[MPR]

Here is my current subwoofer setup. Not sure I'm 100% happy with the amp rack. I do like that it's out of the way, but it isn't secured to the car very well, it's secured using a heavy gauge wire that is secured to the back of the amp rack and runs through the cargo liner panel behind the rack (see pics below) - so it's not going anywhere, but, eh. You can see it behind the amp rack in the first image below. I am trying to avoid cutting/putting holes in anything, except for the pin sized hole in the cargo liner. Still need to do a little more wire organization.

I'm considering either mounting the amp to the sub box, which I've never been a fan of, or building a flat amp rack to sit in front of the subwoofer. But then it's consuming trunk space and may collect more dust/dirt. If anyone has any ideas that avoids drilling/cutting holes into anything, please share.

It is way more bass than I was planning for. The gain on the LC2i is set to output 5V to the RCA's, which is the amps max allowed input, and the amp gain is at around 7 o'clock. The amp does not even get warm to the touch after 1+ hours. Best bang for your buck amp IMO.

• Sundown Audio SA-12 D2 subwoofer (v1, rev3) wired at 1-ohm
• Sundown Audio SFB-1000D amplifier 1000w RMS x 1 @ 1-ohm
• AudioControl LC2i Pro
• Skar ported enclosure, 2 cube feet tuned to 36hz
• Technic PNP plug-n-play harness
• KnuKonceptz 4 awg OFC power wire
• Amp rack built using MDF
• Wire ferrules used on all connections

[MrPickles]

Did you add this to the base radio or the Harmon Kardon?

[MPR]

Originally Posted by MrPickles

Did you add this to the base radio or the Harmon Kardon?

Harmon Kardon - I left the OEM under seat subs disconnected via the Technic PNP harness.

[MrPickles]

Originally Posted by MPR

Harmon Kardon - I left the OEM under seat subs disconnected via the Technic PNP harness.

Oh sweet, I was hoping someone would be the Guinea pig for this. How much do you have in the set up? The Harmon Kardon system is really, really good. But adding an amped sub for real punch I imagine would take it to the next level.

[MPR]

Originally Posted by MrPickles

Oh sweet, I was hoping someone would be the Guinea pig for this. How much do you have in the set up? The Harmon Kardon system is really, really good. But adding an amped sub for real punch I imagine would take it to the next level.

What do you mean by how much do I have in the setup? Total cost?

The stock Harmon Kardon setup is decent for a factory setup, but the bass punch is lacking as there are no true sub enclosures - BMW did what they can to suit the majority. The bass level is now insane.

[MrPickles]

Originally Posted by MPR

What do you mean by how much do I have in the setup? Total cost?

The stock Harmon Kardon setup is decent for a factory setup, but the bass punch is lacking as there are no true sub enclosures - BMW did what they can to suit the majority. The bass level is now insane.

Yes, cost is what I was after. I did a quick Google search on the main components and it seems to be pretty inexpensive. Looks like there's plenty of trunk space maintained as well. I like it!

[MPR]

I already had the subwoofer, everything else I bought. Probably around $1,000 if you need everything.

Here's a breakdown from what I remember

Sub - $250-$300 (I bought it 10 years ago for around $250 IIRC)
Sub Enclosure - $90 on Amazon
Amp - Around $200, can likely be found for even cheaper
LC2i Pro - $140 on Amazon
Power wire - Around $30
Fuse holder - $5 on Amazon
Ground/12+ connectors - $5-$10
MDF - $10ish
Carpeting for amp rack - $10
Adhesive for carpet - $10
Short RCA's - $10
Wire to run from Technic harness - $10ish
Speaker wire - $10

[MPR]

Originally Posted by MrPickles

Yes, cost is what I was after. I did a quick Google search on the main components and it seems to be pretty inexpensive. Looks like there's plenty of trunk space maintained as well. I like it!

There's plenty of space, but it's challenging when taking the below things into consideration.

1. No cutting/permanently changing anything
2. Keep what is visible at a minimum
3. Make it look presentable - this is a $60K BMW

Aside from poking a small hole in the cargo liner, I only removed factory parts that can be put back into place. What I am referring to is the hook thing behind the tail light on the drivers side. With this removed, it gave me a place to route all wiring into the trunk to go to the amp and LC2i. I also removed the little cargo net where the amps are, which I can replace.

While I don't think it looks ghetto, I don't like that it's not more secure to the car. I'm trying to figure out a better place to mount the amp. I may end up tucking the LC2i away under the cargo liner, near the factory amps. There may even be room for the amp down there.

[MrPickles]

You're definitely off to a great start. You've absolutely inspired me. I also appreciate minimal and reversable modification.

