Beginner questions on wiring lights to speaker

[latlog7]

Hi, I'm looking to wire some LED light strips to the bass speaker in my car and I have a plan of action, but just a few quick questions.

I plan on using a relay on the red wire immediately before the speaker so that when the speaker gets power, it will close the relay switch to the lights (which will be powered on a different circuit, with the cigarette lighter). This should be simple, but Im having trouble figuring out which relay to use.

Can I use a regular automotive DC relay, or does it have to be an AC relay?

To find the voltage and amperage rating i need for the relay, can I just get one that has a way high rating to be safe and lazy, or should I check the back of the speaker, or should I measure the current and voltage with a mulitmeter?

 

[Tha fios agaibh]

I wouldn't use a relay because they are very slow at opening and closing compared to the AC signal you'll have coming in. So the relay may just chatter a lot instead of switching on.
A SCR might be a better option. You can do it with a relay if you want, just not directly.

 

[Alec_t]

Google "color organ" for circuits you might find useful.

 

[latlog7]

Thank you, VERY good point about the relay behavior I overlooked. And thank you for the correct terminology, I would have never known that it was called a color organ!