these are playback and record sweeps on a couple channels of the poofygoof studios Otari MX-5050. the repro sweeps are from playback of an MRL NAB calibration tape.
Jay McKnight from MRL suggested I try switching a channel from NAB to IEC and see how it performed, so I did. The extra lines on repiec4.png indicate corrections to turn an NAB cal tape into an IEC one, within a +/- 0.25dB window. I could probably dial in better with more tweaks, but I wanted a quick indicator of whether or not IEC would help me. Looking at the pseudo-IEC calibrated reciec4.png versus the NAB-calibrated record4.png it looks like I'd do well to get an IEC calibration tape. It should be noted that the biasing is identical between these two curves -- the only variable is the record and playback EQ.
sweeps were made with the help of Audio Precision's now obsolete System One test box.
Name Last modified Size Description
Parent Directory 24-Oct-2010 11:22 - reciec4.png 08-Dec-2002 23:53 3k record IEC record2.png 04-Dec-2001 11:36 3k recording on channel 2 record4.png 08-Dec-2002 23:42 3k recording NAB repiec4.png 08-Dec-2002 23:52 4k playing pseudo-IEC MRL repro2.png 04-Dec-2001 12:04 3k playing MRL tape