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Date: March 24, 2003 at 22:22:20
From: norman bates, [oproxy3.rockwellcollins.com]
Subject: Let me show you all the truth........


About 5 years ago I used a watt meter and oscope and notice a 100 watt rms amp (8ohm), clipped just over 50 watts into an 8 ohm speaker. But I didn't know why.

An amplifier is tested into a resistor for watt ratings..

A speaker is actually an inductor that has resistance.

If you use ac theory, a speaker (inductor) actually has a 45 degree phase angle, which means it draws twice the current than a resistor at the same voltage swing signal input.

So if an amplifier says it puts out 450 watts rms into 4ohm, it would probably only put out 225 watts rms into a load that has a 45 degree phase angle.

So 800 watts rms into 4 ohms, would realistically put 400 watts into 4 ohms. 4 four ohm speakers wired in series parallel for a 4 ohm load, each speaker would see a true 100 watts.


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