Pioneer’s sharp-looking GM-D8604 4-channel amplifier can send 100 watts RMS to each of your front and rear speakers, for powerful music that’ll get you and your car rockin’. Highly efficient Class D technology keeps this powerful amp running as cool as it looks, and allows for a compact chassis that fits in a lot of out-of-the-way spaces.

If you’re building a big system in stages, you can use this versatile amp at first to drive a pair of speakers with the front two channels while bridging the rear channels together to power a subwoofer with up to 300 watts RMS. Later on, you can get Pioneer’s big mono amp to drive your subs, and switch this amp over to run all four of your full-range speakers.

If your car stereo doesn’t have RCA outputs, you can use the speaker-level inputs to hook this amp into your system — the amplifier switches its input mode automatically when it detects the high-level signal. And the built-in high- and low-pass filters let you adjust the sound for your car’s interior, whether you’re driving speakers or subs.