Every since I bought my 2001 TT Coupe 6 months ago, I've been dying to upgrade the stock sound system. As a first step in

doing so, here is a DIY for replacing the stock rear subs for a coupe with the Bose System. I chose a Tang Band 6.5" sub

http://www.tb-speaker.com/detail/1230_04/w6-1139si.htm because it is capable of delivering very low frequencies compared to

some others. They are also 4 ohms each while the stock speakers are 2 ohms, but it's always OK to go up in impedance, just

not down below the rating of the amp. The down sides are that it only has 83db Sensitivity, which means you'll need a lot of

power to drive it, and the 4 ohms also drop the power in half from 2 ohms roughly. Although, according to my Bose Concert

manual, the stock system has 180w/5 and the speaker is only 50W RMS and 100W Program. Having installed the speakers now, I

think the stock power is fine for now and they deliver much better lows and the rattling is gone with the bass set to about

+3.

Another thing you will want to do is reprogram your radio using a VAG-COM to change from Bose to Other. This allows the

speakers to receive a better frequency response and you can actually drive them harder. Do a search for this procedure,

please don't ask me how to do it as it is well documented in many places. I bought 100hz low pass filters, but ended up not

putting them in because the rear speakers in the Bose system are already crossed over.

Now don't get me wrong guys, this isn't going to rattle your whole car like a couple of 18" subs with a 1000w RMS amplifier,

but for about $50 a speaker, this is well worth the upgrade.

This installation isn't for the timid, as it will require some power tools, star bits, a dremel, and some hand tools. Below

are the required components:

1. 2 Tang Band Speakers http://www.tb-speaker.com/detail/1230_04/w6-1139si.htm
2. A power drill
3. 3" hole saw
4. A dremel with cut off wheel
5. Socket Set with deep well metric sockets and torx bit
6. 1/16" drill bit
7. 11/64" drill bit
8. Screwdriver for 4th bracket screw
9. Small screw for 4th bracket screw
10. Soldering iron and solder
11. Wire strippers
12. Jigsaw

Here is the procedure:

1. Remove the rear seat. You can just lift up in the front and it will pull out.

2. Lower rear seat backs, remove the seat latch bolt as shown. The side panels are held on with metal snaps. You can pull

firmly and snap it off. In some cases, I had to use a screwdriver to pry to prevent breaking the panel.

3. Remove the stock speaker with torx bit.

4. Remove the stock bracket from the bose speaker using torx bit.

5. Get your sub ready to attach.

6. Cut the stock bracket with a jig saw to create a rounded opening until it fits securely around the new sub.

7. Cut off the stock alignment nub as shown using the jigsaw.

8. Drill new holes in the sub using the 11/64" drill bit. Be very careful to to slip and damage the sub.

9. Connect 3 of the screws in existing holes, then drill the 4th starter hole using the 1/16" bit or appropriate size for

your screw.

10. Solder on the stock connector. The reason you don't want to crimp and use this on the new speaker is because they are

reversed. If you install then the polarity will be reversed. The wire with the white stripe should be on the (-).

11. Fix the hole saw to your drill.

12. The new sub is deeper than the existing hole allows. You must cut out a hole for the new magnet. I used a drill with a 3"

hole saw. The metal is very soft so the hole saw cut it easily. Wear safety goggles because metal flies. Also, cover up your

CD player with a towel to prevent metal shavings from entering. Then hammer the 4 corners out so the larger speaker will fit

snug without rattling.

13. Using a dremel with cut off wheel, carefully cut the backing from the side panel. The new spekaer has more deflection and

it rattles against the side panel if left stock. I figured this out after I had them back together, but I'll save you the

time.

14. Here is a picture of the new sub installed. Attach your side panel and you're done.

 

Here are some more pics.

 

Here are the final pics.

 

Outstanding write up buddy!

I really wanted to upgrade my rears and had no idea how to remove the rear panel, so thanks!

 

Thanks, just thought I would contribute because I usually just leech. Having the subs in for 4 days now and playing with settings, I would probably try to find a sub with 2 ohms impedance and higher efficiency. Although the cost will be higher with a JL Audio that I found. The problem is, in order to drive the rears hard enough, the fronts are distorting at high volume. At normal listening and bass set to +4, it really does sound better than before with no vibration. I will definately put in an amp soon.

 

I have a 10" sub in a custom box i made (with a vinyl "TT" on top) and a small 400W amp. It all goes through a small 9 channel eq and is plenty of base for the size of car!

I want to do a rear seat delete and have a nice enclosure built eventually, we will see...

 

have u tried to wiring them different to see if u can acheive better sound?

 

There aren't many options when using the stock amp. The only option is to wire them out of phase, and I haven't tried that. The problem is really a lack of power to drive them hard.

 

Well at least it sounds better then stock right?

 

I'll be doing a custom fiberglass box for 1 27cm Focal and an audison LRx400 in the Spring for my 02 coupe.