![]() For example, 100mW out of a Walkman headphone jack will produce room-filling sound in a large auditorium, and two 6L6 tubes putting out 20W are enough for fairly dynamic film soundtracks.Īnother point that should be made is that in 1947, the physics of horn speakers was very well understood. The good news about this is that the efficiency is very high because the coupling between the woofer and the outside air is almost perfect above that cut-off frequency. One thing that could be done was to put multiple horns together making a super-wide horn (as used in the Altec X-1), and another was to add baffles to the side of the cabinet, which effectively increased the size of the horn as used in a variety of cabinets and available as retrofits for many others. Once the wavelength becomes wider than the horn exit, the response precipitously drops. The bad news about this is that very low bass extension was not possible, because with a bass horn, the lowest possible frequency was limited by the horn’s exit width. This was in many ways the precursor to the W-Bin bass cabinets of the 1970s, but the direct-firing woofer made for response that remained flat up into midrange frequencies. There is a high-frequency horn on top (a sectoral horn that at the time gave the best pattern control), but the low frequencies are also produced by a large folded horn driven by large woofers specifically intended for high-compression applications. ![]() What makes these speakers interesting today, and what makes them different from nearly anything currently made, is that they are bass horns. Photo 2: Taken in the 1970s, this photo shows the author hanging behind an Altec A-5 loudspeaker and suspended over a stage while changing diaphragms in situ. It is by no means authoritative, it’s just an overview of what is out there, along with some of my personal thoughts about the system. This article discusses some of the things that you should know about the Voice of the Theatre system for theater or auditorium installations. And they still can be found in sound reinforcement service as can many of the larger Voice of the Theatre systems. Today, the A7 is one of the most sought-after speakers for home audio in Japan, in part because real estate is so expensive in Japan that to be able to say you have a pair of A7s is to imply that you have a living room that is so large that it requires a pair of A7s to fill it. Within a few years, they had introduced a number of additional configurations including the classic A7 - a compact version designed for smaller cinemas but which found its way toward becoming perhaps the most popular sound reinforcement speaker of the 1950s through the 1970s. John Hilliard at Altec Lansing took many of the acoustical innovations that came out of the World War II effort and developed a new loudspeaker design for large halls that was completely different from the Western Electric cinema systems of the pre-war era.įirst launched by Altec in 1947, the designs were available in a number of different two-way configurations, built on the same building blocks with Model 515 woofers and the new 288 high-frequency compression drivers, with and without side baffles. The Altec Lansing Voice of the Theatre series was one of the innovations coming out of the post-war era. ![]() Photo 1: An official Altec Lansing photo shows the Voice of the Theatre Speaker range. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |