher. That way your amp is constantly cooled . Just a friendly advice.cya

[BMWZ4]

Sorry, but has nothing to do with how you set the in-cabin ventilation. The amp, as you know is buried in the trunk & covered. Adjusting the ventilation won't keep the amp 'cool'. I guarantee you that if you max the bass settings in idrive & crank the volume for an extended period of time, the bass will eventually drop out - because the amp 'overheats' or however you want to refer to it. Only way to get it back is to shut off the car for at least an hour or more.

[Hudmammas]

Originally Posted by BMWZ4

Sorry, but has nothing to do with how you set the in-cabin ventilation. The amp, as you know is buried in the trunk & covered. Adjusting the ventilation won't keep the amp 'cool'. I guarantee you that if you max the bass settings in idrive & crank the volume for an extended period of time, the bass will eventually drop out - because the amp 'overheats' or however you want to refer to it. Only way to get it back is to shut off the car for at least an hour or more.

Hi again. The cabin ventilation air , exit the cabin through the one way " valve " placed 4 inch over the amp. It makes all the different in the world . Ps . My previous project with my 3 series , i had my audison AV 5.1 K placed in the same location where the factor amp is. And this amp is running pure class a to the tweeters , and it can reach operation temperature of 80 degree . Even though it was in this small space, it never got hot.!
Im not trying to be smart here, but only trying to help . Regards Hudmamma.

[daimeow]

can u reboot it?
1 hv the engine running or start the dash
2 press and hold the power button for 30 seconds (make sure music is still playing while u are holding the key and not the other way)
3 wait for reboot

[BMWZ4]

Originally Posted by Hudmammas

7
Hi again. The cabin ventilation air , exit the cabin through the one way " valve " placed 4 inch over the amp. It makes all the different in the world . Ps . My previous project with my 3 series , i had my audison AV 5.1 K placed in the same location where the factor amp is. And this amp is running pure class a to the tweeters , and it can reach operation temperature of 80 degree . Even though it was in this small space, it never got hot.!
Im not trying to be smart here, but only trying to help . Regards Hudmamma.

Spent the last 20 mins scanning through realoem and can't find any evidence of this exhaust air vent you're referring to. Since you seem to know all about the vent, perhaps you can forward me the realoem link? Is it part # 17 as depicted in the link below?

http://www.realoem.com/bmw/enUS/show...76#64229201647

[BMWZ4]

Originally Posted by daimeow

can u reboot it?
1 hv the engine running or start the dash
2 press and hold the power button for 30 seconds (make sure music is still playing while u are holding the key and not the other way)
3 wait for reboot

I tried that as well...didn't work for me though. I had to leave the car off for at least an hour.

[Hudmammas]

Originally Posted by BMWZ4

Spent the last 20 mins scanning through realoem and can't find any evidence of this exhaust air vent you're referring to. Since you seem to know all about the vent, perhaps you can forward me the realoem link? Is it part # 17 as depicted in the link below?

http://www.realoem.com/bmw/enUS/show...76#64229201647

4 sure . It's number 17 rear ventilation , and It's located above the amplifier . I will send you a picture tomorrow of the ventilation exit point placement , if you want.? Im having the car updated tomorrow so i have to mount the factory amp.
Ps the factory amp dont have any cooling fans ,like the logic 7 amplifier . So it's cooled via the passing ventilation air. Regards Hudmamma

[BMWZ4]

Originally Posted by Hudmammas

4 sure . It's number 17 rear ventilation , and It's located above the amplifier . I will send you a picture tomorrow of the ventilation exit point placement , if you want.? Im having the car updated tomorrow so i have to mount the factory amp.
Ps the factory amp dont have any cooling fans ,like the logic 7 amplifier . So it's cooled via the passing ventilation air. Regards Hudmamma

Yes please send me any info you have tomorrow. I stand corrected.

P.s. also, if you can advise exactly what settings I need to have on the front dash console that makes the air flow though that #17 vent please I would appreciate it. thx.

[Hudmammas]

Originally Posted by BMWZ4

Yes please send me any info you have tomorrow. I stand corrected.

P.s. also, if you can advise exactly what settings I need to have on the front dash console that makes the air flow though that #17 vent please I would appreciate it. thx.

Returning as promised. Here is the vent location. And the constant airflow settings.
The A and M led must be switched off to get the constant airflow into the cabin. And the auto button as well. You can boost the ventilation fan to maximum, just to see if your amp is having a thermal issue. Try max.! If that solve the problem, then turn it down to your preferences. One thing is for sure, the amp will be cooled down this way. Hope this will help.
Regards Hudmamma.

[BMWZ4]

Originally Posted by Hudmammas

Returning as promised. Here is the vent location. And the constant airflow settings.
The A and M led must be switched off to get the constant airflow into the cabin. And the auto button as well. You can boost the ventilation fan to maximum, just to see if your amp is having a thermal issue. Try max.! If that solve the problem, then turn it down to your preferences. One thing is for sure, the amp will be cooled down this way. Hope this will help.
Regards Hudmamma.

OK. Thanks for posting. As I said, I stand corrected and appreciate the feedback and follow up.

I learned something new today about my 235.

[Hudmammas]

Originally Posted by BMWZ4

OK. Thanks for posting. As I said, I stand corrected and appreciate the feedback and follow up.

I learned something new today about my 235.

On problem .

[BMWZ4]

Originally Posted by Hudmammas

On problem .

One other question of you don't mind? This may be a dumb question but is this an intake or exhaust vent?

[Hudmammas]

[QUOTE=BMWZ4;21374769]One other question of you don't mind? This may be a dumb question but is this an intake or exhaust vent?[/
Exhaust "exit" one way

[BMWZ4]

[QUOTE=Hudmammas]

Originally Posted by BMWZ4

One other question of you don't mind? This may be a dumb question but is this an intake or exhaust vent?[/
Exhaust "exit" one way

OK that's what I figured. thx.