I bought an old Marshall-style 4x12 cab that had a "Powered by Celestion" badge on it. It contained G12M70 speakers. They were terrible. Thin-sounding, buzzy, reduced volume, lifeless, ridiculous. I did not even bother to sell them. I replaced them with a mix of EV speakers and C90s, and left the G12M70s in my car. Then a few months down the track I sold the car, forgetting that the speakers were in it. When I remembered, I advised the buyer to use the speakers as fridge magnets and throw the cones away.