Sound fluxuates,crackling sound samsungTX-R3079WH sound goes up and down automaticly

Decided to investigate crackling in front left spkr of my Samsung tv. Turned out to be main board vibrating. I added bushings behind main board mounting screws- crackling gone!

If the sound FLUCTUATES up & down, try turning off the AutoVolume in the sound menu. You didn't say if it's one or all speakers crackling. Crackling is either a speaker or circuitry issue. Adjust the balance away from the speaker that crackles, if it stops, that speaker is probably "fried". If it still crackles, I'd turn off the speakers and run the sound thru a stereo for the quick, cheap fix. My Samsung (10+ years old to be fair) crackles due to a circuit issue but if I SMACK the left side speaker (behind which is the sound board and side panel connectors) it stops for a while. Maddening. I think I broke it squeezing it into the furniture it's in, pressing on the protruding RCA plugs. Dumb design.