Retrofit of the DSP2 audio system from an E85 into my E46
Good day everyone, as I mentioned in the Bluebus thread, I let you participate in my E46 DSP amplifier install sourced from an E86.
My car audio history in that E46 Touring dates back quite a while, I started with a Nexus 7 tablet install an Alpine headunit with a PXA DSP attached to it and two 200L subwoofer boxes fillin up my entine trunk
When the Android headunits became useable an I switched to a 9" Xtrons and a year later I added a DSP board to that unit to improve the sound quality. I also replaced the two massive woofers with a small 8" 15L enclosure that fits into the much smaller M3 trunk floor, that clears the exhaust. After numerous problems with the Android unit and my decision to stick with OEM+ look in my interiour, I deleted all that aftermarket stuff and installed a good condition MK4 navigation professional computer with the CD 16:9 board monitor.
So far so good, I had to invest some time and new parts because I noticed my speakers going bad and figured out, that the E86 Z4M had a quite decent sound system on paper. Some month ago I found an ebay auction for a 2007 Gen2 DSP system from an E86 Z4M and I was lucky to get that for 99€ shipped. E46 and E85/E86 are nearly identical when it comes to onboard electronics and especially bus systems. Then I started thinking, can't we make that amplifier work in an E46 since the MK4 navigation unit is the same in E46 and E86 and so is the monitor (electronically) and the radio unit, since you can replace any BM54 with a naviation professional CID after removing the front facing plate.
First I wanted to keep the original speakers in the E46, but since they are expensive to buy new, and I found a complete set of Top-Hifi speakers from a Z4M, I went with those including a complete wiring harness to steal conectors from.
E85 and E86 make use of the same sound hardware, but different coding data.They also share the same tweeters and midtone speakers with the E83 X3. Main difference between X3 and Z4 DSP systems are the subwoofers:
I looked into the DSP2 unit and verified that its a 10-channel amplifier with 8 normal channels powered by four TDA1565TH with 2x40W each and two additional 30Vrms channels powered by two TDA8926TH in bridged mode for 100W each. These "high voltage" output are driven by an additional internal voltage supply that boosts the supply voltage to around 27V. Because the TDA8926THs run in bridge mode, they are only stable at 8-10 Ohm loads. The two 6.5" Carver subwoofer chassis are rated to 100W at 10 Ohm and have a MASSIVE magnet compared to their overall size. They are designed to work in a 10L unvented chassis each for best efficiency.
Here is a photo of the whole PCB:
The DSP2 amplifier utilizes the same connector as the E46 and share the same pinout except for the high voltage outputs which are wired to the rear woofer pins. So I simply connected the DSP amp to the original wiring and ... nothing. No E46 audio wiring harness configuration has the I-BUS pin occupied in the amplifier connector, so the headunit doesn't know about the DSP being connected and the DSP doesn't know when to turn on. I solved that by hijacking the IBUS signal from the CD changer cable and it worked, volume control was working again and the DSP option immeadiately appeared in my monitor menu. In the meantime, my BlueBus module arrived and I connected it using the digital input on my DSP unit.
To mount the amp I made a small mounting bracked to store it in the orignal position where the CD changer used to be. Almost looks like it was made to sit there!
Success!
Then I turned up the volume and fried the original "Hifi" system woofers in the rear of my touring, so power is there too. With the original speaker setup the the high frequencies coming from the tweeters are WAY too present and midth are nearly noticable at all.
So the next step was making use of the E86 speaker set I now had laying around.
I removed the tweeters from the Z4 plastic assembly and glued them into some old mounts from salvaged E46 tweeters. Perfect, now the highs are softer whilst more precise and match a lot better to the volume of midth and lows.
The midth are currently the old 8ohm speakers from the tourings factory system. Not great, not terrible, but they will be replaced with the silver much nicer looking 4 Ohm Z4 speakers.
This was the initial testing of the woofer chassis, playing into 25L of finest cardboard
After some measuring and calculations I am now left with 10.2L of resonance volume for each subwoofer and the floor can still be installed
Here are some pictures. of the build process
Please excuse the dirty trunk I had the Yurcan X-brace installed and removed it because im moving to another home.
What are the next steps?
My idea is to use a battery distribution block (61136924389) from the E85 and run a 40A fused 2.5mm² wire to the amplifier connector. That should be a plug and play replacement.
Currently my DSP is coded to E86 settings which seems to work best. E85 settings sound like crap if you ask me.
On the long run, Id like to decypher the coding data, especially the filter blocks as they seems to store the actual DSP data like cut off frequencies, filtering, delay, etc.
Once that is done, we can potentially use any speaker setup and run it from the original factory radio
What about other chassis?
Since the DSP2 amplifier has 'only' 10 active channels, you will be missing out the rear bass speakers and have to replace the active subs with any matching 8 Ohm driver in coupes, sedans and convertibles.
Not a huge miss if you ask me, especially not for the driver and front passenger. For the convertible, its the easiest way to go with a dual 8 Ohm subwoofer and replace the original driver.
For coupe and convertible E46s you will have to add additional wires to the front doors, since the tweeter and midtone speaker share the same connection and have a passive crossover installed in the door.
Let me know your thoughts, I'm happy to answer questions too, so don't hesitate to ask.
