David A Ellis
By 1930 sound was making a big noise in the world of film and there were several manufacturers making equipment for the age of movie sound. This of course came at a heavy price, which no doubt left many independent exhibitors worrying about the cost, just like they did when CinemaScope with four tracks arrived and other cinematic advances, the latest being the high cost of digital.
A.W.H (British Photophone) appears to have been one of the cheapest units around, offering set A and set B equipment. Set A was designed for halls with a seating capacity of 1250 and would set the proprietor back £850, with the B unit, designed for bigger halls, costing another £50. The unit is described as having special moving coil loudspeakers, accumulator excited, and the amplifier and rectifier were in duplicate in case of failure. This equipment was chosen by the British Board of Film Censors.
British Acoustic sound was marketed at a higher price, coming in at £1150. A description stated that the amplifier and rectifier equipment was in duplicate and rectifying and power valves were placed away from the operating box. It was stated that the unit had several unique features, one of which was the use of a large aperture instead of a slit. This, it was stated can be adapted to all makes of projectors.
British Talking Pictures would set you back £1220 for disc and film, but in duplicate the bill would be £1545. It was reported in the Bioscope in February 1930, that the disc attachment consisted of substantial casting of aluminium with an extension, on which the arm for the pick-up was mounted. There wass a flexible shaft connection between the turntable and the projector. It was serviced free for one year.
British Thomson Houston offered sound on film and on disc for £1250 for halls up to 2000. Accumulators were avoided. Instead a BTH generator supplied the current for the loudspeaker fields. There was a 12-volt supply for the exciter lamps and an AC supply of around 750 volts. It was stated that amplification was not in duplicate but was run in parallel and that a break down did not mean the cessation of the show, but the volume was reduced by a half, which could be modified by the fader control, which had a substantial margin.
Another cheaper unit was Corophone. Their sound on disc and film systems were £675 for cinemas seating up to 1200 and £775 for larger ones. The reduction gear for the turntables ran in an oil bath with direct flexible drives to the projector. This is one where sound could be adjusted from the hall. The sound on film heads could be fitted to all projectors. The amplifier had three stages with twin output rated at 24 watts with an entirely separate set of valves in reserve for breakdown. The standard set-up included four loudspeakers with baffles and a monitor horn in the box.
Other units included Edibell, Filmophone, Butcher's Electrocord and Klangfilm. Klangfilm supplied five main types of equipment. A 7-watt system supplied the audio for small halls of around 400 seats, 10-watt units for 900 seats, 50 watts for 1200, 100 watts for a large hall of 1700 seats and 200 watts for seating over this. Prices back in 1930 ranged from£1400 to a staggering £3200 with a service charge of £2 10 shillings to £5 10 shillings weekly. This was another unit where sound could be controlled from the auditorium. Fortunately, the equipment could be bought on easy terms and in some cases, exhibitors only rented the equipment.