Let me discuss the differences in build quality and performance between lower-priced amplifiers and more-expensive options. To answer it we're going to look under the hood of two amps. One is a more entry-level and affordable amp and the other one costs a little bit more. So what are you getting for that money?
These are both mono amps of similar power built for driving subs. This one is an entry level amp that sold for about $200. It's a good amp but right away you can see a basic, generic circuit board with a lot of exposed metal traces and wires. That can let noise into the system. It's got small FETs, or Field Effect Transistors, underneath these small heat sinks. That can let them heat up and create distortion. The capacitors are small and the coil is small so you don't have a lot of reserve energy for when you crank the volume.
Now over on this side, we have an amp from Rockford Fosgate priced in the $300 range. On the inside you can immediately see what you're getting for that extra money. You've got this high-quality, custom-built circuit board tying everything together. You've got larger, beefier components throughout and you've got this vented heat sink that goes all the way around the outside and that's going to keep the amp running cool and much more efficiently. Overall, you're getting a better built amp which equals better performance and better sound.
But we haven't talked about one of the most vital factors in amp performance: amp wiring. Your amp depends on a steady supply of power to operate at its peak, and that's why you should invest in a high-quality amp wiring kit when you buy the amp.
If you use too thin or cheap wiring to hook up your amp, you're starving it of the power it needs to do its work. Yeah, the bottom line is that you're not going to get the performance that you paid for.