The Noizeworks - Gigging Musician. Gigging Musician Issue 1 | Page 8

Technical The Power of Filters Filter unwanted frequencies to focus amplifier power and maximise system performance. S SERIES Incredible Sound with Immense Power is Now a Reality. Filters are a great tool for maximising the power of any audio system. Matching the audio signal to the frequency response of the loudspeakers will maximise available amplifier power and minimise wasted energy. Two and four channel power amplifiers with outputs up to 4 x 1480 Watts RMS in compact packages weighing less than 7kgs. S6044. 4 x 1480 Watts RMS at 4 Ohms. 0.05% THD. 2U chassis. 310mm depth. 8.6kgs. Damping factor >500. Class H. Parallel mode for dual channel mono operation. S6000. 2 x 2950 Watts RMS at 2 Ohms. 0.05% THD. 2U chassis. 310mm depth. 8.6kgs. Damping factor >500. Class H. S4044. 4 x 975 Watts RMS at 4 ohms. 0.05% THD. 2U chassis. 310mm. 8.6kgs. Damping factor >500. Class H. Parallel mode for 2 channel mono operation. S3000. 2 x 1570 Watts RMS at 2 ohms. 0.05% THD. 2U chassis. 310mm. 8.6kgs. Damping factor >500. Class H. The RAM Audio info portal is now available at www.thenoizeworks.co.uk Full specifications and brochure downloads on all RAM Audio products. Visit the website to take a look. Gigging Musician All loudspeakers have a frequency response. In other words, a range of frequencies that they are designed to reproduce. Sending a signal to a loudspeaker that contains frequencies that it does not reproduce just wastes amplifier power and energy. By using filters to tailor the signal to the response of the loudspeaker we can ‘focus’ the signal and maximise our amplifier’s available power. Before now, the audio hardware required to filter every channel of an audio system may have been too expensive to implement, but many of today’s digital desks have filters available on every output so the tools required to focus our available amplifier power are more readily available. Also, power amplifiers are sometimes equipped with some very unassuming little switches on their back panels which are often ignored, but can be employed to greatly improve the performance of many sound systems. The need for filtering of audio signals really stems from loudspeaker response. No one has yet invented a single high powered transducer suitable for high level PA applications that can reproduce the entire frequency spectrum. ‘Woofers’ reproduce low and low/mid range frequencies, ‘tweeters’ reproduce high and high/mid range frequencies. For practical applications in modern portable PA systems, we really only need to deal with two types of loudspeaker. The full range speaker, sometime referred to as a mid/high speaker, and the subwoofer, or sub-bass speaker. ‘Full range’ speaker is a bit of a misnomer. We tend to label these speakers ‘full range’ because they provide useful output across most of the frequency spectrum and if we were just going to employ a single type of speaker, this would be it. These loudspeaker systems will usually reproduce most of the frequency spectrum but not the very lower frequencies required for genuine full range reproduction of modern rock, pop and dance music. So to start with a simple system. A pair of full range speakers, driven from a stereo amplifier, from a mixing console. Typically, full range PA speakers produce useful response from around 55hz – 20khz for a speaker based around a 1 5″ drive unit, to 65hz – 20khz for a speaker based on a 1 2″ woofer. Page 8