In most cases Blue SMD led's dont burn out when wired straight to the Speakers but there is still a chance they might. To find out what side is + (Positive) and what side is - (Negative), wire up the LED with two different coloured wires and strip the other ends of the wires and hold them to the speaker and find which way they go to light up the LED, remember this by memorising the colour of the Wire's and which way they go
- Vox