1 Amp or 2 ?
 

Hey guys,

What are the pros and cons with having 1 amp or 2 amps?

I've been looking at a 5 channel amp to drive the 2 front speakers, and a subwoofer which is around $600.

But I've also considered 2 amps for the same price to do the job.
1x 2 channel amp for front speakers, and 1 x mono amp for subwoofer.

I'll list the amps below, but what are your thoughts about this?

I'm thinking at least with 2 amps, I can upgrade one amp or replace in a failure,
without having to replace one more expensive part.
Note: the dual setup also has more power, 500w over 300w.

Single Amp ($600)
Alpine PDX-5
(75 watts RMS x 4 + 300 watts RMS x 1)

Dual Amps ($545)
Rockford Fosgate Punch P300-2 ($230)
(2-channel car amplifier — 75W RMS x 2)
&
Rockford Fosgate Punch P500-1bd ($315)
(Mono subwoofer amplifier — 500 watts x 1 at 1 ohm)

I am running a 700x5 kicker and have no regrets. I have had it in two vehicles now. The five channel would be more versatile if you decide to change vehicles. IMO you don't need that much sub power, unless you are just into loud bass. Plus rockford amps are not as good as they used to be.

This is my planned setup so far:

* HEAD UNIT - Kenwood DNX6160
* AMPLIFIER - Alpine PDX-5 - 5Ch 600 Watt Amplifier
* SPEAKERS - Polk Audio DB6501 - 6.5" Component Speakers
* SUBWOOFER - Rockford Fosgate Punch P3D212 12" - Dual 2-Ohm Coils
* SATELLITE - SIRIUS Satellite Radio Interfcae - SIRIUS Connect SC-C1
* INTERAFCE - PAC SWI-JACK - Steering Wheel Control Interface
* ACCESSORIES - iPod cable - Kenwood KCA-IP301V
* SUB ENCLOSURE - Zenclosures - Rear Facing single 12"

I think you will be more than happy. BIG improvement over stock.

Shame these in-dash head units are so damn expensive LOL

and I still need to budget for all the wiring, dynamat, and door spacers.

Tell me about it! It's the only thing I have left to buy to do my entire audio upgrades. I have attempted to save the money for it like 4 times already and had to spend the money on something else! Grrrrrrr :shakes head:

TROOPER,

The only thing I'd change is the Steering Wheel Interface.

I used the Metra Axxess and it was much easier to install and program than the PAC SWI-JACK. I've installed both (different vehicles) and it was a night/day difference.

Here's some links:

Amazon.com: Metra Axxess ASWC Universal Steering Wheel Control Interface (Black): Electronics

Or here

Axxess ASWC - Steering Wheel Control Adapters and Interfaces - Sonic Electronix

Mono for the sub. 2 channel for the fronts. That way you can get the exact power you want (and need) to the sub and speakers.

That's what I was thinking, but just looking for opinions before I pull the trigger.

I heard the Alpine PDX-5 is good, but not convinced 300w is really a lot to drive a 12" subwoofer.

As I could get 2 Rockford amps for the same price as the Alipne, as per my original post.

But opinions vary on the quality of the Rockford amps.

Trooper,
This is the first car that I've run a single amp in and I have to say I am very happy with it. I opted for the Polk Audio PA1100.5 80wx4 @4ohms and 600wx1 @1ohm. Its a very big amp but no larger than 2 amps side by side and has twice the sub power as the Alpine for a few hundred buck cheaper. Another option is the Kicker 08ZX550.3 70wx2 @4ohms and 420wX1 @2ohms if all your running is 1 pair of speakers and subs this is a good option at a great price.

Wow I forgot about that polk amp, nice amps like the alpines. I use to run a 6 channel infinity amp and liked it.

Checked the sub specs you want to use at 2 ohm load for optimum watts. ( Rockford says: Power Handling 500 Watts RMS
1000 Watts Max)

I have a PDX 5 in my truck. It's driving a JL 12" Wedge box @ 2 ohms. JL Specs the optimum for my driver at 300w at 4 ohms or 600w at 2 ohms.

The PDX came with a bench test birth certificate, it reads 414w for the sub, and 114 for the fronts at 4 ohms. (Double the sub at a 2ohm load to 828w!

Edit: The Ohm rating is the resistance offered by the Sub. Most amplifiers are stable at 2 Ohms, and all are stable at 4. However, most amps are able to put out (roughly) double the power at 2 ohms, because there is "half" the resistance.

If you're going single sub, I recommend going with a 2 Ohm sub (or if it's dual voice coils, 4 ohms).

If you're going with two, I'd go with the 4 ohm (or if it's dual voice coil, 2ohms). The reason for this is because of how you wire them.
(There are 1 ohm stable amps out there, but they're typically only found in higher end amps).

I just used simple ohm's law to come up with that double output rating at 2 ohms. I would have to test it to be sure. But the math is pretty simple.

I have mine bridged for the fronts. Which make it 228w for r/l and sub mono at a 2 ohm load of 828 w for the sub...

It hits hard and clean, no noise, no issues at all. Very stable, never runs hot.

This is a killer little amp. I'm loving it, and you can hide it very easily.

I have a JL 900/5 in my 370z now, and I kind of regret spending the extra money. I cannot see the benefit.

BTW you can get the Alpine for 350 off the net with a warranty. I spent 3x on the JL 900/5, I'm regretting it big time.

I understand these come with tested "birth certificate" numbers, which from what I've seen tend to be higher than actually rated.

But I didn't see any specs stating this can drive double the output rating at 2 ohms (800w+)

The PDX-5 is rated stable for 300w @ 4 ohms, right?

Have you thought about your install location, or care? There is no way you can hide two amps, there simply isn't room. If you don't want them to be seen you'll have build a false floor. With one amp it would be possible to put it under the passenger seat if you get one thin enough.

Another thing to think about is the headunit selection. Getting one like mine that has GPS, iPod and Bluetooth all as separate components makes a big difference. I had to find a place for all those modules (under the pass seat) which effectively eliminated any chance I had installing my amps anywhere other than on top of the box, in plain sight, unless I built a custom false floor for my trunk. it still looks good, but not nearly as clean as it would have if I could have kept the amps out of sight.

And if you're not into HUGE bass, 300 wts should be enough to fill out your sound very nicely. I'm running 500 wts (actually less since it's at about 60% gain) to two 10" Boston Acoustics G5s and while it looks great it's painfully overpowering in this little hatch.

I have both of my amps hidden just fine. One under each seat. No issues with heat, no visible cables, etc.

You have your GPS antennae under the passenger seat?