how to hook up 2 amps in a car

[Opal]

The most reliable way to hook up 2 amps in a car is by using a distribution block for power and a line output converter (LOC) or RCA Y-splitters for the audio signal. This method ensures each amplifier receives clean, stable power and a proper signal without overloading your car's electrical system or causing noise. The core steps involve running a single main power cable from the battery to a distribution block, which then splits the power to each amp. For the audio signal, you'll tap into your head unit's speaker wires or use its RCA pre-amp outputs.

Essential Components for a Dual-Amp Setup

Component	Purpose	Key Specification to Consider
Main Power Cable	Carries current from the battery to the amplifier area.	Gauge (e.g., 4-gauge for average systems)
Distribution Block	Splits a single large power cable into multiple smaller ones.	Fused (to protect each amp)
Amplifier Wiring Kit	Provides all necessary wires (power, ground, remote turn-on).	Kit rated for total amperage of both amps
Line Output Converter (LOC)	Converts speaker-level signals to pre-amp (RCA) signals if the head unit lacks RCA outputs.	High-quality to minimize signal noise
RCA Y-Splitter Cables	Splits a single RCA output into two, sending signal to both amps.	Shielded cables
Ground Wire	Connects amplifiers to the vehicle's chassis.	Same gauge as main power wire

The installation process is methodical. First, disconnect the negative terminal of your car battery for safety. Run the main power cable through the firewall to the trunk or installation area. Mount both amplifiers and connect them to a solid, bare-metal ground point using the same gauge wire. Connect the main power cable to the input of the distribution block, and then run shorter power cables from the block's outputs to each amplifier.

For the signal, if your head unit has RCA pre-amp outputs, you can use Y-splitters. If it only has speaker wires, you'll need a high-quality LOC. Finally, a single remote turn-on wire from the head unit can be connected to both amps to tell them when to power on. Always use a fuse within 18 inches of the battery on the main power cable to prevent a fire hazard. After everything is connected, double-check all connections before reconnecting the battery and testing the system.

[VonBryce]

Did it in my old Mustang. You basically need to split the power like a garden hose. Run one thick wire from the battery to the back, then use a little splitter block—get a fused one—to send power to each amp. The trick is the remote wire; just twist both amp wires together with the one from your stereo. For sound, if your stereo has those RCA jacks, grab a couple of Y-splitters from any electronics store. It’s not as hard as it looks, just take your time with the wiring. The biggest pain is hiding all those cables neatly.

[AlexaDella]

As an installer, the critical step everyone misses is the ground. You can't just screw it to painted metal. You must find a solid, bare-metal spot on the chassis and sand the paint off for each amplifier's ground connection. A bad ground is the number one cause of engine whine and low output. Use a distribution block for both power and ground to keep things clean. Always fuse the main power line at the battery. Prioritize a clean installation over speed; proper cable routing prevents future problems.

[MacEzra]

If you're watching your budget, you can avoid buying a distribution block by daisy-chaining the amps if one has pre-amp outputs. Run power to the first amp, then a short patch cable to the second amp's input. But this only works for certain amps. The cheaper alternative to a fancy LOC is a simple high-low adapter for a few bucks, but it might introduce some noise. Your main expense should be a quality wiring kit; a cheap one can damage your equipment. It's doable for under $50 if you get creative with parts.