Have you tried tracing the wires yet?

Simplistically, either a) you completely blew the speaker, b) you have a break in the wiring from the amp, or c) you blew a channel on your amp.

Check the impedance on the appropriate wires from the amplifier to the speaker. If it measure 0 or a really big number, you need a new speaker. Otherwise, it is the amp / wiring.

Check the signal (AC voltmeter between the leads while disconnected from the speaker) at the amplifier. Signal = wiring break. No signal = new amplifier.

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