What does more power do for Magnepans?

i listen to orcehstral as well as small ensembles. i just don't listen loud and low power amps seem to work for me.

I tried to go back and study some of the math about maggies and power. These were pointed out by others; I am just trying to pass on their work and analysis correctly.

First thing I ran across was the way Magnepan spec's the efficiency. 86db/1m/2.83V. Evidently 2.83V into 4ohms is 2 watts and not the traditional ~db/1m/1w scale. At 1m/2w efficiency works out to 83db.

If you listen to music at a level that produces 83db peaks (fairly restrained, but still dynamic) and sit 3 meters away it flows like this.

2w/1m = 83db with one speaker
Second speaker adds 3db for 2w/1m = 86db
Subtract 3db for each additional meter away from the speakers 2w/3m = 80db
Each additional 3db doubles power required - to add 3db – 4w/3m = 83db
Figure the peaks @ 83db are 6db above the average spl = 1w/3m/76db

This ignores room loading, absorption, and the fact that the 2w/1m/83db is with a test tone, but on the surface, the amount of power needed doesn’t seem that great for modest listening levels.

If you listen at a level that produces 95db peaks it would go something like this…

2w/1m = 83db with one speaker
Second speaker adds 3db for 2w/1m = 86db
Subtract 3db for each additional meter away from the speakers 2w/3m = 80db
Double power for each additional 3db;
4w/3m = 83db,
8w/3m = 86db,
16w/3m = 89db,
32w/3m = 92db,
64w/3m = 95db

64w. Still not a lot of power for what, to me, is a fairly loud 95db peak.

It doesn’t match my (admittedly limited) experience, so I am fairly assured that I have stated something incorrectly or there is another important factor that is missing.

You won’t hurt my feelings by pointing out the flaws in the above but I do find the result interesting if it holds true

Jim S.

One thing wrong with your calculation. One subtracts 3db for every doubling of the distance, therefore 2m=-3db, then 4m=-6db, not 3m=-6db. 3m would be close to -5db, I suspect.

Bob P.

The biggest problem with that calculation is that to obtain a subjective doubling of loudness requires ten times the amplifier power. See: (http://www.gcaudio.com/resources/howtos/voltageloudness.html)

Thanks Bob,

A fundemental misunderstanding on my part. Does change the result, doesn't it!

Jim S.