[FMG20]

Since I found some topics here and there about this matter, thought I'd share my experience so far as well. Long story short, it's not running yet, so you can opt out if you are looking for the solution right away

As I am pretty sure the solution will come rather sooner than later, this might be one to follow.

I eventually went for the "easy" extra, coming from a Match DSP in my MB, I didn't want to go this extra mile just yet, because the HK does already sound pretty damn good with the correct settings (to my taste none the less). Therefore I chose a relatively easy (on paper) and lower cost option, if you will, bang for bucks.

• Harness PnP Technic for the Booster Module
• HELIX AAC.3 LOC (High Low Convertor)
• GLADEN RC600c1 Mono Amplifier
• Audison APBX 10 DS

This video was quite helpful in making a choice on the matter and explains quite well on how to go about going further.

In the video the guy taps the signal from the underseat woofers, as where I bought the (pretty expensive - after shipping + import duties) harness all the way from Florida. I think it's cleaner this way and less hassle.

Since there are already quite some guides and videos on where to find the RAM and BOOSTER module, as well as how to dismount your trunk to get to them and the Battery as well. I will skip this part of the installation and go right to the installation itself.



The PnP Technic harness connects directly into your BOOSTER unit and you can choose wether you want to power the underseat OEM subs with the OEM Amp, or with an added Amp. I chose the first, as I want to add an extra Amp, for the extra Sub. This means you loop the harness and connect Jack 1 to Socket 3. Connector A is not needed in this option and Connector B is used to connect to your High/Low Convertor, in my case the HELIX AAC.3.



As you can see below the HELIX AAC.3 seems to be connected correctly as the LED turns green steadily.



Next is the RCA Line Out from the HELIX AAC.3 to the GLADEN RC600c1 Amp Line in. Additional you can use the Remote cable from the HELIX AAC.3 to wire the Remote on the Amp, which shows as the blue cable in the pictures.



From the Amp we go to the Battery directly on the right side of the trunk with an added fuse on about 15cm from the Battery. Ground can also be found here next to the Battery.

The speaker cable then goes from the GLADEN RC600c1 in bridge mode at 2 Ohm, to the Audison Sub in bridge mode on 2 Ohm.





So far so good. Until...

Yes unfortunately thats where the story ends for now. Nothing but the sounds of Crickets coming from the added Amp/Sub unit.

So I did some troubleshooting, trying to find out what could be wrong. Also went by a local car audio shop to check my install. Contacted Elias from PnP Technic (who was really fast in replying and troubleshooting with me, highly recommended), no luck yet.

Things I have done sofar:
- Amp supports both High and Low level input, tried both modes
- Try to find online what a blue blinking RUN led on the Amp means - No luck on that
- Disconnected everything again, reconnected, tested again, crickets again

Things I have noticed sofar:
- Underseat OEM Subs are running smoothly via the HK OEM RAM Module. Which leaves to believe that the harness is correctly wired
- The installation was quite easy, maybe too easy

Maybe some of you have gone through something similar or have experience with any of the above used components and are able to point me out in some direction(s).

For now I have contacted the reseller of the components to see if they have any clue, as well contacted another specialized car audio installer about an hour away from where I leave. He supposedly has an M3 that is purposed as demo car for some audio brand (couldn't remember which one), as he was recommended by my local shop, to contact.

So guys, plug and play doesn't always seem to do the trick right away. Maybe a component is just faulty, or maybe something is incompatible. Either way, join me if you like, as we venture our way to a possible solution in getting more kicks, drums and bass. Hopefully.

Oh and if anyone has a tip, even if it might seem obvious, don't hesitate to drop it, thanks!

[FMG20]

Since this topic is so hot, with loads of replies and attention, I can't keep ya'll hanging here waiting for another update.

Went back to the supplier of the hardware, he gave some great service even though they outsource the workshop and build-in's. He couldn't find anything wrong or faulty, but the Gladen Amp, kept on blinking saying something might be off. Whilst checking, we noticed that the HELIX.AAC3 convertor was completely melted (housing).

The regular HELIX.AAC3 has a high level input of max 16v. As the HK Booster can go up to 20v output, we thought this would be the culprit. Helix also has a higher voltage level convertor, the HELIX.AAC3 HP which can hold up to 25v. Therefore we switched that out, unfortunately without any result. Everything stayed the same.

So we decided to switch out the Amp and see if the problem lied with the Amp. Totally different brand, because they didn't have another Gladen at that point.

Since I didn't want to drain my batteries I turned on the engine in between and we switched out the amps. Boom, there it was, it was working(!)

Thinking the Gladen Amp was faulty in some way, I turned of my engine, went inside for another coffee and wanted to go on my way again. Back at the car, started the engine again. Poof, like it came, it also went again without any notice. Just silence again. Everything worked fine, Amp was fine Sub was fine, cabling was fine. But it just didn't work anymore.

