Alpine V-Power class D amps - Rated?

[scoob8000 10+ year member]

Just picked up a used Alpine MRP-M500.

It's a Class D mono amp rated at 500 rms @ 2 Ohms.

I can't get 500 watts out of this thing unless I turn my HU volume wayyyy past normal listening volume AND turning bass boost nearly the whole way up.

Preout voltage should be 2.2.

So did I get burnt on yet another used amp purchase, or do these amps just ****? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

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[donky23 10+ year member]

Good question as I was considering picking up the same amp to run my Polk Momo 8's. I will be interested to see others opinions on Alpine's mono amps.

 

[Brian_smith06 10+ year member]

they are nice amps.

so is your gain up much? from what your saying its up all the way(from my understanding) along with bassboost.

 

[Brian_smith06 10+ year member]

oh and i plan to buy the mrp-m1000 to go with my f600.

my f600 is a pretty BA amp

 

[donky23 10+ year member]

I am trying to decide between the MRP-M500 and the MRD-501 to run my little subs.

 

[scoob8000 10+ year member]

This is the amp in question.

Anyone know if they'll do rated power?

 

[eharri3 10+ year member]

Are you jsut setting your gain at the head unit's voltage output rating and leaving it like that?

Could be your head unit isn't making the rated output voltage on the sub RCA pre out. I have the same issue, my MRP-M500 is wired at 4 ohms to my Pioneer Premier 10. I can't get the right voltage on the dmm from my MRP M500 unless my gain is somewhere around 1-1.5 volts and my head unit is rated for four. I don't seem to get a linnear rise in sub volume until it's set right about there. If I try it with the amp at 4 volts the sub doesn't hit until I'm almost near max volume.

It's been this way with a 2 and 4 volt Alpine head unit, with the 2 volt my gain was around .5 volts. And meanwhile my mid-high amp always ends up almost exactly at the input sensitivity level that matches the head unit voltage rating. After some research I found out some Alpine head units have a history of making less voltage on the sub pre-outs, meaning you'll be cranking the gain more than you think is right to get the max output and it'll look like the sub amp isn't doing rated power. I guess I won't know for sure what the issue is until/unless I try it with a head unit that is known to make rated output or close to it at the sub pre out. With my gain this high though my sub hits like it should and sounds clean all the way to my max undistorted volume, with no boost. This thing may be underpowered but if Im reading things right it would have to be underpowered by way more than a 3rd to be this much off. I find that hard to believe even with a low end Alpine, maybe if it was Sony Xplod or something. And even with the gain at less than 2 volts and the volume cranked there's never audible distortion, which I would imagine there would be if the extra power needed to get me the right voltage on the dmm came from a badly clipped signal. When I move the gain knob with the DMM hooked up the output voltage is still rising gradually in this range, no sudden jumps or anything like it goes right from 20 to 40.

I have looked high and low for bench tests or reviews and never seen any.

 

[Adnan 10+ year member]

i had a mrd m605 amp....very clean and excellent sound quality amp

very efficient and easy going on my stock electrical as well

 

[scoob8000 10+ year member]

eharri3,

Same here. No solid information on them anywhere, not even on here. But I got it for a good price.

I'll have to re-check my preout voltage. It's an old JVC deck with low preout levels but I have a small line driver hooked up behind the deck, so my voltages should be up there pretty good.

This Alpine is replacing an old Lightning Audio that was only rated 230@4. I had been running it at 200ish @ 2 though, gain level was barely up from the lowest setting.. That's what surprised me about the alpine. Unless they just like high preout voltages..

 

[ThatChevyGuy 5,000+ posts]

i had an mrd m500 that had no adjustable gain settings on the amp. Pissed me the fook off.

 

[scoob8000 10+ year member]

Did a little more testing. This amp blows, I don't know if it's the whole product line or mine is bad.

HU volume at 25 of 30 for all tests:

Gain all the way up, bass boost off: 9.2 volts

Gain up all the way, bass boost up the whole way: 28.2 volts

I can barely break 425 watts with gain and boost the entire way up.

 

[eharri3 10+ year member]

Hmm I get 36.4 on the dot at maybe 3/4ths on the way up. I think something's wrong here.

 

[TheHammer12 10+ year member]

This is gonna sound kind of crazy, but try unhooking one side of the amp inputs. Thats the way I've got mine bc I had very little power with both sides hooked up.

 

[scoob8000 10+ year member]

Hmm I get 36.4 on the dot at maybe 3/4ths on the way up. I think something's wrong here.

Could ya do me a huge favor? Measure your RCA preout voltage with your deck turned up to where you set your amp up at 36.4. That'll tell me for sure if it's my amp or just low pre-out levels..

 

[liqdfire4755 10+ year member]

guys, it sounds like its the amp line. mine is the same way. i just threw a 12" type r in a 2cu.ft. box tuned to 30hz with the m1000 and i have to have my gain at about 3/4 the way up to get some movement. i have seen some videos of the r's and they get moving with like 700rms. so this thing should be pounding with 1000rms. maybe i will pull my truck in the bay and do some real testing on it tomorrow. and i will try that little trick of pulling out one rca and i will see if there is any change. i am running a pioneer 6000ub which is supposed to have 4 volt outputs. so i dunno. maybe i should check those as well. will post tomorrow night with some results.