View Full Version : Pac Lc-1

05-12-2010, 02:39 PM
I have a question about the suitability of this level controller for my application. I have a two amp system - JL M6600 running the 6 cabin speakers and a Kicker ZX700.5 running the tower speakers and the sub off the 5th channel. I have a remote level controller for the sub installed at the helm so I am all set there. I would like to be able to increase the output off the tower speakers relative to the cabin speakers while on the go. In other words, be able to turn up the tower speakers without turning up the cabin speakers. Currently, I use the fader control on the head unit to balance between by cabins and the towers but I can't access it while on the go since it's in the glove box. If I set the fader at 50/50 cabins and towers, then install a PAC LC-1 inline with the RCAs to the Kicker powering the towers, can I then turn up the output of the tower speakers with the PAC LC-1? I realize that I will only be able to turn it up +8db relative to where the volume is set on the head unit. How does the PAC do this? Does it boost the input voltage coming from the HU and if so, wouldn't it also add distortion?



05-12-2010, 03:02 PM
I can't answer your specific question, but here's how I am using one.

sub amp is separate and uses the same type of bass booster that you appear to have.
separate 4ch amp for the in-boat speakers ran off the fronts of the deck
separate 2ch amp for the tower speakers being ran off the rears of the deck.

I installed the pac lc-1 to allow me to turn the volume off to the towers when cruising. it has not injected any noticable noise into the system..

now I think you may be able to fade the system from in-boat to more sound for the towers thru the deck, then use the lc-1 to crank the towers up to full volume once riding and obtain balance that way while being able to turn it down when retrieving the rider??

it's my understanding that the lc-1 will not increase the output at all, but vary the output voltage from the deck on the affected channel from 0 to max, with max being the volume setting on the deck?


KG's Supra24
05-12-2010, 03:43 PM
From my understanding when i purchased it ....

The Pac-LC1 is nothing more than an external fade knob. It is not going to boost your volume. If your volume is on 25 on the head unit, that is as high as your Pac-LC1 is going to go.

Solution: I went ahead and bought two of them to sit side by side. One for in boat, one for tower. Now I can control each of them to my liking. (still have to use the volume on head unit to get to max volume). If you want to just buy one (due to cost), put the pac-lc1 to your amp running the in-boats, then just fade the in-boats down.

KG's Supra24
05-12-2010, 03:47 PM
it's my understanding that the lc-1 will not increase the output at all, but vary the output voltage from the deck on the affected channel from 0 to max, with max being the volume setting on the deck?


I believe this is exactly how it works.

05-12-2010, 04:02 PM
Al, Sandm and KG are spot on. THat is why i got the ws EQ. I could never get the voluime on the towers past the cabins. You could gain the tower amp much higher than the cabin amp. That may give you the spread you want but you may force some distortion.

You can try to put it on the cabins and lower them, but with the three inputs on the JL you will need to run a lot of RCA's and a y splitter

Mmandley has three to control all aspects of his system. I thought about going that route but my wife suprised me.

05-12-2010, 04:14 PM
Exactly what i did on the last boat as well, one to the cabin amp and the other to the tower amp.

Now i have seen a couple of PAC installations where the where i swear the PAC for the cabins was split via a Y-splitter for a multiple RCA input scenario. I didn't pay much attention to it as it didn't apply to me at the time. But i looked like the PAC cable crossed over between RCA's. I'll have to see if i can find that again.

BTW a PAC is just like a dimmer switch you have on the wall at home to control your lights. It simply reduces the amount of current flowing to any given device.

05-12-2010, 04:28 PM
The amps I have require a special control (same thing as Pac 1 but for HD amps). I have 1 run for the towers and 1 for the sub.


It's just like Razzman says. I can turn the towers off completely as well as adjust up. But they will only go so loud before you have to turn the whole system up.

Figured it's not that big a deal as I rarely have just the towers going and no cockpits!

05-12-2010, 05:21 PM

Not another LC-1 thread!

The LC-1 is a purely passive device and can attenuate the level only but cannot boost. However, there is nothing to keep you from re-setting amplifier gains a little more sensitive in conjunction with the LC-1 in order to obtain a bit more flexability.

Your best solution would be two JL Audio CL-RLC line amplifiers with a remote level control. The controller operates the line driver via a long telephone cord that carries control voltage only from your dash. The line driver remains on the port side with the source and amplifiers. So there are no to and from long RCA transverse cables. The audio path stays very, very short. Another benefit is you'll get a 7-volt line driver for decreased noise floor and increased dynamic range particularly in consideration of splitting a source unit preout into so many amplifier channels and the resulting voltage division.

Operationally it would work like this. One JL CL-RLC would operate the towers speakers exclusively. The other JL CL-RLC would operate all your in-boat speakers including the subwoofer. This way your sub will automatically track with the in-boat controller. However, with the zx700.5 dedicated sub control you can run the sub with a bit of independence in case you want to mix more sub with the tower. You would gain the sub channel a little hot and normally keep the bass control down. This would provide greater responsiveness for the sub but allow you to ignore the dedicated sub control most of the time.

Earmark Marine

ian ashton
05-13-2010, 12:23 PM
Or you could install the LC-1 on your cabin speakers, so you could crank the towers, and turn the cabins down. BAM!

I've used these before, they are a nice cheap little gadget.

05-13-2010, 12:45 PM
Thanks for all the helpful replies, especially David with his usual thorough explanation of how things work. I really learn a lot from reading your posts, David.

The JL line amplifiers seem like the best way to go but they're also pricey. It's not a huge deal for me so I'm not sure I want to spend $100 for two of those.

I think maybe one LC-1 on the in boat speaker amp would be the cheap way to go and accomplish what I want and that is to be able to turn down the volume of the in boat speakers as I crank up the towers. I only have one pair of RCA's going to the JL M6600 with a splitter at the amp feeding 4 channels. Channels 5&6 sum off the other channels. So I can just use one LC-1 before the splitter, right? I am a little concerned about the long RCA runs back and forth to the helm though.

Thanks all.


05-13-2010, 01:12 PM
use one of the jl's mentioned above if you are worried about long rca runs. they will do the same thing but use rj45's for the run to raise/lower the gains. a bit more money than the lc-1's, but you might save the money in not having to buy good quality rca's for the long runs..

otherwise yes, you can use the lc-1 before the splitter.

05-13-2010, 03:30 PM

Yep, you've got it, lc1 befor the splitter.

FYI you can surface mount or thru dash mount as well.

05-13-2010, 03:37 PM
On the other hand, I do like the idea of restoring the input voltage to the JL M6600 since I've got it split in half right now as well as the elimination of the long RCA runs. This might be worth the extra $40 or so for the JL Audio CL-RLC line amplifiers over the LC-1.

05-13-2010, 04:15 PM
unless you have spare rca's laying around, a good set of them are going to run $10-15 each, so the true cost is much less.

05-13-2010, 04:27 PM
One word of caution when discarding the case and flush-mounting the LC-1. Because the threaded shaft is so short you may have to eliminate the case. In doing so you've lost the strain-relief for the RCA cables where they're soldered to the board. As a result you'll lose these on the first choppy day. So add a small splint and a little silicon and heat shrink over the circuit board, RCA, splint and silicon until the silicon oozes out a bit. Loosly strain relief your RCAs with zip ties behind the LC-1 and this should last forever.

Note, the JL control has a longer shaft so it wouldn't be necessary to break it out of its enclosure.

Earmark Marine