[rockyfeller]

First thing to say is that the Technic PnP add a sub T harness, ASD bypass harness and a LOC are 3 different things. Your installer may not necessarily know how the B&O system is wired up and because of ASD it's just not conventional the way it is like most cars out there.

The whole point of using the Technic add a sub T harness is that you don't have to splice into the factory wiring for an audio input to your amp and make a mess. These wires will be inputs that then go to your LOC. By using a harness you can easily reverse this process in the future when you sell the car and revert to stock. No harm done and the next owner won't have a clue anything has been done. Worth $50 if you ask me. Don't expect most installers to give a damn about hacking up your wiring and directly tapping in to get inputs for your LOC. They only care if you're happy right after install and are always looking for the easy and fast way to get it done. If you don't know nothing about cars, it's all hidden behind the carpeting and you'll have the next owner of your car cursing you out if they find out about it.

So it's not about a choice between the kicker LOC or the Technic. You should be using BOTH if you ask me. The harness will run audio through the ASD and that's what causes the ASD rumble to come through the subs. You can live with it, like me. Or opt to have it bypassed.

So to get rid of this you need the Technic ASD bypass harness and it will keep the ASD rumble out of the audio signals to the sub. This is not a required step. Just optional. For most people, it will be worth it for that clean signal. You'll get the pure audio from the head unit. Another side benefit from the ASD harness vs. unplugging is that you will avoid any error codes from coming up. The computer will see it as an error if you unplug the ASD harness. I don't know the impact of sound quality as I don't have the ASD bypass myself, but I'll venture to say it shouldn't have any impact. The harness has no influence on the hardware side of things because it's not processing anything. It's just physically separating the audio signal from the ASD signals purely from a wiring standpoint.

Let me give you a better idea than the ASD bypass though. Just code ASD out! If you have BimmerCode it will cost you nothing. Many installers might not mention this option to you because they simply don't know how to do this. Just look up info on this forum. Easy as pie.

I don't have any experience with the Kicker LOC. Only the AudioControl LC2i. I can't say enough good things about it. It's one of the most popular LOCs out there and really outputs a good signal. I have mine attenuated quite a bit. It has a lot more headroom if I need it. Plus it's a really affordable unit for an active LOC. No need for more than 1 LOC. The whole idea of the LOC is to take audio inputs from the car and output them to your amp. After looking at that Kicker from the link you posted, it looks like it will work good as well. I don't think you can go wrong with either one.

With wiring and distribution blocks there are plenty of quality brands out there. Stinger is pretty good. Stick to no less than 4GA wiring. 2GA even better. You'll need a nice 150A, or more, ANL fuse. And please don't underestimate the value of a capacitor. Some say it's not necessary but I think that's crazy. I swear by them. Make sure you have a bass knob either from your amp or LOC underdash. Invaluable if you ask me. Fine tunes and dials the bass in.

Strong low end is hard to achieve with low profile. No magic about it, they're nearly inversely proportional. We all wish we could have it all but there's really no substitute for airspace. Space saving subs are going to sacrifice low end in order to benefit from the convenience of trunk space. If you're not much of a basshead or don't know any better, sure, it may do. But I do happen to know better and I've never heard a system like that that's ever sounded impressive to my ears. There's just better options out there if you ask me.

I know most of us are from the 90s era of thinking that only 2 subs will do in the trunk. But what does that do? It kills our trunk space and our ears. It's overkill most of the time. Unless you're really after SPL which I'm not. Technology has really improved today and 1 really good sub can sound way better than 2 mediocre ones IMO. I personally just did this upgrade myself a few months back. I now have a single RF 12" that can handle 1200 watts RMS. It kills my old setup with 2 Infinity Kappa Perfects (king of accuracy combined with high sensitivity) Best of all I gained a LOT more trunk space. But truth be told, even with that 1 sub theres still a space premium over a lower powered sub. But that price is well worth it if you ask me. It rocks your socks off and it's more than I need. No one believes me that there's just 1 sub back there till I open my trunk.

If you have a bit more budget, I know I'm old school, but you can't go wrong with JL W7s. Almost 20yr old design but few subs that are as super powerful and accurate. Again, all you need is just one! Your underseat 8" will still fill in its role but more a midbass if compared to your trunk sub. Rounds out the sound perfectly if you ask me.

Lastly I recommend options with loaded subs whenever possible. The enclosures are made specifically by the manufacturer for the sub. No guesswork needed. I've never heard an installer say that they don't know what they're doing. Apparently many just don't. I've heard too many great subs in terrible enclosures or fancy looking fiberglass trunk setups that look awesome but sound terrible. My setup is self installed and kills em.

I know a car interior is not an ideal environment for audio quality but I'm spoiled. The audio setups I have all over my house are so way beyond better and that's what my ears are used to. Personally I'm just not a huge fan of the B&O system. It's good. But way overpriced for what it is. Beyond adding subs it's hard to do much else. If you want to make a substantial difference you just have to do a full replacement. It would be real sad and take a lot of guts to rip out such an expensive and complex system. Personally, I just can't do it. I just accept that there are limits and compromises to be made in order to keep it reasonable.

All this research is worth your time. The end result will be surely something that sounds good to your ears.