I have been doing car audio since I was in high school. I am about to upgrade my system completely. I currently run: Sub Amplifiers: 2x Alpine MRP-M500 mono for subwoofers 500W RMS @2 Ohms Speaker Enclosure: I built a custom ported box tuned to Fb = 34.5 Hz Vb = 3.2 ft^3. Sub Woofers: Rockford Fosgate Punch 3 12" DVC P3D412 x2 Highs Amplifier: Alpine MRP-F300, Which was going to run bridged to my tweets (yeah 300W to my tweets). Mids Amplifier: Alpine MRP-F550, Which I had bridged to my mids. Component Set I was looking at: Alpine Spx-17 Pro New Front Amplifier:Hifonics ZRX2000.4 4 Channel running fronts and rears @ 500W RMS x 4 @ 2 Ohms. (looking at other options) New Sub Amplifier: Hifonics BRX2000.1D 2000W RMS x 1 @ 1 Ohm (Running each sub 1000W x1 @ 2 Ohms). (Before you say Ew Hifonics, this one is CEA-2006 compliant) Mids and Highs: Infinity Kappa 60.11cs in the front Infinity Kappa 693.11i in the rear. Sub Woofers: Rockford Fosgate Punch 3 12" DVC P3D412 x2. (Same) Speaker Enclosure: I built a custom ported box tuned to Fb = 34.5 Hz Vb = 3.2 ft^3. (Same) All the amps in the first Paragraph I'm selling by the way all in good shape (ran the mono's for 2 years, ran the F550 less than a year, bought the F300 refurbished and never had the time to hook it up.) Shoot me an offer if interested.