Welcome back to FRONT of HOUSE’s continuing look at the history of P.A. loudspeakers. In Part 1 and Part 2 (FOH, March 2025, page 44 and April 2025, page 40), we provided a year-by-year chronology of loudspeaker development from the late 1800s through 1969 and Woodstock. Part 3 of this year-by-year look at loudspeaker developments will continue in next month’s issue. The focus this month is on some important loudspeaker design developments from the 1970s. This article also revisits 1973’s Summer Jam, a.k.a. the “Forgotten Woodstock,” which drew some 600,000 attendees to Watkins Glen, NY.
The 1970s marked a turning point in the Tour/Festival-Sound industry. The shortcomings of large-scale sound reinforcement, which had influenced the Beatles’ decision to move from live stage to studio work in the late 1960s, began to be addressed with major events like Woodstock, and in the decade that followed, massive sound systems delivered on the promise of producing ever-louder rock concerts at record-breaking festivals.
As noted last month’s FOH Tech Feature, the most prevalent concert sound systems in use in the 1960s were typically based on older 2-way Altec “Voice of the Theatre” Series loudspeaker models. Designed for use in cinemas and live theatres, they were not up to the task of covering large rock concert venues. And while the Beatles’ concerts at Shea Stadium stand as a defining moment in pop culture, the band’s onstage 100-watt instrument amplifiers and tiny column PA speakers lining the baseball diamond’s infield could barely be heard above the loud cheering coming from the 55,000 fans.
For Woodstock and other events, Bill Hanley responded by designing and building higher-output bass-horns with four of the higher-power-handling JBL 15” woofers. He also made use of Altec 290 HF drivers, equipped with more robust phenolic diaphragms, with limited high-frequency response, as opposed to the better-sounding but less-rugged aluminum diaphragms.
What was needed was a way of splitting up the signal into multiple frequency bands so they could be more efficiently handled by separate amplifiers to reduce distortion, reduce failures and maximize sonic output. The leading concert sound companies were rushing to accomplish just this. The Hanley and Clair brothers, and others, were experimenting by adding super-tweeters to their higher-output bass and MF horns in the late 60s and early 70s.
The Dawn of Festival Sound
These developments were happening at the dawn of the touring rental industry, with the emergence and growth of national sound companies in the early 1970s. Along with Clair Brothers and Hanley, these also included Maryland and Silverfish (later Sound Image) in the Northeast; Carlo, Heil and Stanal in the Midwest; Showco in the South; and A1, Electrotec, FM, McCune, Northwest and Tycobrahe on the West Coast. From their regional bases, sound rental companies would join bands on tour, extending their reach coast to coast and eventually overseas.
Last month’s Tech Feature also noted how, in the mid-60s, John Judnich and Sunn both designed and sold portable 3-way concert sound systems for clubs and concert tours. A few years later, these so-called “high-fidelity” concert sound systems would lead to the development of the 4-way Tycobrahe Sound system for the massive California Jam music festival event in 1974 (more info on that as we return to a year-by-year chronology in next month’s Part 3 article, starting with 1970).
In the late 1960s, Tycobrahe emerged as a Southern California-based sound company. John Judnich, the company’s first engineer, has been credited by some for the development of the first all-in-one 3-way concert system, providing Hi-Fi sound reinforcement to Beach Boys concerts as early as the mid-1960s. This all-in-one active 3-way loudspeaker system, with the same JBL drivers as the passive Sunn Coliseum sound system, was said to help the Beach Boys’ sound crew load in and out of concert venues in about half the time of what was required for the previously used “stack them up” types of systems. With systems getting larger, this became more important, especially at locations where union stagehands were required.
