Car Stereo Forum banner

1 - 12 of 12 Posts

1,097 Posts
Discussion Starter #1 (Edited)
Let me start by saying; as I post this... I am already changing things on the install.
But, that will probably be a never-ending venture; so here's where I'm at so far:

First off, the install subject: BMW X6-M
• 570 horsepower
• Twin-turbocharged 4.4 litre V8
• Zero to 60 in 3.8 seconds
• Will pull a full G in the corners

This thing is an absolute monster...

There are some really nice professional installs posted, and I admire the level of detail put into these.
But, I am just some dude in his (dimly lit) garage, working with everyday tools.
The cuts aren't fancy. There's no 3D printing. And most of the material came from Home Depot or Amazon.

The equipment is all the same as what I had in my previous vehicle:
OEM Head Unit into mObridge DA3 into Helix DSP-Pro Mk II
Amplification: MMATS HiFi-6150D and MMATS HiFi-4250D
Front Stage: Sinfoni Tempo 10, Dynaudio Esotar 430, Audio-Development W800-NEO
Rear Fill: Audiofrog GB10, Audiofrog GB40, Audiofrog GB410 (passive crossover)
Subwoofer: Audiofrog GB10D2

As with all my installs, I have two basic criteria:
1. Sound Quality
2. Stealth Installation

Let's start with the install location. Under the rear floor is a hidden cargo hatch, with a fair bit of room:

With the carpeted floor removed, we have a lot of room to work with:

Covered the floor with sound deadener, and also up the sides (did the sides later in the process):

Next, it's time to cut some 3/4" MDF, to make the sub enclosure and amp rack:

Construction adhesive and brad nails... this thing will never come apart:

Audiofrog specs 0.6 cu.ft. for a sealed enclosure on this sub. My enclosure nets 0.67 cu.ft. after the displacement of the sub.
Test fit, with the bottom layer of the amp rack added:

Now, to start on the power cables...
I've always used Knukonceptz cables and power distribution block. They just work good.

Strip the jacketing back about 5/8", and slip it through the gland:

Bend the wires back over the sheath:

Thread it in with your fingers, to ensure you don't cross-thread:

Then, wrench that bad boy down tight:

Same process with the positive cable:

Here's the distribution block, mounted on the bottom of the amp rack.
Everything is zip-tied and screwed down to the board. 0awg in / 4awg out.
Fused positive on one side (2 X 80amp fuses), and solid negative on the other.
The smaller separate inline holder is a 5amp to the DSP.

I also mounted the Helix DSP onto the bottom layer of the amp rack, and ran the RCA's to it:

Carpeted the sub enclosure, and added some Poly-Fil:

12awg. Knukonceptz speaker cable for the sub:

Sub is in:

Time to bolt-down the lower part of the amp rack... what a rats nest:

But it cleans up nicely...

Now for the top layer of the amp rack:

Pulled the RCA's from the Helix and connected them to the amps:

Again, everything is zip-tied and screwed down secure:

RCA's are connected and Power Cables are connected to the amps:

Speaker cables are all pulled through the vehicle, and connected to the amps:
(this is definitely the hardest part of the entire job)

Time to bring power to the system...
Strip back the 0awg. ground cable:

Slip a ring terminal over it:

And crimp that baby down!

Bolt it down to the OEM grounding lug:

Same process for the 0awg. positive battery cable:

BMW uses a MOST fiber optic system for virtually everything in the car... including the audio system:

In order to tap into that fiber optic network, I used a mObridge DA3.
The DA3 has a built-in DSP, but I bypass that and just use it to tap into the MOST fiber optic.
Helix also makes a similar unit: # SDMI25. The Helix does not have a DSP, just a Toslink output.

Just configuring the mObridge to work with the vehicle, and bypass the internal DSP.
It sends a full-range, completely pure flat signal to the Helix DSP-Pro:

Now, onto the door speakers... unfortunately, I got focused on doing the work, and forgot to take a bunch of pictures.

