[steveintheburgh]

In the interest of sharing the knowledge - below is my successful Factory HK Sub Replacement.

Free-Air Application
Very happy with the results.
$175.00 all in

Sub: Kicker 10C104
https://www.crutchfield.com/S-dYq6wjF9vE7/p_20610C104/Kicker-10C104.html
150W RMS - 4 ohm
$45.00 on eBay

Amp: Kenwood X501-1
http://www.kenwood.com/usa/car/excelon/x501-1/
300W RMS @4 ohm
$85.00 on eBay

Rockford Fosgate 2 Channel Speaker output Adaptor
https://www.crutchfield.com/S-d78WAC7rvi1/p_575RFIF2SW/Rockford-Fosgate-RFiF2SW.html
$10.00 on eBay
*If your Amp choice does not accept speaker level input, go with a Line Out Converter for about the same price.

Harmony 8 Guage Amp Install Kit
https://www.amazon.com/Harmony-Audio-HA-AK8-Complete-Amplifier/dp/B00W5SM17K
$15.00 on eBay

2 square ft of Generic Dynomat
$10.00 on eBay

MDF and Hardware/Spray Paint/Connectors
$10.00


I took a rough measurement of the ski pass opening and cut the MDF to size.
Bottom edge cut at an angle to account for the slanted mount. Used some weather stripping on the bottom to firm that up.

Mounted it using L Brackets which I drilled out to fit the torx screws used to mount the existing sub bracket.

Sound Deadening material cut to size to fill the sides of the ski-pass. I also used 4 small pieces as a sort of washer for the mounting of the MDF to the body (probably overkill)

Amp MDF is a 3/8" bigger around than the amp itself - screwed straight in to the back of the trunk compartment (over the carpet)

Tapped the Adaptor in Pre-Factory Amp using the below connections:
Left+ - 37 (yellow/black) = White
Left - - 29 (brown/orange) = White/Black
Right+ - 8 (blue/black)= Grey
Right- - 16 - (brown/orange) = Grey/Black
If you need Remote Power (this amp didnt) it would go into 10 which is White

Make sure you install an inline fuse which is close to the battery.
There's a ground point just above the battery that works well for the Amp Ground

I'm debating whether to do a customized speaker grill in the center cushion. Honestly, at this point it doesnt seem necessary. Sounds great.

Two final pieces of advice:
1. Get a quality Crimper to do the spade and ring terminals.
2. use plenty long Ground and Power wire to the battery. Cutting to exact size will cause you issues when you re-install the trunks interior.

 

[steveintheburgh]

more pics including HK Wiring going in to the Factor Amp

 

[mrich777]

How does it sound when covered up by the ski pass cover. I just did bsw and would love to do a sub as well.

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[steveintheburgh]

sounds great----leaning towards keeping it intact versus a custom speaker grill

 

[allikanbe]

What are you using for a receiver/radio? The OEM unit sux.

 

[steveintheburgh]

Factory Business CD
It's actually a quality unit......granted from 2004. But makes good sound.

 

[Mbryant616]

I have the same Kicker sub but bought a smaller amp, and I need a bit more power on mine. I may upgrade to your amp. I also agree that you don't need to cut open the ski pass cover. You are looking to FEEL the bass, you don't need to hear it from the cone. It sounds the same on mine with it on or off. I just need more boost to the sub only and less to the factory speakers.

 

[steveintheburgh]

The one I have provides plenty. 300 RMS versus the Subs 150
Glad you are seeing success!

 

[dknightd]

How does that work to take stereo output from head unit, and connect it to mono input on amp?

 

[steveintheburgh]

dknightd
Rockford Fosgate 2 Channel Speaker output Adaptor
https://www.crutchfield.com/S-d78WAC...e-RFiF2SW.html
$10.00 on eBay

Takes the 4 speaker wires and converts to 2 RCA
the sub is Mono

 

[MalHammer]

Nice DIY/build of the free air subwoofer and thanks for answering my question in the other post regarding the amp location.

Apologies for the long post

I am about to do the same exact install as you regarding the subwoofer, although I am going a little smaller. (Subwoofer Rockford Fosgate P2D2 - 8", AMP RF R500X1D 500Watt. Before I do that, I was thinking about upgrading the HU to an Eonon G7150.
You had mentioned in the other post that replacing the factory amp is also a big win, so I have a few more questions for you.

The audio upgrade plan is as follows:
1. Done. Replace all the BWW stock speakers with a BSW Stage #1. They sound much better than stock, but need more lower end, hence the subwoofer project.

2. In the works. Replace the BMW Business CD HU with a Eonon G7150 HU. This HU has 45 watts/channel, but I am not sure it will be enough. Using the supplied wiring harness adapter, I can hook into the BWM audio wiring harness. This will take the line outs to the factory amp, located in the driver side rear arm rest panel .

Question #1 - leave the factory amp or get a new one?

3a. Leave the factory amp in place with all the current (npi) wiring in place to the speakers. Jump step #4 subwoofer install.

3b. If I were to replace the factory amp, what would I need to do besides, obviously getting a new 4 channel amp (4x100w should do it).

Question #2 - 4 channel amp recommendation to drive BSW Stage #1?

