Watts RMS vs. Alternator Amps

[jrodhotrod]

I think I have narrowed down the components for my mazdaspeed 6 audio build but I have a question about how many watts RMS I could safely run off the factory alternator.

From what I have been able to read the factory alternator is 110 amps.

Currently I am looking at around 1,400-1,500 watts RMS at the high end (1,000 watts RMS to the Sub at a 2ohm load and 400-500 watts RMS to door speakers at 4 ohm loads)

Is that going to be too much for the factory alternator and do I need to reduce the deman from either the sub amp or multi-channel amp?

The sub is going to be an IDMAX 12" D4 in a sealed enclosure and recommended RMS is 1,000 watts, but I think I'll be okay with something that pushes around 700 if necessary.

Currently I am leaning towards getting the Alpine MRD-F545 and Alpine MRD-M1005 if I go with a 4 channel set-up (active crossover)

MRV-F545 & MRD-M1005

Also still considering the DLS Ultimate series pairing an A6 with something like an A3 if I can afford it, but this is decidedly more expensive.

thoughts?

 

[got wake?]

you'll be fine with that wattage on the stock alt. i'd suggest getting a good replacement battery and make sure everything is grounded properly.

 

[jrodhotrod]

EDIT: Those claimed numbers may be peak numbers not RMS for actual power...

Shopping Sound Domain for amps on a budget and bang for the buck:

http://www.cardomain.com/item/ROCPUNCH150

If I get a dual 2ohm woofer I could have the claimed 978 watts RMS into a 4ohm load for the sub.

Follow that up with this for the Focal K2Ps in the front doors:

http://www.cardomain.com/item/ROCPUNCH75

Thoughts?

The prices are certainly right leaving me more money for other installation pieces.

 

[got wake?]

the numbers on the alpine amps are RMS ratings. but those 25-life amps are hard to beat for the price. cardomain has pissed of a LOT of RF dealers by selling them so cheap. i'd pick up a bunch if i had the extra cash and just leave them in the packaging for 10 or so years to have some limited edition amps

 

[chuyler1]

^^^
except that you aren't the only one with that idea. The only way something stays exclusive...is when the price stays exclusive.

You should be fine for 1500w with the stock alternator. Just keep in mind that you will rarely use all that power. I tend to stick with 500-800w for sub(s) because I know I'm never going to need more for everyday listening. It saves me money that I can spend on better front speakers.

Back in the day, competitions used to have 4 classes, 1-150, 151-300, 301-600, and 600+.

The 1-150 class was primarily composed of people using cheater amps but I remember reading about some world-class installs that fit in the 151-300 and 301-600 class. These days it seems people shoot right for the 600+ class and don't even bother to worry about powering midrange and highs with amps.

FYI, my current system squeezes by just under 600w RMS @ 4ohms

 

[jrodhotrod]

Yeah, I know the numbers on the Alpine amps are RMS. Just not sure about the claimed numbers on the Rockford amps.

For the money the best bet is to go with the Rockford amps?

If I got that route I'll get the dual 2 ohm IDMAX and run it at a 4ohm load and then run just the front doors off of the Punch 75 using my K2P 165s.

Tying it all together using a Rockford 3sixty.3 and the factory headunit.

As long as the prices are so good I may pick up the Punch 45 in addition to the 150 and 75 for future use to go active on the front doors or do something in the rear doors if I decide I don't like the just front doors route.

You all are the experts, any real reason not to go for this combo?

 

[got wake?]

You all are the experts, any real reason not to go for this combo?

i can't think of a reason to not go for it. the alpine amps are great, but if you can get the RF amps for less, it's worth it. the specs are very underrated on the RF amps. the 45 my buddy tested put out nearly 4 times the rms power rating(shocked)


technically if i switch my DLS A6 to a DLS A3, i'd be in the 1-600 watt class(glare) but DLS now rates the A4's at 85x4, so i'm not sure how it would be ruled. my owners manual state 50x4, so i could probably work my way into 1-600.

 

[jrodhotrod]

good to know.

If I get one of each, I am looking at 43" of amp. Now to figure out where to put it so it doesn't eat in to useable space too much.

 

[chuyler1]

technically if i switch my DLS A6 to a DLS A3, i'd be in the 1-600 watt class(glare) but DLS now rates the A4's at 85x4, so i'm not sure how it would be ruled. my owners manual state 50x4, so i could probably work my way into 1-600.

I'm in the same situation. If and when I decide to compete I plan to just bring my instruction manual with me to prove that I purchased the amp before they changed the ratings and it was my sole intention to compete in the under 601 class.

A5= 1x300 + 2x50 = 400
A8= 4x40 = 160
Total: 560

Bump the A5 up to 1x300 + 2x85 and the total is 640

Either way, I've got a pretty good balance. I need to turn up the gains on the A8 to keep up with the A5 but since they are only playing 400-6Khz and 6Khz-20KHz I don't hear any distortion with the higher gain.

 

[jrodhotrod]

EDIT:

Capacitor education:

http://www.msprotege.com/forum/showpost.php?p=1473630&postcount=3

Found your lesson on Caps. I'll pass on this added expense and just add the battery and grounding kit at some point down the line.

-Jared