In 1964 Cavin started working as chief engineer for McCune Sound in San Francisco; a regional sound company founded in 1932 by Harry McCune.
Cavin supervised the design, production and testing of the company's audio products, and he designed a 16-channel stereo mixing console used at Monterey Pop Festival in 1967.
At the request of Harry McCune, Jr., audio engineer John Meyer was hired by McCune to produce the 3-way JM-3 concert loudspeaker.
Cavin implemented a unity-sum crossover circuit that did not require flipping the polarity of adjacent passband drivers as was common at the time, and he modified the Crown DC-Series amplifiers to allow low-impedance loads of multiple drivers in parallel.
The powerful JM-3 system was revolutionary, proving itself on many rock and pop concerts, starting with Joan Baez and then the Four for McGovern concert with Barbra Streisand in April 1972.
Sound designer Abe Jacob specified the JM-3 throughout the 1970s for his Broadway shows, especially Jesus Christ Superstar and Beatlemania.
Also for Beatlemania, Cavin modified the Electro-Voice 1776 vocal microphones to have less distortion by rebiasing the internal FET and changing the output capacitor.
The JM-3 was the first full-range integrated electronically controlled loudspeaker system used for live sound, a category that expanded greatly in the next ten years.

Cavin led the McCune engineering team in creating the MM-4, the first mixing console intended solely for stage monitors.
Another project was the MC-8 mixer for front-of-house, with 22 inputs, 2 effects sends and returns, 8 subgroups and 4 main outputs, built by McCune engineer Istvan B. "Steve" Kadar.
The MC8 was unusual for having a matrix mixer section, and for its very low noise floor of −130.5 dBv, as referenced to the ideal single-resistor noise floor of −131 dBv at 0.775 volts.
Both of these mixers were used on Beatlemania in 1979.

In 1976, Cavin headed the design of the McCune SM-3 2-way loudspeaker, again using a zero-sum crossover, and incorporating a compression driver design patented by Meyer, its phenolic diaphragm modified to yield higher compliance.
Meyer assisted in time-aligning the two passbands, with Cavin determining that the SM-3 sounded more pleasing when the high frequencies were slightly ahead of the lows, a conclusion reached independently by Don Pearson, sound engineer for the Grateful Dead.
In 1977, Cavin supervised the development of the McCune SM-4 2-way coaxial loudspeaker, based on the classic Altec 604E but with a low frequency driver extensively reworked by Kadar to deliver higher power, and also fitted with Meyer's more compliant high frequency compression driver.
Cavin designed an active all-pass network to time-align the passbands, slightly delaying the low frequencies to match the highs.
Cavin's proprietary improvement to the Altec 604 compared favorably with the same concept implemented via passive components by Ed Long for the contemporary UREI 813 studio monitor: his trademarked Time-Align process.

Meyer was contracted by McCune to design the JM-10 concert loudspeaker, a large single-point-source system intended to replace ten JM-3s.
Cavin chose a bucket-brigade delay to align the high frequency drivers about 1.5 milliseconds back from the mids and lows.
Digital delay devices were tried but they had too much distortion, while the chosen bucket-brigade solution was somewhat hissy.
Cavin designed a noise gate for the JM-10 processing to stop the high frequency hiss when no signal was present.
The JM-10 system was used on the Kool Jazz Festival touring the U.S. in mid-1977.
Cavin accompanied the tour to provide technical support.

In the late 1970s, Cavin designed a 50-pair snake splitter for large events, used to send each microphone signal to multiple mixers such as for front-of-house mix (FOH), monitor mix and a recording truck.
The splitter used Jensen transformers and two latching 27-pair snake connectors for each mixer.
The splitter system was used on many events, for instance the Playboy Jazz Festival at the Hollywood Bowl, which needed dup
In 1964 Cavin started working as chief engineer for McCune Sound in San Francisco; a regional sound company founded in 1932 by Harry McCune. Cavin supervised the design, production and testing of the company's audio products, and he designed a 16-channel stereo mixing console used at Monterey Pop Festival in 1967. At the request of Harry McCune, Jr., audio engineer John Meyer was hired by McCune to produce the 3-way JM-3 concert loudspeaker. Cavin implemented a unity-sum crossover circuit that did not require flipping the polarity of adjacent passband drivers as was common at the time, and he modified the Crown DC-Series amplifiers to allow low-impedance loads of multiple drivers in parallel. The powerful JM-3 system was revolutionary, proving itself on many rock and pop concerts, starting with Joan Baez and then the Four for McGovern concert with Barbra Streisand in April 1972. Sound designer Abe Jacob specified the JM-3 throughout the 1970s for his Broadway shows, especially Jesus Christ Superstar and Beatlemania. Also for Beatlemania, Cavin modified the Electro-Voice 1776 vocal microphones to have less distortion by rebiasing the internal FET and changing the output capacitor. The JM-3 was the first full-range integrated electronically controlled loudspeaker system used for live sound, a category that expanded greatly in the next ten years.
Cavin led the McCune engineering team in creating the MM-4, the first mixing console intended solely for stage monitors. Another project was the MC-8 mixer for front-of-house, with 22 inputs, 2 effects sends and returns, 8 subgroups and 4 main outputs, built by McCune engineer Istvan B. "Steve" Kadar. The MC8 was unusual for having a matrix mixer section, and for its very low noise floor of −130.5 dBv, as referenced to the ideal single-resistor noise floor of −131 dBv at 0.775 volts. Both of these mixers were used on Beatlemania in 1979.
In 1976, Cavin headed the design of the McCune SM-3 2-way loudspeaker, again using a zero-sum crossover, and incorporating a compression driver design patented by Meyer, its phenolic diaphragm modified to yield higher compliance. Meyer assisted in time-aligning the two passbands, with Cavin determining that the SM-3 sounded more pleasing when the high frequencies were slightly ahead of the lows, a conclusion reached independently by Don Pearson, sound engineer for the Grateful Dead. In 1977, Cavin supervised the development of the McCune SM-4 2-way coaxial loudspeaker, based on the classic Altec 604E but with a low frequency driver extensively reworked by Kadar to deliver higher power, and also fitted with Meyer's more compliant high frequency compression driver. Cavin designed an active all-pass network to time-align the passbands, slightly delaying the low frequencies to match the highs. Cavin's proprietary improvement to the Altec 604 compared favorably with the same concept implemented via passive components by Ed Long for the contemporary UREI 813 studio monitor: his trademarked Time-Align process.
Meyer was contracted by McCune to design the JM-10 concert loudspeaker, a large single-point-source system intended to replace ten JM-3s. Cavin chose a bucket-brigade delay to align the high frequency drivers about 1.5 milliseconds back from the mids and lows. Digital delay devices were tried but they had too much distortion, while the chosen bucket-brigade solution was somewhat hissy. Cavin designed a noise gate for the JM-10 processing to stop the high frequency hiss when no signal was present. The JM-10 system was used on the Kool Jazz Festival touring the U.S. in mid-1977. Cavin accompanied the tour to provide technical support.
In the late 1970s, Cavin designed a 50-pair snake splitter for large events, used to send each microphone signal to multiple mixers such as for front-of-house mix (FOH), monitor mix and a recording truck. The splitter used Jensen transformers and two latching 27-pair snake connectors for each mixer. The splitter system was used on many events, for instance the Playboy Jazz Festival at the Hollywood Bowl, which needed dup
Bob Cavin