
Like a base model and then the "step-up" model, then the next for all that have the same general design. Most aftermarket radios have multiple pairs of RCA outputs that can connect to multiple amplifiers. A single subwoofer cable has a single male connector at each end. If you want to use a self powered subwoofer some of them do have speaker level inputs that you can connect the same way you would the passive.

RCA cables come in stereo pairs, in various lengths. Analog (1 x L/R RCA, 1x Subwoofer RCA) Digital (1 x Coaxial RCA, 1 x Optical Toslink) Headphone.

Buy Rockville BluTube 70W Tube Amplifier/Home Theater. If your amp doesn’t have an LFE subwoofer output or LFE input, as is often the case with old amplifiers, try to connect the two with an RCA cable.

The sub has three methods of connecting: A single, mono RCA cable from a LFE/Subwoofer Output into one of the RCA ports on subwoofer.
