My son's Peavey twin speaker 4 ohm stereo guitar amp has a bad speaker.
I am wondering about changing both speakers with a different model speaker however most 12" guitar speakers are 8 ohm. I have been told the result of using an 8 instead of a 4 will result in a reduction of volume, (as a father and resident of the house, this could be a good thing ).
Coincidently, we still have his old Peavey amp that has the identical speaker in the 8 ohm version. I patched the speaker cable from the bad speaker over to the 8 ohm version. My observation is that the volume levels are the same between the two speakers playing together.