Had contact with PnP Technic again to see if he would have any tips based upon this new info/feedback. His advice was not to take the 12v and ground from the PnP Harness, but to take it somewhere from a 12v switched wire/Fuse box and ground from the chassis on the car. So I tried this as well, unfortunately without results.

I'm personally thinking that the issue lies with the HELIX.AAC3 (HP) somehow. And that this convertor just isn't the right fit for the job. Tempted to buy another LOC and see where that brings me.

Also contacted a somewhat more specialized company that does high level upgrades to see if they can fit me in somewhere to check the install and see if they can find where the problem lies. They have some personell issues and a busy planning, so I haven't got my horses up, but they promised to call me as soon as they can fit me in somewhere. Hopefully somewhere in the next 4 weeks.

For those tldr, long story short; switching the hardware worked while connected with the motor running. A shut off and than ignite again after 10 minutes, made the added amp and sub mute again.

Maybe this sounds familiar to someone here, maybe it won't. If it's the latter then let's hope a solution will be found so I can help a future issue with the same system or similar setup.

[I800C0LLECT]

Didn’t read all the details but knowing your equipment I wonder if the LOC is getting overloaded? What is the signal going to the amp? It only accepts 10V

https://www.bimmerpost.com/forums/sh...php?p=30686911

I went ahead and grabbed the one PnP offered. I used auto sense on my RCA so the amp turned on itself through the audio signal. You can do the same with the gladen amplifier

[FMG20]

I went ahead and got myself the LC2i by Audiocontrol which should be able to handle 400WRms or up to 40v. Probably try to fit this one in tomorrow and See what happens.

I really Need to get myself a Multimeter as well, so i can Check all the Input and Output Levels, thanks for pointing that out once more

[I800C0LLECT]

If you don’t have a multimeter you can sort of gain match to the “iconic sounds”. Obviously if they’re ridiculously loud it’s wrong. There’s lots of guys that tune by ear but they’re usually wrong. The by ear will get you close for now.

Also, gain structure changes with volume. By not using a gain knob I can’t adjust for the way bmw factory head unit increases output…I.e. like a speedometer is only calibrated for a specific speed and it’s off outside of that value.

Due to that, I can reach the mechanical limits of the underseat subs very quickly with the extra power I have. In your situation the subwoofer may seem anemic at lower volumes and then get a square wave at higher volumes. I can use the distortion of mid-bass to realize the gain is too high where you can’t. So be careful and don’t let the smoke out.

[MMnut]

Use a multimeter to check if the plug wiring is correct. I just had a simple tap to get high level outputs from the booster wiring loom to my active sub and everything worked perfectly.

Assume G20 is similar to G82 so you can have a reference here
https://g80.bimmerpost.com/forums/sh....php?t=2115198

[FMG20]

Okay so long story short, don't use the ground next to the battery, this particular place doesn't ground very well...

After connecting the LC2i in between the harness and the amp, I still got nothing. And something in my intuition told me to jiggle around some cables, starting with the ground cable. And there was the sound.. FML.

So decided to take the same ground as where the battery is grounded and just added it there. Since then everything all good. Did some tuning with the levels and must say I am all most there, like 90% to my liking as to the end situation that I am aiming at. I might still add a second amp just for the under seat woofers to see where that gets me. I now got the bass that I want, but still miss the punch that I'm looking for.

[I800C0LLECT]

I noticed the punch is missing too. I have added steeper filters to the tweeters and that helped. I also added filters to the underseat woofers so they're mid-bass. That made a difference as well. Eventually, I may swap speakers but it would be nice to have a get together and compare solutions

[FMG20]

I'm curious on how you went on to add those extra filters.
Where in Germany are you located, I am in NRW every now and then for business purposes, but don't mind anyway to cruise some distances in Germany, for obvious reasons

[I800C0LLECT]

I use a JL audio amplifier to power the underseat woofers and that allowed me to add a high pass filter.

For the tweeters, I grabbed some passive hpf crossovers and added them to the doors and center channel. That cleaned up the midrange break up.

I have some low pass filters I haven’t added to the midrange yet. Mostly because the beaming that happens shouldn’t hurt the response all that much since the speakers are off axis. Also, I ran out of the third party connectors I was using so that I didn’t cut the factory wiring.

Also…forgot to update my profile. I’m back in the states again :P Living in Texas now

[FMG20]

Much appreciated, thanks for the detailed description and pictures! This is a bit out of my league for now, so I should do some research first to see if this is something I would start on myself or ask someone with more knowledge and expertise to help me or do it for me.

Haha yes, if there was a tunnel and I could drive all the way to Texas I probably would. HQ of my lady's work is in Texas, so who knows I might join her on her next visit in 2025. Then I will send you a PM, as I am quite curious on how your setup sounds with the mods you made.

