Bang and Olufsen (B&O) Subwoofer / Amplifier Add-On DIY

[mr shickadance]

Sorry for posting on an old thread but I am looking to do this now also. My question is what if the frequency range of the stock sub because if you tap into its signal then I assume that will also be the frequency range of your aftermarket sub. I am afraid that its range does not go very low to get those really low bass notes that I love. Does your setup hit the low notes hard? Thank you.

then just tap the right and left rear speaker for the full spectrum and use the amp's cut-off to tune it down.

The B+O amp int eh back powers all the speakers, not just the sub, so it's just a matter of tapping different wires.

[Pawan2013]

then just tap the right and left rear speaker for the full spectrum and use the amp's cut-off to tune it down.

The B+O amp int eh back powers all the speakers, not just the sub, so it's just a matter of tapping different wires.

The left and right speakers aren't filtered? I would think that they are cut off much higher then the sub would be

[Mr. Spectacular]

I've just got the signal from the Sub wires and am happy with frequency reproduction. Unless you're hyper-audiophilic, that should be plenty. I also have an Audio Control LC2i to assist with bass reproduction past the roll-off point but other than that pretty good. Haven't been able to compare with a setup tapping left and right speakers for the signal though.

[mr shickadance]

The left and right speakers aren't filtered? I would think that they are cut off much higher then the sub would be

they could be, I am not positive, I know if you need to tap a high powered wire and use a LOC to get it into an RCA cable that you typically tap the rear L and R speakers to do so giving you the full spectrum.

I wouldn't imagine the stock AMP is so advanced that it's filtered, but it could be.

I mean the proper way to do it would be to run something similar to a JL Audio Clean Sweep and pull from the stereo outputs from the MMI to begin with. But now you are tlaking about adding a step that could cost more than the sub and amp put together.

If you were seriously considering upping your audio quality, this would be a no brainer, but for people looking to improve the stock sub with something a bit more powerful, than tapping the stock sub leads is just fine.

[jackp311]

Sorry for posting on an old thread but I am looking to do this now also. My question is what if the frequency range of the stock sub because if you tap into its signal then I assume that will also be the frequency range of your aftermarket sub. I am afraid that its range does not go very low to get those really low bass notes that I love. Does your setup hit the low notes hard? Thank you.

No worries. I tapped the factory sub signal for this. No issues with playing low. I have several tracks I use for testing. Some are pure tones. I noticed a pretty flat response down to sub 30hz - the natural gain of the cabin helps as well. Don't let that be a reason to find a workaround, it works perfectly fine. Some folks tap the rear door speakers, that I advise against. If doing that, at least grab the front as they are 8". But either way, I tap at the amp side (who wouldn't) so it's just a matter of grabbing the right wires. So why not grab the sub ones?

[Pawan2013]

No worries. I tapped the factory sub signal for this. No issues with playing low. I have several tracks I use for testing. Some are pure tones. I noticed a pretty flat response down to sub 30hz - the natural gain of the cabin helps as well. Don't let that be a reason to find a workaround, it works perfectly fine. Some folks tap the rear door speakers, that I advise against. If doing that, at least grab the front as they are 8". But either way, I tap at the amp side (who wouldn't) so it's just a matter of grabbing the right wires. So why not grab the sub ones?

Thanks for the reply, so just to make sure, you grabbed the wires coming out of the amp going to the sub, not any wires before entering the amp, correct?

[mr shickadance]

Thanks for the reply, so just to make sure, you grabbed the wires coming out of the amp going to the sub, not any wires before entering the amp, correct?

if you plan on using the high-current wires, yes, pull the ones going from amp to sub.

[jackp311]

That's the only wires you'll be able to use. The amp takes fiber optic in. No tapping of that.

[Pawan2013]

Alright, I think I got this figured out. Thanks for the help everyone!

[SteveYem]

I am using an LC2i line-out converter between the B&O amp and my aftermarket subwoofer amp. The LC2i is wired as such:

* Remote In from switched 12V supply
* Constant +12V from battery
* Grounded to chassis
* Remote Out to aftermarket amp Remote In
* Stock subwoofer wires to Left (+) (-) input of LC2i

The issue is, when I turn off the car but have not opened the door yet, the stereo is still playing but the subwoofer does not fire. I suppose it is due to the LC2i getting switched 12v power for its remote input. The reason I am using switched 12V is that I was unable to make the LC2i work using line-level signal as the remote turn on. I even asked AudioControl tech support if it was due to using only the Left (+) (-) inputs and not both Left and Right, but they said that's not the case because the unit gets its line level remote signal from the Left channel input.

Can anyone suggest a way that I can connect this so that the subwoofer keeps firing when the stereo is running but the car is turned off?

