magictoilet

Note to mods: If you feel like this should go in another audio thread, feel free to delete it and I'll repost it under there. I just didn't want people to sift through many pages of our other threads to find this info.

I have the HK system and wanted to upgrade my system so I'll explain what I did. Note that I am an amateur and could be wrong so feel free to correct me if I'm wrong or say that there's a better way to do stuff. I'm always willing to learn and improve

Understanding our Audio System

All audio systems have a signal flow from an input (source) to output (speakers). Our stock system goes from Headunit (cd, bluetooth, radio, etc.) -> stock amp -> speakers. Somewhere along audio signal flow, you have digital signals and analog signals. No matter what, at some point you have to convert your digital signal into an analog signal because sound waves itself is analog. Without going too deep into the differences between analog/digital sound signals, a pure analog signal flow is like a record player with an analog input while a digital signal flow is like going from an mp3 player (digital) going to your headphones (analog).

This is important because somewhere along our stock system, we have to convert digital to analog. Where you convert it is up to you, there are pros and cons of each such as sound quality or costs. Generally, the less analog signals there are, there are less chances for the sound signals to be distorted. Modern Mercedes uses a MOST (Media Oriented Systems Transport) which is a digital signal.

Revisiting our car's audio signal flow, I will add if the signal is digital or analog:

Headunit ---digital MOST bus--> stock amp ---analog speaker wire--> speakers

A few options for upgrades in terms of cheapest to most expensive and best sound quality. There are different permutations not listed.

1. Headunit ---digital MOST bus--> stock amp ---analog speaker wire--> Aftermarket speakers
Cheapest, but you're still using the stock amp, which has a bunch of equalizations which may or may not sound good. The stock amp also turns down the bass once you get above a certain threshold. A rudimentary example of this means that if you're at volume 10, your sub will be at volume 10. But if you go to volume 20, your sub will still be at volume 10.


We cannot just stick a typical Alpine or JL audio aftermarket amp right after the headunit because the signal from the headunit to the stock amp is transported via a MOST bus, which is a fiber optic cable, and most aftermarket amplifiers only accept an RCA (analog) input. This means we'll have to convert our digital signal to analog. This is where an active line converter comes into play. Audiocontrol LC7i is the one that I'm using. There are many out there like JL cleansweep, but I chose Audiocontrol because it was cheap and it has the anti-bass rolloff as described above. You insert this into your audio signal flow right after the stock amp. The LC7i will take the analog signals that was ORIGINALLY going to your front, rear, and subwoofer speakers, sum up the signals to get a full spectrum of sound frequencies, and send out it's own analog signal to your aftermarket amp. The signal flow is outlined below

2. Headunit ---digital MOST bus--> stock amp ---analog speaker wire--> Line converter ---analog RCA--> aftermarket amp ---analog speaker wire--> stock or aftermarket speakers

Or use a line converter an amp in one unit
3. Headunit ---digital MOST bus--> stock amp ---analog speaker wire--> Line converter an AMP (Audiocontrol LC-4.800) ---analog speaker wire--> stock or aftermarket speakers

More expensive options but better sound quality

4. Headunit ---digital MOST bus-> MOST to SPDIF optical out converter (Hexlis SDMI25 or Audison bit DMI) ---digital optical out--> Digital Sound Processor ---digital optical out OR analog RCA--> aftermarket amplifier ---analog speaker wire --> speakers

5. Headunit ---digital MOST bus-> MOST to SPDIF optical out converter (Hexlis SDMI25 or Audison bit DMI) ---digital optical out--> aftermarket amplifier ---analog speaker wire --> speakers



My system:

Headunit -> stock amp -> Audio Control LC7i -> Alpine PDX-M12 -> JL 10W7 sub in a ported box
-> Alpine PDX-V9 -> front Hertz ESK 165.5 and rear stock speakers

When I tapped into my stock amp to get the signal, I wanted to use a quick connect wire harness so that I could revert back to stock anytime I want. I tapped into:

front left +
front left -
front right +
front right -
rear left +
rear left -
rear right +
rear right -
sub voice coil 1 +
sub voice coil 1 -
sub voice coil 2 +
sub voice coil 2 -

I soldered the harness on both ends of the speaker wires, then soldered some speaker cable into the 3rd harness so that my amp can take the signal. The diagram below will help explain better. I've also attached a pdf of what wires to tap into.


