I just got a good deal on 5 sets of 6x9 speakers and want to put them in the boat. Ive designed some side panels that will accommodate 4 speakers each. What is the best way to wire these up? should I connect all the negatives and positives together or is there a better way to do it?

Also, Im adding two new batteries with their own charger (temporarily until i can afford a 4-bank built in charger to replace my 2-bank) to run the amp.

How long do you think 2 batteries will last on one charge with a 800 watt amp running 10 6x9's?

The headunit and one amp will still be connected to the two original batteries along with 6 speakers so that when my two new batteries run dead, i still have some tunes and starting capabilities.

Any advice on setting something up like this?

If you connect them together in parallel (all + tied together, all - tied together) you'll halve the resistance with every doubling of speakers. Essentially, if they're 8-ohm impedance, 2 will give you 4 ohm and 4 will give you 2 ohm. If they start out as 4 ohm (most common in this type of speaker, you end up with a total of under 1 ohm- almost a dead short. Unless you have an extremely expensive high-end amplifier you won't be able to drive the load- the amp will limit out.

On the other hand, if you connect them in series (+ to - to + to - and so on) each doubling doubles your impedance. Plus, since each voice coil is a variable-core inductor, the signal is significantly altered as it passes from each speaker in the chain. High impedance load means low output power and inductors in the signal path means funky sound with probably no bass.

Get a 4 channel amp that is 2 ohm stable and wire them in parallel. Essentially, hook 2 speakers up to each channel and save the extra pair.

so one way ill get the amp limited out, the other way will give me no bass..

hmm.. still lost on what i should do.

sorry, didnt get to this til after you posted..

hook 2 speakers up to each channel? so + to - on each pair?

First thing to do is make sure you have an amp that is stable and rated for a 2 ohm load, assuming the speakers are 4 ohms each. If the amp is not rated for a 2 ohm load, it won't last very long.

Then hook + to + and - to -.

What amp do you have and what speakers are these???

Two 4 ohm speakers hooked parallel will give a 2 ohm load.

Ok guys.... the speakers are in. Heres what I have. Im still amp shopping.
12- Alpine SPS-690a (250w Peak, 50w RMS, 4ohms)
I will have 4 total batteries. The headunit is hooked up to the Port engine starting battery along with about half of the boats accessories. The starboard battery is just a starting battery with the other half of the boats accessories hooked to it.

I want to run my amps off of the two new batteries Im putting in.

With this information, should I still connect the speakers in series or should I just get 2 amps and run 6 speakers on each amp? Im so confused with all this. I definately dont want to overheat an amp by running it under 1 ohm like chris was saying. But I also dont want to increase my impedance and lose all my sound.

So what if I ran two of these amps and put 6 of the 6x9's on each one. Would that work?
1200W 4 CHANNEL AMP
300 watts x 2 RMS @ 4ohms bridged
150 watts x 4 @ 2 ohms RMS


Also, Im wanting to put in two 10's or 12's depending on how my measurements come out for the fiberglass enclosures under the bolsters. Trying to design something that will still allow me to stand up while driving. thats frustrating in itself. I may just move them into the cabin and build a box in there.

How long do you think Ill be able to listen to this system with the amps running off of their own batteries?

Any help is appreciated..

Also, is that amp too big? Should i drop down in amp size. They make a 600watt in that same category.

How many 6x9 speakers did you install???

What brand amps are you getting/do you have??

Do you have 2 battery switches???

i have over 2000 watts in 4 amps and 15 speakers and have 3 battries with 2 switches but never use the switches and can play off and on all day with no starting problems.