[graceadelica]

Got a number of bootlegs from a trader. The trader thought they were lossless, but when I ran it through the spectrum anylsis on Audacity it shows the frequencies dip, then come back up - as opposed to a straight descent. Anyone able to confirm whether this is the case or not? I'm no expert, but as far as I'm aware - even if it's from an cassette, the frequency line shouldn't go like that. I've got a number of recordings from various different sources - 70's U.S Radio, 70's and 90's audience recordings and they all have the same frequencing dipping going on.

Cheers