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I am in the middle of redoing my trunk so that's why I didn't post any finished pictures of my subwoofer setup. I've spent a ton of time researching and taking stuff apart so I'd like to give back and save some time for you guys! Huge shout out to Duy at Car audio heaven Elite for installing my speakers and putting Hushmat on my doors. I don't have the patience to put down sound deadener so I had him do it. Everything else I did myself.

Catchyname

My car had some upgrades when i got it but I have been removing them to reduce weight.
Audison DSP, alpine type R 15” sub, audison tweeters, no idea what mid ranges are in the doors though.

Factory amp and subs still in place so removing most of this saved me 125lbs

BLKROKT

Great writeup. We’ll link to this in the FAQ.

magictoilet

Here's a quick update since somebody just pm'd me about which connector I bought. I attached an image of which 12-pin connector I bought since eBay links go out after a year or so. Also, I redesigned my whole trunk setup with the wiring to go on the bottom, and an amp box to go above it with 5 fans and led's. I also switched out my ported box into a sealed box for a tighter sound.

With all that being said.. I actually took out everything because I did a roadtrip from socal to norcal and needed the extra luggage space and spare. I liked having the extra trunk space much more than the extra bass that I never put it back lol.

BLKROKT

I like this thread. Have a question though.

I upgraded my speakers to Focal PC 165F composite rears and Focal PS 165FX component fronts. While they sound better than the OE HK Logic 7 speakers, I feel like they should sound much better. My gut feeling is that they’re not getting adequate power from the OEM amplifier.

I don’t really want to add a piggyback amplifier and line converter to hook an aftermarket amplifier in-line. I’d ideally like something that’s easy and plug-and-play although that may not be possible. Is there any amplifier on the market that can either replace the OE unit (accepting those optical inputs from the head unit), or hook in after with an all-in-one solution?

I looked up the Audiocontrol LC-4.800 as you suggested above but couldn’t figure it out from the description. I assume that you cut the analog speaker output wires from the OE amplifier and just insert that amp in with the outputs then going to the speakers, but I could be wrong. If you could quickly walk me through that it would help. Thanks

doncmleon

damn

you are about that LIFE!!! Amazing attention to detail... Love it

magictoilet

You are correct. Cut into factory wires from our stock amp to our stock speakers, and insert the LC-4.800 between it. AFAIK, there is no pure all-in-one unit that can take a fiber optic signal from our headunit AND act as an amplifier as well.
Audiocontrol has a few options for you:

After quickly looking at their lineup, I see 4 options:

1. LC-4.800 $550 speaker level input 4 amp
2. D4.800 $770 same as 1 with DSP
3. LC6.1200 $770 speaker level input 6 channel amp
4. D-6.1200 $1,100 same as 3 with DSP

For options 3 and 4, channels 5 and 6 go to our dual voice coil stock sub. If you're using the stock sub, I'm not sure how much better it'd be and if it's worth it. If you upgrade the stock sub then I think it's definitely worth it.

With that being said, I'd recommend option 2, the D4.800 so that you can adjust the EQ accordingly. When I had my setup without a DSP, I was not 100% satisfied and that's one of the reasons why I took everything out too. It was definitely better than stock, but not worth losing half my trunk and spare for it. If I see the D4.800 go on sale, I'm going to give it a shot since I already have all the wiring ready . I've spent around the same amount for the LC7i + Alpine PDX-V9 anyway so I'm going to to sell them and try to get the D4.800. When/If I do, I'll give another update.

Here are 2 great videos that review both amps:



I was just trying to fill up my time during quarantine and to find an excuse to buy more tools. I literally bought a drill press and like 5+ other tools for this "project" .

BLKROKT

Awesome, thanks so much for that! Crystal clear now. If I wanted to look at alternative amps to the Audiocontrol, am I just looking for 6 channel amps with DSP? Anything special other than that? My Focals take 80W RMS, so I was thinking something like the JL Audio VX700/5i might be better suited at 75Wx4/300Wx1? Am I thinking about RMS vs peak correctly?

So, if I wanted to upgrade the stock sub and keep everything in that same footprint, what would drop in? When I had that rear shelf apart, it appeared to be a pair of 3.25” rear surrounds and a 6x9” subwoofer. Is that correct? Is it worth touching those rear surrounds or not so much?

Since there don’t appear to be any good 6x9” subs made, I guess the option there is to make an adapter to fit an 8” round subwoofer in that 6x9” space? I don’t mind cutting things up.

