Still looking for amps - Alpine MRP?

(hunter660) · (hunter660) **Join Date: Aug 2007** 03-13-2011, 7:56 AM

I have been searching for amps to power my boat for almost two years now and I need to do something this season. Does anyone have any experience with the Alpine MRP series of amps? They seem to be a lot of power for the dollar.

(hogger) · (hogger) **Join Date: Sep 2008** 03-13-2011, 8:02 AM

I just got an M500 for my subs. Hopefully I can get it all hooked up this week and let you know.

(hunter660) · (hunter660) **Join Date: Aug 2007** 03-13-2011, 8:03 AM

Please do. I'm thinking about the M2000 for my pair of 485s.

(shawndoggy) · (shawndoggy) **Join Date: Nov 2009** 03-13-2011, 8:03 AM

boston acoustics has some really good deals on refurb amps on their outlet site that are worth a look.... for two bills the GT 28 is a steal.

the M2000 is a sub amp, I don't think it'd sound too good on your 485s.

(hunter660) · (hunter660) **Join Date: Aug 2007** 03-13-2011, 8:09 AM

Thanks. Most items show out of stock. Looks like some very good prices. I'm just not sure if any of them fit my application. I need to do some more research. Are all of BA amps class AB?

(carcrz) · (carcrz) **Join Date: Mar 2006** 03-13-2011, 8:14 AM

I've got a couple Alpines on Craigslist in Kansas City, MO that I'd be open to offers on. Just let me know.

(hunter660) · (hunter660) **Join Date: Aug 2007** 03-13-2011, 8:15 AM

Send me a PM of what you have.

(shawndoggy) · (shawndoggy) **Join Date: Nov 2009** 03-13-2011, 8:30 AM

I'd look at a pair of the gt-22s. Run each one bridged for 350w @4 ohms. One for each 485, $130 each.

Yes I believe all of the BA amps are AB. Best bet on the cheap for class d full range would probably be a used jl hd 750.1. Those come up on the car audio classified sites from time to time in the $400 range.

(hunter660) · (hunter660) **Join Date: Aug 2007** 03-13-2011, 8:38 AM

Just noticed the Alpines are 20-200Hz,, not 20-20k as I saw in my head. Another example of me seeing what I wanted to. Guess I'm back to JL or WS.

(h20king) · (h20king) **Join Date: Dec 2009** 03-13-2011, 8:53 AM

John I am also in the process of redoing my system and will be using one of these to power my 485's http://cgi.ebay.com/KS-300-4-ARC-AUD...item1c1522a447 lots of bang for the buck

(david_e_m) · (david_e_m) **Join Date: Jul 2008** 03-13-2011, 10:15 AM

Just an FYI. I'm not an Arc Audio dealer so I don't have a horse in this race. But WoofersEtc is on the Arc Audio blacklist (check out the Arc Audio site) so this means zero warranty. The savings isn't enough to have a unit without a factory serial number. Pay an extra 50 bucks and get it from a legit dealer, or go direct from Arc, or negotiate with a genuine dealer, or if you don't necessarily need a warranty then get a used one at a substantial reduction.

David
Earmark Marine

(h20king) · (h20king) **Join Date: Dec 2009** 03-13-2011, 10:33 AM

Good point Dave I just did a quick e- bay search and posted the first link I came to with the amp I went the last route and bought my amps and speakers used but the guys at wetsounds checked everything out and put the 485's in brand new housings so I am confident everything is in proper working order

(hillbilly) · (hillbilly) **Join Date: Aug 2002** 03-13-2011, 2:33 PM

Soundbox had a couple Boston amps for sale in the classifieds, And I know he takes care of his stuff.

If I had the $$$ I would buy his stuff and redo my boat but my 4 month old daughter needs diapers more than Daddy needs new amps !

(murphy_smith) · (murphy_smith) **Join Date: Dec 2005** 03-13-2011, 4:54 PM

Harold - give these guys a call.

Car Audio Depot in Modesto California. They are located about 20 minutes from the Arc Audio Factory. You can wither buy brand new or buy the B stock units. Arc Audio sells all there B stock to Car Audio Depot.

If you give them a call you will want to ask for Ron. Tell him that Murphy sent you. I am sure that he can come pretty damn close to woofers prices and you will get a full factory warranty.

(hunter660) · (hunter660) **Join Date: Aug 2007** 03-14-2011, 3:07 PM

What about the BA GT-28 to power the pair of 485, a second one for my sub, and a smaller BA for the in-boats. How well is my battery going to like this?

(david_e_m) · (david_e_m) **Join Date: Jul 2008** 03-14-2011, 3:20 PM

The Boston Acoustics GT-28 isn't going to deliver power that is extraordinary to a pair of 4-ohm Pro485s. Its really biased for 2-ohms.
Any guess as to why so many B-stock are available several years after they've been discontinued? I know the answer to that as a Boston Acoustics dealer.
A WetSounds Syn4 bridged is a natural for a pair of Pro485s. Another awesome match is the JL Audio HD750/1.
With Pro485s you've got what is possibly the premier tower speaker so I would do it right on the amplifier.

David
Earmark Marine

(hunter660) · (hunter660) **Join Date: Aug 2007** 03-14-2011, 3:23 PM

I can't run the GT-28 at 2ohm?

