In 1974, we decided to make another major upgrade to Showco speaker systems by moving to a four-way system design. Inspired by the Big Bass Horn project, Keny Ron designed a mid-bass horn operating from 300 Hz to 800 Hz that used a fiberglass mouth attached by spring latches to a speaker enclosure containing two 12-inch JBL speakers. Because it operated in a much higher frequency range than the Big Bass Horns, the mid-bass horn was much smaller, very efficient, exhibited good pattern control, and sounded really good reproducing the mid-bass frequency range. Ron also invented a new type of folded bass enclosure featuring a 15-inch JBL speaker mounted inside a four-sided folded horn. The center part of the cabinet was in the shape of a pyramid, so we named it the Pyramid System. We filed for a patent on January 30, 1974—the first Showco patent—which was awarded by the U.S. Patent Office on October 14, 1975. We were still looking for a better bass cabinet than the dual front-loaded cabinet we were using in our indoor systems, so we built some of Ron’s new pyramid cabinets using the new mid-bass horns for our first indoor four-way speaker system, which we used on the Lynyrd Skynyrd 1974 tour. After this initial tour, we did not start using the pyramid bass cabinet in our indoor systems, but Ron used the design in our Showco Manufacturing division, which we founded in 1976. {{< StoryImage id="showco-008-lynyrd-skynyrd-73" title="Pyramid System" caption="Prototype four-way system with Ron Fox pyramid bass cabinets on Lynyrd Skynyrd 1974 tour." credit="© Rusty Brutsche Archive" size="medium" >}} ## Crown DC300A Introduction 1973 The Crown DC300A power amplifier was introduced in 1973 by Crown International, which was located in Elkhart, Indiana. The DC300A was the successor to the DC300 amplifier, which had been introduced in 1967 and was a major advance in amplifier design, with 150 watts per channel at 8 ohms, 300 watts per channel at 4 ohms, and 600 watts into 8 ohms in mono-bridged mode. As part of the four-way system project in 1974, we decided to purchase Crown DC300A amplifiers, mount them in amplifier racks, and use them to power the new mid-bass cabinets and new Hurler bass cabinets. {{< StoryImage id="showco-2-equipment-029-equipment" title="Crown Power" caption="Crown DC300A amp racks 1974." credit="© Jim Bornhorst Archive" size="medium" >}} ## Development of the Hurler Bass cabinet 1974 As part of the four-way system project in 1974, Keny Whitright designed a new bass cabinet that was a double-folded-horn, “W”-type bass cabinet with four JBL 15-inch speakers powered by 600 watts from a Crown DC300A configured in bridged-mono mode. The cabinet was the same size as the dual front-loaded bass cabinets. It performed very well and was extremely loud. Keny originally named it the F Horn, but the inimitable George Wheatley, our sardonic company wit, said the new cabinet was so loud it made you want to hurl, so from that point on the cabinet was known as the Hurler cabinet. The new standard four-way indoor system consisted of four Hurler bass cabinets on each side of the stage, six mid-bass horns, four JBL 2350 radial horns with two JBL 2480 drivers each, two Showco long-throw horns designed by Don Keele with two JBL 2480 drivers each, and two high-frequency horn cabinets, each with two JBL 2390 rectangular horns without lenses and one JBL 2470 driver on each 2390 horn. We discontinued mounting Marantz 16B amplifiers and Showco 200-watt amplifiers inside the bass and horn cabinets. Instead, we powered the entire system with Crown DC300A amplifiers mounted in amplifier racks. Total power was Bass—8 × 600 + Mid-Bass—12 × 200 + Mid-Range—8 × 200 + Long-Throw Mid-Range—4 × 200 + Highs—4 × 100 = 10,000 watts, using 18 Crown DC300A power amplifiers. Here is a photo of the four-way system on tour with Jackson Browne in 1977.

