Vibration test, control and analysis since 1961
Spectral Dynamics started in San Diego with one instrument: a tracking filter built to find the true resonances of an airframe. Six decades later the same engineering priorities, clean measurements and honest specifications, run through every Panther and Jaguar system we ship.
| 1961 | Founded in San Diego |
| 1965 | SD105 solid-state sine servo controller |
| 1967 | SD108 multi-shaker phase servo |
| 1969 | SD301 real-time analyzer |
| 1970 | SD320 shock spectrum analyzer |
| 1978 | Merger with Scientific-Atlanta |
| 1993 | Spectral Dynamics, Inc. formed |
| 1995 | GenRad STP joins SD; Puma released |
| 1998 | Jaguar released |
| 2000 | Lynx released |
| 2024 | Panther released |
| 2026 | AI-assisted Panther |
A 5 Hz "resonance" that wasn't there
In the 1950s Laurie R. Burrow Jr. ran ground vibration tests on new aircraft at General Dynamics. On one swept sine test the data showed a resonance at 5 Hz that the structural designers said was impossible. Burrow traced it to harmonic excitation of the airframe's real 10 Hz mode, and concluded that a test engineer needed a way to strip harmonics, noise and distortion out of the response as the sweep progressed.
His answer was a narrowband tracking filter that stayed locked to the drive frequency across the audio range. When General Dynamics stopped work on its 880 and 990 jetliners in 1961, Burrow and Bud Gillies bought back the patent and prototypes, and Spectral Dynamics Corporation of San Diego opened for business in November 1961. Its first product, the SD101 Dynamic Analyzer, was that tracking filter.
The lesson behind it, that a test result is only as good as the measurement under it, still drives how we design. Panther and Jaguar both carry per-channel tracking filters for swept sine work for exactly that reason.
1961 to 1993: from one instrument to three divisions
The original Spectral Dynamics grew into three divisions: data acquisition and analysis, including vibration control; machinery monitoring; and government products.
- 1963 – 1965
Sweep oscillators and sine control
The SD104 sweep oscillator and SD105 sine servo controller, introduced in 1965 as the first all-solid-state sine servo, moved Spectral Dynamics firmly into shaker control and replaced motor-driven sine servos in labs worldwide.
- 1963 – 1966
Mechanical impedance and modal analysis
The SD1002 automatic mechanical impedance system and the SD109A Co/Quad analyzer let engineers see mode shapes and move transducers to find nodes in near real time. Spectral Dynamics also helped finance the founding of Structural Dynamics Research Corporation (SDRC) in Cincinnati, with Laurie Burrow as its first board chairman.
- 1969 – 1971
Real-time analysis and shock
The SD301 real-time analyzer, introduced in the fall of 1969, cut a PSD measurement from 22 minutes to seconds. The SD320, introduced in 1970 as the first standalone shock response spectrum analyzer, became the aerospace standard for SRS measurement for nearly 20 years.
- 1970s
Computer-based vibration control
Customers asked Spectral Dynamics to close the loop around its analyzers, and the company wrote control software on Digital Equipment PDP-11 computers. The SD1009 digital vibration control system followed, then the SD1200B, which ran up to ten shakers on independent random tests under one computer, and the SD1600 acoustic control system for reverberant chambers.
- 1970 – 1973
Rotating machinery and sonar
A real-time Campbell diagram system for turbine run-ups, the SD119 trim balance analyzer used by airlines, and the DYMAC machinery monitoring division (1973). A Government Products Division, formed in 1970, built sonar analysis systems for the U.S. Navy.
- 1978 – 1993
The Scientific-Atlanta era
Spectral Dynamics, public since 1967, merged with Scientific-Atlanta in 1978. By the mid-1980s its San Diego operation had over 450 employees across three divisions. Products included the SD360 FFT analyzer, the SD380 four-channel analyzer, and the SD390, an analyzer with a built-in PC that could run STAR modal in the same box.
1993 onward: Spectral Dynamics, Inc.
In the early 1990s Scientific-Atlanta refocused on cable television and radar. Its machinery monitoring division went to SKF, and in 1993 PIND Testers, the particle impact noise detection company led by Stewart Slykhous and Jim Tucker, bought the Spectral Dynamics name together with the data acquisition, analysis and vibration control business and key engineering staff. The combined company became Spectral Dynamics, Inc.
In 1995 Spectral Dynamics added the Structural Test Products division of GenRad, which made the same class of data acquisition and vibration control systems and owned STAR modal analysis software. PIND testing, the original Spectral Dynamics product line and the GenRad line have run under the Spectral Dynamics name ever since. Alongside the controllers below, the combined engineering groups built rotating machinery systems for turbine engine programs and the Felix PIND system.
Controllers since 1993
- 1995
Puma
A PC-based vibration control and analysis system, developed by the San Diego engineering team.
