Tape Trail Reel to reel, cassette and other analogue tape formats.

---

[ Follow Ups ] Thread: [ Display  All  Email ] [ Tape Trail ]

---

[ Alert Moderator ] [ Edit ] [ Delete ]

---

Re: Playback Equalization

69.140.199.80

Posted by mkmelt on May 13, 2005 at 16:59:24

In Reply to: Playback Equalization posted by toilinthedark on May 13, 2005 at 15:03:32:

The playback equalization for Type II and type IV tape does not cut the high frequency response, it just boosts the response using a lower (70usec vs 120usec) time constant, hence higher turnover frequency. If you play a Type II tape using the playback equalization for Type I, you will artificially boost the high frequencies (along with the tape noise) beyond the boost expected by the tape manufacturer. Type I tape requires a lower turnover frequency, as indicated by the 120usec time constant for this tape formulation.

To compute the turnover frequency use the following formula:

f = 1/(2Pi x t) where f is the turnover frequency, Pi = 3.14159(etc.) and t is the time constant in microseconds (1x10-6 seconds).

where t = 120usec, f = 1326Hz
where t = 70usec, f = 2274Hz

So you can see that the turnover frequency for Type I tape (120usec) is almost a full octave lower than for Type II tape. The slope of the curve is the same, but the Type I treble boost starts at a lower frequency.

You should play the Type I tapes using the playback equalization for Type I, and play any type II, III, or IV tapes using the Type II playback equalization.

This post is made possible by the generous support of people like you and our sponsors:

Sonic Craft

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2025, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---