How do I attach a BOSS BASS1500 Amplified Subwoofer to my SONY CDX-GT24W CD Player?

First of all you will have to connect the power supply cables to the BOSS. There are three screw terminals at the back of the Sub unit. Connect the - ( negative ) terminal on the Sub Amp with a black wire to the body of the car.You can loosen any seat nut and wrap the wire around it and tighten it. Then connect a Red wire from the Sub Amp terminal marked + ( positive ) to the battery + terminal under the hood of the car. Make sure the Black & Red wires are heavy duty cables which can conduct at least 20 Ampere of current. Then connect the third terminal marked Remote with a blue wire to the Sony remote cable. This cable need not be thick as it only triggers the Sub Amp to turn on & off along with the head unit ( also known as control cable ).
Next you will need a long 2RCA to 2RCA ( at least 5 meters long ) cable to connect the Sony Head units audio out to the Sub Amp input socket.You can get a Car Amp wiring Kit like shown below.
Next make sure that the Sub Amp remote control is turned to halfway position, Phase selector switch is set to 0, Subsonic filter is ON, Low pass filter is in middle position & Bass boost knob to 0.. Play some dance music on the Sony adjust the Sub Amp remote volume level to suit your taste ( don't turn it up very high because when you turn up the volume it might distort ). Next flip the Phase switch from 0 to 180 and back a few times carefully listening to the bass and set it to whichever position you feel the bass is full and punchy. Last AQdjust the bass boost knob to your liking again try not to boost it too much. Keep experimenting with different music. Enjoy