Hello I am an amateur stereo guy in need of advise on setting my amp. I have the gain set to 21 volts on the front and rear of 4 channel with a 1khz test tone I have the gain set to 41 volts on the 1500d amp with a 50hz test tone Those settings were given to me by a friend My question is where to set the crossovers? the low pass/high pass filters the subsonic knob and the 2 push in buttons I currently have the front channel run on the crossover on the head unit set to 100khz with a 24 slope Rear channel is off on deck, and set on low pass on amp but not sure what the settings should be on the amp, the deck does not give me a low pass option on rear channel The sub is currently not hooked up yet so not sure if I should use the subwoofer x-over on the deck or the amp? I have a sundown 100.4 sundown amp, a sundown 1500d amp, and a Kenwood excelon model kdc-x994 head unit Vehicle 2000 toyota corolla Speakers"\: channel 1/2 of 100.4 amp Front door CDT CL-S50A 5.25 separates * 5.25" 2-Way Component System * Mid: Stamped Powder coated 5.25" * Crossover: 2-Way SatNet-400 * Tweeter: TW-19 Deluxe 1" silk soft dome * Power Handling: 100 watt RMS * Frequency Response: 65-20kHz * Sensitivity: 90.8 dB * Impedance: 4Ohm * Surface & Flush mount swivel tweeter channel 3/4 on 100.4 amp Rear deck: w/ .0992cf sealed enclosures mounted underneath speaker hole in trunk. M6 - CDT Audio 6.5" 300 Watt Mid-Bass/Sub-Bass Drivers # Mounting Depth: 2.94" # Diameter: 6.5" (170mm) # Sensitivity: 88.1dB # Power Handling: 150w RMS (300w Peak) # Prequency Response: 10-4000Hz # Nominal Impedance: 4 Ohms # Voice Coil Diameter: 1.37" (35mm) # Peak Xmax: 10mm # Magnet Weight: 30oz # Free Air Resonance: 52Hz # Voice Coil DC Resistance: 3.8 Ohms # Mechanical Q (QMS): 2.46 # Electrical Q (QES): 0.516 # Total Q (QTS): 0.426 # Compliance Volume (VAS): 15.05; 0.53 ft3 # Moving Mass, Diaphragm: 20.0Gr # Motor Force Factor: 5.68 Tm Sub in trunk 1500d amp Digital Designs 3512 dual 2 ohm wired down 1ohm SPECIFICATIONS Voice Coil Diameter 3.0" Magnet Weight 240 oz Power Handling RMS/Peak 1200/4800 Suspension Travel 80 mm Nominal Impedance D.5, D.7, D1.0, D2.0, D4.0 Ohm