Speaker Help!

heys guys. i bought a 17 foot tri hull and im setting up my speakers and head unit up. i set up my whole car stereo system, so i basically know what im doing, i have an amp, 4 speakers, a 10' sub woofer, and my head unit. i dont have an alternator, or battery chargers. i have 3 marine batterys though. im wondering whats the best way to set up what i have. i heard amps kill your battery. should i even use my amp? should i use a seperate battery for the woofer and one for the amp? HELP! i love diagrams they help the best if you have time! thanks guys.

Re: Speaker Help!

How long do you plan on listening to the tunes between charging the batteries?

When you say "marine batteries", are they starting batteries or deep cycle?

Unless you have an amplified sub, you will need the amp to power the sub. More details about the amp would be great also. 2 channel, 4 channel, mono?
watts (RMS)?


As a start (if your batteries are deep cycle) I would hook up two batteries in parallel ("+" to "+" and "-" to "-"), this will give you greater battery capacity and still give you 12v. I would use these two batteries as "house" batteries to power your stereo and other non-essential items. The third battery would then be used as your starting battery. This way no matter how long you play your tunes and how low the house batteries go, you will always have your starter battery to start the boat and get you home where you can recharge your house batteries for your next trip.

Re: Speaker Help!

I agree with slia67. Do you have an on board charger for shore power??

Re: Speaker Help!

crazy rooster said:

i dont have an alternator, or battery chargers. i have 3 marine batterys though. im wondering whats the best way to set up what i have. i heard amps kill your battery. should i even use my amp?

Click to expand...

How does your on board trio of batteries get charged?

Is the head unit powered?

Does the sub have a built-in amp?

If you want to even things out for the sake of your battery/ alternator/ generator, use a capacitor built for this purpose to pad the system. The sub , in theory, will be taking /using the most load


Just for an example, the system in my work van consists of:
Un-powered Alpine head unit( pre-outs only)
Alpine flex 4 amp

Alpine v-power mono amp
4 MB Quart reference series speakers
1 10 inch eclipse sub

I can run this for approx. 5 hrs at a medium/fairly high volume before it has drained the 950CCA battery to the point were I am even concerned about it starting, but that is not one the water!!!!

BTW- I agree w/ Slia for the battery setup...

Re: Speaker Help!

crazy rooster said:

heys guys. i bought a 17 foot tri hull and im setting up my speakers and head unit up. i set up my whole car stereo system, so i basically know what im doing, i have an amp, 4 speakers, a 10' sub woofer, and my head unit. i dont have an alternator, or battery chargers. i have 3 marine batterys though. im wondering whats the best way to set up what i have. i heard amps kill your battery. should i even use my amp? should i use a seperate battery for the woofer and one for the amp? HELP! i love diagrams they help the best if you have time! thanks guys.

Click to expand...

If you want to use the sub and it isn't powered any other way you'll need the amp for that. The amp will draw 99% of the total current. Depending on the size, the draw could be anywhere from 5-15amps (unless you bought a beast of an amp) In all likelihood you'd get somewhere between 4 and 6 hours of continuous use out of a good (200ah) deep cycle battery. The starting battery is not going to go dead from the deck alone even with it powering your speakers and using the low level outputs to the amp. The amp will need to go on a separate deep cycle battery however. This way, if your battery goes dead for the sound system, you only lose the sub and the boat still has juice to start. I've had my deck running for 12 hours along with two depth finders that all run to my main "starter" battery and i"ve not had a single problem. I have no amps though.