Thanks!

magictoilet

The tricky thing with our HK setup is that we have a factory amp that we need to work with. I'm looking at the JL amp and even though it takes "speaker level inputs", the max speaker level input is 16V. "This type of input architecture also allows the VX700/5i to cleanly accept any analog audio signals up to 16 VRMS, without using a line-output converter"(http://mediacdn.jlaudio.com/media/mf...700_5i_MAN.pdf). You'd have to test what voltage the stock HK amp outputs and make sure it's not close to 16 V. The Audio control LC-4.800 accepts up to 40V (400watts) max. If our stock amp doesn't send anywhere close to 16 V to our speakers, then you should be good to go with the JL amp since there looks to be a pretty configurable DSP on there. One feature that the AudioControl has over JL is the AccuBASS feature. When our headunit goes above a certain threshold, the bass does not go up to protect the sub. AccuBASS keeps the bass signal steady.


Our sub seems to be this size:
1 × 200 mm × 270 mm racetrack double voice-coil subwoofer
which is approximately 8" by 10.5".

I think there's only 2.5-3" of depth so you'd have to take that into sub considerations as well. JL has some shallow mount subs that get decent reviews. I'd imagine an adapter wouldn't be that hard to make, but I'm just not sure how much space you have above and below the rear parcel.

skullbox15

Nice work and great info. I did something similar in my C32 and remember mapping the wires from that ****ty bose amp. Itt was a royal pain in the *** to upgrade the audio compared to "normal" cars.

Kriston

Amazing work! Love the audio setups.

Im a bit of an audiophile myself. But the only thing i listen to in the C63 is the exhaust note

magictoilet

I remember in my C320 10 years ago I had a member on here install my JL 1000/1 and 10W7 for me because it was daunting as hell back then. Now that I have youtube, a garage, and the right tools, it doesn't seem so bad.

I take frequent 200+ mile road trips so the exhaust note gets boring after a while


Update: I just bought an open box AudioControl D4.800 amp off of eBay for $500. I'll give an update with my thoughts after I install it. Funny how one members pm lead me back to trying out a new setup... Since this is a 4 channel amp, I was thinking of using channels 1 and 2 to power my hertz components up front, and channels 3 and 4 to the stock sub to see if I can squeeze more out of it. I'll let the factory HK amp handle the rest of the speakers.

magictoilet

I installed the AudioControl D4.800 over the weekend but only spent around 15 minutes tuning the dsp. It's still not exactly to my liking but I knew I wouldn't be able to tune it to my liking that quickly and tuning is part of the fun

I took the mounting location idea from one of the first DIY sub amp install guides on here and luckily the D4.800 fits with plenty of room to spare behind the factory amp.
Steps:

1. Remove factory amp bracket (5 nuts I believe)
2. Use cardboard to cut out a shape of my mounting piece behind the amp and right around the wheel well location. That's why you see a curve in my black plastic.
3. I used a 1/4" sheet of UHMW plastic. 12" by 24" ( ) . I actually used part of it for my J-hooks for my squat rack so that's why I bought a little bigger than I actually needed.
4. Trace out the cardboard onto the plastic sheet, cut it, and then mount amp to the UHMW plastic sheet.
5. Our amp bracket has an unused hole location on the left side, so I just used a long 1/4" screw with 3 nuts to hold the plastic in place.
6. I ran another set of 4 gauge power wire on top of the spare wheel, and my 4 gauge ground on the bottom of my wheel well. I originally wanted to have my ground cable on the left side of the trunk but I didn't find a good grounding location so I just used our factory ground location on the right side of the battery. We have wires going to the rear left taillight so I just zip tied the ground wire to the same wire run.
7. I'm extremely happy that I installed my 12 pin connectors and labeled everything when I first started my audio projects in this car because I hooked up my inputs and outputs in less than 5 minutes. I can play around with if I want to use channels 3 and 4 to power my sub or the rear speakers. I highly advise anyone who is about to cut up their factory wire harness to do this too. I can switch back to my factory amp setup in 5 seconds!

Initial thoughts is that my front speakers can go a LOT louder compared to stock now and quality is a little better than my stock amp. This is only after 15 minutes of playing around with the EQ so I'll give another update when I'm finally happy with my tuning and share my equalizer setup but I'll need to find some more free time first

swedepat

Question.

