The audio in the VHS format is recorded and played back by either the tape moving across a stationary head, away from the video heads, or, in the case of HiFi Stereo VHS VCRs, by a process called Depth Multiplexing, in which separate heads on the rotating VCR head drum record the audio under the video recording layer, instead of on the same layer as the video signal, as 8mm and HI8 do.This audio recording is done via the same heads that do the video recording. 8mm/Hi8 audio is recorded in AFM HiFi mode, while the audio on a miniDV tape is recorded at either a 12-bit or 16-bit digital format. 8mm and Hi8 audio are recorded differently than VHS.

Since 8mm/Hi8 tapes are recorded and played at different speeds than VHS, even if the tapes could into a VHS VCR, the VCR still can't play back the tapes at their correct speeds since these speeds to don't match VHS tape recording and playback speeds.This means that VCR would not be able to keep the tape lined up properly with VHS tape heads. Since the control track information is different on an 8mm/Hi8/miniDV tape than on a VHS tape, a VHS VCR cannot recognize the 8mm/Hi8/miniDV control track info.

The control track tells the VCR what speed the tape is recorded in and helps the VCR keep the tape lined up with rotating head drum on the VCR properly.

Along with the recorded video and audio signals, there is a control track.

This means that a VHS VCR's video heads can't read the taped information correctly since a VHS VCR requires a 1/2-inch wide tape to playback.

8mm/Hi8 tapes are 8mm wide (about 1/4 inch), and miniDV tape is 6mm wide, while VHS tape is a 1/2-inch wide.

Inside of vhs tape