Alpine MRP-M45 amp enough to power a Stealthbox?

jnowlin · #1 (**permalink**) 02-21-2008, 12:49 AM

Is an Alpine MRP-M45 amp enough to power a Stealthbox in a 2007 Supercrew? I know it's not ideal, but I'm not looking for bone jarring bass, just sound quality mostly. But would it be so underpowered that it would sound awful? Here are the specs on the amp:

mono subwoofer car amplifier
220 watts RMS x 1 at 4 ohms (400 watts RMS x 1 at 2 ohms)
variable low-pass filter (50-200 Hz, 24 dB/octave)
tuned Bass EQ (0-12 dB bass boost at 50 Hz)
subsonic filter (15 Hz, 24 dB/octave)
MOSFET power supply
CEA-2006 compliant
STAR Topology (minimizes internal noise and prevents ground interference)
speaker- and preamp-level inputs
gold-plated screw terminals
fuse rating: 20A x 2
8-gauge power and ground leads recommended — wiring and hardware not included with amplifier
9-3/4"W x 2-3/8"H x 9-9/16"D

Here are some specs on the Stealthbox:

Stealthbox® custom-fit subwoofer
sealed fiberglass enclosure
10" 4-ohm W3v3 subwoofer
fits under driver side rear seat
power handling: 100-500 watts RMS (1,000 watts peak power)

Woofer: One 10" JL Audio W3v3-4 subwoofer is loaded in this sealed enclosure and wired as a 4Ù load at the enclosure's 5-way post speaker terminal.

Thanks for your input.

Fosters · #2 (**permalink**) 02-21-2008, 02:34 AM

I have an alpine 4 channel amp, probably same family of amps as that one (MRP something...) and quite honestly, i'm dissapointed with it's output. power ratings for most amps are pretty much meaningless. The only thing that I've noticed is somewhat of a decent indicator is the fuse size. The bigger the fuse, the more current it'll use, the more it should put out. with that being said, JL subs can handle a lot of punishment, and I don't think that amp will push it to it's max, but rather the sub will use up all it can give without a problem. It will be decently loud, don't get me wrong, but that sub would be able to handle more. Your best bet I think is to rewire it for 2ohms if you can.

bridge · #3 (**permalink**) 02-21-2008, 08:04 AM

No need to rewire, 4ohms at the speaker is fine. Your amp has enough power to push that speaker. Those stealthboxes are designed to make a minimum power rating sound great. I've run them with as little as 100watt/4ohm amps and was pleased.

jnowlin · #4 (**permalink**) 02-21-2008, 10:03 AM

Thanks guys. I really appreciate the input. Even though it may not be necessary to rewire the sub, it would be a good idea if possible, right? Does anyone know if it can be rewired to 2 ohm?

Fosters · #5 (**permalink**) 02-21-2008, 04:57 PM

Quote:

Originally Posted by jnowlin

Thanks guys. I really appreciate the input. Even though it may not be necessary to rewire the sub, it would be a good idea if possible, right? Does anyone know if it can be rewired to 2 ohm?

if it's a dual voice coil, you can rewire it to 2ohm.

http://www.crutchfield.com/learningc...rs_wiring.html

bridge · #6 (**permalink**) 02-21-2008, 06:47 PM

While that amp may be capable of 2 ohms, it may not be 2 ohm stable. Run the amp/speaker at the 4 ohm setting first. If it sounds good go with it. If not you can rewire the speaker per the schematic on JL's website. I've done the same thing your asking about and learned that amps tend to be fickle at 2 ohms. Good luck with your install.

XolieX · #7 (**permalink**) 03-03-2008, 07:51 PM

if you talking about the stealthbox that is 500watts, its the sealed box. i strongly recommend going with the ported box. its only 300 watts, that amp you got that is 220 will run it absolutely beautifully. that amp might be on the very small side for that set up.

i know this is an old post, but who knows if you already bought the box. go with ported.

PORTED IN THE WAY TO GO!!!!

Panzerbrumbar · #8 (**permalink**) 03-04-2008, 07:59 AM

I just put that same Alpine MRP 450 in hooked to a Kicker 07TCVT102 10" 2ohm Thin Mount Truck Enclsoure it seems to have plenty of power still tweaking with all the adjustments but very happy with the sound and everything fits great all said and done it was just shy of 500 dollars really good investment I think.

jnowlin · #9 (**permalink**) 03-04-2008, 10:16 AM

Thanks for the replies. Xoliex, its funny that you say that about the ported Stealthbox because that's what I ended up going with. I haven't hooked it up yet, though. Do you guys think I should just run the amp at 4 ohms (220 watts) or try to run it at 2 ohms (400 watts)? As Xoliex said, the box is rated for a max of 300 watts RMS.

