Introduction and current ideas

[4EVRLRNING]

First of, I wanted to introduce myself and say sorry for a long post. My name is John Martin, 28 years old. I normally go by SATAN on car forums. That is how people usually know me. I am a metal fabricator for MAINLY for the z31 model 300zx. I build custom exhaust and intake manifolds and all kinds of stuff. I have a 1985 300zx, that I am aiming to get in the 9 second range very soon. Current fastest is 11.5. Anyways, that is not why I am here though...

Recently my wife picked up an SUV. I used to be mildly into car stereos about 8 years ago. My last good pair of subs were 15" Solo's powered by an Infinity Beta amp.

NOW, I just picked up a pair of dual 4ohm 15" L7s". Now I know what you are gonna say, "L7's are not great for SQ". I am aware, however my wife will never know so that doesn't matter. What matter's to me is SPL. I currently have an older MTX 81000d amp also known as the 1501, same amp. It is rated at 1500 dynamic at 2 ohms. I currently have 1/0 wire and a 150 amp breaker. I plan on doing "The big three" upgrade when I install all of this stuff.

Now, I want to get a bigger alt eventually but here is what I am thinking, and I would like some feed back on the idea from people who have experience. I would like to get 4 car battery's and wire them in a Parallel, then wire them to the amp. This would give me a good amount of current at 12 volts. The speakers as I mentioned are dual 4 ohms, I would wire each in a parallel then parallel them together to give me a 1 ohm load. Now, I know the amp is not supposed to be stable at 1 ohm, but it would not be the first time I have gone below what is recommended. The 4 batteries would ONLY be used on competition days as I know it is hard on the alt to keep them charged. The rest of the time it would just be the 1 battery up front.

This is all just from a little reading I have done in the past couple days. I have read a little about batcap's and how they are cool and then some people say they are just a regular blah blah battery nothing super special or whatever. I will make those decisions when the time comes I guess.

Anyways sorry for a long post, but it was an introduction.

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[helotaxi 5,000+ posts]

Not hard on the alt to charge the extra batteries unless you let them discharge a lot.

 

[4EVRLRNING]

Also, one thing I am wondering about... Would 4 batteries be over kill for that one amp? Eventually I wan't to do two Crunch gp2500's. One for each sub wired at a 2 ohm load. But for now, is 4 car batteries just to much for one amp at 1500watts? If the amp cooks... whatever, but I don't want to blow shit up either LOL.

I guess the logical question is how do you figure out the best combination of batteries for you amp set up. If you wan't to flame and say "You need to search" Feel free.

 

[helotaxi 5,000+ posts]

Adding a single extra battery will be more than enough for that amp. Add a second when you add the second amp.

 

[Ed Lester 10+ year member]

The 81000D and 1501D is a very efficient amp and I have run one from a single optima yellow top and stock alternator and still made full power from the amp with no ill effects.

This amp is not rated at 1 ohm but can certainly run 1 ohm. I found the most power came from .7 ohm loads.

A strapped pair at 2 ohm made over 4400w per coil in my setup. Each amp was making 2200w at 1 ohm.

The Crunch GP2500Ds are rated at Max power and will make about 1250w each.

These 2 amps will operate just fine from a single large battery like the Kinetik HC2400 or Power Master D3100 or 2 medium batteries like Optima Yellow tops. It will not be necessary to upgrade the alternator to charge these batteries since they will charge easier than your stock battery.

 

[4EVRLRNING]

The 81000D and 1501D is a very efficient amp and I have run one from a single optima yellow top and stock alternator and still made full power from the amp with no ill effects. This amp is not rated at 1 ohm but can certainly run 1 ohm. I found the most power came from .7 ohm loads.

A strapped pair at 2 ohm made over 4400w per coil in my setup. Each amp was making 2200w at 1 ohm.

The Crunch GP2500Ds are rated at Max power and will make about 1250w each.

These 2 amps will operate just fine from a single large battery like the Kinetik HC2400 or Power Master D3100 or 2 medium batteries like Optima Yellow tops. It will not be necessary to upgrade the alternator to charge these batteries since they will charge easier than your stock battery.

Hmmm, ok, I was under the impression they were virtually the same. Thank you for clearing that up. However, which of the two amps did you run in the description you typed, the 81000d or the 1501d? I guess my question is which of those two was the one making 2200w at 1 ohm?