[- maciek -]

I've owned my E39 M5 for about 5 months now. I am only now starting to upgrade the HiFi. I want to purchase the Umno-Tech USB MP3 interface (www.umno-tech.com). I was asked if my current radio has DSP. I also purchased a used BM54 radio from year 2009 but haven't installed it yet. and here are the questions:

- why does it matter, when ordering the USB MP3 interface, if my radio has DSP or not? the interface for the non-DSP radios is much cheaper

- is DSP only an equalizer?

- will my BM54 radio which was produced in 2009 also have DSP?

- what is the difference between the BM24 and the BM54 and BM54 back?

I tried to search but didn#t find enough info to answer my qiestions

I appreciate your feedback

 

[matt13]

The problem is "DSP" can refer to two different things: 1) the DSP equalizer you can access via the in-car display and 2) the way the car transmits the audio signal (digital vs analog). It matters if you have the second DSP, because you'll need an analog->digital (A/D) converter for almost all aftermarket devices. You can check to see if you have DSP by seeing if there's a coax cable running to your CD changer in the trunk. For example, my car has the DSP equalizer but not the "DSP" digital signal in the trunk.

Check out these install instructions for some photos:

http://www.bavariansoundwerks.com/p...tion_Kit_Instructions_-_DICE_E39_With_DSP.pdf

http://www.bavariansoundwerks.com/p...ation_Kit_Instructions_-_DICE_E39_Non_DSP.pdf

 

[RichardP]

What matt13 is saying is broadly correct.

If you have an E39 with DSP that was built approximately before September 2002 then it will very probably have a digital coaxial audio connection to the CD Changer. If you have a car without DSP, or with DSP and made after September 2002 then it will have an analogue 6 pin audio connector.

If you have the digital audio CD Changer input then you will require an Analogue to Digital converter to connect up almost any of the third party USB/iPod interfaces as they replace the CD Changer and use the analogue 6 pin input.

Regarding the BM54 radio, this may be easy to install, it may not! Again it depends on the build date of your car. If you already have a BM24 radio then you will require a round pin to flat pin harness adapter and a DIN to FAKRA antenna adapter. If you also have DSP then you may require the system re-coding, otherwise the radio will not send the correct signals to the DSP amp and you may find that the audio cuts out after 1 minute.

The main differences between the BM24 and BM54 are external and relate to the connectors as described above, their functionality is very similar. I'm not sure what you are refering to by 'BM54 back' but there is a special version of the BM54 that has the round pin connector, part number 6933455.

 

[- maciek -]

Regarding the BM54 radio, this may be easy to install, it may not! Again it depends on the build date of your car. If you already have a BM24 radio then you will require a round pin to flat pin harness adapter and a DIN to FAKRA antenna adapter. If you also have DSP then you may require the system re-coding, otherwise the radio will not send the correct signals to the DSP amp and you may find that the audio cuts out after 1 minute.

The main differences between the BM24 and BM54 are external and relate to the connectors as described above, their functionality is very similar. I'm not sure what you are refering to by 'BM54 back' but there is a special version of the BM54 that has the round pin connector, part number 6933455.

I was told there is no such thing as re-coding of the BM54. can you double check this please?

also, I heard that the main reason why people change from the BM24 to the BM54 is becuase the BM24 break down often. Apparently they are not made well. Is this correct?

 

[sunny///M5]

What matt13 is saying is broadly correct.

If you have an E39 with DSP that was built approximately before September 2002 then it will very probably have a digital coaxial audio connection to the CD Changer. If you have a car without DSP, or with DSP and made after September 2002 then it will have an analogue 6 pin audio connector.

If you have the digital audio CD Changer input then you will require an Analogue to Digital converter to connect up almost any of the third party USB/iPod interfaces as they replace the CD Changer and use the analogue 6 pin input.

