We took two identical Celestion Rockdriver Junior guitar speakers and doped one of them. Check out how it affected the sound! The speakers are mounted in a Marshall model1983 2x12 PA column and the M160 BeyerDynamic ribbon mic ispositioned exactly in the middle between the two speakers. The guitar is a 2010 Gibson Les Paul Black Beauty R7 VOS and the amp is a 1977 Marshall 2204.The video focuses on how the sonic charchter of the speaker is changed by the doping. However the doping has other functions as well, for instance it prevents cone-cry at higher volumes.