In my previous home my components sat on two shelves fitted into a 5' wide alcove along a side wall in the listening room. I happened to have placed the turntable at the far right end of the upper shelf.
One day I happened to lean over the turntable while a CD was playing with some reasonable bass content. With my head in that corner of the alcove I was surprised by the bass loading. So I thought, that can't be good for the cartridge/stylus to be playing in that location. After I moved the table away from the corner to where the arc traced by the tonearm was near the mid-point of the shelf playback became cleaner and with increased definition.
That was an acoustic loading problem.
One day I happened to lean over the turntable while a CD was playing with some reasonable bass content. With my head in that corner of the alcove I was surprised by the bass loading. So I thought, that can't be good for the cartridge/stylus to be playing in that location. After I moved the table away from the corner to where the arc traced by the tonearm was near the mid-point of the shelf playback became cleaner and with increased definition.
That was an acoustic loading problem.