This isn't just about amps though, an efficient speaker will need to dissipate less heat through the voice coil.
This would apply to Class AB amps that are not especially good. One can always go and find a good example of a class AB amp, or with high efficiency speakers, class A becomes feasible.
@AllenB
In a domestic setting , heat thru VC is an non -issue, every amplifier i have looked at make more distortion at or below 1 watt , most amplifiers are at their best when ran at 33% of rated output, most if not all class A/AB amps are operating in class-A below 1 watt.
If you were to look at Pano's domestic setting speaker voltage test, you wil lsee most are using less than 5 volts.. VC heat induced distortion is an non -issue IMO...
In a domestic setting , heat thru VC is an non -issue, every amplifier i have looked at make more distortion at or below 1 watt , most amplifiers are at their best when ran at 33% of rated output, most if not all class A/AB amps are operating in class-A below 1 watt.
If you were to look at Pano's domestic setting speaker voltage test, you wil lsee most are using less than 5 volts.. VC heat induced distortion is an non -issue IMO...
Yup. Agree with Allen.
What does high efficiency really mean? We look at 100db/W and think, wow that thing can play loud.
But high efficiency also means the speaker is more sensitive to low level variations in signal. This means it can retrieve more detail, pull out more nuances, and in the end, sound more like real music. Of course, all this assumes a well designed speaker. High-eff doesn't guarantee good sound.
Now, there are examples of low-eff speakers that manage to sound good also. Not that it can't be done. Just that a high efficiency system is logical, in terms of amplifier design also, even though that may not be what the market wants you to think.
What does high efficiency really mean? We look at 100db/W and think, wow that thing can play loud.
But high efficiency also means the speaker is more sensitive to low level variations in signal. This means it can retrieve more detail, pull out more nuances, and in the end, sound more like real music. Of course, all this assumes a well designed speaker. High-eff doesn't guarantee good sound.
Now, there are examples of low-eff speakers that manage to sound good also. Not that it can't be done. Just that a high efficiency system is logical, in terms of amplifier design also, even though that may not be what the market wants you to think.
I beg to differ.
All voice coils change temperature no matter how low the voltage is. It turns out that smaller voice coils tend to need more current for a given SPL and they have less copper (the thermal mass) so they tend to change temperature more. A large coil in an efficienct speaker will need less current and it has more copper so its temperature change is far far less than the lessor efficient one. And this difference will remain constant with output, i.e. the change differential is linear with output. This means that there will be very large resitance variations in a less efficient loudspeaker when compared to the more efficient at any and all voltage levels.
Is this audible? I am not sure, I plan to test this in the next year. But it is interesting to note that the difference in temperature and hence resistance changes between a less efficient loudspeaker and the more efficient one can be 30:1 to more than 50:1 and even higher when one compares a typical 1" direct radiating tweeter to a compression driver. It is not hard to believe that what might be inaudible in one could certainly be audible in the other.
Perhaps this is what we call "dynamics" without really knowing what "dynamics" is.
I don't have this problem myself, and if yours is noticeable...?
Crossover distortion can be an ugly beast. It doesn't go away with level and if you can hear it less it's only because the music is beginning to drown it out. In cases where the first watt may be the best sounding, the second may be the worst?
Is there quantifiable proof of this? Sounds like a wives tale. If anything, those low level details would be lost in the electronics' noise floor with a HE speaker because the electronics are operating at very low levels. Those same details would be higher above the noise floor with a less sensitive speaker, because the average level is higher.
Dr Geddes's point on thermal modulation is valid, although I'm not sure it means much at TWEETER frequencies. Some guys in Wisconson at AVS Forum had a get together with very high SPLs, and among the speakers, two very sensitive compression driver designs were considered equally dynamic to an ~84db ribbon speaker (although the latter caused the amplifier to clip), while some ~90db speakers were considered second tier.
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Hello Dr Geddes,
Interesting to see your results , as I have tried in the past to measure this and was not successful , there was no deviation in FR after running sweeps at 1,5,10, 25 watts nor in the impedance phase and magnitude.
I have to say it does appear the pro high efficiency crowd Tend to use VC induced distortion as a kind of strawman argument, as test after test on speakers used in a domestic setting has shown this not to be the case.
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Why should it be any less. For what it's worth, I find the greater improvement in 'dynamics' moving up from a 1" dome tweeter.
Well, something is causing the improvement. Do you have one of those tests we could have a read of?
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