[14S4GWM]

Did they give you an explanation as to why it's not working at all for the signal switch? Did you make sure it was switched on inside the unit.?

The only thing I can think of is to run an unswitched line to it but that's not what you want to do. I'm sure shickadance will have something to say.

[SteveYem]

Did they give you an explanation as to why it's not working at all for the signal switch? Did you make sure it was switched on inside the unit.?

The only thing I can think of is to run an unswitched line to it but that's not what you want to do. I'm sure shickadance will have something to say.

The line level remote turn-on feature (GTO in AudioControl speak) is set from the factory to be enabled. There isn't a switch, but rather a little jumper plug in the side of the unit that can be moved from the 'Enable' to 'Bypass' position. I tried doing that yesterday but when I put it in Bypass mode it didn't seem to do the trick. I will try that again today, though.

EDIT: While I'm in here asking questions......The first challenge was installing everything which I have completed, save for my remote turn-on question above. Now it's time to tune this thing. As it stands now, kick drum sounds OK but any time there are extended bass notes or a moving series of bass notes, it just sounds boomy/muddy/bad. Is there a tuning-for-dummies guide that might go over the following items:

* Where to set the AccuBass, Main and Bass level knobs on the LC2i
* What frequency to set the crossover on my amp
* Where to set the gain on my amp versus the gain levels on the LC2i

Keep in mind I am running an 8" sub as I'm sure that makes a difference for tuning.

[mr shickadance]

crutchfield has a great write up on how to tune your amp for your sub.

[SteveYem]

crutchfield has a great write up on how to tune your amp for your sub.

Thanks, I will do some reading this weekend.

Meantime I have another issue: for whatever reason, my LC2i does not power on from the line level input coming off the stock amp, so I had to run my +12V remote input from switched +12v fuse panel up in the front driver side of the cabin. The amp that powers the sub receives its +12V remote signal from the LC2i. I noticed that when I turn the car off (i.e. shut down the engine via the ignition button) the stereo keeps playing as usual, but the LC2i and amp turn off. I then tried moving the jumper from the GTO position to the Bypass position on the LC2i and it behaved the same way.

Is there a way around this or is it the nature of the beast due to getting its +12V remote signal from a switched source?

[Mr. Spectacular]

@steve. That's the nature of the beast. You don't want that draw on the battery anyways without the alternator running. How often do you anticipate being in the car ignition off bumping your tunes?

Also, for future reference of others, getting switched power can be done from the back fuse panel in the B8's, but it seems easiest to pull switched from the front fuse box in the B8.5's since they don't have a switched row in the back trunk.

🏼


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[mr shickadance]

Thanks, I will do some reading this weekend.

Meantime I have another issue: for whatever reason, my LC2i does not power on from the line level input coming off the stock amp, so I had to run my +12V remote input from switched +12v fuse panel up in the front driver side of the cabin. The amp that powers the sub receives its +12V remote signal from the LC2i. I noticed that when I turn the car off (i.e. shut down the engine via the ignition button) the stereo keeps playing as usual, but the LC2i and amp turn off. I then tried moving the jumper from the GTO position to the Bypass position on the LC2i and it behaved the same way.

Is there a way around this or is it the nature of the beast due to getting its +12V remote signal from a switched source?

The reason is because your speaker line level input is not going to trigger that, you want something that will deliver a 12v signal on turn on. Common is is to tap the cigarette lighter for a amp turn on lead, as they shut off when the car shuts off.

[doug97gxe]

anybody saw this http://www.ceoutlook.com/2015/10/27/...-in-ten-years/

as a JL Audio hater i'm really considering this.. i wonder how much cleaner it will be

[zcspec]

I attempted this project with no success. The 2015 allroad does not have a row of red 12+ switched sources. Even Best Buy recommended for me to grab the switched source from the cigarette lighter from the front. I'm not about to tear up my car just for that. Anyone try anything different?

[Drunktank]

I think the red row went away with the B8.5. Either way, just run a small wire from up front on the very left side dash fuse door, under the door sills to the back. It will take you 10 minutes and you don't have to remove anything.

[SteveYem]

I think the red row went away with the B8.5. Either way, just run a small wire from up front on the very left side dash fuse door, under the door sills to the back. It will take you 10 minutes and you don't have to remove anything.

I did this. I found it to be a bit of a pain in the ass and took me longer than 10 minutes, but it was much better than tearing apart any of the interior to tap the cigarette lighter. I bought a Tap-a-Fuse which plugged right into an empty slot in the switched +12V bank.

