I have been experimenting, a little over four months with my new Involve, I use a Sansui QRX 3500 receiver with a decrete mode. I have been using the standard stereo cartridge. I found out using the 4 channel cartridge by JVC and a Shibata stylus. I can hear four decrete channels, on SQ matrix . ( I know many will laugh at this) Sometimes the front channels will be without sound and you hear individual back channels with different insturments coming from them. These are SQ and QS formats. Has anyone ever tried using a 4-channel cartridge? I have been experimenting with quad recording and equipment since they came out in the early 70's. I am no expert, but just having fun. My conclusion, is this the Shibata stylus goes deep into the record groove and picks up the hidden sound waves. Comments please