New ceramic drivers from SB Acoustics

Likely just an deeply oxidized surface of the aluminum. Al2O3 is what makes it 'ceramic'; it's the oxidation on the surface, making it a ceramic sandwich cone.

Later,
Wolf

As long as the quality of the Al2O3 is well formed via hard/deep anodizing, then it will still increase the modulus of elasticity a good amount, with its attendant attractions and detractions.
 
Speakers are driven by voltage amps which don't care about the load (except when max power is considered). So maybe it is best to just work with 2.8 volts as the standard.

If you are concerned about max loudness with a given driver with a specific 2.8/meter spec, that is an amp question.

B.
 
No, speakers should be tested with:
2.83V/1m, for SPL sensitivity;
fixed 90 dB/1m SPL (and 95 dB, 100, 105...), for distortion.

"Sensitivity" doesn't seem like the right word.

It's really efficiency, sort of, because you are declaring that one watt of electric input results in a certain wattage (power) of output. Granted that's the opposite of what I previously argued.

Of course, if expressed in percent instead of dB, it would be a horrible sounding figure like .1%.

Or maybe "decipercentage"!

B.
 
"Sensitivity" is exactly the right word, according to International Electrotechnical Commission standard IEC 60268-5:2003, where "sensitivity" is defined as measured SPL with input power of 1 W at a distance of 1 m on the reference axis (that is, 2.83 V signal for 8-ohm rated loudspeaker).
Nothing is horrible with 0.1% efficiency for a loudspeaker, except maybe to some hard-core green ecologists. Anyway, I prefer pro drivers (about 1.5% to 3.5% efficiency) for my hi-fi loudspeaker projects.
 
Speakers should be tested with same watts, not same voltage because distortion will be much higher with higher watts.

I agree that it would have been more fair to do the comparisons in regard to the same power input in reference to Re. The same voltage measurements might work more in favor of 4 ohm units sensitivity wise and less distortion wise. People tend to stick to simpler methods of comparing performance specs. Hardly anyone cares to explain things to customers for the more they do that, the less likely the sale will happen.

Sorry for the OT, I remember a fuel consumption test once done in Top Gear (British) where a couple of higher end sports cars by Ferrari, Lamborghini, Audi...etc were filled with a small amount of fuel and driven on a test course to the extreme and after a couple of miles each car would have stopped. The consumption for a Ferrari has been about 120 litres/100 km and Audi came with the lowest 80 litres/100 km, calculated. The others were somewhere in the middle.
 
The consumption for a Ferrari has been about 120 litres/100 km and Audi came with the lowest 80 litres/100 km, calculated. The others were somewhere in the middle.

The Lamborghini Gallardo is announced at 17 L/100 km (and some users are perhaps affirming to consume a lot less).
https://fr.wikipedia.org/wiki/Lamborghini_Gallardo

What is it with all the drivers in the series exhibiting the big trough at or around Fs?
one would think that at those frequencies, a driver would be in its pistonic range, and the freq response to be relatively straight...

This measurement artefact seems to affect all their datasheets.
 
... spec sheet says sensitivity is 87.5 db/2.83V/1m
But looking at the curve, we can see it reaching 87.5db@31.6cm.... What gives?

What is it with all the drivers in the series exhibiting the big trough at or around Fs?
one would think that at those frequencies, a driver would be in its pistonic range, and the freq response to be relatively straight...

Because measurements are done with IEC baffle at close distance of 31.6 cm (and than scaled to 2.83V/1m).