Here's the front door skin removed:

Not much to see here... except that I needed to pull half of the lower dash out, to run the speaker cables through the Molex, into the doors:
(what a total pain in the ass, pulling cables through an already packed Molex)

Cables pulled through:

The OEM speakers aren't total garbage... but they're far from great:

This is one of the current changes...
I used MDF as the base speaker ring, but just today I went and bought a piece of HDPE plastic.
It'll annoy me, knowing that MDF might swell-up from humidity and temperature changes.
I'll be pulling the door skins off again, and replacing that MDF with HDPE:

Tweeters are mounted in the OEM sail panels. Had to cut it a bit to make the Tempo 10's fit:

Doors all sealed up with sound deadener:

And for the final ingredient... to replace these weak under-seat woofers:

Somehow, they produce a decent amount of midbass... but I'm sure I'd blow them up, if I attached them to my MMATS 4250:

Replacing them with this... Audio-Development W800-NEO:

Put some sound deadener in the base of the under-seat enclosure:
It is open vented into the side pillars of the vehicle.

Cut some speaker rings / extenders out of HDPE plastic:

Cut the ridiculously long speaker posts down with a hacksaw:

And soldered the speaker wires to them:

Then mounted them into the OEM floor boxes:

That's about it...
Put everything back together; door panels back on, seats bolted back down, dash and trim put back in place.

As mentioned; I am already going to change a few things... just because I'm a sucker for 'the latest and greatest':
1. The mObridge DA3 is getting swapped for the newly released model: DA.G2-PRO. I expect it to arrive early next week.
2. The Helix DSP-Pro will be getting replaced with the new DSP-Ultra, when it becomes available.

The MMATS 6150 powers: Front Tweeters (150W each), Front Midrange (150W each), Rear Fill (150W passive per side).
The MMATS 4250 powers: Underseat Midbass (250W each), Subwoofer (500W bridged).

I did a bit of basic tuning and time alignment. Just enough to make it sound decent. Actually, it sounds really good!
But until I get the new components (mObridge and Helix DSP), I'm not going to spend hours tuning it.
I'll do it properly, once everything is installed.

Total install time: about 30 hours.

226 Posts
I haven't posted here in a while, but this popped up on my TaT app. Very nice machine and build to go with it, but you already know that ;)

Sent from my Pixel 2 XL using Tapatalk

20 Posts
Beautiful work and very helpful as I plan my 2016 X6 F16. The X6M is a beast. Our Xdrive 35i is no slouch but it is really my wife's car or I might have been tempted to step up to the 8 cylinder M. I did add an MPPK tune though.

I’ll likely have a few component differences and only do some of the work myself and have a professional installer do the hard stuff. Wish I had your experience and skill but I don’t want to do my first upgrade alone on a relatively expensive car.

Thanks for all your help so far.

487 Posts
If you tune the helix with auto eq and save the files you can then re import the eq files to the ultra as well ;)

Nice simple system you have there 👍🏼 Like it!

219 Posts
Having those under seat woofers is fantastic - door woofers in my experience sound like ass no matter how much dynamat you use. Are those woofers run infiinite baffle then ? at some point the backside vents into a large frame rail ?

1,097 Posts
Discussion Starter #7
Are those woofers run infiinite baffle then ? at some point the backside vents into a large frame rail ?
Ya, the floor boxes vent into the side pillars.

1,097 Posts
Discussion Starter #9
Happy with the single GB10 sub?
It's a great sounding sub. Fast and precise.
It doesn't produce huge booming bass. But fills the low end nicely.
If a guy was after 'big bass', then I would recommend a GB12.

1,097 Posts
Discussion Starter #10 (Edited)
Couple updates (per my original post):

The new mObridge DA-G2.PRO arrived this morning.
I removed the DA3 and replaced it with the new unit... sounds the same.

I pulled the door skins off, and replaced the MDF speaker rings with HDPE ones:


1,097 Posts
Discussion Starter #11
The new mObridge DA.G2-PRO has 10 output channels, which is what I needed (9 actually).
It also has a new algorythm to upmix a center channel (which I'm not using - but maybe in the future).
These are the two main advantages over my prior mObridge DA3.

I spent about 4 hours tuning the new mObridge DA.G2-PRO unit today.
It's a bit more work than my previous Helix DSP-Pro, but I believe I have got it sounding just as good.

The advantage with the Helix, is that it has a built-in RTA, and can auto-tune (helps to get the baseline EQ'ing done).
The mObridge has none of this, so I needed to do RTA measurtements with REW, and then manually adjust the EQ settings for each (and every) speaker.

My original plan was to also get a new Helix DSP-Ultra (when it is released)... but I'm not so sure now. After properly tuning; the mObridge sounds REALLY good.
1 - 12 of 12 Posts