Liberty Instruments' IMP and IMP/M system
(Note: sorry, but the IMP system hardware is no longer available from Liberty Instruments.)
IMP was our first system, originally introduced in 1993 in a series of construction/use articles in Speaker Builder Magazine. Since that time nearly 1000 IMP systems have been put into use by hobbyists, engineers, even research laboratories. In 1994, an MLS capabilities were added to IMP -- the result was IMP/M (new software and a hardware enhancement for the original IMP system), also introducing a new graphical user interface running under normal MSDOS. This modestly priced, portable, do-it-yourself FFT measurement system literally changed the nature of speaker building worldwide.
IMP/M is unique among DOS based measurement systems in that it requires no hardware modifications to the computer with which it is used -- the IMP/M hardware module connects to the computer via the PC's parallel printer port, allowing IMP to be used by nearly any PC compatible computer or laptop. This allows IMP/M to be used in portable measurement systems or to be easily swapped between computers in minutes. IMP/M's portability and elegent operation has kept this system popular, in spite of its hardware limitations (4096 point FFT sizes, single multiplexed measurement channel, FFT only operation).
Now, IMP's capabilities are overshadowed by more recent moderately priced measurement systems. IMP/M is no longer available as far more capability is available using our Praxis system