EP22. The Sound of Walkman Silence 

No audio, just 11 Walkman playing silence at full volume so all you can hear is the noise floor. Here are the tape players I measured:
Emerson EW96B
Sony WM-FX141
DigitNow BR602
Panasonic RQ-J50
Jensen SCR-75
Ibanez RP200
Lenox 820 (Speed Modified)
Radio Shack CTR-88 (Speed Modified)
Byron Statics KCS-315
Semier SM-336
GE 305027A