Do speaker wires have to be the same length for each speaker?

This is almost as entertaining as a closely matched UFC bout.

I prefer same length, but I need to ask the OP: "Why NOT the same length?"

If you're running in-wall, got it.  But if not in-wall, you've got plenty of space in your listening room if you have to drape/coil/hang/etc. (there goes another discussion...) the excess on the longer side.

Having one shorter than the other would be better than splicing to make them the same length.

if the right/left length differential is greater than 5% it will ruin the stereo imaging

if greater than 15% it will void the warranty on your speakers

if greater than 25% it will be may cause a short circuit in your power amp

if greater than 40% it will be a fire risk and you should only listen to music with nomex suit on and fire extinguisher in hand

😂

I'm gonna have to go with the OCD thing too, in the house. Funny thing I've done a lot of auto/equipment installs for stereo gear. I use to cut and trim all the extra wire. Nothing was the same length.. Butt connectors everywhere then shrink and zip tie everything.

5,000 watts in an excavator cab.. Like the guy gave a crap. Using a 10,000 pound breaker, breaking concrete with the volume at 10. Have to have ballistic glass just to keep from blowing it out..

I'm not a robot

The person who asked if he could splice 12 to 14 ga. wire.; - - -  well to that I'd say "with the equipment "laundry list" you stated, the last thing I'd be worrying about is wiring." Coat hangers might even be O.K. This person must really be on a tight budget. I don't think "HIGH END AUDIO" is the hobby for you.

Sorry for the sarcasm !