Four-Frequency Calibration Tapes: 1 kHz, 10 kHz, 16 kHz, and 50 Hz, ¼ each

These "minimalist" four-frequency Calibration Tapes contain a 1 kHz signal for setting level, a 10 kHz signal for setting azimuth and high-frequency equalization, a 16 kHz signal for checking high-frequency response, and a 50 Hz signal for checking the low-frequency equalization.