I got the replacement 8" microsub+ and an LC2i in case I needed it, and we finally had temps low enough I could get this thing installed!
Last time I noted that with a 0db 50hz test tone at 25 volume, and bass and subwoofer sliders in the center, the voltage output from the stock subwoofer speaker wires was 7.1volts.
Today I also did a couple scope tests, and saw that with the same 0db 50hz test tone and subwoofer slider in the middle, the peak volume I could go to before clipping from the factory amp was volume 27. (I think most recorded music is like -6db, so most of you can probably go to 33 or so before clipping with normal music).
....this was one of those projects where nothing really came together right. I had a bear of a time getting the power wire through the firewall, as I didn't want to drill a hole. It seriously took me 2 hours just to run the power wire, and I'll post a couple pics to help the rest of you...The place to get through the firewall is tucked away behind everything and hard to get at from both the engine bay and the interior. There's a sealed boot on the bay side, which I went ahead and snipped a small hole in so I could feed the power wire through while taped to hanger wire. It was still ridiculous trying to get the right angles to feed it through the hole, but I finally got it:
...then once I finally finished with that, I spent far too long dicking around with trying to grind my ground wire end larger to fit over the 14mm rear seat frame bolts, when I finally realized I didn't want to do that, and there was a small 10mm factory ground right there! D'oh
The vampire taps to the factory sub wires went fine, and I excitedly hooked everything up to the Microsub+ and....nothing. No sound, no pop, no power light. I measured everything with the multi-meter, and had voltage and ground, and even jumpered over a remote wire in case the auto-turn-on stuff wasn't working....nope, still nothing!
After breaking for dinner, I began to recall a buddy once telling me to never trust the old glass fuses for amp power wires. I guess they have a tendency to get too hot in the engine bay, and actually de-solder themselves inside the cap ends...so they'll look peachy on visual inspection, and per my findings today, even possibly show 12v on a multimeter. However, when you try to pull any kind of load through them, the voltage tanks because there's no real connection there. Well sure as sheet, that was exactly the power problem! I pulled my old glass fuse (same style as the one picture below), and tossed on a flat fuse I got from a wiring kit, and problem solved! woohoo green power light on the Microsub+!
![Image]()
So then as I was testing with my 50hz test tone, I just couldn't level match anything at all. JL Audio support was right, and the high voltage inputs from the factory line straight to the microsub+ inputs were just too much. I tried cutting 1 pair of the high level inputs to lower the overall input level, but this didn't work, as the JL auto-turn-on functionality would no longer work. So I went ahead and tapped in power/ground for the LC2i and put the high-level inputs there, with RCA's from the LC2i to the JL amp. I also used the L2Ci's auto-turn-on, and remote out to send the remote to the JL amp. I played around with some tests and level matched by ear as best as I could, leaving the "accubass" stuff disabled, but can still only get about 1/4 LC2i gain and 1/4 JL gain before I start hearing what sounds like distortion (though the port chuffing from the box is throwing me). I'll play some more tomorrow.
The only other thing of note here, is that the JL Support guy was right again... I had left the stock sub hooked up, and was running both, and it just wasn't sounding right, and flipping the phase on the JL didn't fix it. I finally remember that he had said there could be some strange feedback between the two subs, so I pulled the clip for the stock sub and the JL sounds and feels much more alive! I can't explain what the problem is, if there really is some sort of pressure interplay back-feeding signal down the wires, or if it's just some phase issue that's not 180 degrees out. But I guess I'm leaving the stock sub unplugged.
I dig the JL, but at the moment it's not quite measuring up to the $450 price tag. The port noise is bugging me at higher volumes, though I don't have the rear seat re-installed yet, and I'm sure that'll change the dynamics some. I'll also try to volt-measure the RCA's off the LC2i to ensure I'm not over-feeding the JL. If I find anything else interesting I'll come back and update this post. For now, I'd suggest
the sealed JL PowerWedge+ 10" in the same spot would probably sound better. I'm not hating on the 8", I'm satisfied with my purchase (with the discounted price I got), but it just hasn't wowed me yet.
**Update: I confirmed the LC2i can put out 9.5 volts to the RCA's and since the JL amp only wants like 1.5v max, it makes sense that the gain adjuster on the LC2i can't go above about 1/4 turn. I did a bit more tweaking of the setup, and really like the "musicality" of the 8" sub, and I think if I could flip it around to stuff that port over against the door, perhaps I wouldn't be so bothered by the chuffing. However, my wires won't reach the extra 2 feet to flip it, and when thinking about purchasing extra wiring/adapters I decided I'd rather just try out that 10". So I'm working with Crutchfield to pay a bit more $$ and exchange for the sealed 10". I'll do another post to write up what I think of it compared to the 8". For someone who wants a deal on a perfect condition open-box 8", keep your eyes on Crutchfield page over the next couple of weeks
