Choosing the right amp

[AceX]

It's a question that if it's been asked once, it's been asked a hundred times; "What amp should I run in my car?"

The answer is not very simple, nor should it be. Choosing an amp can be very intimidating as you have alot of parameters to look for and match to the rest of your system.

Here's a few things to look for when buying an amplifier:

1. Power. Quite simply, it's the reason that you're buying an amplifier in the first place, but you can't just look at peak power (which is a BS spec anyway). You have to look at the RMS output at the matching impedence (ohm rating) of your speakers. Matching the RMS output to that of your speakers will make everything sound great and will ensure that you get the most out of your speakers.

2. Flexiblity. The more an amp can do with less, the better. Mounting options, bridging, crossovers, and all that stuff should be taken into account, but for the sake of simplicity, let's just say that the more flexible the amp is with how you can run it, the better.

3. Signal to noise ratio (SNR). This is very important for sound quality. This will determine how good everything sounds and the higher, the better. When buying a monoblock subwoofer, you don't have to worry about this statistic because in a subwoofer application, it won't matter.

4. Efficiency. This is more for the power draw on the system than anything I feel. For a 4ch amp, you can probably count on a 50% efficiency rating (500watts in; 250watts out). 500watts in, divided by the (car running) battery voltage (14.4v) is ~35A. This means that the amp, when working at maximum capacity, will draw ~35 amps from the system. Use this number to make sure that your electrical system can make the sacrifice. You don't want your headlights dimming because you wanted to listen to some teeth rattling music...

You can also use the efficiency to determine the quality of the amplifier. Going by the previous calculation of 35 amps, and you see a 25A fuse on the side of the amp, someone is lying to you. If a manufacturer is lying to you, don't buy their crap because it's just that, crap.

5. Appearance and heatsink. Let's face it, none of us want an amp that loks like crap, especially if we plan to display it. Besides, what's the point of having a nice system if you can't display it?

Most often, the heatsinks for the amp is built into the case and serves as the support base for the board inside. The larger the heatsink, the better. Thermal efficiency means alot, especially if the amp is going to be in a confined space and not out in the open air. It's also very important in areas where the weather is hotter.

6. Price. In my experience, you get what you pay for, that's why I always buy higher end amps. To this day, I haven't purchased an amplifier that didn't cost at least $500. Some may feel that this is stupid on my part, but Like I said, you get what you pay for. Now, I realise that not everyone is like me and has a ton of money to drop on amps and everything, so Price may actually be the first thing that you want to establish when buying your amplifier. If you know that you can only spend $300 for an amp, then only look at amps at that price and then pick the best form that group. Just because an amp is cheaper doesn't mean that it can't perform as needed. Most people will be happy with a low/mid level amplifier for their system.

My personal reccomendations for amplifiers:

4ch amps:

ARC Audio FD4100 or FD4150
Zapco 360.4
JL Audio 300/4 or 450/4

Monoblock (sub) amps:

ARC Audio FD600.1 or FD1200.1
Zapco 500.1 or 1100.1
JL Audio 250/1, 500/1, 1000/1
Pioneer Premier PRS-D1100M

[Hoods69BadBowTie]

You did not mention anythying about power caps? I got a nice power cap to save my electrical system. Do you run one or? I thought I would just throw it out there. Kinda goes right along with amps. Great post though. Pretty straight forward and specific.

[AceX]

Power caps really can't do a whole lot for a system, and in keeping things simplistic, I decided to leave them out.