2016 BMW M3 , time for another build

[NealfromNZ]

After 11 years it was time to replace my 2001 e46 m3 ( build below )



This time around I purchased a 2016 F80 M3. It was a UK import and a bit of an odd spec. Had all the look faster bits , connected office, lane control , self park , but a base audio amp & speakers. So 25w x4 amplifier / synthetic engine sound module. 2x 6.5 under seat woofers and 4x100mm dual cone door speakers. Original owner must have been focused on performance aspects. Spec suited me as straight forward to improve audio wise. Wanted a simple 3 way stereo front stage and rear door components for a bit of rear fill and rear passenger duties for when my daughter is play her Spotify playlists.





What I did like about the audio system however was BMW head unit is well featured so can cover USBs , analog input, DVD, HD radio and classic Bluetooth. It can also be coded to use the Most audio bus and provide digital audio outputs to provide 16bit / 44.1 kHz. I started to research products that could integrate into the factory system. My last build became quite complex integration and although it could play HD audio this time around I just wanted simple factory control and 16bit audio is good enough for me this time around.

So requirements was active front stage , passive rear stage , trunk sub a total of 9 channels of amplification. Other considerations was the car runs a 12 v lithium battery so have a reduced reserve but does have a higher current rating. Car is used as a daily driver and can sit in traffic so alternator output at this level also a consideration. So class D /G / H amps would be the direction for the build.

 

[NealfromNZ]

Amplifier choice was a process of elimination. Short list wants were Most25 adapters, DSP , at least 60 watts or doors, 100 watts on underseat woofers , 300 plus on Sub whilst trying to keep it hidden. Mobridge had a all in amplifier. A Most25 8.1.1 amplifier.
So specs were
Most25 digital fibre connection
BMW AMP behaviour cloned
DSP with two maps switchable via BMW surround button
1 Rca out / power on
6 x 75rms channels into 4 ohm
2 x 150rms channels into 4 ohm
1 x 400rms sub channel into 2 ohm

Speaker wise I settled on the following
2 sets of Focal ES100k 100mm components for doors
2 Morel BMW 8 inch woofers for underseat
Re-use the Boston SPG555 and passive radiator from BMW E46. ( sub designed in 2006 and still going strong ! )

Mobridge 9 channel amp, class d , 1.1k watt and the size of an iPad !

Focal door midbass speakers and 3D printed door adapters


Focal K2 Tweeters and BMW mounting trim and brackets

Underseat woofers, Morel BMW 8 inch

And Boston SPG555 and passive radiator.

.

 

[NealfromNZ]

Decided to build a parallel speaker wiring loom. The factory harness didn’t have enough wires to run active three way front stage and whilst it could have been augmented decided leave it as is so easier to revert to standard when the car is sold.

I brought some silver plated OFC cable, BMW door plug pins and sockets, pro audio speakon connectors and plug for sub. For the Mobridge amp I also brought a TE Porsche Bose connector to eliminate the need for a patch harness.

Used .75mm2 wire for tweeters and Midbass , 2.5mm2 for midbass ( should have used 1.5mm2 due to connectors ) and 4x1.5mm2 for sub. Used a power drill and a vice to twist cable together and crimped connectors onto cable.

I then ran cables through to door connectors and used unused positions in the door connectors. Ran two pair into each door for tweeter and mid bass.

For the underseat woofers I also used factory BMW connectors to make it simple to plug into the BMW factory enclosures.

Front door speakers will run active , but rear doors are passive.

Rather than mount crossovers in door I simplify the wiring within the door and mounted the crossovers in the trunk next to the amp location. To be honest it’s not best practice to mount the crossovers side by side with the coils so close together but as these are rear fill or for rear passengers so I’m not concerned with possible effects.

And last was the TE connector so all speaker wire terminates into the amp.

As the BMW M3 didn’t have a fibre optic cable between head unit and amp location I purchased a Aliexpess 5m clone and patch cable and ran it to the trunk.

 

[NealfromNZ]

Next was mounting speakers into doors and adding sound deadening. The rear factory door cards didn’t have tweeter mounts and the front doors lacked a pillar mounts.

I had a dilemma with the M3 with sound treatment. I didn’t want to go overboard as part of its character is the noise it makes. So just treated the interior side of the doors and the door card.

Also did trunk lid and still to do boot floor.

Speakers installed

And Sub

 

[NealfromNZ]

Mounted mobridge amp onto factory bmw amp bracket and rear trunk well location, then simple 4 gauge feed to battery.

 

[JStewart]

Mounted mobridge amp onto factory bmw amp bracket and rear trunk well location, then simple 4 gauge feed to battery.

Not seeing anything simple about any of this. Car audio makes home audio look like a walk in the park. Nice work!

 

[NealfromNZ]

Next part was coding the BMW infotainment system to use the Mobridge amp rather than using analog 4 channel amp and synthetic engine sound module.

I brought a Wi-Fi OBDII dongle and an iPhone app called BimmerCode. The put the app into expert mode and coded the BMW to use the Most digital transport and changed the amplifier variant Harman Kardon. Once done the audio streams ( music , parking distance control , chimes , bluetooth calls ) are sent digitally to the Mobridge amp.

