Audio options help

pnickisson · 06-20-2009, 05:14 PM

Hi all.

I have the BM54 radio amp. Noticed that i'm not getting any sound out of the passenger side rear speakers (but am getting it everywhere else). Having tested the speakers are OK, and the wiring is OK then it must be the BM54 amp that has become faulty on that circuit.

bearing in mind that I wish to retain the head unit as its radio/sat nav/bluetooth/computer/TV monitor + CD Changer and also want to put in a sub in the ski pass would you be able to suggest my best option.

As I see it from my limited knowledge of this area they are as follows

a) get a new BM54 amp (not cheap) and then cut into the rear speaker wires and wire it to a new amp that powers the new sub.

b)get a new amp and sub and run the sub from the signal on the rear right (would the one circuit be powerfull enough to power the sub) and this option still leaves me with no sound on the left.

c)as above but also take the signal from right rears be able to power the left rears and new sub as well????

d) get a new 5 channel amp and run all signals from new amp to all the speakers both front and rear and the new sub (but would this mean I lose radio mute facilities when answering phone) etc.

Thanks for any help offered as this is a totally new area to me and so all help and adice is gratefully appreciated.

325CI2004 · 06-20-2009, 06:06 PM

heres what i would do.

1. Buy a bm54 amp from the classifieds. Buy amp and sub for the trunk.

or.

2. Buy a 5 channel amp, new interior speakers, and a low wattage sub/box.

If you run a 5 channel amp to stock speakers, chances are they will blow rather quickly.

pnickisson · 06-21-2009, 05:29 PM

Thanks for advice.

Prefer the sound of the 5 channel amp option (as it saves me £300 on BM54 radio amp).

Only thing not sure about would be which wires are which on the connector to the BM54 amp. I know which are the output speaker wires but not sure which are the input speaker wires.

and does the muting of the phone etc still occur if I get a 5 channel amp.

packrat555 · 06-21-2009, 05:39 PM

it seems unlikely that the amp would loose only the right rear. usually when amps fail it is the final output stage and fuses blow.

are you sure you have a good right rear signal going into the amp from the head unit?

pnickisson · 06-22-2009, 06:04 PM

I have checked the headunit and the connectors are firmly located in their connecting holders. What I cant seem to workout though is which wires are the input signal to the amplifier from the headunit.

I have found 2 diagrams of the pinout of the amplifier

here is a wiring diagram for the BM54 - its the diagram titled '2002 and newer Radio Module - w/Nav'.

http://www.xoutpost.com/articles/x5/...formation.html

here is another diagram

http://www.bmwfaq.com/f17/conector-40-pins-bm54-246561/

Is it apparent to you?

06-20-2009, 05:14 PM	#1
pnickisson Registered User Join Date: Oct 2007 Location: Manchester Posts: 13 My Ride: 330i 100k View My Garage	Audio options help Hi all. I have the BM54 radio amp. Noticed that i'm not getting any sound out of the passenger side rear speakers (but am getting it everywhere else). Having tested the speakers are OK, and the wiring is OK then it must be the BM54 amp that has become faulty on that circuit. bearing in mind that I wish to retain the head unit as its radio/sat nav/bluetooth/computer/TV monitor + CD Changer and also want to put in a sub in the ski pass would you be able to suggest my best option. As I see it from my limited knowledge of this area they are as follows a) get a new BM54 amp (not cheap) and then cut into the rear speaker wires and wire it to a new amp that powers the new sub. b)get a new amp and sub and run the sub from the signal on the rear right (would the one circuit be powerfull enough to power the sub) and this option still leaves me with no sound on the left. c)as above but also take the signal from right rears be able to power the left rears and new sub as well???? d) get a new 5 channel amp and run all signals from new amp to all the speakers both front and rear and the new sub (but would this mean I lose radio mute facilities when answering phone) etc. Thanks for any help offered as this is a totally new area to me and so all help and adice is gratefully appreciated.

06-20-2009, 06:06 PM	#2
325CI2004 Registered User Join Date: Aug 2006 Location: San Diego, CA Posts: 851 My Ride: 09 335I View My Garage	heres what i would do. 1. Buy a bm54 amp from the classifieds. Buy amp and sub for the trunk. or. 2. Buy a 5 channel amp, new interior speakers, and a low wattage sub/box. If you run a 5 channel amp to stock speakers, chances are they will blow rather quickly. __________________ 09 E90 335i Alpine White/Chestnut Brown

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread:

06-21-2009, 05:29 PM	#3
pnickisson Registered User Join Date: Oct 2007 Location: Manchester Posts: 13 My Ride: 330i 100k View My Garage	Thanks for advice. Prefer the sound of the 5 channel amp option (as it saves me £300 on BM54 radio amp). Only thing not sure about would be which wires are which on the connector to the BM54 amp. I know which are the output speaker wires but not sure which are the input speaker wires. and does the muting of the phone etc still occur if I get a 5 channel amp.

06-21-2009, 05:39 PM	#4
packrat555 Registered User Join Date: May 2009 Location: Texas Posts: 496 My Ride: 2001 325i View My Garage	it seems unlikely that the amp would loose only the right rear. usually when amps fail it is the final output stage and fuses blow. are you sure you have a good right rear signal going into the amp from the head unit?

06-22-2009, 06:04 PM	#5
pnickisson Registered User Join Date: Oct 2007 Location: Manchester Posts: 13 My Ride: 330i 100k View My Garage	I have checked the headunit and the connectors are firmly located in their connecting holders. What I cant seem to workout though is which wires are the input signal to the amplifier from the headunit. I have found 2 diagrams of the pinout of the amplifier here is a wiring diagram for the BM54 - its the diagram titled '2002 and newer Radio Module - w/Nav'. http://www.xoutpost.com/articles/x5/...formation.html here is another diagram http://www.bmwfaq.com/f17/conector-40-pins-bm54-246561/ Is it apparent to you?