My car audio history in that E46 Touring dates back quite a while, I started with a Nexus 7 tablet install an Alpine headunit with a PXA DSP attached to it and two 200L subwoofer boxes fillin up my entine trunk
When the Android headunits became useable an I switched to a 9" Xtrons and a year later I added a DSP board to that unit to improve the sound quality. I also replaced the two massive woofers with a small 8" 15L enclosure that fits into the much smaller M3 trunk floor, that clears the exhaust. After numerous problems with the Android unit and my decision to stick with OEM+ look in my interiour, I deleted all that aftermarket stuff and installed a good condition MK4 navigation professional computer with the CD 16:9 board monitor.So far so good, I had to invest some time and new parts because I noticed my speakers going bad and figured out, that the E86 Z4M had a quite decent sound system on paper. Some month ago I found an ebay auction for a 2007 Gen2 DSP system from an E86 Z4M and I was lucky to get that for 99€ shipped. E46 and E85/E86 are nearly identical when it comes to onboard electronics and especially bus systems. Then I started thinking, can't we make that amplifier work in an E46 since the MK4 navigation unit is the same in E46 and E86 and so is the monitor (electronically) and the radio unit, since you can replace any BM54 with a naviation professional CID after removing the front facing plate.
First I wanted to keep the original speakers in the E46, but since they are expensive to buy new, and I found a complete set of Top-Hifi speakers from a Z4M, I went with those including a complete wiring harness to steal conectors from.
E85 and E86 make use of the same sound hardware, but different coding data.They also share the same tweeters and midtone speakers with the E83 X3. Main difference between X3 and Z4 DSP systems are the subwoofers:
- On the E83 X3 BMW introduced the central bass layout where the subwoofer is located under the front seats and has a huge resonance volume behind the side skirts.
- The Z4 runs a "traditional" 3-way audio system in the front, and additional rear fill with two mid tone speakers and two massive subwoofers (for an OEM) in Carver design.
I looked into the DSP2 unit and verified that its a 10-channel amplifier with 8 normal channels powered by four TDA1565TH with 2x40W each and two additional 30Vrms channels powered by two TDA8926TH in bridged mode for 100W each. These "high voltage" output are driven by an additional internal voltage supply that boosts the supply voltage to around 27V. Because the TDA8926THs run in bridge mode, they are only stable at 8-10 Ohm loads. The two 6.5" Carver subwoofer chassis are rated to 100W at 10 Ohm and have a MASSIVE magnet compared to their overall size. They are designed to work in a 10L unvented chassis each for best efficiency.
Here is a photo of the whole PCB:
The DSP2 amplifier utilizes the same connector as the E46 and share the same pinout except for the high voltage outputs which are wired to the rear woofer pins. So I simply connected the DSP amp to the original wiring and ... nothing. No E46 audio wiring harness configuration has the I-BUS pin occupied in the amplifier connector, so the headunit doesn't know about the DSP being connected and the DSP doesn't know when to turn on. I solved that by hijacking the IBUS signal from the CD changer cable and it worked, volume control was working again and the DSP option immeadiately appeared in my monitor menu. In the meantime, my BlueBus module arrived and I connected it using the digital input on my DSP unit.
To mount the amp I made a small mounting bracked to store it in the orignal position where the CD changer used to be. Almost looks like it was made to sit there!
Success!
Then I turned up the volume and fried the original "Hifi" system woofers in the rear of my touring, so power is there too. With the original speaker setup the the high frequencies coming from the tweeters are WAY too present and midth are nearly noticable at all.
So the next step was making use of the E86 speaker set I now had laying around.
I removed the tweeters from the Z4 plastic assembly and glued them into some old mounts from salvaged E46 tweeters. Perfect, now the highs are softer whilst more precise and match a lot better to the volume of midth and lows.
The midth are currently the old 8ohm speakers from the tourings factory system. Not great, not terrible, but they will be replaced with the silver much nicer looking 4 Ohm Z4 speakers.
- Update 2024.04: I replaced the old E46 mid tone speakers with the E86 ones and they work much better. It sounds more natural with the more present midth.
- Update 2024.04: That was a bad idea, 3 Ohm resistance is too low for the TDA1565TH and after some bass heavy tracks it shuts off the front woofers. Improvement pending.
This was the initial testing of the woofer chassis, playing into 25L of finest cardboard
After some measuring and calculations I am now left with 10.2L of resonance volume for each subwoofer and the floor can still be installed
Here are some pictures. of the build process
Please excuse the dirty trunk I had the Yurcan X-brace installed and removed it because im moving to another home.
What are the next steps?
- Definately have to fit the bass and midtone speakers, but I have an idea how to do that.
- I bought two E90 door panels and stole the speaker mounts from it. Hopefully I can make them fit and still have the cover installed for a clean factory look.
- Z4 Bass speaker in the front doors should be easy too. I just have to install the MDF mounts and open the door panel. Maybe I give the original HK speakers another try, before doing that.
- The subwoofer assembly needs a nice finish, I thought about wrapping it in alcantara, or paint it with Warnex. Additionall it will get a nice speakon terminal if I ever need to remove it.
My idea is to use a battery distribution block (61136924389) from the E85 and run a 40A fused 2.5mm² wire to the amplifier connector. That should be a plug and play replacement.
Currently my DSP is coded to E86 settings which seems to work best. E85 settings sound like crap if you ask me.
On the long run, Id like to decypher the coding data, especially the filter blocks as they seems to store the actual DSP data like cut off frequencies, filtering, delay, etc.
Once that is done, we can potentially use any speaker setup and run it from the original factory radio
What about other chassis?
Since the DSP2 amplifier has 'only' 10 active channels, you will be missing out the rear bass speakers and have to replace the active subs with any matching 8 Ohm driver in coupes, sedans and convertibles.
Not a huge miss if you ask me, especially not for the driver and front passenger. For the convertible, its the easiest way to go with a dual 8 Ohm subwoofer and replace the original driver.
For coupe and convertible E46s you will have to add additional wires to the front doors, since the tweeter and midtone speaker share the same connection and have a passive crossover installed in the door.
Let me know your thoughts, I'm happy to answer questions too, so don't hesitate to ask.
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