The left channel on my K11LT had gone out. It had been flaky for some time, I figured the speaker was blown. But it died after the fairing replacement/painting job that CalMoto in Mtn View screwed up (like they always do in their service dept).
I'd been considering upgrading the speakers for some time and had chosen a couple contenders. I decided to go with the Polk Audio DB401 over the Infinity Kappa 42.9i for a few reasons. The Infinity has a dongle crossover and I didn't like the idea of that weight swinging around or having to secure it. Also, the Infinity speakers were 2 ohms to the Polk's 4. 2 is unusual and will put a high load on an amplifier. I spent many years doing live sound and I know there aren't many amplifiers rated for 2 ohm. The Polks are also marine rated, although the Infinity speakers use a polypropylene woofer (plastic), so that wasn't a concern.
Before I ordered the speakers, I figured it might be a good idea to make sure the radio wasn't shot. It would suck to get it torn apart only to discover the radio was blown. I removed the radio and quickly discovered the root of the problem. The fader knob/cable assembly was shot. It was bent too much too often over the years when being serviced and half the connectors were flaky. I could get things to work by wiggling them, but I couldn't get them to stay working. They were all bent towards one side, too. I straightened out the whole grid, but that didn't help. It was too far gone.
Fortunately, BMW had 14 in stock (as if any more are being made...) They now have 13. For $80 or so, I got a whole new harness. It took 4 weeks to get here from Germany, though. I could have picked up a used one real cheap probably, but was concerned about the longevity. The stock part wasn't too steep on the cost, so I went with a new one.
The harness is very easy to swap out. I couldn't find my needle nose pliers to remove the lock ring around the knob, so I used some circlip pliers I have. They did the job.
With the radio out, removing the inner top fairing piece which holds the two speakers (and the map light) was easy peasey. I had it out in 5 minutes.
I checked the original speakers with the new harness first. They worked well. Not blown. Odd, since I hear other people blow them often. And I like my tunes loud enough to hear... I guess I got lucky on the speakers.
I unpacked the DB401s and realized I'd have a mounting problem. They have four holes. The mounting ring around the stock speakers has three. And there are three mounting pillars in the fairing. The ring had too small of an inner diameter to fit well over the new speakers. Close but no cigar. And that didn't solve the 3 to 4 hole problem. I could find a way to shave the inside of the ring 1/16" and cut off the 4 corners... That would mount. But it was a bit of work and I don't have to tools to do that anyways. I figured I'd come up with something.
I unplugged a stock speaker and swapped in a Polk, just sitting loose. Using the balance knob, I faded back and forth. Both sounded good. Centered, it was obvious the Polk not only sounded a bit better but was considerably louder as well. I put the other Polk in, hooked up my GPS and played some MP3s.
Holy Hand Grenade of Antioch! Yup, we've got freeway volume now!
Now I just needed to find a way to mount the speaker. I was about to call it a night went it hit me. Screw one hole in directly and if you can get the other two screw's washers to clamp down on the lip and hold it in place. Kind of a hack, but it might work. :hmm:
I gave it a go and it holds. I think I want to go with slightly larger washers on the bottom two screws, though, just to make sure nothing slips out when I hit a nasty pothole.
Here's a picture of the mounting:
The Polks are about 1/8" deeper than the stock speaker and the magnet is MUCH larger. IIRC, I paid about $60-65 for the pair.
I haven't finished putting it all back together yet, it got dark on me (no garage), but at this point, I just need to get slightly wider washers (for extra safety margin), wire up the speakers, replace the top inner fairing piece, reseat the radio and we're done.
Figuring out how to pull the radio was a bit odd, but it's actually easy if you know where to shove the long end of an allen wrench of the appropriate size. Using a flashlight helps. I used multiple wrenches, too, since there are three mount points and I only have two hands. It's kinda hard to use one hand to pull up on the radio (evenly) and the other hand to insert three wrenches. But you can stick em in there and leave them holding the clip open. Thanks Frankenduck for the tips on that, btw. Sorry, no pictures of that, but I think he posted one somewhere...
If you have a K11LT and just want to replace the speakers because they're blown or want better speakers, give the Polks a shot. They're a very reputable brand and if I can do the swap out that easily, it's a simple job for anyone. You do have to pull the radio to get to two of the screws to remove the inner upper fairing, though.
I'll post later on the roadworthiness of these speakers, but given the tests I did tonight, they kick ass. WAY better than stock.