Axiom Home Page Forums General Discussion Technical Questions Power Consumption

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Sure... your amplifiers wouldn't draw the number of watts they're rated for unless you were arc-welding with them... at regular levels, you'd be able to count the power consumption in watts on one hand.

Bren R.

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Jay, apparently you were using maximum power figures which are rarely(maybe never)used. A speaker playing at a comfortably loud level uses about 1 watt. Split-second peaks can use much more, but it wouldn't be likely to be more than about 100 watts. Using maximum power on all the channels simultaneously can be tested in the lab, but doesn't happen in home audio.

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Okay, this gets more complicated, but when there's a power consumption number given it usually isn't at maximum power(unless it specifically said maximum). Usually for a receiver it's how much power is consumed with all channels operating at 1/8th of maximum. That may sound odd, but it's part of the Underwriters Laboratory requirement for testing for overheating. Example: 7x100 watt amps, 1/8th of that is about 90 watts, at 1/8th power this class of amp is roughly 20% efficient and would consume about 450 watts to output 90, and the 450 watt consumption figure might be on the back of the receiver.

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Hi,

Chatting the other day with Tom Cumberland, Axiom's electronics engineer, I quizzed him on this subject and he noted that the current draw of the EP500 would typically be between 0.5A and 1.5 amperes depending on the playback level.

He said that 1 ampere would be a "safe prediction" at moderate listening levels.

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Thanks for sharing this info Alan. I'm always curious about such things. Did Tom happen to tell you the power consumption when the EP500 is idle with no source? I have always wondered just how much it draws when not in use. I am told not much due to the dsp nature of the design, but again I am curious.

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Dllewel: Thanks for sharing this info Alan. I'm always curious about such things. Did Tom happen to tell you the power consumption when the EP500 is idle with no source? I have always wondered just how much it draws when not in use. I am told not much due to the dsp nature of the design, but again I am curious.

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Alan: I did ask and he said "about as much as a night light," but didn't quote specific figures. . .

Regards,

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I've finally measured this for myself! I bought the P3 Kill-A-Watt device on Amazon and did some measurements of my EP500 (and many other things ).

What I was realy interested in was the subs power consumption when not in use. I measured the EP500 sitting idle and found it to be just 12 Watts. Now I don't feel too wasteful in leaving them on all of the time.

I decided to try some in use measurements. Here are some numbers while playing multichannel music (Beatles Love DVD) with the system (inlcuding sub) calibrated to 75dB with the receiver test noise);

Master volume at -30dB = 14 Watts
at -20dB = 32 Watts
at -15dB = 69 Watts
at -10dB = 121 Watts

These were the peak readings I observed while I replayed the same segment of audio (Track 14. Within You Without You). I also performed this test using only 1 of my 2 EP500s that I re-calibrated to 75dB before the measurements.

Having the volume at -10dB for music gets pretty loud but I know the EP500 could handle a lot more. Movies have LFE peaks that are probably 10 dB higher than this music mix.

So my next experiment was to try playing some loud LFE segments of a couple movies. But even with my reciever volume all the way up at 0dB, I really couldn't top the above numbers from the Beatles music test. The music readings seemed to be more consistant too. Overall, these wattage numbers were lower than I was expecting.

I am guessing this is because this device only updates its reading every 1 or 2 seconds, and the subs transient power peak may be too quick for me to really see. This device does great with a more steady draw. But it was a fun experiment none-the-less.