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dpolen 12-24-2013 08:05 AM

Amp Selection/Config...requesting advice please
I'm looking to build on the stock stereo in my 2012 X2. Stock setup is the Clarion HeadUnit and the 4 JL speakers in the cockpit and bow. I would like to add a sub and a pair of tower speakers.

I'll go with the 10" JL Infinite Baffle for the sub and probably the cheaper JL MX tower speakers...nothing fancy, but very impressed with the quality of the JL Audio stuff.

Here's where I could use some help...the Amp. I'm thinking about buying the JL M700/5 amp and setting it up as follows...
Channels 1 & 2 for Tower speakers
Channels 3 & 4 for the four Cockpit speakers
Channel 5 for the sub

I'm confident I'd be fine for the tower speakers and the sub, but what about dropping the Ohms on the amp for the cockpit speakers on Channels 3 & 4...Does this make sense, or am I just better off putting in a separate amp for the tower speakers?

Thanks in advance for any advice or opinions.

Merry Christmas!

ZachDaddy 12-24-2013 09:12 AM

There are many different opinions on amplifiers on this forum. IMO that is too many speakers for what your asking it to do...I'd run the m700/5 your suggesting on the interior and the sub. Then run a second amplifier for the tower speakers...

My 2 cents

MLA 12-24-2013 09:37 AM

We regularly run 6 in-boats and a sub on a 5 or 6 chnl amp, so for 4 in-boats, sub and a pair on the tower, I see no issue with the M700/5 handling this load.

But, for the tower speakers, especially a single pair of coaxial, I would suggest a bit more power then 75W rms. So I would go with a dedicated amp for the tower speaker. This will also be a slight benefit for the 4 in-boats. With each on their own chnl, they will receive 75W rms as opposed to 50W.

EarmarkMarine 12-24-2013 05:04 PM

Your choice of equipment sounds like a really good plan to me. I think that in the end you would be much happier with the system if you made 2 adjustments to your plan, and I'll lay out a couple of ways that I see to do it.

You could use the M700/5 to run everything, as you planned. That would give you 100 watts x 2 on the cabin speakers (50 watts per speaker), 75 watts x 2 on the tower speakers, and 180 watts on the subwoofer. In my opinion this is a little light on power, but it will work.

The 2 adjustments that I would suggest are:

1) Plan for an amplifier dedicated to the tower speakers. Even if you don't do it now you can design the system with that upgrade in mind by fabricating an amp panel large enough to mount an additional amplifier and 2 distribution blocks (if needed).

Also, if the power/ground cable run is a long one go ahead and run 2AWG cables now instead of 4AWG cables so that if/when you decide to add the tower amplifier you already have the correct gauge power/ground cables to support 2 amplifiers. If the power/ground cable run is a short run you could skip that step and just run an additional 4AWG cable run when you added the second amp.

For the second amp I would suggest the JL Audio M400/4 bridged into 2 channels, giving you 200 watts x 2 on the tower. This would also mean the M700/5 would be putting out the full 75 watts x 4 to the cabin speakers, which is 50% more power to the cabin speakers than if you were to run the 4 cabin speakers off of 2 channels of the M700/5.

2) Upgrade those tower speakers from the cheaper MX Series to the slightly more expensive but much better suited for the tower M Series. The additional up-front investment in the M Series will really make a difference. The M Series has a 1" dome tweeter versus the 3/4" dome tweeter of the MX Series, and while the MX Series speakers are great for in the cabin, the smaller tweeter just doesn't project as well in a tower application.

That gives you a 2-stage plan where you can try it with just the M700/5 and if you decide that you want more performance you are already set up to add the second amp. But definitely consider the M Series for the tower, you will be glad you did.


Rossterman 12-24-2013 09:31 PM

Polk audio D class stuff is pretty sweet for the money. I run pad1000.1, 4000.4, and 5000.5 and they flat crank!!!

dpolen 12-25-2013 10:33 AM

Thanks for the feedback and suggestions guys! Greatly appreciated.

Merry Christmas and Happy Holidays!

jprcrprv2 12-29-2013 09:28 PM

I was shopping amps the other day and the local dealer recommended the JL 800/8 for the tower and cockpit speakers. After looking at the specs it made sense and was cheaper than running separate amps for tower and cockpit. Just something to consider.

dpolen 12-30-2013 09:44 AM

Interesting idea, I will ask my dealer to price that one out for me...would be nice to have just one amp in the boat for simplicity.

EarmarkMarine 12-30-2013 02:26 PM

The 800/8 can be a good choice, depending on your application. But running it in 8-channel mode would not be my first recommendation for dpolen's application.

The reason is this...the 800/8 amplifier will put out 75 watts per channel at 4-ohms, 100 watts per channel at 2-ohms and 200 watts for 2 channels bridged into 4-ohms.

In dpolen's system, that would give him 75 watts to each of the 4 in-boat speakers (Channels 1,2,3,4) which is good; 200 watts to his subwoofer (Channels 5 & 6 bridged) which is good; but only 75 watts to each of his tower speakers, (channels 7 & 8) which is a bit underpowered for the JL Audio MX770 or M770 tower speakers IMO. I like to power tower speakers with a bit more power than the bare minimum because you're typically asking the tower speaker to play quite a bit louder than the in-boat coaxials.

So while the 8 channel amp does seem like the perfect all-in-one solution, I think he can get better performance with the 700/5 and 400/4, although at a slightly higher cost. If the budget is the main concern then the 800/8 will work, but at that point the 700/5 will give similar performance at even less cost.

jprcrprv2 01-01-2014 01:16 PM

I would have to agree after reading the op post again. I did not take into account a subwoofer would also be run off the same amplifier.

The reason I said look at the 800/8 was how plan to run my set up. I will be using 1-4 for cockpit and then bridge 5,6 and 7,8 for the towers with a 1000/1 on the subs.

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