Regarding the BM54 radio, this may be easy to install, it may not! Again it depends on the build date of your car. If you already have a BM24 radio then you will require a round pin to flat pin harness adapter and a DIN to FAKRA antenna adapter. If you also have DSP then you may require the system re-coding, otherwise the radio will not send the correct signals to the DSP amp and you may find that the audio cuts out after 1 minute.

The main differences between the BM24 and BM54 are external and relate to the connectors as described above, their functionality is very similar. I'm not sure what you are refering to by 'BM54 back' but there is a special version of the BM54 that has the round pin connector, part number 6933455.

My car is build in 05/2002 an has no coax cable.

As far as I know, the coax cable was mounted together with BM24.
With BM54 (old and new generation) the cd changer is not connected with coax.

 

[RichardP]

I was told there is no such thing as re-coding of the BM54. can you double check this please?

This is why I said 'System' and 'may', not 'radio' and 'will'!

With SOME systems the system needs to be recoded, with others it does not. This may be because some DSP amps needs to know what radio module is installed or it may be something else. As with many BMW components there are different manufacturers of the DSP amps, that although they look similar and have the same user functionality, can be significantly different with respect to their lower level interface characteristics.

also, I heard that the main reason why people change from the BM24 to the BM54 is because the BM24 break down often. Apparently they are not made well. Is this correct?

It is true that there are a lot of problems with the BM24 and dry joints. What is not so clear cut is if the BM54 is immune to this problem or just that the problem has not manifested itself yet as all BM54's are newer than all BM24's. Time will tell. What is should be true is that a BM54 made in 2009 should be more reliable than any BM24.

 

[RichardP]

My car is build in 05/2002 an has no coax cable.

That's about the oldest car with a BM54 I've heard of, but I've heard or newer cars with the BM24!

This is why I said 'approximately', there appears to be no specific cut off date. It may be that all M5's have the same cut off date as they were built in the same plant, but other E39's built at other plants have different cut off dates that relate to when that facility used their allocation of BM24's.

The situation is different when the vehicle does not have Nav, some cars made in 2005 use the digital coaxial CD Changer audio.

As far as I know, the coax cable was mounted together with BM24.
With BM54 (old and new generation) the cd changer is not connected with coax.

This I also believe to be the case.

In some cars, X5's in particular, BOTH coaxial and 6 pin connectors are connected. Usually only the 6 pin analogue connector is actually used, it's as though the people on the production line were not clear what should be installed so did both just to make sure!

 

[sunny///M5]

That's about the oldest car with a BM54 I've heard of, but I've heard or newer cars with the BM24!

In Europe I think BM54 is mounted from 2001 - and there are many version out there:
- BM54 old generation from 09/2000 up to 09/2001: round connection pins
- BM54 new generation up to 09/2001: no AUX IN possible without opening the unit
- BM54 new generation 09/2001 up to 09/2002: AUX IN possible with 300kOHm bridge in the cable
- BM54 new generation 09/2002 up to 09/2005: including AUX IN, no MP3 Tags on monitor possible
- BM54 new generation from 09/2005: including AUX IN, MP3 tags are shown on monitor (if you have MP3 changer)

This is why I said 'approximately', there appears to be no specific cut off date. It may be that all M5's have the same cut off date as they were built in the same plant, but other E39's built at other plants have different cut off dates that relate to when that facility used their allocation of BM24's.

The situation is different when the vehicle does not have Nav, some cars made in 2005 use the digital coaxial CD Changer audio.

Of course, each plant fitted first the older generations

This I also believe to be the case.

In some cars, X5's in particular, BOTH coaxial and 6 pin connectors are connected. Usually only the 6 pin analogue connector is actually used, it's as though the people on the production line were not clear what should be installed so did both just to make sure!

Interesting info ...

 

[vadeper]

I want ask, coax on DSP is normal 44khz 16 bit digital input? Or special BMW digital communication?
Example I running CD in my CD magazine, and send different signal to this wire, will work?

Thank you

 

[RichardP]

Pretty sure the digital coax is a standard SPDIF input with the exception that it uses an SMB rather than the usual RCA connector.

 

[vadeper]

Very thank you