The JMI Vox AC-50 "Big Box" Speaker Cab and Swivel Trolley

The AC-50 "Big Box" speaker cabinet and trolley evolved from the AC-30 sized cabinet that Vox originally sold with the AC-50 single channel amplifier heads.

Several signs point to the initial "Small Box" cabinet design being the result of a hurried effort to supply a speaker system to the Beatles for their new 50 watt AC-50 heads.

These original "Small Box" speaker cabs had two 15 watt Celestion Alnico blue speakers, yielding a total power handling capacity of only 30 watts. This was not well matched to the far greater 50 watt output of the AC-50. Additionally, the cabinets were not sufficiently deep to enclose the back of the Midax horn, leaving it exposed and protruding from a hole in the back of the cabinet.

The new AC-50 "Big Box" cabinet corrected both of these problems. Two 25 watt, 12" Fane speakers allowed a total cabinet power rating of 50 watts to match the output of the head. The overall depth of the cabinet was increased to properly enclose the Midax horn.

A Goodmans Midax horn with a 2 uf oil filled crossover capacitor was included in the AC-50 "Big Box" speaker cabinet. This horn was included in the speaker cabinet to compensate for the reduced amount of treble available from the AC-50 amp head. This lack of treble was especially evident when comparing an AC-50 to a "Top Boosted" AC-30.

A tubular steel, chrome plated swivel trolley on swivel casters was also developed for the AC-50 "Big Box" cabinet.


The VOX Showroom!

Photos and editorial content courtesy Gary Hahlbeck, North Coast Music

Any and all material presented herein is protected by Copyright.
© 1998 - 2023 The Vox Showroom and North Coast Music, all rights reserved

The images and editorial content in this web site may not be copied or reproduced
in online auction sites such as eBay, Reverb and Craig's List. Sellers may provide a link
to the Vox Showroom web site if they wish to refer to this copyrighted material.