Magnetic Reference Laboratory (MRL) is an American company founded in 1972 that makes and sells Calibration Tapes for analog audio magnetic tape reproducers in the Open Reel format.

Origins

In 1972 John G. McKnight

John G. McKnight

John G. McKnight is a co-founder of Magnetic Reference Laboratory in San Jose , California, where he was Engineering Vice-president from 1972 to 1975, and has been the president since 1975. He also develops new products and directs engineering at MRL.-Biography:McKnight was born in Seattle,...

 was laid off from Ampex

Ampex

Ampex is an American electronics company founded in 1944 by Alexander M. Poniatoff. The name AMPEX is an acronym, created by its founder, which stands for Alexander M. Poniatoff Excellence...

, as was Tony Bardakos, who was making the calibration tapes for Ampex at the time. Along with Ed Seaman (also an ex-Ampex employee), McKnight and Bardakos decided to start their own calibration tape business, and thus Magnetic Reference Lab (MRL) was born in 1972.

Products

MRL makes a wide variety of calibration tapes (a tape that "contains test signals used to calibrate [...] a tape reproducer so that it will conform to the accepted standards") that are sold world-wide. Examples of available test signals include:

• Multifrequency (general purpose, for setting reproducer gain, azimuth, and frequency response from 32 Hz to 20 kHz)
• Polarity Calibration
• Special signals for Sound Technology or for Audio Precision measurement systems
• Fast Swept-frequency for use with an oscilloscope
• Slow Swept-frequency for use with a plotter
• Single frequencies
• Broadband Pink Noise
• Broadband White Noise
• Chromatic Sweep for use on a reproducer's vu meter

Customers

MRL's calibration tapes are used by anyone who wants to have their analog audio magnetic tape reproducer properly calibrated, including:

• Professional music studios
• Radio stations
• Audio departments at major universities
• Theme parks