AUDIO enthusiasts can not afford to miss the latest international high-end show, says Fung Kam-chuen, a director of Audio Distributors Co. ''They can get to listen to all the best brands,'' Mr Fung said. ''The idea is to let the public know what is going on in the audio market.'' Audio Distributors offers equipment ranging in price from $18,000 for a JPW Ruby speaker system to $288,000 for a Quadrature DSP/1 speaker system. Mr Fung said the local audio market was depressed; China was the exception. ''People in Hong Kong have not spent a dime on audio for a year, or a year and a half. You could say hardly a sale was achieved. Business has gone down so drastically there is really no business at all. All the business has moved to China.'' Mr Fung attributed much of the fall in business in Hong Kongto immigration: many people who could afford audio equipment had moved to China recently, taking their spending power with them. ''There are so many ads selling apartments or houses in China. If 100,000 families have bought houses on the mainland - a fairly mild estimate - and each spent $100,000 on fitting them out, there goes the money,'' he said. Also, there were Hong Kong people who bought flats in China and occupied them only part of the time. They tended to buy a second television set before investing in stereo equipment. However, they still made up an important part of the potential audio market, he said. Mainland customers tended to buy systems that cost from $10,000 to $25,000. The most promising markets in China were in Sichuan, Beijing and Shanghai, he said. Mainlanders were prepared to buy equipment with unfamiliar names, he said. Audio Distributors' products include Quadrature speakers, Luxman and Pass amplifiers, JPW speakers and Theta converters. A love of music drew Mr Fung into the audio world. ''It started when I was about 16,'' he said. ''I was a schoolboy and there was not much to do except sit by the radio and listen to music. ''After I graduated, I thought it was time to invest in an audio system and, by and by, I joined the audio field. I worked with an audio company which was famous at the time and, in 1976, I started my own company.''