ResonantLive Sound Archive

Equipment file · Acoustic measurement system

MLSSA

DRA Laboratories · 1987

Evidence status · documented

Identity and core specifications are documented; some historical fields remain unavailable.

MLSSA, introduced in 1987 by DRA Laboratories, derived impulse and frequency response by cross-correlating a pseudo-random maximum-length sequence with a device's output. Its method was published by Rife and Vanderkooy in the AES Journal in 1989.

Introduced
1987
Category
Acoustic measurement system
Intended use
MLS impulse and frequency response measurement of loudspeakers and rooms
Production
DRA Laboratories (Douglas Rife), PC card and software

Why it mattered

  1. 01

    The first commercial MLS system, bringing fast loudspeaker and room measurement to many engineers.

  2. 02

    It underpinned later measurement tools such as [[smaart|Smaart]].

Engineering record

Method
MLS stimulus cross-correlated with output, then FFT; bandwidth 1–40 kHz[2]
Theory
Rife and Vanderkooy, 'Transfer-Function Measurement with Maximum-Length Sequences', JAES 1989[1]

Original pricing

No reliable period price located

2026 equivalent

Not calculated without a reliable original price.

Public price evidence was not sufficient to publish a defensible original figure.

Use in the field

No named deployment could be tied to this exact item by a checked source yet. Know of one? Suggest it on the contribute page.

Manuals & original documents

Sources

  1. 1About DRA LaboratoriesDRA Laboratories · reference
  2. 2MLSSA BrochureDRA Laboratories · brochure

Contribute to the record

Know more about MLSSA?

Corrections, firsthand information, original documents, and credited photograph sources are welcome.

Your email is private and will not appear in the archive. Contributions are not published automatically.

Back to all equipment Back to Digital control and the line array

Help build the archive

A missing piece? A correction?

Contribute to Resonant

Support the archive

Resonant is built one verified record at a time: research hours, archival image rights, and the hosting that keeps every era, equipment file, and citation free to read. If this archive is useful to you, a donation of any size keeps the next entry moving.

How donations are used
Venmo@mercer-aplinOpen Venmo, tap the pay field, type the handle, then send any amount.Send any amount · no account needed to viewCash App$MercerAplinOpen Cash App, tap the $cashtag field, type the tag, then send any amount.Send any amount · no account needed to view

Payments go directly to the archive’s editor through Venmo and Cash App. Resonant is an independent project rather than a registered charity, so donations are not tax-deductible and nothing is sold or subscribed to in return.