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Maybe someone can clear this up for me. I was bored this afternoon so I decided to figure out exactly how much power im using on my 15 amp power circuit in my living room.

I came to the conclusion that my Home Theater without the sub uses 829 Watts or 6.9 Amps. I then did the math with the subwoofer added in. Using the 675 Watt or 5.6 amp power consumption spec for the EP500 sub. I came up with a total of 12.5 amps.

Now, with that said, there is also a ceiling fan and lights on this circuit. With that added in, the total is 17amps!

Can someone please explain how I am using 17amps of power on a 15amp circuit???

My house was built less then a year ago so all the electrical wiring was done under heavy codes I assume. Can someone help me shed some light on this. Even if I was mistaken and it was a 20amp circuit (which it isnt) I would still be comming very close to the 80% load on the circuit.

Thanks for the help.

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.

So, uh, how do we arc weld with our amps? I kind of like multi function products...

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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.

ah, ok that makes sense. thanks

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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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.

yes, i was using the power rating on the back of all my gear, DVR, TV, DVD player, and so on. i didnt realize those numbers are for MAX use. i thought it was just a number that the product required.

i knew you guys would clear it up for me.

thanks again

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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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.

Ok got ya. Thanks.

2 more questions.

1. Is it correct to assume that it dosent matter if everything is plugged into 1 outlet or if everything is spread across the whole circuit. Aslong as the load isnt greater then 15amps it dosent matter. Is my thinking correct or no?

2. On the Outlaw sub that I have ordered. Its specs are as follows:

150WRMS/800W Peak

Power Outlet Requirement 300Watts

Can someone explain to me what "RMS" is and what exactly the peak spec means. Also, the power outlet requirement is 300watts yet the sub has a peak level of 800watts. Dosent this mean that at some point the sub may require 800watts? If so why would its requirement only be set at 300watts in the spec?

thanks

rms = root mean squared, that is the number you want to go buy, in an ac signal, you can do some math and determin how much real power is being provied all the time, vice peak power, which is usualy double rms power, that is the difference between 1 wave and the next, the maximum difference in potential, a lot of car amp companies will rate their products with peak power, to get larger numbers, when the rms number is what you really care about.

hope this explains it, if anyone can add anything feel free.

link

http://en.wikipedia.org/wiki/Root-mean-square

I have my whole HT including TV, sub, 3 channel amp and 3 monoblocks on my powercenter and only pull 6 amps when the system is cranked.

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.

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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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.

thanks alan

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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.

from what i was told, the ep500 uses about as much energy as an alarm clock when not in use.

dllewel:

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

Regards,

And here I was worried what would happen if I forgot to turn it off at any given moment.

In other words what all of you are saying is that the sub will go dormant after the signal stops and will only consume the power of a night light...so I need not worry about losing my sub to non usage.

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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,

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.