MK7 audio overhaul: 2.1 active system

[JackRabbitSLIM]

Hello all, I'm new here and am just finishing up my audio install on my '17 GTI base model and want to share it.

I have been interested in audio since my first car at 16 years old, '95 Honda Civic hatch baby! 14 years later I'm still going strong. I've been building home stereo speakers and installing car audio always trying to out-do my last system. I'm currently working at Honda as an electrical test engineer specializing in communication networks.


The GTI presents some issues, the main one being that almost all vehicle settings are controlled through the infotainment headunit. Therefore, I "have" to keep the head unit. I usually prefer to install a whole new system, wires and all, and just leave the OE equipment waiting to be reconnected when the car is sold.

So, what am I going to put in? The main source will be bluetooth audio with a digital out. Not a popular choice to most people, for some reason most of you people love your Andriod Auto and Apple Car Play, for the life of me I cannot figure out why. Whatever.

On a more serious note, the main reason I'm doing this is to guarantee a full range, untampered, signal that I can rely on. My car is base model and it is normal, in my work experience, for the music signal to be high pass filtered at a relatively high frequency, like 60 or 70 Hz on the OEM equipment.

I don't run rear speakers and haven't ever missed them. I always suggest systems in this configuration. Extra speakers add tuning complexity for no benefit and almost always make the overall image and sound stage worse.

The system is: Bluetooth Audio (digital out) -> miniDSP CSDP 6x8 -> Alpine 4ch mini amp -> Morel 634TiW woofers, Moral MDT 12 tweeters. miniDSP offers tons of great products, if you haven't heard of them check them out if you are into stereo, home theater or hifi in general. In this case it will be my crossover, EQ, and time alignment. I had a few different ideas about the subwoofer and ended up taking the easy way out and going with a JL 12W6 in their enclosure.

Emotiva BT - digital source
miniDSP - DSP unit and main volume control via hardwired remote.
Alpine 4ch - 4 ch amplifier for mid/trebel
Morel TiW 634 - mid woofers
Morel MDT12 - tweeters
JL HO12W6 - subwoofer
Alpine S-A60M - subwoofer amplifier

The miniDSP is inserted between the OE amplifier and the speakers. I cut the OE haness (yup) and used those speaker level outputs as inputs to the miniDSP. The Emotiva BT is a separate input to the miniDSP. The whole point of doing this will be to keep all of the VW phone call features working as normal. When I receive a call (rarely) I have to change the input on the miniDSP via the remote.

 

[JackRabbitSLIM]

This is the un-corrected vs. corrected curves of the overall system using the miniDSP. This was about as flat as I could get it, but I do EQ everything after flattening it out.

 

[Cuzoe]

If you don't plan on going back, and I assume with the amount of work you've done that you don't plan to, then by all means cut the OE harness, haha. That sub box is huge, how is it secured back there?

I think people don't like Bluetooth because the factory system only seems to support lower quality codecs (presumable for greater compatibility). The same song playing over Bluetooth in the car sounds noticeably worse than playing via Android Auto. The difference is somewhat less pronounced between Bluetooth and Apple Carplay, likely because the Android Bluetooth stack isn't great, and varies between android versions/phones. If you're using the other AA/Carplay features the improved audio is a nice side bonus.

 

[JackRabbitSLIM]

If you don't plan on going back, and I assume with the amount of work you've done that you don't plan to, then by all means cut the OE harness, haha. That sub box is huge, how is it secured back there?

Going back will still be super easy. I terminated the wires that I cut with couplers so I'd just have to re-connect them. Right now the sub is secured by gravity, it weighs 60lbs and the carpet/carpet interface has kept everything where I left it.

 

[Adurm]

How many eq bands do you have with the mini dsp? I run a portable hi res player to audiocontrol dm810 for now, expecting to use 9 channels eventually. The 810 is disappointing compared to my previous audison bit 10d in that the audiocontrol has 30 bands while the bit had 64 i think. Where the audiocontrol triumphs is its output voltage is a solid 10v unclipped. It can be dropped to 5v if needed. The bit gave me 3.6v before clipping. Consider fabbing a fiberglass spare tire enclosure and remove the factory floor and create a .75 inch mdf floor with the sub facing up.

 

[Faceman]

Nice work!

