Active loudspeaker cabinet lined with metallic screening material - to which connections are made from mains interference suppression filter and casing of tweeter

摘要

The housing (1) of the cabinet is lined with e.g. sheet iron (2) and encloses a digital power amplifier (3) and a frequency switch (4) with wiring (14,15) to a woofer (5) and tweeter (6). Voltage is applied to the amplifier (3) via a glass fibre line (10), and mains power via a cable (11) and interference suppression filter (12) earthed to the screen (2), as is the casing of the tweeter (6). A perforated metallic screen (9) is fitted across the mouth of the woofer (5). ADVANTAGE - Simple and inexpensive countermeasures against HF interference arising within appts. restrict its radiation to acceptable level.