Electrical for M4a

[adulbrich 5,000+ posts]

Hey, like the title states, I'm wondering what I need to run an M4a. It will be wired at 1 ohm for daily. I will also be running an Ampere 125.4 for an active front stage.

Going by the 55 ah per 2k rms, I'll need about 200 ah of batteries.

I have a 320 amp Singer hairpin alternator. Would that and 3 Sam's club Duracell batteries be enough?

What voltage drop is acceptable, and what should I not let it drop below? Gains will be set wit a 0db test tone and o-scope.

All music I play is from itunes, so I'm not worried about signal quality.

Thanks!

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[BigBen 10+ year member]

The m4a can draw over 700a. So minutes about 220 from your alt leaves 480a needed. 4 g31 plus your bay under the hood.

 

[adulbrich 5,000+ posts]

The m4a can draw over 700a. So minutes about 220 from your alt leaves 480a needed. 4 g31 plus your bay under the hood.

Does the brand of group 31 matter? The Duracells are half the price of an XS D3100. I may try and fit another alternator

Also, same Big Ben from caraudioclassifieds?

 

[BigBen 10+ year member]

You'll get better performance from a better battery. XS isn't the brand to judge all others by. Yea they're good, but you can find as good for less. Northstar makes a beast, odyssey pc2150, JuiceBox banana is equal to those 3, another great alternative is the JuiceBox black cherry that can be had for ~$200 each. Why cheap out on the most important part of the build? Short change your electrical and your amps will pay the price. Save a few bucks on wire. Don't waste it on XS, Knu, it Sky High Car audio cable. You can get high quality, pure copper welding cable for less than half the cost of the big name brands. $2ft for 2/0 welding cable, or $5+ per door for car audio cable.

 

---------- Post added at 07:49 AM ---------- Previous post was at 07:49 AM ----------

 

Yes, same Ben

 

[adulbrich 5,000+ posts]

I was looking about Northstar, but didn't have experience with them. I'm hesitant to buy a juicebox. Are they good quality for the money? I may do some of the black cherries or bananas if they are. Someone on here runs the Duracells and says they are solid

 

[BigBen 10+ year member]

I run black Cherries in 2 setups. They hold a higher resting voltage than my xs did. The difference in the black cherry and banana is capacitance. Basically it's the difference that an xs d3100 is to the xp3000. Same size and voltage but the d3100 and banana will or perform the black cherry and xp3000 by a small margin

 

[adulbrich 5,000+ posts]

How does internal resistance compare? Also, is the extra capacitance worth the extra money?

 

[massivespl]

When I ran a dc 7.5k I had dc 280alt and 3 Juicebox bananas in back and full tilt for a full song lowest I'd drop is 12.2v

 

[massivespl]

And Duracell marine g31 are 179 at SAMs club and u can get black cherrys for 240 shipped. Those are the best for the money

 

[adulbrich 5,000+ posts]

And Duracell marine g31 are 179 at SAMs club and u can get black cherrys for 240 shipped. Those are the best for the money

Which are better? Duracells or black cherries?

 

[massivespl]

The Duracell came out alittle ahead of the black cherry in tfades test if I remember correctly. But both are stout battery's. The Duracell is 179+tax so like 220 out the door

 

[adulbrich 5,000+ posts]

I have other batteries to exchange for the core charge. Thanks for the info

 

[adulbrich 5,000+ posts]

So what voltage drop is too bad? How hard can I push it? I keep my Banda in the 13's, but I know the M4a is over-built. How low can I take it? Are 12's ok?

 

[shauncox26]

The m4a is rated at 11.9v so anything above or a couple tenths should be fine. I personally dont like falling below my batteries resting voltage just to be safe.

 

[adulbrich 5,000+ posts]

Yea, I definitely won't let it get below 12v