BMW 440i Build

[JimmyDee]

This is a reiteration of my post from DIYMA, except I've deleted the multiple changes and upgrades, to just present you with the final product...

First of all, the vehicle:
2018 BMW 440i Gran Coupe with M-Performance Package.
Perfectly balanced 50:50 weight distribution. 359 Horsepower. 369 lb-ft of torque. 8-Speed Z-F Transmission.
It's not the fastest car I've ever driven (although it's ridiculously fast). It's not the most expensive vehicle I've ever driven.
But I would argue that it might be the 'best driving' vehicle I've ever been behind the wheel of. Goes exactly where you point it.


My neighbors think I'm crazy, and my wife just shakes her head... it's not even shocking to her anymore. Just 'the norm' with every new car I get.
But within a few days of ownership; I had the whole interior ripped out, with leather seats, door trims, and carpeting sitting all over my front lawn.

Some of the equipment for this build was leftover and re-used from my previous Audi SQ5 build:
Sinfoni Tweeters, mObridge DA3, Helix DSP-Pro II, MMATS amplifiers, Audiofrog GB10D2 sub.

The intent, as with all my builds, was:
1. Sound Quality.
2. Stealth Build - using factory locations.
3. Don't lose any trunk space. This is a daily driver, and I have 2 kids.

Unfortunately, as with all of my projects, I got busy with the build, and didn't take very many pictures.

I used my Sinfoni Tempo 10 tweeters (pulled from the Audi) in the front doors. Had to modify the inside bracket to mount the tweeters in the OEM location.
I love the sound of these tweeters. I would argue that they are the most detailed small format tweeter I've ever heard. They absolutely sparkle.
I love them so much, that I've used them in my last 3 vehicles. Just haven't found anything better to replace them with... in that size.


I decided to 'go for it all', and installed Dynaudio Esotar 430 mids in the front doors. Made spacer rings out of HDPE.
Holy crap... are the Esotars ever detailed! An amazing speaker. Expensive as heck, but worth every penny.

Doors are all treated with Noico 80mil Sound deadener.
Wiring (power and speakers) is all KnuKonceptz Kolossus.
Power is KnuKonceptz KFN Fused Distribution Block.
RCA's are Stinger 4000 Series.

For the 8" underseat midwoofer; I installed Audio-Development W800-NEO's.
I had to make a spacer ring for these, so I ordered a couple pieces of 1" thick HDPE from Amazon, and used the factory speaker to trace a template.
Note for anyone that is wanting to do this; I used 1" thick HDPE - but 3/4" will also work fine. If I were to do it again, I'd use 3/4".
I cut it out, using a jigsaw. I know there are guys who have better tools, and do nicer finished cuts... but I have a jigsaw, and this is the end product.

Put some Noico Sound deadener inside the factory floor enclosure. This enclosure is not sealed. It vents out the side.
Mounted the spacer ring onto the factory enclosure, using the 4 OEM fastening points.


My only beef with the W800NEO's is that they come with HUGE (I mean really huge) speaker terminals. They extend way past the botton of the Neo magnet!
Not sure why they would design a low profile speaker, and then put these monsterous terminals on them? Kinda defeats the whole intent of a shallow mount.
At any rate... I just cut the terminals down with a hacksaw. They are soft copper and cut easily.
Gave the inside of the terminals a quick scuff with a file, and soldered the speaker cables onto them.
It may look crude / archaic... but I'll never see them. And it works perfectly.


Here's the W800NEO mounted on the spacer ring. Fully bolted in.


As above, I didn't take any pictures of the rear doors, but they have Audiofrog GB10 tweeters, and Audiofrog GB40 drivers in them.
These are running passive with a GB410C crossover in each door. The crossover is MASSIVE, and I had to remove it from the enclosure.
I wrapped the crossover guts/electronics in plastic, and then mounted them to the frame of each door.

I used my mObridge DA3, to tap into the car's fiber optic system. I just use it as pass-through into my Helix DSP-Pro II.

I built a 2 tier amp rack, and mounted both the mObridge and the Helix under the amplifiers.
The USB cable for the DSP tuning is coiled-up on the right hand side of the amps.

I am running a MMATS HiFi-6150 amp, as well as a MMATS HiFi-4250 amp for this build.
The 6150 runs: the front tweeters (Tempo 10), the front midrange (Esotar 430), and the rear fill (GB10 / GB40 / GB410C).
The 4250 runs: the 8" underseat midwoofers (W800NEO), and the other 2 channels are bridged for the sub (Audiofrog GB10D2).

The sub is an Audiofrog GB10, running at 4ohm.
I was challenged to find a good (stealth) location for it... and voila, look at this cavernous space at the rear of the trunk! (that's the car battery at the bottom)

Again, didn't take any pictures of the build, but I made a fiberglass mold of the stock piece that fits in there, then used that to build a stealth sub enclosure.
3 layers of fiberglass mounted onto a 3/4" MDF front, and then carpeted.


Took about 30 hours total to do the build, then another 8 hours to tune it. Overall, I'm very pleased with how it turned-out.

I'm always impressed with how the Helix DSP can take a good sounding system, and make it a phenominal sounding system.

The Esotar 430's are absolutely STUNNING! Perfect sound reproduction from 200Hz to 4500Hz.

The W800NEO's were the real surprise. I have them running from 65hZ to 250hz.
I anticipated they would pound... but I didn't anticipate that they would actually sound good (mounted under the seat).
To my surprise; they actually sound really good, and offer surprisingly good detail - even with the seat (and my ass) as a sound baffle!

Then there's the MMATS amplifiers...
I don't think I'll ever go back to Class A/B again, after using these amps. They are that good. Yes... they are that good.

[tacofox]

Nice Build! that subwoofer stealth box is a beauty! and I actually really like your jigsaw speaker rings

[Niebur3]

Very nice build!

[DavidRam]

Beautiful car and build!

[el_bob-o]

Nice install. I remember at some point in the nineties a few people started cutting holes in the floorboard in front of the seats and mounting mid woofers. I know the BMW's have them under the seats but I've always been curious about how well it blends from under your legs and or booty.

[JimmyDee]

Nice install. I remember at some point in the nineties a few people started cutting holes in the floorboard in front of the seats and mounting mid woofers. I know the BMW's have them under the seats but I've always been curious about how well it blends from under your legs and or booty.

Thanks.
I did sand the rough edges down on the speaker rings. I wasn't too worried about making them cosmetically pretty, as I'll never see them.

The W800NEO's can take a fair bit of power... and I have 250 watts going to each of them.
You need that kind of output, to get them to blend properly with the rest of the vehicle.
I'll admit; it's not the best place to put a speaker... but they do blend nicely, when you have enough power going to them.

[banshee28]

I decided to 'go for it all', and installed Dynaudio Esotar 430 mids in the front doors. Made spacer rings out of HDPE.

So I have an older 3-Series that I am planning on putting in these same Amazing 430's in soon!!! So far I was planning on mounting them into the stock locations, but wondering if I should consider something like this instead. It looks really nice and solid!!

If so, is there anything special I will have to do here? Did you have a template for those, or did you custom make them?