So I bought a JL 12W3, a JL JX500 amp, an LC2i interface unit, and installed it all in my XF last weekend. Everything works, but I'm just not overly happy with the volume level. Don't get me wrong, I don't really want to rattle my neighbors' dishes, but I'd like to be able to know that I spent the extra money for a good reason.

I will admit that I don't really know how to twist all the knobs on the LC2i and the amp. I've just been turning stuff and seeing how it sounds. There are a LOT of adjustments.

any tips? am I expecting too much out of what I've purchased?

 

Really need to know more about your gear to be much help...

What is the voice coil configuration of the sub? Is it a single, 4ohm coil?
Does your XF have a factory sub?
Where are you taking your signal for the LC2i?
Where have you set the gains on the amp?
What kind of enclosure have you put the sub into?

To start with, if it's the sub I think it is, it's rated at 500wrms @ 4ohms. The amp you have bought, assuming it is the JX500/1D, puts out 300wrms @ 4 ohms. This isn't too bad, but ideally something around 5-600wrms would've been better.
FYI, amps are a little like car engines, just because they put out a rated amount of power, doesn't mean that's what you use all the time. Your Jag may be rated at 2-300hp, but when you're doing 60 on the freeway you're probably only using 100hp or so. Stereos are the same, you might hit 300w for a split second on a base note, but the rest of the time it will be putting out less, so having an amp rated slightly higher than your sub is perfectly fine.

The next question is how have you set up the LC2i. If your car has a sub already, then you will need to be tapping into this signal, otherwise you might not be getting any bass signal at all!
Even if you don't have a sub, you will still need to make sure you are getting a full range signal. The LC2i looks like it will split the bass out. This will be done with a low-pass filter. By changing this up and down you will limit which frequencies it is outputting. 80-100hz is probably a good place to start. You will also need to make sure the low-pass filter on the amp is set higher than the filter on the LC2i.

Next is setting gains/levels. From what I can find online, the LC2i can handle signals up to 400w. Your factory signal will be A LOT less than this, so you can probably turn it up quite a long way.
Setting gains can be complicated... but a good place to start is to turn the car stereo up to somewhere around 2/3 to 3/4 of max volume (or less, if it starts to distort and sound bad).
Then you have to adjust the gains on the amp and the LC2i. This may take some experimenting, but I would start with the amp gain on about 1/3rd, and adjust the LC2i until you get the volume you require. If it is still too quiet, turn the amp gain up a little and repeat...

If you still don't get any decent volume, then you will really need to get someone to have a look at it in person, sorry.

If you could post up any pics of the units and how they are set up at the moment, that would be a big help too.

 

the 12w3 is a 2 ohm single coil
my xf has the base system, so no sub.
taking the signal for the LC2i from the rear speaker lines
I have the gain on the amp pretty high, but I'm not sure if I'm doing something wrong, because I don't think most people do.
I built the suggested sealed enclosure on the JL site.

the 12w3 is rated at 500w rms at 2 ohms, which is the output of the amp.

The LC2i doesnt have a "cross over" per se... it does have some sort of "bass replacement" setting for factory head units that roll off the bass at higher volumes to conserve the factory speakers.

I will try to adjust the gains some more... I'm just confused as to which to turn up first... the LC2i or the amp gain...

I'll play around with them when I get back home. I'm out of the state right now, but when I get back, I'll post some photos.

Thanks for the help.

 

Sweet, thanks for that. Sounds like you should have plenty of power to drive the sub then...
If you have the gain on the amp quite high, this is unlikely to be the problem... unless you've blown the amp!

I would turn it back down to about 1/3rd, just to be safe, and use the LC2i to adjust the volume.
Based on the instructions I found here: http://rs.audiocontrol.com/company_3...3-13Update.pdf
It sounds like you start with the AccuBASS Level control fully down, the Threshold control fully up, and then slowly increase the Level until you get decent volume.

There is also a video about setting gains here:

 

oh nice! I don't know why I didn't check youtube. That's how I learn to do everything.