BMW i Forums - View Single Post - BMW Active Sound Booster for Maserati sound

evanevery · 12-11-2018, 11:11 AM

Still waiting for that call from Maxhaust...

Meantime, I have given some thought to what Maxhaust is doing and how they are integrating their system into our cars. I'ld like to have an easy way to switch back and forth between "Maxhaust Sound" and "BMW Sound" and maybe even "Maserati Sound". (PRIMARILY cause the "Maxhaust sound" ain't working in my car right now...) I think I figured out how to do that so I'll share my thoughts here...

1. Maxhaust essentially only uses 4 wires from the BMW harness. Two of them are clearly CANBUS and the other two almost have to be the wires which supply sound to the BMW amplifier. It appears that in our configuration, Maxhaust doesn't provide any amplifier, they just steal the sound input wires and inject a different audio signal (Maxhaust sound or Maserati Sound) and feed that to the BMW AMP.

2. CANBUS wires: Maxhaust clearly documents their use of the CANBUS wires (Blue, White). We remove these from the BMW Connector but we also replace them with the Orange/Black and Orange/Brown wires. As CANBUS is a multipoint bus, its pretty clear that Maxhaust is just tapping into the bus (Blue,White) while continuing to pass the bus to the BMW Sound Module (via Orange/Black and Orange/Brown). The CANBUS is where Maxhaust gets the vehicle real-time RPM information (also other info I expect). It might be that the car will post an error if the BMW Sound Module is missing off the bus. In any case, I think the BMW Sound Module is still on the bus, even after the Maxhaust install.

3. Sound Wires: The only other wires we disturb during the install are the Black and Black/Grey wires removed from the BMW Connector. Through the process of elimination, these HAVE TO BE the wires used to provide the sound signal to the BMW Amp. First, its the only other wires we mess with, and second, they are REMOVED from the BMW sound module so it doesn't provide any conflicting sound.

4. The BMW Sound Module is perfectly active (even after the Maxhaust install): Based on the above, the ONLY thing we have disconnected from the BMW Sound Module is the wires which carry sound to the amp. They are now connected to the Maxhaust module. This makes perfect sense - and overlooks a very convenient opportunity!

5. Switching Sound Source: Since BOTH the BMW and Maxhaust Sound modules appear to be active at all times, and only ONE of them has the amp wires attached at any given time, all we need is a simple DPDT (Double Pole Double Throw) switch to select which source we would like to use! Sound wires could come to the switch from BOTH the BMW and the Maxhaust module. We could then use the switch to select which source we would like to pass to the Amp. It would be a very simple, cheap, and effective solution and I have no idea why Maxhaust wouldn't already do this!

...Hold on it gets better! "Order in the next two hours and..."

6. Maxhaust "Blue" Connector: Everyone appears to hate this connector (for good reason). It appears many folks have broken their pins when trying to move them from the BMW connector and have just bypassed the Maxhaust Blue Connector. Why not just replace it completely with another (more useful, better designed, more functional, easier to use, readily available) connector? We would have to replace both the female and male connectors provided by Maxhaust...

7. The New Connector (8-Pin): The Maxhaust connector has 4 pins (Power, Ground, Sound+, and Sound-). The new connector set I am proposing, would have 8 pins. Here are the pins I would use for the Connector which is attached to the vehicle:

- Sound+ from BMW Sound Module (Black to BMW Module)
- Sound- from BMW Sound Module (Black/Grey to BMW Module)
- Sound+ to BMW Harness (Black to BMW Harness)
- Sound- to BMW Harness (Black/Grey to BMW Harness)
- CANBUS Hi (Blue tap)
- CANBUS Lo (White tap)
- Power + (from Fuse Box)
- Power - (from Vehicle Gnd)

Here are the corresponding pins which go to the Maxhaust harness:

- (not connected)
- (not connected)
- Sound+ from Maxhaust Harness (Color TBD)
- Sound- from Maxhaust Harness (Color TBD)
- CANBUS Hi to Maxhaust Harness (Orange/Brown)
- CANBUS Lo to Maxhaust Harness (Orange/Black)
- Power + to Maxhaust Harness (Red)
- Power - to Maxhaust Harness (Black)

Here is where the magic happens. A second "loopback" connector, which when plugged in (instead of the Maxhaust harness), will put the BMW Sound Module back in service!

