View Full Version : amp selection question

07-26-2007, 09:03 PM
my car has 2 front door speakers with tweeters and crossovers and 2 rear deck speakers w/ tweeters and crossovers. i'm pretty sure they're wired in series.

(alpine type-r 13s fronts alpine type-r 17s rears)

i'm looking to buy an amp and a subwoofer (just a single 10 or 12 inch)

i was thinking about the alpine mrp-f450 (http://www.crutchfield.com/S-KgVIfW...50&i=500MRPF450)

will that be sufficient to amplify everything? it's a 4 channel amp so i put the driver side speakers on one channel, passenger side speakers on another and the subs on 3 and 4 right?

also my alternator only puts out 80amps and im guessing not at idle.. :(

if my head unit has pre amp outputs, how do i wire that?

07-26-2007, 11:19 PM
For the same price as that Alpine amp at Crutchfield, you can get a 5-channel amp, or a 4-channel plus a subwoofer amp.

Here's a 5-channel for $199:

Here's a 4-channel and a sub amp, for $90 + $100

Your alternator is fine.

For preamp outs, it's quite simple. The headunit has RCA outputs, the amp has RCA inputs, just get a wire long enough to connect them. You'll need a wiring kit, I suggest looking over at www.knukonceptz.com for some quality, inexpensive kits for under $50.

Hope this helps!
-- Kevin

07-27-2007, 04:28 PM
what advantages does a 5-channel have over a 4 channel? sorry im a noob.

thanks for the suggestions. so much cheaper :)

also, is there a way so that i can just use one amp to power my speakers AND the subs? or is that what the 5 channel does?

edit: just read the details of the 5 channel and i bought em since i just want 1 amp.

07-27-2007, 05:37 PM
The advantages of a 5-channel, is it combines your 4-channel amp, plus a subwoofer amp, in one convenient package.

The advantage of a seperate 4-channel and subwoofer amp, is more flexibility in configuration, you can upgrade individual components easier, and it's usually cheaper for the same amount of power than a 5-channel.

Oops, just read your edit, so never mind, I guess :)

07-27-2007, 05:45 PM
Ack! I just read the specs for the speakers you're using, and that Pheonix Gold amp is actually a little too small. It'll work, but you'd be better off getting something with more power. I'll see what I can find...

07-27-2007, 06:13 PM
Hmm, not having much luck finding any 5-channel amps with about 100x4 @ 4ohms for anywhere near the $300 price. Lanzar makes one (the VIBE531) for that price range, but I have no idea if that's a good brand or not.

So it's like I said in the previous post, it's a lot cheaper to get a 4-channel plus a mono for the sub. If you want to do 2 amps, then there are tons of options.

07-27-2007, 06:39 PM
hmm 125w x 4 @ 4 ohms is not enough?

07-27-2007, 06:54 PM
That's max power output. The number you want to look at is continuous power output, which in this case is 50w x 4 @ 4 ohms. The Alpine SPR-13s is rated for 100w continuous, and the SPR-17s is 110w.

So unless you want to spend $400-$500 for a 5-channel with that kind of power, plus 150-200 watts for a subwoofer, then it looks like the most cost-effective way will be 2 amps.

Here's a 4-channel that will do 150x4, for $140. Combine that with the Profile subwoofer amp listed above, and that should be a good combo.


07-27-2007, 10:31 PM
lol this is what i get for buying too quick. i'll return the amp when i get em.

i'm kinda worried about where to hide these i dont think these will fit under the seats and i guess its gonna have to be mounted sideways on the trunk i guess?

07-27-2007, 11:25 PM
Here's a 4-channel that will do 150x4

That's max power.

07-27-2007, 11:31 PM
That's max power.

Doh! I was looking at a lot of amps... Oh well, we'll just keep looking.

07-27-2007, 11:33 PM
lol this is what i get for buying too quick. i'll return the amp when i get em.

i'm kinda worried about where to hide these i dont think these will fit under the seats and i guess its gonna have to be mounted sideways on the trunk i guess?

If you bought them online today, you can probably cancel the order.

As for where to mount them, I guess it depends on what kind of car you have.

07-27-2007, 11:47 PM
4 door sedan. well i already got a shipping tracking email

07-28-2007, 12:06 AM
For the $300 price tag of that Alpine amp, here's what I recommend instead:

Kicker KX800.4 (http://www.hifisoundconnection.com/Shop/Control/Product/fp/vpid/3146059/vpcsid/0/SFV/30046/order/asc/order_by/title) $190

Kicker KX400.1 (http://www.hifisoundconnection.com/Shop/Control/Product/fp/vpid/1331439/vpcsid/0/SFV/30046/order/asc/order_by/title) $120

Assassin 12" (http://www.soundsolutionsaudio.com/shop/index.php?act=viewProd&productId=160) $120 (yes, it'll take the 400w rms of the KX400.1 amp)

There have been a few members here that have stated the refurb amps from hifisound work great and have never had a problem.

07-28-2007, 07:23 PM
Good deal on the Kickers.

I've been looking at more 5-channel amps. All of the ones that have enough power, are big(and expensive). All of them are over 2 feet long, and wouldn't fit where the OP wanted to mount it. So that leaves trunk-mounted, in which case there's no reason not to go for seperate amps.

And you never know, maybe the 50w per channel of the PG amp will be plenty loud for him. It's definitely an improvement over the stock power, especially when you add a subwoofer.

07-28-2007, 07:41 PM
Agreed, but the overhead would be nice, IMO.

08-05-2007, 10:33 PM

quick question

what gauge wires should i go with for the PG 900w 50wx4 continuous and 150Wx1 @ 4 ohm sub channel

getting my amp hooked up tuesday appreciate any help

08-05-2007, 11:09 PM
4-gauge for the power, 14-16 gauge for the speakers should be fine.

08-07-2007, 09:28 PM
thanks kross, got her installed with 4 gauge /14 gauge


08-08-2007, 03:42 PM
Nice. How does it sound?

08-09-2007, 07:39 AM
it sounds really good even with no subwoofer....but im getting the sub today and installed tomorrow :) RE SE 12" in a 1.0 sealed box