More Audio Question

Hi All Stereo Experts. Sorry for the long post.

This is what I've aquired so far:
1. Kicker COMP 10" Sub in a QLogic Box that I'm going to mount under the drivers feet area. 125 W RMS at 4 Ohms.
2. Sony CDX-F7705 Head Unit with the Wired Sony RM-XM10W remote.
3. Fusion T-Series Combo tower speakers 250W RMS each at 2Ohms.
4. My existing system already has a 4 channel amp with 4 speakers in the cabin and it OK.

What I'm thinking of getting. Need Opinions:
1. I was going to drive the Kicker Sub with an MTX 251D Mono channel AMP. Seems' pretty good for the price. Opinions?
2. I was going to drive the tower speakers with an MTX Thunder 502 2 channel amp. It puts out 250 W RMS at 2 Ohms. Opinions?

The next part I get a little foggy about:
1. I think I need a second battery. I've got a blue top optima for my primary cranking battery and was going to get a yellow top for the secondary stereo battery.
2. When I put in the second battery, do I just need a battery isolator, and what brand should I get?
3. Do I also need a Perko switch? Not sure what this thing does.

Once she's all wired up, I'll have 4 speakers in the cabin driven by my existing 4 amp that puts out about 125W RMS per channel at 4 Ohms. I'll have the tower speakers and the sub both powered by their own AMPs too as mentioned above.

The last thing I need to do is be able to drive more or less power to the tower speakers vs the in-cabin speakers. I want to be able to push alot of power to the tower for the rider to hear, while not blowing out everyone in the boat. I've seen this product called an LC-1 or an LC-2 that looks like it might do the job, but I'm not sure if that's the right thing.

Any help from any of you experts would be great.

Thanks

Oops, a couple of other questions:

1. Does it matter how far the AMPs are from the Head Unit? In other words the length of the RCA cables? I was going to run it from under the arm rest to the AMPs under the observers seat area.

2. What gauge speaker wire should I use for my tower and in-cabin speakers?

thanks

I'll answer a few. Do a search on isolators for the pros/cons. you'll only need one isolator/relay or switch. I'm using the Stinger isolator /relay and have no voltage drop(one of the main concerns when using isolator) . How old is your first battery? Remember if one is older/weaker i will pull down the newwer to its voltage level. As far as RCA's...make sure they have decent insulation on them. if not you'll pick up "ground noise". The length is that big of a deal. A good 12-16 gauge wire will be more than enough for tower cabin speaker. I use 16 ga. in mine. you can use the fader to control tower vs. cabin speakers. (How many RCA outs (off the radio) do you have?)cheaper and easier.

Adam:

Thanks for your input. My current blue top is new last year at the beginning of the season, so it's not too bad.

I don't want to use the fader because the front speakers in the cabin are right under the windshield and I need to fade them out a little compared to the ones near the back seat else the volume is too loud for the driver and observer and not loud enough for the back seat. I need a separate control for tower volume I think.

Great info on the Isolator, RCA and speaker wire. Thanks

bump...

Opininons on the MTX amps?

John,

I had your exact question about controlling the tower speakers separately. I went to the local shop and purchased a knob that can be placed between two rca cables and allows me to turn the speaker input up or down on the tower speakers alone.

So what I'm saying is, I have a cable from the unit to the knob, then another cable from the knob to the amp. By turning the knob up or down I can control the volume of the tower speakers independently. My problem is where to mount it. I currently have it hanging out of the cargo compartment where the amps are and resting on the seat. I'll eventually drill a hole next to the glove box and mount it there somewhere - does anyone have a better idea where to put it? I'll try to get you a picture.

(Message edited by talltigeguy on January 17, 2005)

I am putting the volume controls on my new stereo also. I will have one for the tower, one for the boat speakers, and one for the sub. Much easier than trying to get into the fader control, and seems more versatile.

John you might want to look into a relay for your two batteries. I know with isolators you can get a drop in voltage. Malibu had a boat at the Atlanta boat show that was pimped out with speakers and I was talking the audio guy that installed it and he had two Optima batteries and they were on a relay. I don't know the ins and outs of the relay, but I know several people on this board has experience with them. Hope I helped some. Good Luck

Oh yeah, when I installed my system I just put the interior speakers on the front channel and the tower speakers on the rear channel. Worked great for me. Just make sure your head unit has the triple outputs. It gives you much more control over everything.

what you are looking for is the PAC LC-1...it is a external volume control.

All:

Thanks for the tips.

talltigeguy: Do you know the manufacturer and model number of your volume control knob? I plan on running mine all the way back over by the driver's seat and mount it on a drop down panel I'm custom building that is mounted below the dash. I've already got my ballast pump switch mounted there.

Lance: I think I'm going to go with an isolator/relay combo unit. Thanks.

Mike: Isn't the LC-1 for just Subwoofer control? Also, I know your an expert, what do you think of the MTX amplifiers (Thunder 502 and 251D) for my application?

Thanks

The LC-1 is a simple gain control that works for any frequency. It's not amp specific, not a bass gain control like most amps offer.