I attend a recording school, and recieved a reel of 2 inch to record a project on. Judging by the amount of labels on the box, I could tell that I was the fourth person to use this reel. God only knows how many times it has been recorded on. When I was mixing down my project I noticed a distinct hiss in the background. I was using a +6 tape, and I found out later that the machine I tracked on was alligned at +3. The mixdown machine was alligned at +5 and my levels looked good. Could the hiss be from me not hitting the tape hard enough, or is it because it has been recorded and scrubbed several times.