XolieX · #10 (**permalink**) 03-05-2008, 06:37 AM

the stealth box is wired for 4ohm so just use a 2 channel amp, a 300 watt amp will be ideal and a real clean 300 watt amp. however ur alpine 220 amp should be good enough because the ported design was only 50 more dollars and its lower power meaning you could use the same amp possibly. and having a ported design will make it sound like 2 10's in there.

XolieX · #11 (**permalink**) 03-05-2008, 06:41 AM

ok i read the reply more in detail, if you are using a mono amp that 220 at 4ohm and 400 watt at 2ohm. well the only choice you got is to run it at 4ohm or 1ohm and 1ohm isn't a option for you. the sub is a dual 2 ohm.

besides, the higher ohm you run the amp the longer the amp will live and won't get hot! running a amp at 1ohm will get hot and live a short live even though its 1ohm stable!

however, its always better to have a lil more power than too little. if you can get a 2 channel amp thats 400 watts rpms, that'll be perfect. you would enjoy having head room with your amp to sub combo.

hell, there is a rockford fosgate 325.2 amp in sale at crutchfield for 139 and that amp is 325x1 but i'm sure its more like 400 watts because rockford always puts out more power than they state.

jnowlin · #12 (**permalink**) 03-05-2008, 10:19 AM

Quote:

Originally Posted by XolieX

ok i read the reply more in detail, if you are using a mono amp that 220 at 4ohm and 400 watt at 2ohm. well the only choice you got is to run it at 4ohm or 1ohm and 1ohm isn't a option for you. the sub is a dual 2 ohm.

besides, the higher ohm you run the amp the longer the amp will live and won't get hot! running a amp at 1ohm will get hot and live a short live even though its 1ohm stable!

however, its always better to have a lil more power than too little. if you can get a 2 channel amp thats 400 watts rpms, that'll be perfect. you would enjoy having head room with your amp to sub combo.

hell, there is a rockford fosgate 325.2 amp in sale at crutchfield for 139 and that amp is 325x1 but i'm sure its more like 400 watts because rockford always puts out more power than they state.

Thanks again for the reply. Unless I'm reading JL Audio's website wrong, the sub is a dual 4 ohm. It is a 10W3v3-4 sub. Am I wrong? I certainly don't profess to be an expert in this area. If I am correct, I can run it at 2 ohm according to the link from Crutchfield above. Is that correct? If so, it looks like that may be optimal.

XolieX · #13 (**permalink**) 03-05-2008, 03:10 PM

the v3 box is the sealed box and its 500 watts. the v2 is the ported and its 300 watts. they are wired for 4ohm. they are dual 2 ohm speakers, with that, you can only come up with 4ohm or 1ohm loads.

what i'd do is just call crutchfield and ask them exactly what it is. i'm sure it a 4ohm load which makes it easier on you because you can get a cheapy 2 channel amp that produced 300 watts.

jnowlin · #14 (**permalink**) 03-05-2008, 04:13 PM

Quote:

Originally Posted by XolieX

the v3 box is the sealed box and its 500 watts. the v2 is the ported and its 300 watts. they are wired for 4ohm. they are dual 2 ohm speakers, with that, you can only come up with 4ohm or 1ohm loads.

what i'd do is just call crutchfield and ask them exactly what it is. i'm sure it a 4ohm load which makes it easier on you because you can get a cheapy 2 channel amp that produced 300 watts.

What's really confusing is that JL Audio's website has changed recently with respect to the ported box. I agree that it used to say that the ported box is 300 watts. However, in looking at it today, I noticed that it has changed: http://mobile.jlaudio.com/products_s...hp?fit_id=1512

What is really confusing for me is that I bought this Stealthbox and amp used, and if the Stealthbox has changed, I'm not sure which one I have.

XolieX · #15 (**permalink**) 03-06-2008, 03:24 PM

well the 10w3v"2" is the old school style woofer, and the 10w3v3 is the new school woofer. the way to tell is the old school just had JL in the middle of it. and the new school has w3, w6 or w7 at the bottom in small letters, real sleek looking woofers.

find out what you got! if you got the new school one, then you want that 500 watts. if not, 300 is what you got then that 220 watt amp you got will do ok!