jay47

Ok, looking to buy a new amp and I have noticed that there are some differences in prices and ratings. So this Alpine MRP-M650 has an RMS of 600 X 1 at 2 ohms and the Kicker ZX 400.1 as a rating of 400 watts RMS at two ohms. They are the same price. Is one of these rated at 12 volts and the other at 14? They both are "CEA compliant" however it may help, but why the big difference in performance for the same price? I just need an amp to power to Kicker L5 10's (450 watts RMS each). Which would you choose?

buckshizzo

iTrader: (2)

if you are gonna power speakers look at the 4 ohms power rating, for subs go with the 2 ohms power rating. 12 volts is your battery and 14 volts is your alternator.

jay47

ok, I know to use the 2 ohm rating cuz its amps, but as far as the RMS ratings go, why do they have the same price for a difference in 200 watts RMS. Is Alpine overating their amps, is Kicker underating? Is kicker overpriced, Alpine underpriced? That is what I would like to know. Also, you said that your battery is 12 volts, so that means that the power cable I have hooked up to the battery should power 12 volts, or should it be more. Thanks for the help.

buckshizzo

iTrader: (2)

the alpine seems to be a better deal because it has more power, but your subs are only 450 watts rms; make sure your subs can handle the power. i would go with the kicker because it's closest to what your subs can handle. As far as your cables they should be fine, most cables can handle the voltage running from the battery. Sometimes companies will put lights, meters, and other useless stuff on the amp to make it look more flashy and this drives up the price; brand name also infuences the price. Don't be concerned with how it looks on the outside, it's just a gimmick.

jay47

Ok, I see that you said that my subs only have 450 watts RMS, but because I have two of them, won't the amp split the power between the two, meaning that if I had an amp with 900 watts RMS, I would be able to push the two subs to their RMS and not have to worry about the amp frying? The last amp that I had was a RF 551s, and it fried, but I heard that that model of RF wasn't very good. Also, I also agree strongly with what you said about flashy stuff, I just want a good amp. Does anyone here have any experience with Alpine amps? I have an Alpine cda 9851 deck, and I love it, but are their amps any good? Thanks for your time.

urwhat

iTrader: (1)

if each sub is 450wrms then you need an amp that does 900wrms at whatever impedence you wire it at. say if you had two 4 ohm subs, you can wire it at 2 ohms or 8 ohms. but you just need to find an amp that puts 900wrms at 2 ohms using my example, but it may be different for what you have setup. if the amp itself fried, it probably over heated, try using larger power wire like 4 ga from a decent company. the cheapy brands just use like super thick insulation to make it look big, but really its like a speaker wire inside. knukonceptz seems to have the largest wire and is cheap. the knukonceptz when compared to the best monster cable was probably 1/3 to 1/2 size bigger than the monster. (the metal part, but the total wire thickness was the same)

make sure you arent clipping the amp to hell by putting all the ***** to max. bass boost is a terrible thing, introducing all sorts of distortion and clipping problems into your music. also make sure the amp is getting enough cooling.

for pretty cheap prices on amps try www.sonicelectronix.com i think is the website. they have a bunch of other things for pretty decent prices as well. also ebay is a good place to find stuff cheap, but the only bad thing is if it breaks, you wont have a warranty to go back on.

05reverb

iTrader: (1)

what kind of subs you have? SVC, DVC? how many ohms do they have? if your wanting 900 watts RMS, im thinking you should get the alpine mrd-1005 (1000 watts RMS @ 2 ohms). It all depends on your subs, they need to be able to be wired at 2 ohms. if not, then another amp would be best. I have a alpine mrd-605 driving my type-r and love it, the mrd-1005 is the same except puches 1000 watts instead of my 600 watts.

82801BA

Usually look for the difference in THD if they are of the same price. But I don't really trust the ratings for an amp that says "Made in China". For a sub, THD is not really a big deal, as all you hear is lower bass (different story for midbass up). So power is the one you should need to compare. For speaker protection purposes, overpowering is SAFER than underpowering. You get more head room as you are not pushing to the limit of the amp, which can kill speakers faster by clipping (heat damage to the speaker). But as for the sub, it's hard to tell it's clipping. Overpowering can cause over excursion to the speaker (mechnical damage to the speaker), but you will hear it and adjust it right at the first pace.

jay47

Its a DVC sub so I would like to hook it up at 2 ohms. How should I do this? Do hook it up in series or parallel for a 2 ohm load? Oh, and I am using 4 gauge wire from Schosche (however you spell it), not the best but I don't want to put in any more damn wires in this thing. I think that I clipped my last amp because I had a remote gain and I turned it up all the way one day after the amp had been on for about 2 minutes, so I know it wasn't too hot, and then it just cut off. I checked the inside out and some of the square transistor things had been fried, dust everywhere. I'm really just thinking about getting a Kicker ZX 750.1, can't afford more than that and I think it'll get the job done. But, thanks for your help guys.

