Speaker whine (BM53)
 

When I bought my 3.0 E53 three months ago, the BM53 unit was faulty, only getting sound through one speaker, then it would cut out after about a minuet. After reading through numerous posts, sounds like a common problem. It had no speaker whine though.

I recently sent the BM53 unit out for repair, just received it back and re-fitted it, I'm now getting sound (music) through all speakers working like it should, but it seems to have developed another issue now-

High pitched whine which increases with the engine RPM's, happens with the head unit switched on or off (board monitor). If I disconnect the BM53 unit in the back, no more whine?

Not sure where to look first? Maybe something's not 100% with the BM53 repair, it only started since I refitted it after the repair.

Has anyone else experienced anything like this?

-BUMP-

Anyone experienced speaker whine with the stock stereo system?

I'm not sure of best approach in diagnosing this fault?

speaker whine is usually because something in the radio that was shielded has become unshielded. Speaker whine is typically caused by interference from the alternator which is why it increases and decreases depending on engine speed. I'd take it back to whoever did the recent work and let them know you didn't have THIS problem before they worked on it.

Thanks Fifty150hs for the reply, that pretty much explains it. The whine is driving me nuts!!

I've been working on cars for years, but I'm very much a novice when it comes to car audio, always stick with factory units.

The repair to the BM53 unit was carried out overseas- had to mail the unit, so wanted to be 100% sure that was the issue before retuning it.

I had a good look trough the whole car today, checked all the cables front to back (there is so much wiring in the back of these X5's!), checked the earths etc.

I removed the BM53 unit, and plugged in a single DIN aftermarket head unit via an adaptor at the BM53 harness connector- the whole system worked without issue- the whole factory harness/amp/speakers etc. No high pitched whine.

Plugged the BM53 back in, high pitch whine is back. There must be an earthing issue with the repair that was done?

I've emailed the repairer about returning under warranty to get sorted properly, so we'll see how we get on.

Hi, did you get the issue fixed? I have same issue with BM54 after repair.

After eliminating everything else in the system, it was the BM53.

I ended up sending it back to the repairer, they said they had opened it up and couldn't find anything that would be causing a whine. They did say it sometimes happens with the stage 2 repair, mine had the stage 1. Got it back with same issue.
I'm in New Zealand and it was repaired in the U.K. So wasn't a cheap exercise with postage backwards and forwards etc. Waste of time and money.

I ended up buying a known good unit off eBay U.S. for a decent price after keeping an eye out on there for a while.
Fitted it- works perfect now. I fitted an aux socket and couldn't be happier with it.

Wouldn't bother with a repair again.

How did you know it was a "known good unit" and can you advised me on what I should do? I also like you, had my BM54 repaired within the UK from a company called 'Cartronics' and I get the annoying whining sound even when the radio is turned off.

The BM53 was advertised as Fully working with all channels working without issue. Still a gamble as the seller can be B.S.ing, but it was cheap and worked out Ok.

The repair you had done will be guaranteed by that company, so if they are local you could returning with the complaint, let them know your not happy with it.
But to be honest, in my experience you might as well find a used good one. The repair involves some butchering to the PCB within the BM54 so not ideal really.

They are $$$ new, used they are still expensive for what they are, but you do see them come up on ebay cheap from time to time.
Its been a few years since I lived in the U.K. do you still have self service breakers yards like pick-a-part? might be worth keeping an eye out?

The good thing about the repair is that the sound quality is far superior than the stock version of the amp. If I just buy another unit online then i won't be happy with the sound quality. The alternator whine at the moment is drowned out by any music I play if the volume is high enough, but it is just annoying when there is no music playing.

Sorry to bring up this old thread. But does the OP still have the X5? Just want to know if your BM53 is alive and well and if it could read MP3 ID tags?

I have a 2003 4.6is with BM53 and recently installed an OEM 6 cd mp3 changer. The music plays fine but no song information is available.

I don't know if there's a firmware upgrade available to enable the id tag display or if we have to change to BM54?

Yes the used BM53 is alive and well! I wouldn’t bother trying to get one repaired in future.
No mine doesn’t support MP3 ID tags, I have a BMW 6 disc changer and I also fitted an AUX input.
The BM53 units had additional options through there life- you can identify this from the build date on the sticker- it’s the code that starts with KW, then month and year.

For AUX support you want one built after Sept 2002, which you should have.
For MP3 ID support you want one built after Sept 2005.

Stick with a BM53 if you’re in the US. BM54 is the same generation of units, but set up for different market- Euro frequencies etc. BM53 supports Sirius in the US too, whatever that is?

Thank you for the prompt reply, OP. That makes sense since my X5 is an US model! I'll stick with BM53 for sure.

I have installed the oem aux cable which works great. AUX shows up on the nav screen right after I installed the cable. This really helps a lot since I can plug in my iphone and basically get music and even navigation direction through the car's speakers.

I am using a motorola bluetooth speaker for my handsfree phone functions for now. It's a bit of a hassle but does work in a pinch.

By the way, do you know if it is possible to flush the firmware on older generation BM53 to enable the ID tag support ?

I've also been searching for ways to add tv tuner and rear view camera functionality, have you tried to install these 2 options?

Yes the AUX is great, don’t use the IPhone so much for music now though, as I find it annoying no control at head unit. Happy just using the CD changer. Never thought of using it for the Nav audio though- that’s a real good idea!

No firmware update doable, you have to buy the correct BM53 unit unfortunately.

To add a tv tuner you will have to mod your existing analogue tv unit with a digital receiver. U can get them from China cheap online but make sure it’s correct frequency for your area.
An input for reverse camera can be added at same time.
There is info on this out on the net, doable if your handy with electronics, or there are companies out there that you can send your analogue tv unit to for modification.

I gave up on the idea of getting the tv and factory nav working, not worth the $$$, and my X5 is a Japanese import so the Ariel receivers etc. are different to rest of the world.
I use my IPhone for Nav.

One of them Dynavin head units would do everything you asked about, but not sure about them units.

Not sure about going to Dynavin, but it's cheap enough if it doesn't work as promised, I can always revert back to oem setup.

There's this company in UK, carphonics, that modifies the BM53/54 units with some success. They can upgrade the amp to 50 watts per channel and add functionalities such as bluetooth handsfree, streaming, and flash firmware to support sirius radio and mp3 id tag.

It's not cheap, but having better music with the oem setup is certainly pretty attractive option.

I just don't know how good their work is. I've heard of people who upgraded their BM54 with much better sound, but suffers from alternator noises.

The only time I have noticed engine whine noise, is sometimes when the car also has an alpine amplifier upgrade.
The engine whine can happen with a stock Bm54/53 as well.

Alternator and battery can also have an influence. When the Bm54/53 is in stock form, it drains less power. With the amp kits, it uses more power.

Out of the 1000s Bm54/53 units I have done, I’ve had about 3 people with engine whine issues.
The original poster.
Someone who came back to me and we put original untouched unit in his car and still the same engine whine.
And a current one, who had the engine whine issue before sending his unit to me and still has it afterwards.

All 3 with X5s. So could be an x5, alpine amp, or some other electrical current issue somewhere else in the car.

Eventually all the Bm54/53s will be upgraded/repaired, as they all start losing channels, especially in X5s.

Any other questions do let me know.

Ps. Can upgrade the firmware on both Bm54 and bm53. Also upgrading Bluetooth ULF units to generation 13.