- 1997
Rotating Machinery Analysis on Puma
Rotating machinery analysis came to Puma, carrying forward work that began with the real-time Campbell diagram system of 1970. The same capability continues today as Panther RMA.
- 1998
Turbine balancing on Puma
Turbine balancing was added to Puma, continuing the trim balance work that started with the SD119 analyzer used by airlines.
- 1998
Jaguar
A control and analysis system designed for high channel counts, with hardware and software built by the same team. Its multi-shaker MIMO software followed in 2000.
- 2000
Lynx
A compact, expandable controller for labs and production testing that need full control capability in a small footprint.
- 2024
Panther
Spectral Dynamics' current-generation vibration control system: 24-bit acquisition, a full single-exciter application suite, and hardware that expands in 8-channel chassis.
- 2026
AI-assisted Panther
Panther V12 adds an AI assistant built into the user interface, with access to live test state, data and error logs for diagnostics and reporting. Panther MIMO Random and MIMO Sine extend Panther to multi-exciter control.
Six decades of multi-shaker control
Most vibration testing is single-exciter work, and most of what we build serves it. Multi-shaker control is a smaller part of the market, but it is where control theory is tested hardest, and Spectral Dynamics has worked on it for most of its history.
- 1967
SD108 phase servo
Spectral Dynamics' first multi-shaker effort. An eight-channel SD108 system controlled eight 50,000 lbf hydraulic shakers on a swept sine test of a quarter-scale Saturn attachment ring for NASA. Nobody then had a way to compensate for cross-coupling between shakers, and the test was only a partial success. It defined the problem the next generations would solve.
- 1996
Synergistic Technologies joins Spectral Dynamics
The acquisition brought Dr. Marcos Underwood's optimal and adaptive multi-exciter control work in-house, along with a team that designed control hardware and software together.
- 1998 – 2000
Jaguar
Jaguar was released in 1998 for single-shaker control, and its MIMO software followed in 2000. Spectral Dynamics engineers have since presented more than 30 papers on multi-shaker control.
- Today
Panther MIMO
MIMO Random and MIMO Sine bring the same multi-exciter control to Panther, including six-degree-of-freedom configurations.
Single-exciter control comes first
Panther is Spectral Dynamics' main vibration control system, and most Panther systems run one exciter. Its MISO capabilities stand on their own:
- A full application suite: Random, Sine, Shock, Sine-on-Random, Random-on-Random, Mission Simulation, field data Replication and Rotating Machinery Analysis.
- Measurement quality: 24-bit ADCs and greater than 110 dB system dynamic range, specified as delivered performance.
- Data recording: multiple independent data streams at different sample rates, with gap-free stream-to-disk across all applications.
- Room to grow: 8-channel chassis that expand to 128 phase-synchronized channels with the STAR Sync Box.
The same priorities since the tracking filter
Clean data before clever software
Low noise, alias-free sampling and true dynamic range decide whether a control loop is working on the real structure or on artifacts.
Specs you can verify on your shaker
We publish delivered system performance, not theoretical converter figures.
Engineers helping engineers
Applications engineering, service and customer training have been part of the company since its first years.
Frequently asked
When was Spectral Dynamics founded?
Spectral Dynamics Corporation of San Diego opened for business in November 1961, founded by Laurie R. Burrow Jr. and Bud Gillies around a tracking filter Burrow had invented for aircraft ground vibration testing.
How is today's Spectral Dynamics related to the original company?
The original company merged with Scientific-Atlanta in 1978. In 1993 PIND Testers bought the Spectral Dynamics name, the data acquisition, analysis and vibration control business and key staff from Scientific-Atlanta, and took the Spectral Dynamics name. In 1995 it added GenRad's Structural Test Products division, which made the same kind of systems and owned STAR modal software, and ran all of it as Spectral Dynamics, Inc.
What vibration controllers does Spectral Dynamics make today?
Panther, our main vibration control system, covering single-exciter MISO control and, with Panther MIMO, multi-exciter control; Jaguar for high-channel-count multi-axis MIMO control; Lynx, a compact controller; and Puma.
When was Panther introduced?
Panther was released in 2024 as Spectral Dynamics' current-generation vibration control system. Panther V12, released in 2026, added an AI assistant built into the user interface.
How long has Spectral Dynamics worked on multi-shaker control?
Spectral Dynamics delivered its first multi-shaker control system, the SD108 phase servo, around 1967. The modern line began when the company acquired Synergistic Technologies in 1996, leading to Jaguar MIMO software in 2000 and now Panther MIMO.
Company history through 2001 is drawn from Tony Keller, "The Making of a Great Company: How Spectral Dynamics Came to Be," Sound & Vibration, January 2017 (50th Anniversary Issue), pp. 64–83. Read the full article (PDF).
Six decades of vibration test experience, applied to your lab.
Talk to your sales representative about Panther for your test program.