 

[NealfromNZ]

Not seeing anything simple about any of this. Car audio makes home audio look like a walk in the park. Nice

I think I’m probably taking the install for granted compared to pervious installation. Previous build took quite some time as had two amps, dsp, audio feeds from everything. I modified 3 of the BMW factory infotainment modules and built a media centre ( Kodi ) into the CD stacker.

In many ways modern car audio infotainment systems have become simplied.

Below was my “all in” moment, I swore I’d never do another install like that


https://www.avnirvana.com/threads/bmw-e46-m3-budget-build-av-system.5434/post-41319

 

[JStewart]

Below was my “all in” moment, I swore I’d never do another install like that


https://www.avnirvana.com/threads/bmw-e46-m3-budget-build-av-system.5434/post-41319

Whoa! That’s quite a piece of work there.

 

[Joentell]

Beautiful car and beautiful build. I used to have a 2016 manual Alpine white F80 M3. I loved that thing. The HK system was not very good imo. I disabled the fake engine sound. I wasn't brave enough to do what you've done to the audio system. Old cars were so much easier to work on. Bimmers are also notorious for being tough to work on. Props to you!

 

[NealfromNZ]

Beautiful car and beautiful build. I used to have a 2016 manual Alpine white F80 M3. I loved that thing. The HK system was not very good imo. I disabled the fake engine sound. I wasn't brave enough to do what you've done to the audio system. Old cars were so much easier to work on. Bimmers are also notorious for being tough to work on. Props to you!

Cheers , The F80 is quite a fun car , but like you I wasn’t a fan of the fake engine noise coming via the audio system. At least yours had HK , base audio isn’t far off a budget car sound system. It did take me a few months of reading BMW tech articles and reading up on the Most audio bus before deciding on approach. But the bus system is vary similar to IT networks I use to work on in the 2000s so seemed straightforward.

 

[NealfromNZ]

Next stage is tuning the DSP , and this is where I admit I’m a novice. My experience with DSPs to date has really been setting speaker gains , basic time alignment and running passive component speakers and a sub.

Nothing like jumping in boots and all and going to a three way active front stage with sub and for rear fill passive components. For speaker measurement I’m armed with REW and MiniDSP umk1 USB microphone. Also grabbed tape measure to get a base line on speaker driver distances to the drivers for time alignment.

Speaker wise ended up the the crossover points
Front stage
Focal K2 Tweeter ( 20mm ) 3500-20khz
Focal Es100k door midbass (100mm) 175-3500hz
Morel IPsubBMW underseat woofer (200mm) 45-175hz

Rear fill / Rear stage
Focal es100k tweeter and door midbass (175 - 8khz or 175-20khz )

Sub ( and oldie , but good one ! )
Boston Acoustics SPG555 & Passive radiator tuned for 34hz. 15-80hz. ( It’s rolling off from 60hz)

 

[Sonnie Parker]

Awesome install... thanks for sharing.

 

[NealfromNZ]

Reminds me , need to add the DSP tuning which is a work in progress. But isn’t REW a fantastic application for tuning !

 

[JStewart]

Reminds me , need to add the DSP tuning which is a work in progress. But isn’t REW a fantastic application for tuning !

I’d be very interested to follow your work on this if you’re willing to share.

Also, do you aim the tweeters in your photo in any particular direction?

 

[NealfromNZ]

I’d be very interested to follow your work on this if you’re willing to share.

Also, do you aim the tweeters in your photo in any particular direction?

View attachment 67302

Sure,
It’s actually a function and design of BMW tweeter mount. They aim for a mid point at ear height mid way between drivers and passenger seat in the front and it’s similar in for the rear door tweeter. So you do end up listening to them slightly off axis which is quite good for where they are positioned.

Not sure if you can see the offset in these pictures, but it made it very easy during the aftermarket tweeter installs.

I just needed to use a dremel tool to machine down the focal tweeter rims about 1mm and remove the small factory tweeter keys from the mounts.

 

[JStewart]

Sure,
It’s actually a function and design of BMW tweeter mount. They aim for a mid point at ear height mid way between drivers and passenger seat in the front and it’s similar in for the rear door tweeter. So you do end up listening to them slightly off axis which is quite good for where they are positioned.

Not sure if you can see the offset in these pictures, but it made it very easy during the aftermarket tweeter installs.

I just needed to use a dremel tool to machine down the focal tweeter rims about 1mm and remove the small factory tweeter keys from the mounts.

Thanks! The ones in my Honda are in the same spot but they’re aimed a little more towards each other. The issue I’m having is the driver side is super sensitive to head position. I think it’s reflecting off the molding above the instruments so there’s an extra dose of reflections depending. I’m going to look into a way to direct them as yours are.

 

[NealfromNZ]

It should help a bit and also you’ll be less off axis n the drivers side. It should help. You may also get less direct window reflection from the passenger side tweeter bouncing off the drivers side window.

This is what a raw sweep looked like on my tweeters and door mid bass before any eq. This graph is smoothed but as you can see they behave differently due to one being slightly more of axis and some bounce of windows and steering wheel area.

 

[NealfromNZ]

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