(david_e_m) · (david_e_m) **Join Date: Jul 2008** 03-14-2011, 4:38 PM

Sure, the BA GT-28 is well suited for 2-ohms. But, how does a single stereo amplifier and a single pair of 4-ohm speakers equate to 2-ohms? Am I missing something?

(hunter660) · (hunter660) **Join Date: Aug 2007** 03-14-2011, 4:40 PM

Wire them in parallel to 2 ohm.

(hatepain) · (hatepain) **Join Date: Aug 2006** 03-14-2011, 4:52 PM

Joe, its a two channel amp so if you were to use this amp you'd have one on each channel (this would be underpowered). You cannot run it bridged at 2 ohms.

(hunter660) · (hunter660) **Join Date: Aug 2007** 03-14-2011, 4:54 PM

Why does everyone call me Joe???

(shawndoggy) · (shawndoggy) **Join Date: Nov 2009** 03-14-2011, 4:55 PM

or two gt-28s, each bridged to one channel to do 700w @ 4 ohms. That's a lot of amp rack real estate though.

(Thrall) · (Thrall) **Join Date: Oct 2010** 03-14-2011, 5:16 PM

David, I think he's running a pair of 485's, so 4 speakers total?
First, whatever David says is good advice, but I don't think the GT-28 would be a bad choice for your sub or for the tower speakers.
I had a GT-28 pushing a 450W (or 900W??? dual voice coil) Boston sub and it did great. I switched that amp to powering 4 JL 7.7's on the tower, rated at 150W RMS, 2 speakers per channel wired in parallel and the amp is more than enough for those speakers.
I'd imagine it would work good for a solid 200W per speaker with 4 speakers at 2ohms.
If you can get a GT-28 for a couple hundo I think that's a steal. I believe the PO of my boat paid around $800 for it new.
That's it there behind the JL amps.

(shawndoggy) · (shawndoggy) **Join Date: Nov 2009** 03-14-2011, 5:19 PM

Quote:

Originally Posted by Thrall

David, I think he's running a pair of 485's, so 4 speakers total?
First, whatever David says is good advice, but I don't think the GT-28 would be a bad choice for your sub or for the tower speakers.
I had a GT-28 pushing a 450W (or 900W??? dual voice coil) Boston sub and it did great. I switched that amp to powering 4 JL 7.7's on the tower, rated at 150W RMS, 2 speakers per channel wired in parallel and the amp is more than enough for those speakers.
I'd imagine it would work good for a solid 200W per speaker with 4 speakers at 2ohms.
If you can get a GT-28 for a couple hundo I think that's a steal. I believe the PO of my boat paid around $800 for it new.
That's it there behind the JL amps.

you only have one power and one ground run?

(david_e_m) · (david_e_m) **Join Date: Jul 2008** 03-14-2011, 6:11 PM

Each Pro485 has two 8-ohm 8-inch drivers that are internally paralleled for a nominal load of 4-ohms per pod.
Without quoting final pricing (like 40 cents a watt or anything crazy like that) if you want to get by super cheap then get two brand new JL Audio JX360.2s bridged and you'll have 720 total watts. The JL JX 1000 watt Class D monoblock subwoofer amplifier is a little giant and an amazing watt per dollar value also. New 'A' stock btw.

David
Earmark Marine

(hunter660) · (hunter660) **Join Date: Aug 2007** 03-14-2011, 6:21 PM

David, how would you compare running two of the JL JX360.2s verses a WS SYN4? I know the rated power is 360 vs. 400, and we are talking A/B vs D?G?H?

How will the two compare in volume and sound quality?

(david_e_m) · (david_e_m) **Join Date: Jul 2008** 03-14-2011, 6:31 PM

I would have to go with the higher power and higher efficiency.

(hatepain) · (hatepain) **Join Date: Aug 2006** 03-14-2011, 7:12 PM

Sorry Jon. Ha! I have that amp and had no idea it can go to 2 ohms bridged.

(david_e_m) · (david_e_m) **Join Date: Jul 2008** 03-14-2011, 8:22 PM

2-ohms bridged. Which is the same as 1-ohm stereo. Maybe in an air conditioned cabin but not for long on a July or August day in a locker of a towboat.

(Thrall) · (Thrall) **Join Date: Oct 2010** 03-15-2011, 12:09 PM

Quote:

Originally Posted by shawndoggy

you only have one power and one ground run?

Yeah, I only ran 1 set of wires. 4ga, short run, about 4' from the dist block, so it works fine.

(hatepain) · (hatepain) **Join Date: Aug 2006** 03-15-2011, 12:18 PM

Quote:

Maybe in an air conditioned cabin but not for long on a July or August day in a locker of a towboat.

Yeah its pretty rare to find and amp that even list that rating.

(hatepain) · (hatepain) **Join Date: Aug 2006** 03-15-2011, 12:21 PM

Quote:

you only have one power and one ground run?

I too have only one power and ground run to my GT-28. Its also 4 guage about 6-7' off of the distro which is a 1/0 run too it. I've never once had a problem like that, even at heavy volumes for very long periods of time.

(shawndoggy) · (shawndoggy) **Join Date: Nov 2009** 03-15-2011, 1:10 PM

Quote:

Originally Posted by hatepain

I too have only one power and ground run to my GT-28. Its also 4 guage about 6-7' off of the distro which is a 1/0 run too it. I've never once had a problem like that, even at heavy volumes for very long periods of time.

LOL, good to know. I guess I'm gonna be double covered with both power and ground inputs being used.