{{< StoryImage id="showco-24-jackson-browne-jul-015-jackson-77" caption="Jackson Browne four-way Showco system 1977 tour." credit="© Jim Bornhorst Archive" size="large" >}} {{< StoryImage id="showco-035-equipment" caption="Several Showco four-way systems setup in the shop 1975." credit="© Jim Bornhorst Archive" size="large" >}}

## New Four Way Master Crossover Drive Panel 1974 In 1974, we designed a new four-way master crossover drive panel that had separate VU meters, separate illuminated colored mute switches, and volume controls for the four frequency ranges. We continued our color code of green for bass, yellow for mid-range, and red for highs, and we added blue for mid-bass. We used three-pin XLR connectors with the sexes reversed for the bass and mid-range drive lines, and four-pin XLR connectors with the sexes reversed for the mid-bass and high-frequency drive lines. Jim Bornhorst designed the electronics, including the crossover circuits and line amplifiers. I designed the metalwork chassis and did the artwork for the front panel to match the Superboard artwork. When the Superboard was put into service, we began operating sound systems in stereo, with the stage-right speakers carrying the left channel and the stage-left speakers carrying the right channel. We therefore mounted two, and sometimes four when we were controlling the front fill and rear fill separately from the main system, new four-way crossovers in the mixing accessory rack. This photo is Jim at the Superboard mixing the Jackson Browne 1977 tour. The accessory rack has four new four-way master panels.

{{< StoryImage id="showco-1-people-060-showco-people" caption="Jim Bornhorst mixing Jackson Browne 1977 Tour with four of the new four-way master panels." credit="© Jim Bornhorst Archive" size="responsive" >}} {{< StoryImage id="showco-miscellaneous-audio-gear-76-master-panel" caption="Showco Four-Way Master Panel Model 1015, 1974. Four-way electronic crossover and line amplifiers that drove the power amplifiers in the speaker stacks." credit="© Rusty Brutsche Archive" size="responsive" >}}

## New Four Way Drive Line JBox 1974 In 1974 I designed a new drive line JBox to accommodate the new four-way sound system. {{< StoryImage id="showco-9-73-sound-gear" title="4-Way JBox" caption="New drive line JBox for four-way sound system featuring four double sets of XLR connectors for left front, right front, left rear and right rear drive line outputs to connect to the Crown DC300A amp racks, a male and female set of XLR connectors for monitor A and monitor B outputs and Mono 1 and Mono 2 outputs, three mic XLR connectors for mic inputs 28, 29 and 30, two sets of XLR connectors each for the sound intercom and lighting intercom systems and the paralleled male and female 81 pin chassis mount snake connectors. " credit="© Rusty Brutsche Archive" size="medium" >}} ## Continued Evolution of Stage Monitors 1974 {{< MultiGalleryComponent galleries="1986-desks-acc-racks, miscellaneous-audio-gear" >}} The stage monitor systems continued to evolve. In 1974 Showco purchased Stevenson Interface Electronics 30 X 8 monitor mixing consoles which provided eight separate mixes for the monitor engineers to use onstage. We also developed bi-amped floor monitor speakers. Jim Bornhorst built modular electronic crossover units that were small and compact and provided multiple channels of two way and four-way crossovers for the floor monitors and M4 cabinets. Jim also built a 8X8 matrix mixer that took the eight mixes from the Stevenson consoles and created eight additional mixes for a total of 16 available mixes for the monitor engineers to use for large stage setups. {{< StoryImage id="showco-miscellaneous-audio-gear-79-monitormix-4" title="Stevenson Console" caption="Stevenson Interface Electronics 30 X 8 Monitor Mixing Console 1974." credit="© Rusty Brutsche Archive" size="medium" >}}

