Need Advice From Stereo Gurus

[chatafkup]

I am installing a new system in my boat. My boat has a V8 with a DUAL DEEP CYCLE BATTERY SYSTEM on a marine battery switch (select 1,2 or both) and an alternator that puts out 75 amps.

My system that I am installing is as follows:

A 320W amplifier powering 4 polk MMC650 6.5's 2-ways 80W RMS @ 4 ohms

&

A 500W amplifier powering 1 Kicker 10" 400W RMS shallow mount sub @ 2 ohms in a .8-.10 cubic foot sealed box.

My question is DO I NEED A CAPACITOR and should I stuff the box with polyfill?

Personally I dont think I need a capacitor, but I'm not sure on the polyfill stuffing. What do you guys think? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Thank you

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[Twistid 5,000+ posts]

no cap, polyfill is your choice, you should be good with the 2 deep cycle batt's

 

[hemi=22s 10+ year member]

no cap man waste of money

 

[hemi=22s 10+ year member]

whats the recommend air space on the sub

 

[chatafkup]

.8 to 1.3 cf is the recommended air space. I'll be right there, but room is limited.

Coincidentally, I was thinking about adding an isolator and a third battery because I like playing the radio while I'm on the beach.

Do you think the two amps will kill one battery fairly quick?

If I do play the radio on my current battery setup, I would choose battery 1 and leave the other for starting.

What do you guys think?

Thanks again

 

[JUHL 10+ year member]

if you really wanna do things right, i suggest you get a High output alternator and, or a 2nd battery... and stay away froms caps, they are pointless and will only hurt your electrical system in the long run

 

[chatafkup]

I already have a two battery system, you mean add a 2nd for the system through an isolator....is that what you mean?

 

[BEAVER.989 10+ year member]

I believe you'll find polyfill beneficial to your systems sound for two reasons.

1. Most manufacturers recommend enclosures that are smaller than optimal, anyway.

2. You will not be benefiting from cabin gain since you're dealing with an open space in a boat.

 

[ultimate157 5,000+ posts]

if you really wanna do things right, i suggest you get a High output alternator and, or a 2nd battery... and stay away froms caps, they are pointless and will only hurt your electrical system in the long run

No electrical upgrades needed whatsoever for his setup. THAT is a waste of money.

I would add some polyfill to the sub's enclosure.

 

[chatafkup]

I wonder how long one battery will last if played on the beach without the engine running? I know it's a weird hypothetical question.

 

[kovemaster559 5,000+ posts]

I wonder how long one battery will last if played on the beach without the engine running? I know it's a weird hypothetical question.

depends on the AH of the battery

 

[benchambers80]

3rd bat on an isolator, and polyfill it

 

[chatafkup]

3rd battery on an isolator, that's what I was also thinking. I found one for 85.00.

What is "AH" of the battery mean?

 

[ultimate157 5,000+ posts]

Ampere Hours... way of measuring electrical charge.