05reverb

iTrader: (1)

is the sub dual 4 ohm coils? if so, wire it parrellelle (+ with +, - with -), that will give you a 2 ohm load. and the way your talking is like you only have one sub??...anyways if you only have that one sub, you wouldn't need the 750.1, cause you said your sub could only handle 450 rms, so the alpine mrd-605 would be good enough (600 rms).

05reverb

iTrader: (1)

is the sub dual 4 ohm coils? if so, wire it parrellelle (+ with +, - with -), that will give you a 2 ohm load. and the way your talking is like you only have one sub??...anyways if you only have that one sub, you wouldn't need the 750.1, cause you said your sub could only handle 450 rms, so the alpine mrd-605 would be good enough (600 rms).

diskreet

iTrader: (1)

I have decided that I will only buy an amp that puts out the same wattage across all voltages.

dma001

According to Crutchfield: "The input voltage used to measure the power output. Most car batteries, though rated at 12 volts, actually deliver 14.4 volts."

Back when Crutchfield sold US Acoustics amps, they were marketed as one of the few whose RMS ratings, THD, etc. were measured with a 12V input voltage, thus showing that the amps were more efficient - their performance would (supposedly) be the same as equivalent amps whose measurements had been taken with a 14.4V input voltage.

I dunno if it's actually true, but I know that even when I crank my system, the amps stay relatively cool. I like 'em!

diskreet

iTrader: (1)

A car battery is 12 volts. 12.3 or maybe just a tiny bit higher when FULLY charged.

The alternator outputs 14.4 volts. So your electrical system in your car sees 14.4 or less, but usually doesn't dip below 12 unless you are drawing huge amounts of current from your alt and battery.

urwhat

iTrader: (1)

that still wouldnt matter, you would need one rated at 12v. if an amp was rated at 14.4, then you would still probably suffer from power loss if voltage drops below 14.4.

for example, my amp is unregulated, but it was rated at 12v. the minimum amount of power i can expect is the rated 1200w rms at 2 ohms. however, if i supply it charging voltage. the power does jump to 1600-1800w rms.

diskreet

iTrader: (1)

Some amplifiers deliver the same power (watts RMS) across all voltages (usually 11.8 - 14.4 volts).
My JL 500/1 does it. Some PPI do it. I think some rockford and alpines also do it now.
Its some complex circuitry but it works.

I have taken a couple electrical engineering classes so I can assure you I am not BS'ing you here.

urwhat

iTrader: (1)

well thats the point of having regulated amps, is that wattage stays constant. though, the amp will work harder trying to deliver that power if its not getting enough juice. overheating would probably be an issue if you have it stuck on the minimum power. ive seen the death of quite a few amps that suffered from large voltage drops due to small power wire, or just too much draw.

though the wattage is the same throughout all volatges.. it takes that much more amps to drive to teh same wattage from the lower voltages. for example. you may only need 30 amps at 14.4volts to make 300w (these are just example numbers) but you might need 45 amps to do 300w at 12 volts. i know theres mathematical equations to come up with the right numbers but im lazy and just got on my summer break.

diskreet

iTrader: (1)

So you are saying a 500watt rms, at 14.4 v, amplifier has to work harder to output 500watt rms at lower voltages.
Why wouldn't they just make a 500watt rms, at 11.8v, amp that regulates power at higher voltages? I am sure that at least some companies take this approach, especaially the really high end amps.

As for overheating, my 500/1 gets warm, but I have never got it to be hot anywhere. The heatsink ususally never even gets warm, and the metal just over the amp is always touchable.

urwhat

iTrader: (1)

basically. cheaper amp companies want to make their amps look better by rating them at higher levels because most people just see 1000w and go wow! like some companies just put 1000w max for an amp that only puts out 150w rms. its mainly just to boost the numbers so that they look better and the consumer is fooled. its all a marketing gimmick. although, thats not really true for high end companies because usually their consumers are experienced and know what they are buying, so there is no point in trying to make something appear better than it really is. plus it just adds to their reputability if they dont try to decieve their customers.


quite a few companies actually market their amps for a wattage at 12 volts because they have nothing to prove.