{{< StoryImage id="showco-2-equipment-038-equipment" caption="Stage monitor rack for Stevenson 30 X 8 monitor console. Left side top down are 6 four-way crossover modules, 12 two-way crossover modules, noise gates, Crown D60 headphone amp, patch bay, Crown PSA2 amp. Right side holds eight 1/3 octave EQ units and a storage drawer. " credit="© Jim Bornhorst Archive" size="responsive" >}} {{< StoryImage id="showco-2-equipment-033-equipment" caption="Stage monitor rack: left is 6 four-way crossover modules, 12 two-way crossover modules, patch bay, right is reverb unit, 3 EQ units, drawers. " credit="© Jim Bornhorst Archive" size="responsive" >}} {{< StoryImage id="showco-2-equipment-037-equipment" caption="Jim Bornhorst-designed 8 X 8 matrix for the Stevenson Interface Electronics 30 X 8 monitor mixer to add eight additional mixes for a total of 16. " credit="© Jim Bornhorst Archive" size="responsive" >}} {{< StoryImage id="showco-3way-biamped-floor-monitor" caption="Showco Bi-Amped three-way floor monitor with JBL K120 12” speaker, JBL 2391 Lens Horn with JBL 2470 driver and two JBL ring radiators. " credit="© Rusty Brutsche Archive" size="responsive" >}}

## Clair Brothers Introduces the S4 Sound System 1974 In 1974 Clair Brothers, our biggest competitor, introduced a new four-way sound system where all of the JBL components were mounted in the same cabinet and no horns were used except for the mid-range drivers. The cabinet was called the S4. The design was a major departure from the horn loaded systems that Showco was using.

{{< StoryImage id="showco-clair-brothers-s4-cabinet" title="Clair S4" caption="Clair Brothers S4 speaker cabinet with two JBL K150 18 inch 150 watt speakers for bass, four JBL K110 10 inch 75 watt speakers for mid bass, two JBL horns with JBL 2440 60 watt drivers for mid-range and two JBL 2405 30 watt ultra high frequency slots for highs. The cabinet was powered with Phase Linear 700 power amplifiers which delivered 350 watts per channel into 8 ohms. The system used a three-way electronic crossover with 200 Hz and 1200 Hz crossover points and a 7 kHz passive crossover mounted in the cabinet to crossover between the JBL 2440 drivers and the JBL 2405 slots. The S4 cabinet measured 45 x 45 x 25 inches and was designed to fit two cabinets side by side in a semi-truck trailer. The cabinet weighed 425 pounds and had integrated rigging hardware in each cabinet for hanging the speakers in arenas and outdoor stadiums. Assuming each component was powered with its RMS power rating, each S4 cabinet would have been powered with a total of 780 watts. Clair introduced the S4 system on a Rod Stewart tour in 1974 and it was used on the 1975 Rolling Stones tour. Showco stayed with horn loaded bass and mid bass cabinets until the introduction of the AS and AX sound systems in 1983 and the Prism system in 1986 when mid bass and bass horns were no longer used by Showco." credit="© Rusty Brutsche Archive" size="medium" >}} {{< StoryImage id="showco-clair-s4-indoor-array" caption="Clair S4 Indoor Array." credit="Facebook PA of the Day post May 9, 2019" size="responsive" >}} {{< StoryImage id="showco-clair-s4-outdoor-array" caption="Clair S4 Outdoor Array." credit="thegearpage.net post by quilsaw May 26, 2024" size="responsive" >}}

## Development of Showco M4 Speaker System 1974 The introduction of the Clair S4 in 1974 did inspire us to build a full range cabinet to replace the three-way mini-system. Keny Whitright designed the M4 full range speaker. {{< StoryImage id="showco-2-equipment-027-equipment" title="Showco M4" caption="Showco M4 full range cabinet designed by Keny Whitright 1975." credit="© Jim Bornhorst Archive" size="medium" >}} Keny used four JBL 2130 100 watt 12” speakers for bass, four JBL 2120 60 watt 10” speakers for mid bass, two JBL 2395 elliptical mid-range horns each with a JBL 2480 120 watt driver and four JBL 30 watt high frequency ring radiators. Recessed steel cups with rigging eyelets were mounted on the top and bottom with the eyelets connected to ½” steel rods that ran all the way through the cabinets. The M4 was powered by two Crown DC300A power amplifiers that delivered 900 watts to each M4. We used the M4 primarily as a front fill speaker and as a side fill stage monitor where it was typically rigged above the stage pointing down on the performers. The M4 used the new Showco four-way master crossover panel with a 40Hz high pass filter and crossover points at 350 Hz, 1200 Hz and 7kHz.

Showco History