@ditusa , one would expect that some advancements have been made in the last --- 60 --- years. @atmasphere , I would think that the frequency effects of compression would be more worrying than a change in maximum output? Perhaps this is another case for active speakers. |
I would expect though, @atmasphere, that powerful less efficiency speakers have considerably more thermal mass at least, so more thermal transient immunity. I have no feel for their relative ability to dissipate heat though. Certainly they have come a long way. Trying to visualize some of the more advance companies, i.e. Magico, I would expect some reduced sensitivity to power compression from the design of their motor structure and the reduction of inductance effectively taking out a circuit element. I have only given it, now, about 10 minutes thought though :-) .... Is there a hardcore technical speaker designer in the house? |
So now you are poking holes in those that proselytize first order cross-overs for better time alignment :-) In many ways speakers are much more interesting that the other parts of an audio system, but so much less time seems to be spent discussing them beyond the cursory. Aesthetically or for practical reasons, efficient speakers, which I assume are normally large, may not be practical. I did mean more immune. Thank you for the correction. |
Thank you for the post. Very interesting. This is something that was in the back of my head to look at for a while but never took the time. To me it makes all these discussions, not to mention the concept of 4, 5, 6 figure speaker cables rather foolish. Given the electromechanical nature of the drivers, it could be difficult to measure the electrical resistance of the driver(s) in circuit during operation. Perhaps as an academic exercise you could limit the frequency of the incoming signal to say 50 or 60 Hz, and then use a small DC stimulus to measure the DC resistance. You would be severely response limited, perhaps 100 millisecond rise time. I expect someone has given this a lot of thought and has a better method. Also interesting about the speaker becoming a different speaker at different driver levels. There was an interesting post on ASR recently where a person was "fixing" a commercial speaker. He did response and impedance measurements at multiple drive levels. There were some significant differences, though less after his changes. You are convincing me more and more that active is the way to go long term. |
@audiokinesis , I was more thinking smart people, i.e. like what I see with Kii, as a start, will figure out some way to compensate for these effects in real time. From a simpler aspect, would not an active cross-over system be more immune to the effects of variable voice coil resistance on speaker response including critical crossover points? |
I know many here hate ASR, but it would be good to collectively push them to do more frequency response measurements at varied power levels, and perhaps at different frequency sweep speeds to induce this issue. I personally don't see Stereophile doing that and I definitely don't see suppliers going out of there way to highlight problems. |
@johnk , I see no physical mechanism by which a horn speaker would throw better than a dynamic speaker. The impedance matching improves efficiency, but it is still effectively a point source so it must follow the inverse square law. Only a line array and the equivalent electrostatic or planar speaker would have improved throw. The room response would be different though. @audiokinesis can you comment on room response of line arrays?
@atmasphere @audiokinesis , I expect that electrostatic speakers and large planar speakers must be fairly immune to these power compression / thermal modulation effects within limits? By virtue of the large number drivers and small amount of power per driver, line arrays must be pretty immune as well.
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