Hi, fairly new here. I just got an 02 BB back in March. It has a Kaaz diff and I has just put in a Berk 3in catback so for obvious reasons, I can't really hear my music anymore. Lol I was thinking of amplifying my speakers only. I'm not really trying to put in a sub so I got a 2 channel amp. Car already has some infinity 6.5's and tweeters bridged with a crossover. Car also came with an Alpine HU. My question is, when wiring the speaker wires FROM the amp to the car speakers, could I just cut the speaker wires from the HU adapter connected on the car harness and splice the speaker wires I'm trying to connect to the amp on those same wires I'm thinking about cutting? I thought of this as I'm trying to avoid having to run wires through the door grommet so I thought, the adapter already has speakers wire connected to the car harness so why not just run it there? Please let me know if my idea is idiotic. Thanks in advance!

 

You don't mention what sort of amp you have or where you plan on mounting it, but yes, you can can cut the speaker wires in the adapter harness and connect the amp's speaker wires to them. Please don't cut the wires in the car's harness though!
The OEM wires running into the doors are not very big (22ga, maybe?), so if you're planning on running serious power you might want to upgrade them, but Infinity speakers are generally pretty efficient so you probably won't need huge power.
Finally, if you do decide to run new wires into the door, it's not actually that difficult.
Here's a relevant thread.

 

Thanks for the reply! I’m planning on just running a 2 channel Pioneer Amp that I have laying around from my old sub. Was thinking of mounting it under the passenger seat so I won’t have to run the wires too much.

 

I'm actually buying the KTP-445A to do just this. Should be just plug and play. It'll be here Thurs so we will see.

 

Hate to be the bearer of bad news but my buddy and I installed one in his S and immediately removed it. It didn't make his Alpine head unit sound any better. He listens to a lot of rap so that's what we were sampling. No improvement in bass, maybe a tad better in mids and highs if at all. He sent it back. I have an older traditional Alpine 60x4 amp powering my door speakers and it is 100 times better. Sounds like there is a sub in the car. Let us know if you have any success with the 445A.

 

Yeah it's not as powerful as a dedicated amp but its better than stock (or without it)..will see when it gets here.

 

I think you're right. I installed it and it makes very little difference. Volume does get boosts a bit but def not worth the price...going to pull it out and return it when the new replacement head unit gets here (sub output of the old one is not working). Alpine quality is def not like it was back in the days....these craps now are all made in China.

 

Go for the 445u instead, or any other mini amp that does ~100x2.

 

Do you even know the difference between the 445u and 445a ??

 

Whatever you decide, the doors need sound insulation. As higher wattage causes a lot of stuff to start rattling. Including the rear view mirrors.

I think this works best.