You mentioned this is putting out more bass than you intended. Any thoughts on stepping down to a 10" sub?

[MPR]

Originally Posted by MrPickles

You're definitely off to a great start. You've absolutely inspired me. I also appreciate minimal and reversable modification.

You mentioned this is putting out more bass than you intended. Any thoughts on stepping down to a 10" sub?

I'm going to stick with my 12" sub and just keep the amp gain low, this will keep the it running cooler, which will be good if I do tuck it away. The amp has a bass knob that I am going to mount up front, so if I'm ever in the mood for insane bass, I can easily crank it.

If I was piecing together a new system, I would consider going for a 10" sub, it's plenty if you give it enough power and the enclosure will be slightly smaller.

[MrPickles]

Thanks for all the info. I'm definitely going to look into doing something like this. Looking forward to see what you do in the meantime.

[Coconut]

Do you know the frequency range the stock 8” bass drivers play? From the research I’ve done, BAVSOUND shows these drivers playing from 20-500hz. To me it I don’t think they go down to 20hz, they probably have a subsonic filter around 40hz. They maybe actually play up 500hz since they are pulling double duty for sub-bass and midbass. You mentioned disconnecting the 8” woofers, does that mean your sub is playing >100hz??

[MPR]

Originally Posted by Coconut

Do you know the frequency range the stock 8” bass drivers play? From the research I’ve done, BAVSOUND shows these drivers playing from 20-500hz. To me it I don’t think they go down to 20hz, they probably have a subsonic filter around 40hz. They maybe actually play up 500hz since they are pulling double duty for sub-bass and midbass. You mentioned disconnecting the 8” woofers, does that mean your sub is playing >100hz??

I do not know but was wondering about that through this install project. I was thinking I may now be missing mid range. I may reconnect the OEM sub amp, worst case scenario the stock subs are doing work for nothing.

[Coconut]

I’m guessing you have your sub lowpassed around 100hz. If so you definitely are missing a chunk of that midbass. You can test this out by playing a frequency sweep to hear where the null is. However it still might be coming through from the rear speakers depending which HU mode you’re in. Either way it’s not ideal to have your rear speakers handle the midbass since it is directional. What you could do is reconnect the underseat drivers and hook up an inline high pass filter to block out anything below 100hz or whatever your subs low pass is or perhaps AudioControl makes a 2-channel crossover so you can hook up near the factory amp in he trunk.

[MPR]

Lowpass on the amp is at 80hz, and the high pass filter on the amp acts as a subsonic filter, which is set to around 30hz which I used test tones to set with a multimeter. I have a feeling the stock system handles bass and midbass through the same amp and I'm going to reconnect it tomorrow.

[Ruebarb]

With the Technic harness plugged in, I'm missing the rear right speaker, bass only. I got an email into them, did you have anything like this? Thanks

[MPR]

Originally Posted by Ruebarb

With the Technic harness plugged in, I'm missing the rear right speaker, bass only. I got an email into them, did you have anything like this? Thanks

I had an issue where I was getting minimal bass and my sub amp was clipping on basically bare minimum out out.

It turns out that the plug on the Technic harness fits into both of the modules in the trunk and I had it plugged into the highs/mids amp instead of sub amp.

Not sure if this is the cause of your issue. Did you make sure the other plugs on the harness are connected correctly, as a pass through?

[Ruebarb]

Originally Posted by MPR

I had an issue where I was getting minimal bass and my sub amp was clipping on basically bare minimum out out.

It turns out that the plug on the Technic harness fits into both of the modules in the trunk and I had it plugged into the highs/mids amp instead of sub amp.

Not sure if this is the cause of your issue. Did you make sure the other plugs on the harness are connected correctly, as a pass through?

I had no idea there were 2 amps, every pic I have seen had it plugged into the radio.

Which should it be connected to A or B?

[MPR]

Originally Posted by Ruebarb

I had no idea there were 2 amps, every pic I have seen had it plugged into the radio.

Which should it be connected to A or B?

The bottom unit B, IIRC

[Ruebarb]

Originally Posted by MPR

The bottom unit B, IIRC

Thank you, a big Doh moment. Well, guess it should work correctly now if I plug it into the right device.

[VegasG42]

Were all these things needed to complete the install ?





Doing the precursory research to add a sub to the base stereo , and don't want to buy anything that's not needed

https://technicpnp.com/product/base-...audio-systems/

[MPR]

VegasG42 I bought the $65 kit, and you use I believe all except maybe one small plug. If you go with the No LOC option, you must provide your own LOC, which I did with the LC2i Pro.

Top HiFi (Option 688) Add-a-Sub Harness for RAM/Booster audio systems - T-Harness only/No LOC-150