Since I have a spare Amp what would be the best way to add this extra amp for the underseat woofers (connection wise). I have the PnP Technic harness with the extra connector. Should I then add this 2nd Amp to the 1st Amp line out, or tap in from the line out of there isn't one? Or somewhere else?

Thanks again, your knowledge and the time you take to explain is very valuable to this forum!

[I800C0LLECT]

The easiest answer might be to use a 5-channel amplifier. I used the Technic PnP harness and it came with an optional plug in wire to power the underseat subwoofers with aftermarket amplifier. That was the easiest way to add a high pass filter for my setup. I am using JL Audio vx1000/5i

I bridged the main channels of the amp down to 2...one for each underseat subwoofer. Obviously, the 5th channel went to my actual subwoofer. I am using 18dB slope on the underseat woofers @50Hz and 12dB low pass filter on the subwoofer at 50Hz.

[FMG20]

Originally Posted by I800C0LLECT

The easiest answer might be to use a 5-channel amplifier. I used the Technic PnP harness and it came with an optional plug in wire to power the underseat subwoofers with aftermarket amplifier. That was the easiest way to add a high pass filter for my setup. I am using JL Audio vx1000/5i

I bridged the main channels of the amp down to 2...one for each underseat subwoofer. Obviously, the 5th channel went to my actual subwoofer. I am using 18dB slope on the underseat woofers @50Hz and 12dB low pass filter on the subwoofer at 50Hz.

Thanks, I will think about this option. But as I have another monoblock lying around I will maybe try to add this one to the party in my trunk.

I'm running into another issue, you could say I am between audiophile and recreative listener. My genres are mainly Techno, Ambient, HipHop, RnB, Hardcore and more electronic music.

As for Techno, Hardcore and EDM I am fine with the current output. But as for Ambient, HipHop and RnB I feel like I'm missing a part of the frequency that should be there. That is where I think the roll off from the LC2i starts to kick in at 33Hz. This is very noticeable in tracks from Massive Attack for example. Why they started at 33Hz in their newer version of the LC2i is a mystery to me, for such a decent product.

As I believe there is no roll of to be heard in the HK system in BMW on the bass as I crank up the volume, it must be the 20-33Hz that I'm missing? Anyone who could confirm this before buying the pro version? This will then be HighLow Convertor number 4

And why do some convertors actually start at 10Hz? Should I be better off with one of those? Then you are looking at the LC7i I believe, but that one has so many channels and is a lot more expensive. And it doesn't have the Subwoofer/Bass line out like the LC2i and the LC2i Pro have.

Any help would be appreciated!

[snekjumpr]

Originally Posted by FMG20

I'm missing a part of the frequency that should be there. That is where I think the roll off from the LC2i starts to kick in at 33Hz. This is very noticeable in tracks from Massive Attack for example. Why they started at 33Hz in their newer version of the LC2i is a mystery to me, for such a decent product.

Any luck filling in the low end? I'm planning a similar build using the PnP Technic harness with their included LOC, a monoblock amp, and dual 10" woofers.

Did you try to level match/set the gains of your system to the LOC like in this video?

I think the guy is correct that it's often overlooked and is the best way of achieving maximum dynamic range.

[FMG20]

I actually bought the LC2i Pro and am quite satisfied and probably adjusted good enough by now. I came from a Match DSP with top notch adjusting done by an audiophile. So coming to the HK factory in the BMW was a big disappointment in regard to bass, on both hearing and that feeling in your belly. I went a step towards a better situation with the LC2i regular, but was missing that lower frequency's. Another step in reaching a desirable situation was installing and tweaking the level and gain. With the final step being the installation of the LC2i Pro version, which completes the sound even more for my personal liking. I do still feel that I am missing something, but I can't be bothered anymore to spend more time and money for now.

So it's not yet to be compared in regard to the total experience I had with the DSP, but it's getting quite close and I am more than happy with the final result.

By the way that is one old looking YT video haha But yes still very basic and good advice

[xtrozero]

I'm looking to do this with my G20 M340i, as my only gripe with the HK system is the bass is lacking. I'm fairly happy with everything else like what was mentioned in this post. So far I've narrowed it down to this technic harness and LOC150i, or the MATCH UP 10DSP. Can anyone help me understand the benefits of the DSP over just using the technic harness to add a trunk sub? I'm confused as to whether or not the DSP is worth it or not, maybe the DSP would add some punch to the underseat subs? Help please lol

[phc77]

Originally Posted by xtrozero

Can anyone help me understand the benefits of the DSP over just using the technic harness to add a trunk sub? I'm confused as to whether or not the DSP is worth it or not, maybe the DSP would add some punch to the underseat subs? Help please lol

https://audiointensity.com/blogs/dsp...ultimate-guide