LC7i
Is it possible to take signal from say front and rear channels and still use oem amplifier to drive the front and rear speakers?
Kind of just 'tap into wires' setup.
Then to drive a new sub with it´s own amplifier from the lc7i with then auto adjusted leveling?

magictoilet

Totally! You can either follow the video below or use T-taps or solder.


Also, no need for the LC7i if you only want to add a subwoofer. The LC2i does exactly like what you want and I have the LC2i pro with remote (as of this post, it's $99 on amazon and $130 with remote). I have the LC2i in my LS460L and am doing exactly what you want to do.

swedepat

Nice!
Thanks for the answer. =)

swedepat

Thanks for this thread, i´m very happy with the result, i might change the hertz amplifier for a rockford monoblock later on, i just had this on a shelf.
Now the bass is more linear as i wanted.

Picture is just after i tested it, it hastn´t been cleaned up yet.
I now have a grill above the woofer and more clean cable routing, but no picture.
I had easy uninstall in mind when designing it, i can take all out in about 3-4minutes, and did also the trick with connectors on oem speakercables so i easy can plug them in again if taking all this out, i can still have a stereo if boot room is needed =)

magictoilet

Looking great swedepat! How'd you mount your amps onto that plastic piece? I'm assuming you mounted it onto the XM radio plastic piece cover.

Also.. I'm picking up a new sub today and should have my "third" setup soon Each time it gets smaller and smaller lol.

swedepat

Tnx

I actually didn´t mount them directly to the plastic piece.
I have a 19mm MDF board with some 'legs' to make room for cables and such under the board.
It is connected with some sheetmetal brackets into the bassbox, and simple zipties in front hooked into the strap hooks in the floor.

all with thought that it will leave no marks if taking it all out, and it is easy to take it out also, if space is needed.

magictoilet

I'm done with my 3rd and hopefully final interation..

Final equipment used:
Audiocontrol D4.800 DSP/line out controller/amp to power the fronts and rears
Hertz ESK 165 front components
Sound deadening in front doors
Alpine PDX-M12
Image Dynamics IDMax 10" in ~1.3 cubic ft. box

Thoughts: I'm extremely satisfied with this system. Everything is clean sounding even at high volumes and I'm still tuning my equalizer every so often to perfect it to my liking. I've had over 20 different sub/amp setups over the years and as I've grown older, I definitely notice the cliche trend of liking SQ more compared to the loud look at me sound so that's why I decided to go with a sealed box.

Install notes:
I removed the stock plastic part that covers the XM radio unit and used those 2 T40 (I think) mounting bolts to secure my own 1/2" mdf platform.
On the platform, I have a sealed front facing sub box because I wanted to create a plexiglass viewing window showing the sub magnet. The sub box is around 12.5" tall and 23.5" wide, and around 15" deep on the bottom. I forgot the exact numbers and have it written down somehwere.
On the left of the sub box, I have the audiocontrol D4.800, and on the right I have the Alpine PDX-M12. All mounted via threaded inserts into the sub box.
I ran the power wiring under the trunk carpet. 2 separate runs, one to back left for the audiocontrol and one to back right to the Alpine amp.
I also had to redo one of my wire harnesses and extend it.

Next steps:
In the sub box, I will reroute the wiring to go straight back so it is not visible from the front.
If enough interest, I'll create a video that shows each part of the install closely.

If anyone is in SoCal and wants to hear my setup before you dive in yourself, feel free to PM me, I love discussing car audio

jaenschw

Well done! Looks fantastic!

DRBC43AMG

Where do you put your toothbrush when you go on a trip?

magictoilet

Thanks!

Take a guess

jaenschw

@magictoilet - awesome setup! Do you find the bass from a single 10" sub is sufficient, I assume 2 x 10" subs would be overkill?

magictoilet

In my opinion, a single 10 or 12 in a sealed box is perfect for an all around daily setup that you can listen to it for hours on end and won't feel fatigued, and takes up the least amount of space while still giving you decent lows. I know there are 8 and 6.5" subs but they don't get as "low"... Note, if you ONLY add a sub and don't upgrade your front speakers, then anything more is definitely overkill and will overpower your music. All you'd hear is bass and that gets boring real quick.

If you asked when I first started messing with car audio, I'd say dual 10 or 12 in ported box every single time but that's just to immaturely show off to my friends. I'd only turn it up like 1-5% of the time I was actually in the car...
Ironically.. last night I picked up a 13W7 in a ported box to play around with in my Lexus LS460L but I have a different build criteria for that car.