[doug97gxe]

I attempted this project with no success. The 2015 allroad does not have a row of red 12+ switched sources. Even Best Buy recommended for me to grab the switched source from the cigarette lighter from the front. I'm not about to tear up my car just for that. Anyone try anything different?

relay .. been using it since Sept now no problems

Finally got my ID Max in.. The directions for the turn on lead was for a B8.. There is no red row for the B8.5 all the rows in the truck were live .. Ended up tapping a relay





I first fired her up I had my amp on 5 from my prior car wow the bass blew me away .. Currently running it at 3 and I turned the bass down in the mmi to 1/4

However im still tuning.. Also have some 175 amp quick disconnects to install since I have kids and will need the trunk free at times




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[zcspec]

Just a quick update to my remote source dilemma. The solution to my issue was literally right underneath my nose. In the process of removing the side panels in the trunk, I disconnected a 12+ power plug and completely forgot it was there. I'm not sure if the A4/S4 have it, but the alloard has this power source plug in the back. It supply's 12+ when on, and turns off with the ignition. The installer from Best Buy and I completely disregarded the connector as I told him it didn't plug into anything. Well, I tested the plug, problem solved! Now I need to decide if I want an "all in one" or do I want to go with a separate amp and sub. I just want the low end filled; not trying to shake the fillings from my daughters teethes when they sit in the back.

[doug97gxe]

Just a quick update to my remote source dilemma. The solution to my issue was literally right underneath my nose. In the process of removing the side panels in the trunk, I disconnected a 12+ power plug and completely forgot it was there. I'm not sure if the A4/S4 have it, but the alloard has this power source plug in the back. It supply's 12+ when on, and turns off with the ignition. The installer from Best Buy and I completely disregarded the connector as I told him it didn't plug into anything. Well, I tested the plug, problem solved! Now I need to decide if I want an "all in one" or do I want to go with a separate amp and sub. I just want the low end filled; not trying to shake the fillings from my daughters teethes when they sit in the back.

Pic of source?

[zcspec]

Pic of source?

[jason bouchard]

So I have a 2014 S5 Coupe (b8.5) with the Bang and Olf system. I located the Blue and yellow and the White and Yellow wires and was just about to splice into them until I saw this post, my questions are:*

- So for the newer B8.5 models its the Blue and Brown and Blue and Red wires or the Blue and yellow and the White and Yellow wires ??

- also is the blue/brown the Neg and the Blue/Red the positive?

- Any drawbacks with keeping the stock sub connected and just tapping the wires for my amp/ and LC2?

- And lastly, has anyone found any wire that is a remote or turn key powered 12v+ line for the converter and amp remote wires?
( I see the pic of that relay above, which pin of the relay works and that is a switched power source?)

Also, which 12v+ did you guys use for your 2Ci line out unit? would it be okay using a switched power line for that and maybe just use the remote line connection? I did everything tonight except for the 2Ci box connection and the remote wire. everything else is ran connected etc.*

Thanks guys and Happy Easter

[Fresh.S4]

I have the BO amp from the trunk if anyone needs. Pm me

[jason bouchard]

So I got everything working, used the pin from the relay so the amp shuts off with key off. and I used the red and blue and brown and light blue twisted pair of wires, everything is installed. but I have some questions:

with the 2ci line out converter, I have the two speaker wires from the stock B&O and lengthen them and connect them to the 2Ci do I bridge them using the + of the left side and the - of the right side? or do I just use one side?

The reason I ask is because it doesn't really sound all that good, I am using a 10inch sub and 400 watt amp which I have in my TT, and which sounded great in that vehicle.

Thanks

[mys4.org]

So I got everything working, used the pin from the relay so the amp shuts off with key off. and I used the red and blue and brown and light blue twisted pair of wires, everything is installed. but I have some questions:

with the 2ci line out converter, I have the two speaker wires from the stock B&O and lengthen them and connect them to the 2Ci do I bridge them using the + of the left side and the - of the right side? or do I just use one side?

The reason I ask is because it doesn't really sound all that good, I am using a 10inch sub and 400 watt amp which I have in my TT, and which sounded great in that vehicle.

Thanks

When I was running the LC2i I tried all combination of wiring the channels and ran into the same issue... it just doesn't sound that great. I've said it before and I'll say it about but I'm not a fan of the LC2i. I went with an amp with a built in line out convertor and it sounded better. It still doesn't sound as good as a dedicated sub out line from an aftermarket head unit. The problem is the factory amp is screwing with the sub signal with odd frequency cut-offs... Not a lot we can do

[jason bouchard]

damn that sucks, any way to turn off the "cut-off" my amp has some low level input connections but I lost the little connector with pin-outs ( its an old kenwood)

[primaryw]

Question for the B&O owners.

Is there an actual bass roll-off from the B&O amp?

Just had a line level converter installed and I'm feeling like there is missing bass. I didn't go with the LC2i and am thinking that was a mistake. But it's a correctable mistake, ya!