# Amp Selection for Boat



## Silverbullet555 (Apr 26, 2010)

I am working on upgrading the system in our boat and would like some advice from the knowledge base on this forum. I don't do a lot with car audio so I am not too knowledgeable on different brands which is why I am looking for help.

As of now, the speakers in the boat consist of 10 Polk DB651 which have a 60W RMS rating.

The 4 speakers on the tower are wired in parallel as 2 pair. The other speakers are all wired individually. 

Space is not a tremendous issue, though size does matter. 

Going with marine equipment is not necessary based on where these will be mounted and how we store our boat.

Budget is of a concern as I am looking to keep it reasonable. Acoustics in a boat also suck so there is no point in overspending on something that will never live to it's potential.

We like all kinds of music from Classic Rock, Rap, Country, R&B, etc.

I do intend to add 2 subs in the future so I want to plan ahead for that. Don't need to buy that equipment yet, but it might come in to play in this case.

I've considered Alpine amps (MRP or PDX) and Kicker Amps

Hopefully I can get some good advice so as to not overspend, but also not sell my system short.

I'm just looking for Amp advice in this case. Subs will come later on.


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## SomeGuy748 (Feb 24, 2010)

We pull Kicker out of boats here. Seems Kicker must have signed a deal with some of the boat manufacturers. I guess the Kicker boats would sound better if they weren't so under powered. Have you looked into Exile? I would read some of the wake board forums. Exile gets a lot of attention there. Here is a link to their website but it doesn't cover a lot of the marine stuff they do. I wouldn't hesitate to call them either if you're looking for suggestions.

Exile Audio 

We use mainly MTX marine product for smaller systems and then Exile for the big ones. The amps make serious power and you can abuse the hell out of them.


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## Cobalt232 (Jul 22, 2009)

I have a JL Audio 6 channel in my boat driving 6 MB Quart coaxials and it is plenty loud, even underway. It's a car amp as I am in fresh water 100% of the time so salt does not come into play. With 10 speakers you could run 4 speakers off 2 of the channels and 4 off of the other 2 channels of a 4 ch amp. With a 6 ch amp you could run the other 2 speakers off the 5th and 6th channel. I am assuming that the Polks are 4 ohm speakers? Most decent amps will run 2 ohm stereo loads with no problem. Or you could run 2 4 channel amp and use the last 2 channels in bridged mode for the sub, when you get one.


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## Silverbullet555 (Apr 26, 2010)

A couple that caught my eye over the last few days.

Eclipse EA-4200 4 channel. [email protected], [email protected] $129 each at crutchfield.

I would need 2 of them and could run 4main speakers and 2 front speakers at 4 ohms and 4 tower speakers at 2 ohms.

JL XD 600/6. [email protected], [email protected] (12.5v). $329 new on ebay.

I could get by with 1 if I can run the main speakers and front speakers at 4 ohm while running the tower speakers at 2 ohms. 

In both cases, I would get another amp to run the subs later on.

Thoughts?


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## schmiddr2 (Aug 10, 2009)

MB Quart NAU 660 (NAU660) 6-Channel Marine/Boat Amplifier/Amp

Saves you some money and should be pretty close in terms of power.


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## Silverbullet555 (Apr 26, 2010)

The MB one is not cea compliant which bothers me a little. But it does save some money.


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## slade1274 (Mar 25, 2008)

PDX-5 will drive them all. I don't think the complaints about noise floor is an issue with the boat setup so you would benefit greatly from the efficiency of the design. I ran one in the car and it puts out the rated power and then some. A great all in one that will cover you even with the subs.


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## darinof (Feb 6, 2009)

Go with a alpine pdx or jl audio hd amps since they will draw less from your battery and they are small.


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## Silverbullet555 (Apr 26, 2010)

I think I am really overthinking this and I just need to order the amps and get going.

The one question I really need to answer now is can I run 2 channels at 2ohm and 2 channels at 4 ohms on the same amp?

My tower speakers consist of 2 double pods. The wiring is done in the tower with only 2 channels run so I will wire each double pod in parallel. The rest of the speakers are individually wired so they are 4 ohms. 

Could I run the tower speakers and 2 of the cabin speakers off the same amp since 2 channels will be at 2ohms and 2 at 4 ohms?

I hope that made sense.


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## RLJ676 (Apr 16, 2010)

I would strongly recommend class D amps for a boat if you don't have (or want) a bunch of batteries. I am swapping out a JL 300/4 for a memphis 4 channel D class this summer to save battery. Not to mention when not running the motor the JL would go into protect at loud volume because it wanted so much juice and the starter battery+ G31 wasn't enough current.


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## schmiddr2 (Aug 10, 2009)

Silverbullet555 said:


> I think I am really overthinking this and I just need to order the amps and get going.
> 
> The one question I really need to answer now is can I run 2 channels at 2ohm and 2 channels at 4 ohms on the same amp?
> 
> ...


Yes you can...as long as you run it in stereo mode and not bridged mode.

I also agree with the class D amplification route. I suggested the MB quart because it fulfills the needs of the speakers for cheap, although not so good for the battery power.


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## Silverbullet555 (Apr 26, 2010)

RLJ676 said:


> I would strongly recommend class D amps for a boat if you don't have (or want) a bunch of batteries. I am swapping out a JL 300/4 for a memphis 4 channel D class this summer to save battery. Not to mention when not running the motor the JL would go into protect at loud volume because it wanted so much juice and the starter battery+ G31 wasn't enough current.



I do have two batteries already with one as the house battery and one as the starter battery. Good point about going into protect mode when it trys to draw a lot when not running.

I have a friend that says he can get JL at discount so we will see if that comes through.


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## Silverbullet555 (Apr 26, 2010)

I've been doing a lot of reading and it seems that good information is hard to find. Maybe I am looking in the wrong spot.

I considered using 3 Eclipse EA4200 amps or an MB Quart Nautic 660 or 2 alpine pdx's or it seems like a million other choices.

I think I am narrowed down.

Choice 1: I found two Alpine MRP-F550 for $150 each. I would go with both and get a 3rd amp for subs in the future. Cost would be $330. I have the necessary cables already.

Pros: Cheaper, Class A/B, more flexible, higher output.
Cons: 2 amps, more space, more current draw, more heat.

Choice 2: JL XD600/6. Run the tower speakers off of 2 channels at 2 ohms, the main cabin speakers of of 2 channels at 2 ohms and the front 2 speakers of the final 2 channels at 4 ohms. $500 delivered

Pros: Size, current draw, heat, simplicity.
Cons: Cost, lower output, less flexibility.

Thoughts?


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## RLJ676 (Apr 16, 2010)

Silverbullet555 said:


> I do have two batteries already with one as the house battery and one as the starter battery. Good point about going into protect mode when it trys to draw a lot when not running.
> 
> I have a friend that says he can get JL at discount so we will see if that comes through.


Same battery setup as I have it sounds like. I'm not sure about the other JL amps (HD's are D I believe), but the slash's seem to be real current hogs. Not to mention the power supply keeps the power constant at various ohms so I wasn't gaining anything from running at 2 ohms.


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## slade1274 (Mar 25, 2008)

In my experience JLs tend to be current hogs period... even the class D compared to the peers. I have already stated my opinion above that the PDX will be the best solution to your particular needs..... The efficiency/size/weight/power will be worth the extra few bucks if you feel that you need more than a PDX-5. Having run one in the past, I still believe it will do everything you want it to in one small efficient package.


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