Regardless of who was first with this new concert sound approach, Tycobrahe Sound would emerge as one of the prime PA companies in the early-to-mid-1970s. Along with Judnich, Tycobrahe was led by founder/president/owner Bob Bogdanovich and senior engineer Jim Gamble. Others playing key roles included director of operations Jim Chase along with Ralph Morris, David Pelletier, Gary White and Brian Krokus. Tycobrahe’s speaker systems made use of JBL drivers, including two various 15” woofers, one 375HP compression driver on a 2” horn and two 075 ring-radiator tweeters. Subs and various fill HF horns were added separately as needed for the application. The modular loudspeaker system was very effective and practical, and it formed the basis of the Tycobrahe touring system of that era, according to Jim Chase and Brian Krokus (see Fig. 1)
As concert tour operators pushed power beyond the capabilities of column speakers and Voice of the Theatre drivers, the cost of keeping early sound systems in working order continued to rise, and in some cases, the expense of continually repairing damaged drivers outstripped the cost of the speaker systems themselves.
By the 1970s, Altec Lansing, which had reached loudspeaker prominence in the 1950s and 1960s, was facing increasing competition from JBL, particularly for rock concert sound reinforcement. JBL design engineer Ed May developed the compact 4310 monitor. This, and its domestic conversion, the L100, would become the most successful loudspeakers yet produced by any company at that time (See Fig. 2). JBL was also cutting into Altec Lansing’s share of the cinema loudspeaker market, and by 1977, more recording studios were using JBL monitors than all other brands combined, according to Billboard.
Other companies taking new approaches during the 1970s included Community, which led the way toward calibrated outdoor loudspeaker testing. Community tested its own products versus competing loudspeakers at set distances and published the results. Community came up with its LMF (See Fig. 3), one of the first compression loaded mid-bass horns, along with a full product line of weatherproof HF fiberglass horns noted for their sound quality.
Also during the 1970s, American audio engineer and inventor D. B. (Don) Keele Jr. led the development of the constant directivity horn design, securing patents for several Bi-Radial™ horns for JBL and two different series of horns for Electro-Voice. Keele, an AES Fellow, has published more than 40 technical papers on subjects including speaker boxes, loudspeaker horns, computer aided design, anechoic chambers and loudspeakers with Constant Beamwidth Transducers.
Beyond the U.S., BBC Elettroacustica Professionale (later B&C) started collaborating with other Italy-based speaker companies including Montarbo, Lombardi Amplificazioni and FBT, enhancing sales through improvements in product quality as the popularity of rock ‘n’ roll and pop music concerts drove worldwide demand for pro audio loudspeaker systems.
The ‘Forgotten Woodstock’ of 1973
In August 1969, Woodstock drew an estimated 400,000 to Max Yasgur’s dairy farm in Bethel, NY with nearly three dozen acts performing over more than three days. In July 1973, another festival — Summer Jam — was attended by even more festivalgoers — 600,000. Held at Watkins Glen racetrack on July 28, this one-day event, now often called the “Forgotten Woodstock,” featured music from The Allman Brothers, The Band and the Grateful Dead.
The event’s promoters agreed to limit ticket sales to 150,000, but four times as many arrived near the site. While not considered as prominent a cultural milestone as Woodstock, there were parallels including huge crowds, rock music, a mostly peaceful vibe and plenty of marijuana use on site. And if the non-ticket holders had to be content to remain too far from the stage to see much of the performances, they were at least able to hear the music. Ken Sander, a former road manager and music industry insider, recounted the sound system provided for the event in a two-part series for PS Audio’s Copper magazine. “The bands had pressed promoters — Finkel and Koplik — to hire Bill Graham’s FM Productions to provide a 50,000-watt monster sound system,” along with lighting and staging. “This sound system introduced a new concept — digital delay lines — to compensate for the speed of sound in air.” Electronics company Eventide was hired to bring three digital delay units — each capable of 200 ms (milliseconds) of delay. Four speaker towers were placed 200 feet from the stage, their signal delayed 175 ms to compensate for the speed of sound, between the main stage loudspeakers and the delay towers. Six more speaker towers were placed 400 feet from the stage, requiring 350 ms of delay, and six more towers were placed 600 feet from the stage, with 525 ms of delay, the sound coming through all three units. As the last delay towers were being set up, it became evident that more amplification power would be required for audio coverage of the record-setting crowd, so Alembic sound engineer J. Furman was sent by helicopter to buy five more McIntosh amps, almost overloading the helicopter on return.
Reach David K. Kennedy at www.D-K-A.com
