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<blockquote data-quote="Brian jojade" data-source="post: 141251" data-attributes="member: 211">Re: Calculating Consumption in Watts, Total System Draw1/8 rated power is generally a good rough estimate of what your average power draw may look like. However, that doesn&#039;t take into account the peaks that can happen, which will draw significantly more.&nbsp; My new QSC amps have power meters built into them. Under most scenarios, they are drawing 2-3 amps. But it doesn&#039;t take much more and suddenly that jumps up to 12 amps. It&#039;s a pretty significant difference if you&#039;re looking at maximum possible current draw.If you are looking at the current draw to determine how big of a circuit you should use, you are safer estimating 1/3 power instead. That gives you enough headroom in the event that things get a little louder than normal. It&#039;s also important if the cabling creates a voltage drop at the outlet.&nbsp; Switching supplies can keep going when voltage drops, but they draw more current to compensate. If your draw is right on the edge, that 50&#039; of extra extension cord could be enough to push you over the edge. With the rig you have listed, I&#039;d want 2 separate 20 amp circuits to run everything safely.Of interesting note, the spec sheets for the DSR&#039;s say that current draw is 100w at 1/8 power, yet they list the power rating of the speaker at 1300W continuous.&nbsp; That math just doesn&#039;t work out. An amplifier can&#039;t produce more watts that it consumes. (it&#039;s actually joules of energy, and their calculations assume dynamic content so the amp capacitors can draw an average amount of power to build up their reserves to be used during peaks.) Anyway, if you put a continuous output at 1/8 power that drains the reserves, the amp would have to pull from the outlet to compensate for what it needs.&nbsp; This is extremely important to take into consideration when running from a generator.&nbsp; When plugged into the grid, there is more power available at the outlet for brief spikes than the breaker is rated at. The breaker will only trip when the average power exceeds the rated threshold for a period long enough to heat the breaker.&nbsp; Eg, if you have a kick drum hit that clips the amp, the amp could draw power for a brief moment and not trip the breaker.&nbsp; With a generator, that reserve does not exist. Total output power pretty much caps at the rated power, and thus those reserves are non existent.&nbsp; When sizing a generator, I recommend using the FULL rated power of your amplifiers so that you have plenty available.&nbsp; You may not need that much if you don&#039;t turn your amps to full, but on the same token, if you aren&#039;t turning your amps up to full, you could have gotten away with smaller amps too.</blockquote>

[QUOTE="Brian jojade, post: 141251, member: 211"] Re: Calculating Consumption in Watts, Total System Draw 1/8 rated power is generally a good rough estimate of what your average power draw may look like. However, that doesn't take into account the peaks that can happen, which will draw significantly more. My new QSC amps have power meters built into them. Under most scenarios, they are drawing 2-3 amps. But it doesn't take much more and suddenly that jumps up to 12 amps. It's a pretty significant difference if you're looking at maximum possible current draw. If you are looking at the current draw to determine how big of a circuit you should use, you are safer estimating 1/3 power instead. That gives you enough headroom in the event that things get a little louder than normal. It's also important if the cabling creates a voltage drop at the outlet. Switching supplies can keep going when voltage drops, but they draw more current to compensate. If your draw is right on the edge, that 50' of extra extension cord could be enough to push you over the edge. With the rig you have listed, I'd want 2 separate 20 amp circuits to run everything safely. Of interesting note, the spec sheets for the DSR's say that current draw is 100w at 1/8 power, yet they list the power rating of the speaker at 1300W continuous. That math just doesn't work out. An amplifier can't produce more watts that it consumes. (it's actually joules of energy, and their calculations assume dynamic content so the amp capacitors can draw an average amount of power to build up their reserves to be used during peaks.) Anyway, if you put a continuous output at 1/8 power that drains the reserves, the amp would have to pull from the outlet to compensate for what it needs. This is extremely important to take into consideration when running from a generator. When plugged into the grid, there is more power available at the outlet for brief spikes than the breaker is rated at. The breaker will only trip when the average power exceeds the rated threshold for a period long enough to heat the breaker. Eg, if you have a kick drum hit that clips the amp, the amp could draw power for a brief moment and not trip the breaker. With a generator, that reserve does not exist. Total output power pretty much caps at the rated power, and thus those reserves are non existent. When sizing a generator, I recommend using the FULL rated power of your amplifiers so that you have plenty available. You may not need that much if you don't turn your amps to full, but on the same token, if you aren't turning your amps up to full, you could have gotten away with smaller amps too. [/QUOTE]

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