The speaker in my cab is unlabled. How do I know which side is positive and which side is negative on a 10 inch speaker?

The speaker clips are at 12 o'clock in the cab
If it's a single speaker cab then it doesn't matter which side is which. The only time you really need to worry about specific poles is when you're wiring multiple speakers together so they're in phase with each other.
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2003 Gibson Flying V w/ Moon Inlay
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[thread="1166208"]Gibsons Historic Designs[/thread]