Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site opus.UUCP Path: utzoo!watmath!clyde!floyd!harpo!ihnp4!zehntel!hplabs!hao!seismo!ut-sally!opus!rcd From: rcd@opus.UUCP Newsgroups: net.audio Subject: Re: AR speaker info wanted Message-ID: <240@opus.UUCP> Date: Fri, 16-Mar-84 14:25:15 EST Article-I.D.: opus.240 Posted: Fri Mar 16 14:25:15 1984 Date-Received: Tue, 20-Mar-84 01:55:44 EST References: <1840@tektronix.UUCP> <352@dual.UUCP> Organization: NBI, Boulder Lines: 34 <> > I have two notes on the AR-11s. > > First off, it is very very easy to blow out the mid and high freq drivers. > ... > 2nd, opinion. I myself do not like the sound of the dome tweeters they > use in the AR-11s. Too harsh for my tastes... Obviously I don't know the circumstances around this - but I would conjecture that these two are related and perhaps not the fault of the speakers. When an amplifier is overloaded, meaning that it is asked to deliver more power than it has, it will "clip". What that means is that as the amplifier tries to follow a rising signal, it runs into the upper limit of its power supply's capability. The top of the waveform gets chopped off. In some amplifiers, this cutoff happens very abruptly so that you get a "corner" in the waveform. The effect is the same as an impulse with gobs of high-frequency power. The sound is extremely harsh, and letting an amplifier run in clipping mode for very long can put trash into the higher-end speakers that will fry them. People tend to overlook this phenomenon because speaker systems are normally rated in terms of "system capacity" which assumes a reasonable frequency distribution. However, in a system regarded as capable of operating with a 100 W amplifier, it may only take 10 watts to blow out a tweeter. Another reason that the phenomenon is overlooked is that an amplifier in clipping can produce bursts of power which far exceed its rated power output - yes, a 10 watt amplifier can produce 50 watts of pure high-frequency crap for short intervals. So (as he finally returned to the point of the discussion), it could be that the speakers were being driven by an overworked amplifier driven into clipping, and they were being killed by the amp. -- {hao,ucbvax,allegra}!nbires!rcd