Wiring option #1: Use the provided wiring harness from the new HU to stock BMW wiring harness to the amp location. Then sort out the individual wires for each of the speaker locations to the amp. Then from the amp use the stock BWW wiring harness to the speakers.

Wiring option #2: (seems easiest): Run line out from the new HU via RCA to the new amp and then use the stock BMW wiring to the speakers

Wiring option #3: (seems the hardest) Run line out from the new HU via RCA to the new amp. Then wire each speaker with new wiring from the amp.

Question #3 - Which is the best/easiest wiring option?
Question #4 - I know that the factory amp has crossovers built into it. Do I need to do anything about the crossovers or can I run the speakers wire straight to the speakers?

4. Subwoofer Install - I planned on doing the same type of subwoofer install as you in the ski pass through. I am going to build a 5 sided box from MDF for the subwoofer with the back open to the trunk.

Question #5 - Is there any benefit to having a 5 sided box vs only having the subwoofer mounted on the one side with dynomat for the other sides?

Question #6 - MDF thickness 1/2" or 3/4"?



Thanks for your responses.

 

[steveintheburgh]

I cant speak to replacing the factory amp as I left mine - and frankly it's been fine. I also left my stock HK speakers and Business CD HU as well, though.
In theory, removing the sub from the factory amp should free up some power.....take that for what you will.
End of the day I'm very happy with the sound I am getting w/ the factory speakers/amp/after market sub and sub specific Amp.

As for 5 and 6
I used 3/4 just because that was available.
1/2 would probably suffice and would be better if you are building a box in the ski pass (less bulk)

As for a box or Dynomat -
The audiophile will say an enclosure (or MDF sides) would be better.
I personally think mine turned out perfectly fine for about 10.00 in material and cutting to fit w/ a razorblade.
NOTE---my sub is designed for Free Air versus some that need an enclosure.....so keep that in mind.

Building a box shouldn't be too crazy a task. There are DIYs here and online.
There's also a guy on eBay that sells a pre-made box. (search "e46 sub enclosure"). He also sells the mounting board which is precisely cut to fit. I decided it was overkill for what I was going for....

Good luck!

 

[steveintheburgh]

Another thing to keep in mind...Convertibles a HORRIBLE environment for trying to capture quality sound. Top down worse than top up---but both are not ideal.
Thus I went for the most noticeable bang for the buck w/ the sub upgrade.

 

[MFNATIK]

Great post! Looks great what you did!

 

[CarbonZHP]

Probably a better option than what I did. Had to cut the box down to fit mine

 

[MFNATIK]

Tapped the Adaptor in Pre-Factory Amp using the below connections:
Left+ - 37 (yellow/black) = White
Left - - 29 (brown/orange) = White/Black
Right+ - 8 (blue/black)= Grey
Right- - 16 - (brown/orange) = Grey/Black
If you need Remote Power (this amp didnt) it would go into 10 which is White

Steve - do you have a pic of this part? And where is the pre-factory amp location? I hope its not in the driverside passenger area in the cabin is it? I thought I saw the amp attached to the side wall when I had my rear interior out to clean. I suppose the rear seats will all be coming back out since I'll be removing the factory sub and installing the new unit. Any advice is appreciated! Sub is supposed to be here on Thursday!

 

[steveintheburgh]

Thats exactly where it is.
You're going to have the entire back seat out, along w and the drivers side rear panel.
You're going to want to unmount the bracket, then unplug it. Before the plug will be where you tap in.
You'll want to confirm that the numbers on the plug and the wire colors co-relate.

I originally used quick tap connectors. Ended up just cutting the wires and using Wire Nuts - they felt more secure to me.

my main advice is to check out some other DIYs on this forum. the more info you have going in, the better.
also-from my post above:
Two final pieces of advice:
1. Get a quality Crimper to do the spade and ring terminals.
2. use plenty long Ground and Power wire to the battery. Cutting to exact size will cause you issues when you re-install the trunks interior.

 

[MFNATIK]

more pics including HK Wiring going in to the Factor Amp

The one picture I think you left off (wiring to factory amp) is the one that would be really helpful for me. Hopefully you can repost it. Thanks!

 

[MFNATIK]

Thats exactly where it is.
You're going to have the entire back seat out, along w and the drivers side rear panel.
You're going to want to unmount the bracket, then unplug it. Before the plug will be where you tap in.
You'll want to confirm that the numbers on the plug and the wire colors co-relate.

I originally used quick tap connectors. Ended up just cutting the wires and using Wire Nuts - they felt more secure to me.

my main advice is to check out some other DIYs on this forum. the more info you have going in, the better.
also-from my post above:
Two final pieces of advice:
1. Get a quality Crimper to do the spade and ring terminals.
2. use plenty long Ground and Power wire to the battery. Cutting to exact size will cause you issues when you re-install the trunks interior.

Thanks for confirming for the good advice. I like you idea of using the low level inputs from the pre-amp than tapping into the speaker level sub output. You're right, any extra power saved from not powering the sub would be better off for the amp and other channels. I'm sure it only has one power supply like most modern amps.

 

[steveintheburgh]

That's referencing the card showing the wire colors and pin outs. I didn't take a pic of the the factory amp.

What you will encounter is a bunch or wires wrapped together. You unwrap them - single out the wire in question and go to work one at a time. Once finished, re-wrap the whole gob back together.

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