- Sound+ from BMW Sound Module (Loopback Wire "A")
- Sound- from BMW Sound Module (Loopback Wire "B")
- Sound+ back to BMW Harness (Loopback Wire "A")
- Sound- back to BMW Harness (Loopback Wire "B")
- (not connected)
- (not connected)
- (not connected)
- (not connected)

All you need to do is unplug our new improved Maxhaust Harness Connector and plug in our "Loopback Connector" and the car is fundamentally back to its factory configuration (providing sound from the BMW Sound Module)!

Why is this better than a simple selector switch? Because not only can you easily switch the car back to the factory config, but you can also easily switch to a completely different sound module (Maserati Sound module) as long as you modify that connector in a similar fashion!

(Now I don't want to get too crazy, but you could also make another connector to feed completely rogue sounds (from a BlueTooth Audio Receiver or MP3 player, for example) to the BMW amp as well. Want you car to sound like the car from "The Jetson's"? In fact, we could wire in a remote relay (on OUR side of the connector) to switch on-demand from the onboard BMW Module to a source of our choosing. Maybe an Arduino with a sound generator? ...add a CANBUS shield to monitor the cars RPM... Anyway, I digress... First things first...)

So all three Sound Modules (BMW, Maxhaust, Maserati) can be easily switched back and forth using a single connector. All you need is to add a couple of 8-pin connectors. You will also have to manually cut/tap/solder the 4 associated wires in the BMW harness (Blue, White, Black, Black/Grey), but I think its well worth the minimal extra effort. It makes a much more flexible and maintainable installation.

While I wait for Maxhaust to sort out my problems, I am going to do exactly that. It keeps my factory sound fully available (unlike the current Maxhaust config which "steals" Pin 1 and 2 from the BMW connector). Their "blue connector" sucks in any case and it apparently has caused lots of problems for other folks as well. It will be easy enough to change the connector on their harness in comfort at my workbench. I have a soldering station and a full selection of shrink tubing to professionally insulate the solder joints. I hate electrical tape...

I just purchased two different sets of 8 pin connectors to see which type I like best:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I'm confident enough in all the above info that I'm going to start on this for my own car. I've also asked to purchase a Masertai Sound Module/harness for comparison.

In any case, I'll confirm all the above info if/when Maxhaust calls me back...

