speaker attenuation

I have a set of speakers for the rear channels of a surround sound system that play too loud. Balancing the receiver outputs is not doing the job because of the jumble of different speakers and amps used in the whole set-up

What value of resistors or volume pots should I use to bring the levels down? Depending on the music I’m playing, they need to come down between 5 and 20 dB’s. One stereo volume pot or individual ones for each speaker seem to me to be the answer

It’s been a LONG time since high school electronics, and I hope one of my fellow dopers can help me.
Radio Shack doesn’t have guys who can answer these questions anymore, they just want to sell me phones.

Far better to take care of the problem at the preamp or amp stage. Otherwise you’ll need resistors able to handle the full wattage of your speakers, and 100 watt resistors aren’t cheap.

In-line resistor on a speaker circuit isn’t really ideal since speakers are an inductive load. Generally if you want to put in a volume control post-amp, you use something with transformers. There are plenty of stereo speaker-level volume controls on the market - essentially multi-tap transformers with a rotary switch. If they’re advertised as “impedance-matching” they’re to allow adding multiple speakers to a single amp (to drive several sets throughout your house, for example). You don’t need that using the control just for a single set.