Why do Maggies need a lot of power?

Due to the dynamic nature of music, recorded peaks above the average power level required may climb past 10 dB's. In terms of amplifier power, 10 dB's is equivalent to 10 times the amount of power. As such, your calculations ( which i did not verify ) would mean that you would need AT LEAST 640 wpc in order to sustain said listening level and not have the amp go into compression i.e. clipping off the peaks.

Another variable is that sound does not travel uniformly through the air. Depending on the type of driver used ( horn, planar, etc.. ), the physical array ( front firing, dipole, bipole, line array, etc.. ), size of room and your listening distance, SPL's will vary accordingly. If you also factor in that most drivers DO go into compression when being pushed, you might be able to see that any "formula" for SPL's is "generic" unless you have a LOT of specific info about the installation.

If you look at the design of a Maggie ( or any other panel type speaker ), it is obvious that they can't produce a lot of driver "throw" or "excursion". Since it takes large excursions to move a lot of air ( both required for volume and / or low frequencies ), this type of design is limited in several aspects. Once you hit a given drive level, the power is converted more efficiently into heat than it is sound. As such, many engineers try to work within the "efficiency window" with these types of designs and limit low frequency response by using a dynamic driver for the bass and / or increasing the radiating surface area of the panel. Trying to get deep bass, high spl's and minimize compression / distortion is a very tough juggling act to do. That is why all but the largest speakers using a LOT of drivers are the only ones that can do it and do it well. Sean
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I think that a lot of what people mean by speakers "opening up" when being fed by a measurably bigger amp is actually related to the lack of dynamic compression that the bigger amp doesn't have to deal with. Not only does the sound improve in terms of spl capacity, it sounds far more liquid, natural and suffers from far less grain and grit. Loud actually becomes LOUD, yet it does not sound as loud because the amp is not "straining" ( rhymes with "graining" ). You can listen louder AND suffer less fatigue.

This is also one of the reasons that active multi-amping can sound so much better i.e. the strain has been taken off of one amp and divided amongst two, three, four, etc.... The system picks up more dynamic headroom and each amp benefits from less strain and a smaller amount of reactance to deal with in a limited bandwidth. Sean
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Ake: I think that there is a VAST discrepancy amongst what many of us here call "average" listening levels. What is "average" to a "rocker" might be "roaring" to a person that listens to chamber music, etc.. On top of that, listening distance, size of the room, types of speakers used, etc... will all vary this equation.

From my personal experience with Maggies, i would suggest using a tube amp that was capable of at least 100 wpc rms or a SS power amp that was at least 200 wpc rms @ 8 ohms. This "should" equate to at least 300 wpc and preferably closer to 400 wpc @ 4 ohms for the SS amp. "Tube watts" tend to come across as being more powerful due to the more "natural" way that they clip i.e. they do not sound near as stressed or grainy when being driven hard. Quite honestly, i don't think that you can have TOO much power with speakers of this nature.

This brings up another dilemma though as many higher powered SS amps do not sound as good as some smaller models do. Much of this can be negated by looking for a manufacturer that uses high quality parts and gain matches all of the output devices. Such designs tend to be of high bias ( Class A or very rich Class AB ) and should deliver excellent sound even at lower volumes. Obviously, these will probably cost a little more, but then again, nobody said this hobby was cheap : ) Sean
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