12-11-2018, 11:11 AM	#79
evanevery Lieutenant Colonel 1113 Rep 1,904 Posts Drives: iXM60, i8 Rdstr, M4, i7 M70 Join Date: Feb 2012 Location: Wisconsin iTrader: (0)	Still waiting for that call from Maxhaust... Meantime, I have given some thought to what Maxhaust is doing and how they are integrating their system into our cars. I'ld like to have an easy way to switch back and forth between "Maxhaust Sound" and "BMW Sound" and maybe even "Maserati Sound". (PRIMARILY cause the "Maxhaust sound" ain't working in my car right now...) I think I figured out how to do that so I'll share my thoughts here... 1. Maxhaust essentially only uses 4 wires from the BMW harness. Two of them are clearly CANBUS and the other two almost have to be the wires which supply sound to the BMW amplifier. It appears that in our configuration, Maxhaust doesn't provide any amplifier, they just steal the sound input wires and inject a different audio signal (Maxhaust sound or Maserati Sound) and feed that to the BMW AMP. 2. CANBUS wires: Maxhaust clearly documents their use of the CANBUS wires (Blue, White). We remove these from the BMW Connector but we also replace them with the Orange/Black and Orange/Brown wires. As CANBUS is a multipoint bus, its pretty clear that Maxhaust is just tapping into the bus (Blue,White) while continuing to pass the bus to the BMW Sound Module (via Orange/Black and Orange/Brown). The CANBUS is where Maxhaust gets the vehicle real-time RPM information (also other info I expect). It might be that the car will post an error if the BMW Sound Module is missing off the bus. In any case, I think the BMW Sound Module is still on the bus, even after the Maxhaust install. 3. Sound Wires: The only other wires we disturb during the install are the Black and Black/Grey wires removed from the BMW Connector. Through the process of elimination, these HAVE TO BE the wires used to provide the sound signal to the BMW Amp. First, its the only other wires we mess with, and second, they are REMOVED from the BMW sound module so it doesn't provide any conflicting sound. 4. The BMW Sound Module is perfectly active (even after the Maxhaust install): Based on the above, the ONLY thing we have disconnected from the BMW Sound Module is the wires which carry sound to the amp. They are now connected to the Maxhaust module. This makes perfect sense - and overlooks a very convenient opportunity! 5. Switching Sound Source: Since BOTH the BMW and Maxhaust Sound modules appear to be active at all times, and only ONE of them has the amp wires attached at any given time, all we need is a simple DPDT (Double Pole Double Throw) switch to select which source we would like to use! Sound wires could come to the switch from BOTH the BMW and the Maxhaust module. We could then use the switch to select which source we would like to pass to the Amp. It would be a very simple, cheap, and effective solution and I have no idea why Maxhaust wouldn't already do this! ...Hold on it gets better! "Order in the next two hours and..." 6. Maxhaust "Blue" Connector: Everyone appears to hate this connector (for good reason). It appears many folks have broken their pins when trying to move them from the BMW connector and have just bypassed the Maxhaust Blue Connector. Why not just replace it completely with another (more useful, better designed, more functional, easier to use, readily available) connector? We would have to replace both the female and male connectors provided by Maxhaust... 7. The New Connector (8-Pin): The Maxhaust connector has 4 pins (Power, Ground, Sound+, and Sound-). The new connector set I am proposing, would have 8 pins. Here are the pins I would use for the Connector which is attached to the vehicle: - Sound+ from BMW Sound Module (Black to BMW Module) - Sound- from BMW Sound Module (Black/Grey to BMW Module) - Sound+ to BMW Harness (Black to BMW Harness) - Sound- to BMW Harness (Black/Grey to BMW Harness) - CANBUS Hi (Blue tap) - CANBUS Lo (White tap) - Power + (from Fuse Box) - Power - (from Vehicle Gnd) Here are the corresponding pins which go to the Maxhaust harness: - (not connected) - (not connected) - Sound+ from Maxhaust Harness (Color TBD) - Sound- from Maxhaust Harness (Color TBD) - CANBUS Hi to Maxhaust Harness (Orange/Brown) - CANBUS Lo to Maxhaust Harness (Orange/Black) - Power + to Maxhaust Harness (Red) - Power - to Maxhaust Harness (Black) Here is where the magic happens. A second "loopback" connector, which when plugged in (instead of the Maxhaust harness), will put the BMW Sound Module back in service! - Sound+ from BMW Sound Module (Loopback Wire "A") - Sound- from BMW Sound Module (Loopback Wire "B") - Sound+ back to BMW Harness (Loopback Wire "A") - Sound- back to BMW Harness (Loopback Wire "B") - (not connected) - (not connected) - (not connected) - (not connected) All you need to do is unplug our new improved Maxhaust Harness Connector and plug in our "Loopback Connector" and the car is fundamentally back to its factory configuration (providing sound from the BMW Sound Module)! Why is this better than a simple selector switch? Because not only can you easily switch the car back to the factory config, but you can also easily switch to a completely different sound module (Maserati Sound module) as long as you modify that connector in a similar fashion! (Now I don't want to get too crazy, but you could also make another connector to feed completely rogue sounds (from a BlueTooth Audio Receiver or MP3 player, for example) to the BMW amp as well. Want you car to sound like the car from "The Jetson's"? In fact, we could wire in a remote relay (on OUR side of the connector) to switch on-demand from the onboard BMW Module to a source of our choosing. Maybe an Arduino with a sound generator? ...add a CANBUS shield to monitor the cars RPM... Anyway, I digress... First things first...) So all three Sound Modules (BMW, Maxhaust, Maserati) can be easily switched back and forth using a single connector. All you need is to add a couple of 8-pin connectors. You will also have to manually cut/tap/solder the 4 associated wires in the BMW harness (Blue, White, Black, Black/Grey), but I think its well worth the minimal extra effort. It makes a much more flexible and maintainable installation. While I wait for Maxhaust to sort out my problems, I am going to do exactly that. It keeps my factory sound fully available (unlike the current Maxhaust config which "steals" Pin 1 and 2 from the BMW connector). Their "blue connector" sucks in any case and it apparently has caused lots of problems for other folks as well. It will be easy enough to change the connector on their harness in comfort at my workbench. I have a soldering station and a full selection of shrink tubing to professionally insulate the solder joints. I hate electrical tape... I just purchased two different sets of 8 pin connectors to see which type I like best: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 I'm confident enough in all the above info that I'm going to start on this for my own car. I've also asked to purchase a Masertai Sound Module/harness for comparison. In any case, I'll confirm all the above info if/when Maxhaust calls me back... __________________ The Jiggery-Pokery is Strong with this One https://f80.bimmerpost.com/forums/sh....php?t=1645366 https://f80.bimmerpost.com/forums/sh....php?t=1197553 https://f80.bimmerpost.com/forums/sh...4&postcount=35 Last edited by evanevery; 12-11-2018 at 12:34 PM..
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