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Posted By: LRA watts - 03/23/09 03:00 AM

is there any way to calculate the number of watts currently 'in use' by the receiver. Having 200w capable speakers (m22ti), is it possible to find out how much power they are using at a specific volume level on the amp (like -10db)?

I'm wondering how to figure if my AVR has breathing room, regarding power output.

is rated 130w at 1khz and 110w/ch for 20-20khz
Posted By: SirQuack Re: watts - 03/23/09 03:17 AM
I suppose hooking up a multimeter to the speaker jacks on the back of your receiver, and monitoring the volts, then converting that to watts would work, if you want to take all that time.

Or you could probably estimate by using a Radio Shack SPL meter from 1meter away from a speaker. The problem is that music fluctuates and is so dynamic, it would not be 100% accurate.

The m22's give you 93dB (very loud) only using 1 watt at 1 meter. So monitoring dB from 1 meter away, you could estimate how many watts your using.

1 watt = 93dB
2 watts = 96dB
4 watts = 99dB
8 watts = 102dB
16 watts = 105dB
32 watts = 108dB
64 watts = 111dB
128 watts = 114dB

you get the picture, do you see why your receiver is adequate and you most likely don't need an amp. \:\)
Posted By: JohnK Re: watts - 03/23/09 03:20 AM
Luc, the volume setting on the receiver isn't really determinative of the power being used for particular material. If you have an SPL meter you can get a reasonably accurate picture of how many watts are being used at a particular instant. At a typical 9-10' listening distance in a typical room, M22s(mine and yours)will be using about 1 watt for a comfortably loud listening level of 85dB. If the meter showed a louder peak of 95dB occurred, that used 10 watts. If a much louder peak hit 105dB(about the maximum that should be even briefly used if hearing damage is to be avoided), that again used 10 times as many watts, i.e., 100. Depending on what the actual maximum capability of your receiver is(likely slightly higher than the rated number), it should be clean up to around 106-107dB. Note that even if the receiver output is clean at those levels that there may be some distortion heard from the speakers.
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