When you see an amplifier's RMS power out, you will usually see it rated at 4 ohms, 2 ohms, and sometimes 1 ohm if it is a subwoofer amplifier. This rating tells you how much power the amplifier will put out, per channel, when it sees a 4 ohm, 2 ohm, or 1 ohm load. You can change the impedance by wiring more than 1 speaker per channel and wiring them in either series or parallel. Most car speakers have single, 4 ohm voice coils and car subwoofer range from single 1 ohm voice coils up to dual 8 ohm voice coils. There are configurations in between, but that's a whole other story. If you are look

Technically you do not need a bass knob, but we definitely recommend them. When you add a bass knob to your subwoofer amplifier, you can quickly and easily control the subwoofer level to dial in the subwoofer output to your preference. No two songs are recorded exactly the same. You might be listening to some classic rock which has little to no bass in the recording. If you have a bass knob, you can turn the bass up to enhance the overall sound quality. If your have your music on shuffle, the next song could be some 80's or some hip-hop which has significantly more bass, or maybe even too much

The size of your amplifier power wire will depend on the amount of current your amplifier is drawing from the battery. Typically, you double the RMS output of each amplifier, and divide by 13.8. This will tell you the total amount of current your amplifier setup is drawing from the battery. From there, if you are running more than 1 amplifier, each amp will need power from the distribution block based on the current draw of each specific amplifier. In general if it is under 400 watts RMS, 8 AWG. If it is 400W-1200W you can use 4AWG. If it is 1200-1500W use 2 AWG. If it is over 1500 watts, use