09-24-2012, 05:25 PM
I believe, based on the insulation on the backside of the cardboard used on my (and Mars') 47-1230 sets, that the purpose of the cardboard was not so much for keeping the dust off of the phonograph, but to help direct the sound out the front of the set rather than having it escape from the back. It does give seem to give it a nice deep, rich sound!