In 1974 we decided to make another major upgrade to the Showco speaker systems by going to a four-way system design. Inspired by the big bass horn project, Keny and Ron designed a mid-bass horn to operate from 300Hz to 800 Hz that used a fiberglass mouth attached by spring latches to a speaker enclosure with two 12 inch JBL speakers. Ron also invented a new type of folded bass enclosure that featured a 15 inch JBL speaker mounted inside of 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. {{< 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 Brutsché Archive" size="medium" >}} ## Crown DC300A Introduction 1973 The Crown DC300A power amplifier was introduced in 1973. It was a major advance in amplifier design. As part of the four-way system project in 1974, we decided to purchase Crown DC300A amps and mount them in amp racks to power the new mid bass cabinets and the new hurler bass cabinets. {{< StoryImage id="showco-2-equipment-029-equipment" title="Crown Power" caption="Crown DC300A amp racks 1974." credit="Photo Jim Bornhorst" 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” speakers. Keny originally named it the F Horn but George Wheatley 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. {{< StoryImage id="showco-24-jackson-browne-jul-015-jackson-77" caption="Jackson Browne four-way Showco system 1977 tour." credit="Photo Jim Bornhorst" size="large" >}} {{< StoryImage id="showco-035-equipment" caption="Several Showco four-way systems setup in the shop 1975." credit="Photo Jim Bornhorst" 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 and volume controls for each of the four frequency ranges. We continued with our color code of green for bass, yellow for mid-range, red for highs and we added blue for mid-bass.

{{< 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="Photo Jim Bornhorst" size="responsive" >}} {{< StoryImage id="showco-miscellaneous-audio-gear-76-master-panel" caption="Showco Four-Way Master Panel Model 1015 1974." credit="Showco Recovered 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="Showco Recovered 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="Showco Recovered 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="Photo Jim Bornhorst" 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="Photo Jim Bornhorst" 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="Photo Jim Bornhorst" 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="Showco Recovered 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="Showco Recovered Archive" size="medium" >}}

{{< StoryImage id="showco-clair-s4-indoor-array" caption="Clair S4 Indoor Array." credit="Facebook PA of the Day" size="responsive" >}} {{< StoryImage id="showco-clair-s4-outdoor-array" caption="Clair S4 Outdoor Array." credit="thegearpage.net / quilsaw" 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="Photo Jim Bornhorst" 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.