

MSI-DFAT®: Since 1999
Spacecraft Acoustical Testing
The Maryland Sound International-Direct Field Acoustic Test (MSI-DFAT®) Company is a sister company of Maryland Sound International (MSI), which is one of the world’s leading production companies. MSI expanded into spacecraft testing in 1999 performing acoustic tests at Orbital Sciences and has since completed over 160 tests for many satisfied clients. MSI-DFAT® has created an effective and unique modular method for the purpose of acoustic testing aerospace structures and related flight equipment.
Development of the MSI-DFAT® System Timeline
2018
Introduced Rectangular Control and operational improvements
Further improved spatial uniformity and coherence levels
Allows up to 24 control mics
2009
DFAT® Subcommittee (DTE400) of the IEST HIAT (DTE040)
Contact Albert Lee or Dick Foss at LMSSC
2000
MSI equipment, manual equalizer control to 144dB
1998
Demonstration
Renkus-Heinz equipment, 134dB
Failed 6.5” horns & 1” compression drivers due to overheating/5-8 sigma peaks
2012
Ali Kolaini at NASA/JPL
2003
Spectral-Dynamics
SISO Controller
Narrow-band random control applied to acoustic spectrum
Single (average) Input, Single Output (drive)
All random test features available for acoustic testing
1999
MSI equipment, manual equalizer control to 134dB
1994
2011
matrix switch
Sound field shaping
Narrow-band tones at discrete locations
2002
NI LabView and Sound & Vibration Tool Set
1999
Modified Renkus-Heinz equipment
Employed peak compression & improved cooling to achieve 138dB
Failed 6” horns & 1” compression drivers due to overheating at 144dB
1966
2010
Spectral-Dynamics
MIMO Controller
Narrow-band random control applied to acoustic spectrum
Multiple Input/ Multiple output (drive)
Improved spatial uniformity & lower coherence
All random test features available for acoustic testing
2000
System Test
Norsonic 731 Spectrum Shaper & 830 RTA used for closed-loop control
1998
Testing performed at Ball Aerospace using JBL equipment to 135dB OSPL
