Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site utcsrgv.UUCP Path: utzoo!utcsrgv!ray From: ray@utcsrgv.UUCP (Raymond Allen) Newsgroups: net.audio Subject: Re: High power amps are sometimes useful - (nf) Message-ID: <1473@utcsrgv.UUCP> Date: Tue, 7-Jun-83 12:29:19 EDT Article-I.D.: utcsrgv.1473 Posted: Tue Jun 7 12:29:19 1983 Date-Received: Tue, 7-Jun-83 16:15:34 EDT References: <1089@hp-pcd.UUCP> Organization: CSRG, University of Toronto Lines: 20 Actually, your speakers must not be very efficient. If you were to try to reproduce a symphony orchestra recording at concert hall volume levels (where the musical peaks could exceed 100dB) then, on these peaks, your amplifier would have to produce instantaneous power on the order of 5000 to 10000 watts!!! Although there is little likelyhood that an attempt to produce such power would destroy your amplifier (since the transients are of very short duration) some simple mathematics would indicate that to produce 5000 watts across 8 ohms requires 200 volts. Very few commercial amplifiers use a power supply of this high of a voltage (dare i say none?). The result? Your amplifier will simply clip, and thus distort the output. To be perfectly fair, it is important to note that i have never seen an audio power amp which has power meters which actually give a true indication of the power that the amplifier is producing. All the amps that i see just use a voltmeter on the output with a scale that is calibrated for watts which assumes that the amp is driving an 8 ohm resistive load. Most real-world speakers are quite reactive and, thus, this type of meter is less than useless. The only thing that you can be sure of is that the actual power is less than or equal to (if the load is a pure resistance) the reading on the meter.