 

[JackRabbitSLIM]

How many eq bands do you have with the mini dsp? I run a portable hi res player to audiocontrol dm810 for now, expecting to use 9 channels eventually. The 810 is disappointing compared to my previous audison bit 10d in that the audiocontrol has 30 bands while the bit had 64 i think. Where the audiocontrol triumphs is its output voltage is a solid 10v unclipped. It can be dropped to 5v if needed. The bit gave me 3.6v before clipping. Consider fabbing a fiberglass spare tire enclosure and remove the factory floor and create a .75 inch mdf floor with the sub facing up.

miniDSP has 6 EQ bands, but that's a little misleading. Each input channel (6 total), has it's own 6 bands. Then, each output (8 total) also has 6 bands. I use the output side for flattening the response of the individual speakers. miniDSP can do normal PEQ or you can import biquad filters generated from measurement software (REW). Once the curves are flat I EQ on the input side. I've never run out of PEQ bands, but maybe my goals are different.

The output voltage on miniDSP is super low, 2V. Please teach me why I should care, serious question. I do get some clipping but it starts way past my volume comfort threshold. I have headroom on the amplifiers too.

I had a very similar setup in my MK5 with the sub facing up in the spare tire well. It was a shallow MMATS 10" in a sealed enclosure. I was never happy with the sound so I went away from it. There are probably much better speaker options now, but back then my results were super muddy with that speaker. I decided for my current setup I would just go really big and make a quick disconnect for the sub so I can remove it quickly if I need the trunk space.

 

[Adurm]

Thank you for all that info! In regards to the 2v output and why it's concerning to me, i feel i have to turn my amp gain higher to match that thus creating hiss or distortion. I might be way off with that theory and don't have any science backing it up, just my ears. I did have a bit more tweeter hiss with th bit ten 3.6v vs the dm810.

 

[Faceman]

Thank you for all that info! In regards to the 2v output and why it's concerning to me, i feel i have to turn my amp gain higher to match that thus creating hiss or distortion. I might be way off with that theory and don't have any science backing it up, just my ears. I did have a bit more tweeter hiss with th bit ten 3.6v vs the dm810.

I have a MiniDSP hooked up to my home subs and went balanced for the reasons stated above.

 

[Adurm]

Faceman, balanced gives you more voltage to the amp? I've never delved into balanced too much. All i know is it's supposed to be cleaner.

 

[Faceman]

Yes, better noise rejection and higher voltage.

 

[c31561]

Great work! I did something similar and sounds so much better.

 

[Rgeeezy]

If you don't plan on going back, and I assume with the amount of work you've done that you don't plan to, then by all means cut the OE harness, haha. That sub box is huge, how is it secured back there?

I think people don't like Bluetooth because the factory system only seems to support lower quality codecs (presumable for greater compatibility). The same song playing over Bluetooth in the car sounds noticeably worse than playing via Android Auto. The difference is somewhat less pronounced between Bluetooth and Apple Carplay, likely because the Android Bluetooth stack isn't great, and varies between android versions/phones. If you're using the other AA/Carplay features the improved audio is a nice side bonus.

If someone wouldn’t want to cut their factory wires, is there any available harnesses to prevent that? Like for wiring a dsp, you could take an oem speaker harness from the source and run those wires to the dsp and then wire the new speaker outputs from an amp with a reverse harness back into the oem speaker harness. Sorry if that was confusing. Lol.

 

[JackRabbitSLIM]

Before I cut the harness I tried to break out the wires using this backup camera harness. It has both sides of the OEM brick that you would need. Each of the couplers can be taken out of the brick. I did verify that this would work but I had a really hard time fitting it all in the space above/behind the OEM audio unit (the part that looks like a CD player). I didn't re-try that harness after removing the glove box though, so you may have better luck if you do it that way.

That harness is for adding a rear view camera, so you will lose your backup camera unless you do something additional.

Cutting the OEM harness really isn't a big deal. You just need to buy the couplers with the correct terminals and then crimp the terminals to the wires and pop them into the coupler. I do understand the trepidation that people may have. The way I see it, it is completely reversible.

 

[Rgeeezy]

Before I cut the harness I tried to break out the wires using this backup camera harness. It has both sides of the OEM brick that you would need. Each of the couplers can be taken out of the brick. I did verify that this would work but I had a really hard time fitting it all in the space above/behind the OEM audio unit (the part that looks like a CD player). I didn't re-try that harness after removing the glove box though, so you may have better luck if you do it that way.

That harness is for adding a rear view camera, so you will lose your backup camera unless you do something additional.

Cutting the OEM harness really isn't a big deal. You just need to buy the couplers with the correct terminals and then crimp the terminals to the wires and pop them into the coupler. I do understand the trepidation that people may have. The way I see it, it is completely reversible.

Nice! This is something I may try. If you’re able to remove the specific blocks for speaker output would you still lose backup camera functionality? Or that would only happen if you use the kit as intended without taking it apart.