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. |
@lonemountain wrote: "my point about dynamic range was "system dynamics" not one system vs another. The 86dB efficiency speaker on a 250W amp has more total dynamics to cover incoming source material of a wider dynamic content than the 102dB/20w amp system. " In your example upthread, the 86 dB/250 watt system has a maximum SPL of 110 dB, while the 102 dB/20 watt system has a maximum SPL of 114 dB (actually the math says 115 dB). How is 110 dB max SPL "more total dynamics" than 114 dB max SPL? The only way I can see that happening is IF the system noise floor is at least 5 dB lower for the 86 dB/250 watt system, and that’s not something you have included in your example. (Dynamic range does not start where the amp is producing 1 watt; dynamic range starts at the system noise floor. I mention this because, upon re-reading, one of your posts above seems to make that assumption.) And here’s another real-world effect which may come into play: If the 20 watt amp is a tube amp (which is likely), and if the 250 watt amp is a solid state amp (also likely), clipping will become audible and objectionable about 3 dB sooner on the 250 watt solid-state amp than on the 20 watt tube amp. In other words, you can push the AVERAGE SPL 3 dB higher on the tube amp than on the solid state amp before clipping becomes audible and objectionable. So instead of the 102 dB/20 watt system having 4 (or more precisely 5) dB more dynamic range from the raw math, real-world that difference may be more like 7 (or 8) dB. Duke |
@deludedaudiophile wrote: "You are convincing me more and more that active is the way to go long term." Going active will have no direct impact on driver compression effects, but if you are "rolling your own", going active may make it easier for you to use drivers which have inherently low compression characteristics. Duke |
