How is it an amp makes less power at 1Ω than at 2Ω

[SamIam71]

I am looking at an Alpine MRX-M110, wanting to put it on two Sundown sa's.

Their website specifies its output to be 650 W @ 4Ω, 1,100 W @ 2Ω, and 800W @ 1Ω.

I had to peruse through the owners manual to find if it had a 1Ω rating, and it did, but it was lower than the 2Ω rating.

While I am at it, you guys think this amp is a good match for those subs. They are rated at 400-600 Watts, but people say they ca take more. I was looking at the MRX-M240, but it is nearly twice the price and makes roughly twice the power at each rating of resistance. But, 550 true,clean watts seems like it would be plenty to make them hum.

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[thevic24 5,000+ posts]

The power supply is regulated. At 1 ohm, it most likely takes as much current to make the 800 w rms as it dose to make the 1100 w rms @ 2 ohms. That and its probably not really

meant to run a 1 ohm load even though it has a spec for it. If it were, I am sure that Alpine would have designed the power supply and output stages to make the extra/more @ 1 ohm.

 

[SamIam71]

On the website, it only gives the ratings for 2Ω and 4Ω, I had to look at specs for it in the owner's manual and it gave the 800w at 1Ω rating along with the others I suppose it is stable at 1Ω, but never intended to run that way. It is just the first time I ran across this. Is it something exclusive to digital amps?

 

[Jeffdachef 5,000+ posts]

On the website, it only gives the ratings for 2Ω and 4Ω, I had to look at specs for it in the owner's manual and it gave the 800w at 1Ω rating along with the others I suppose it is stable at 1Ω, but never intended to run that way. It is just the first time I ran across this. Is it something exclusive to digital amps?

Alpine amps are geared for operating at 2 ohm impedance so best solution? look for another amp besides that one. One that does power at 1 ohm. Try soundqubed 1200.1D or if you want even more power, go with a ct sounds AT1400.1D these amp's quality wont lose to any alpine amp, gives loads of clean power with great efficiency.

 

[SamIam71]

I plan to run this at 2Ω if I get it and let it push 1,100W to two SA12's

 

[thevic24 5,000+ posts]

I plan to run this at 2Ω if I get it and let it push 1,100W to two SA12's

I would think if you design and build the box to be super efficient(or as much as can be) it should do just fine.

And that power limited thing is not the norm really for D class amps...just some. Its like saying "hey, I'm a 2 ohm stable amp...*but* I can take a 1 ohm load..."

Not to sure how long the amp would play with a real 2ohm load thou...(before going into thermal..). I think that rating (for this amp) if just to let you know it will do a 1ohm load

safely if needed...

 

[winkychevelle 10+ year member]

I plan to run this at 2Ω if I get it and let it push 1,100W to two SA12's

so your efficiency question is void

get a quality amp and stop worrying about efficiency for only 1k of power.

3 steps

1. good power wire preferably 1/0awg

2. big 3 upgrade in 1/0awg

3. decent batt under the hood 55ah is my min recommendation

if you still have bad voltage drop its time to test the alt cuz its prolly on the way out.

dimming lights is almost impossible to get rid of without a capacitor in line with just the lights

 

[SamIam71]

Cool, thanks man.

 

[SamIam71]

so your efficiency question is void
get a quality amp and stop worrying about efficiency for only 1k of power.

3 steps

1. good power wire preferably 1/0awg

2. big 3 upgrade in 1/0awg

3. decent batt under the hood 55ah is my min recommendation

if you still have bad voltage drop its time to test the alt cuz its prolly on the way out.

dimming lights is almost impossible to get rid of without a capacitor in line with just the lights

I have no worries, only a question about characteristics of an amp that was answered. I trust Alpine to be make a quality product.