Meyer Sound’s SIM 1 & SIM 2 were stepping stones that brought us out of the stone age & into modern sound system design & optimization. SIM stands for “Source Independent Measurement”. The current version is SIM 3. All SIM platforms are based around a stand alone hardware / software system. The following is taken directly from Meyer Sound’s own website.

SIM 3 – 2003

SIM 3 launches, representing a major advance, greatly increased power and added features at a fraction of the original size and cost.

Sim 3 Brochure
Sim 3 webpage

SIM 2 – 1992

The SIM II FFT analyzer, released in 1991, receives the prestigious R&D 100 Award from R&D Magazine, for such innovations as its three simultaneous transfer functions.

SIM 2 has long since been discontinued but is still found on work benches. Here is a link to the SIM 2 website.
SIM 2 webpage

SIM 1 – 1986

Based on the Hewlett-Packard 3582A dual-channel FFT analyzer, the first generation SIM’s novel source independent measurement capability immediately garners Mix magazine’s prestigious TEC Award for Outstanding Technical Achievement (in) Acoustics Technology.