[josh358]

These speaker impedance swings are really only of interest when power amplifier output impedance becomes significant.

Why I'm not wild about high output impedance amps. It seems to me a very chancy and inconvenient way to trim amplitude response. If the speaker is well design, your chance of making it sound worse is a lot higher than your chance of making it sound better.

There is, of course, the dynamic current capability of the amplifier......but that is another subject.

Since the specs on consumer amps are usually sketchy, as a matter of practicality, I find you can just match the 4 ohm RMS power of the amp to measured peaks. With most reasonably good solid state amps, the dynamic headroom will then be just about right to account for vagaries in level setting and acoustics. You can generally just go with the 1 meter spec as well, with line source dipoles at normal listening distances the falloff is just about matched by room gain.

[josh358]

115db is ear splitting and will cause you to go deaf....

I concur with Scotty on this one....

One disadvantage of tubes is that no matter how you hook them up, they will only be the rate wattage, i.e., will be the same wattage at 4ohm as they are at 8...

Jim

Those 115 dB levels are instantaneous peaks, not average levels. Not earsplitting on acoustical instruments, which have a 10-20 dB peak/average ratio. 115 dB would definitely be earsplitting and harmful on compressed pop.

In fact, while it gets you into the plausibly realistic range, and will handle the typical symphony, the peak levels of acoustical music can be higher than 115 dB. The best paper I've see on this is this one, see Fig. 2:

http://www.zainea.com/Dynamic%20range.htm

They measured peaks of up to 127 dB on acoustical jazz, 122 dB on "percussive classical," whatever that is.

[*Scotty*]

I agree Josh, actually a 115dB peak with average levels in the 70s wouldn't sound loud at all, that kind of instantaneous peak SPL is frequently encountered when listening to live symphonic music, cymbal crashes come to mind. If the recording is any good you could get lucky and have a 10 to 1 crest factor. The excellent recording of Tchaikovsky and Prokofiev's Romeo and Juliet pieces that Russell recorded in Kiev with the Ukrainian Radio and Television Symphony Orchestra is a great example of this, lots of dynamic range, but they don't sound very loud due to the low average sound pressure level.
Scotty

[medium jim]

I agree Josh, actually a 115dB peak with average levels in the 70s wouldn't sound loud at all, that kind of instantaneous peak SPL is frequently encountered when listening to live symphonic music, cymbal crashes come to mind. If the recording is any good you could get lucky and have a 10 to 1 crest factor. The excellent recording of Tchaikovsky and Prokofiev's Romeo and Juliet pieces that Russell recorded in Kiev with the Ukrainian Radio and Television Symphony Orchestra is a great example of this, lots of dynamic range, but they don't sound very loud due to the low average sound pressure level.
Scotty

All good, I listen to classical more often these days and I have a couple different recordings of the New World Symphony by Dvorak that has some peaks, as well as some others, but I doubt they peak more than 10db. 

On my trusty digital spl meter, it is capable of measuring max peaks and the most I have seen is 111 with the average spl in the upper 90's...this was while listening to Atom Heart Mother by Pink Floyd.  I'm sure that I had a moment of soft clipping, but not unmusical to the point of annoyance or want to go out and shop for more tube wattage.

Jim

[bdp24]

Has anyone heard a Maggie (particularly from the 1 series) with the PS Audio 200 series power amp?

[Freo-1]

Something with scads of power.  Any of the new class D offerings from some of the sponsors here, or D-Sonic, Wyred for Sound, etc. will work quite nicely, and won't break the bank. 

I'm not sure there is such a thing as too much power when it comes to driving Maggies.

[k6davis]

I've had great success driving my 1.7's with the Class D Audio SDS 470C, which I discovered right here on AudioCircle.

It's an unusually modestly priced amp. I was impressed by the very favorable reviews here and the fact that it delivers 300 watts into 8 ohms and doubles that to 600 watts info 4 ohms. I find the sound to be extraordinary... smooth, very transparent, detailed without being edgy and the Maggie's love all the power and current it produces. Plus, as with most Class D designs, it's relatively small & light, highly efficient and it runs cool.

I can't speak to about how it compares to other (far more expensive) amps, but I am thoroughly pleased with it. I imagine myself sticking with it as I upgrade most of the rest of my system over time.

http://classdaudio.com/audio-amplifiers/sds-470c-custom-class-d-amplifier.html