What does more power do for Magnepans?

Germanboxers...As you say, 96 dB is too loud for listening. I was running a test.

Being a retired engineer, I have made a bunch of measurements, including looking for compression. I saw no compression up to a SPL where I would fear for the safety of the speaker. The only time I have had maggies "bottom out" was with non-musical LF thumps, such as might occur due to a wiring defect. Using a subwoofer to get the high excursion LF signal out of the maggie helps a lot.

I would very much like to try a big Atma-Sphere amp, but my lottery tickets always have the wrong number on them.

Eldartford,

Thanks and I do remember your thread now that you brought it up. I've read so many maggie threads it becomes a blurr. I am slowly learning how to figure this stuff out myself. (Mostly by putting my foot in my mouth).

Quick question if you have time. How do you measure voltage across speaker terminals? Voltmeter in series with either pos. or neg. side? Can you do this with a cheap RS multi-meter and get an "accurate" measurement?

Jim S.

Stilljd...Even a "cheap" multimeter is plenty accurate enough. (An oscilloscope. if you had one would be the best because you could see the peak voltage directly). My RS meter is digital, and displays a new measurement about once per second. As the music volume varies you monitor the reading and take the highest one as the short term (1 second) rms value.From the rms value you can estimate what the peak would be. The meter is connected directly across the speaker terminals, at the amp or at the speakers. Not in series. That would be for a current measurement, but don't try that with a voltmeter.

You will be happy to see how little power is applied most of the time at moderate volume, but the increase during loud passages played loudly is surprising.

Thanks Eldartford.

Jim S.

Just to follow up. I got to sit down with a RS multi-meter, SPL meter, and check voltages at the speakers for different levels and kinds of music. Because the 1.6's are setup "active" (acoustic crossover is around 700 hz) I was able to easily measure the input into the high frequency and low frequency sections.

Playing tracks of Allison Krauss (acoustic ensemble) and Dandy Warhols (bass heavy psychedelic) with fairly narrow dynamic ranges at levels I occasionally listen at… 93-95db peaks measured @ 11 feet (observed) produced these peak voltage readings (observed);

A. Krauss track
HF ~ 1.8 – 1.9 V
LF ~ 3.9 – 4.1 V

D. Warhols track
HF ~ 1.8 – 1.9 V
LF ~ 4.2 – 4.3 V

In my limited understanding, these readings should be higher by a factor of 10, but I probably have a setting wrong on the multi-meter.

What struck me was the power consumed by the low frequency section of the 1.6’s. Twice the power was needed in the mid/bass panel over the QR section in both cases. This leads me to two observations.

I need to change from the current horizontal biamp to a vertical biamp. Both amps are the same Arcam Alpha 10’s and their transformers would probably benefit from sharing low frequency duties.

I might be able to use more, or cleaner, power to the speakers. 43V observed peak / .707 = 60V theoretical peak. 60V/4ohms = 15 amps. 15A x 60V = 900watts!!!!!! In one channel! The Arcams are 170W@4Ohms. Active is supposedly 4X, so it works out to about 680 watts. Not to mention we are on a 15 amp circuit.

Not the end of the discussion by any means. But interesting.

Jim S.