Why exactly mass? Do you mean uncontrolled impedance peak which translates into SPL peak at the mechanical resonance? If yes, I probably didn't elaborate my thought reasonably well. Mechanical peak should be managed in other meaning anyway, for example, using motional feedback or just with throwing it away from intended operating range of the woofer, what is rarely possible. Tube amplifiers cannot control it very well so resulting woofer's SPL is in fact a mix between voltage-controlled SPL and impedance curve and it creates mild EQ-ing for mediocre (in terms of inductance and motor linearity control) fullrange drivers - users usually report great listening experience using fullranges in conjunction with tube amps which is result of lack of appropriate perfect-voltage-source damping and impedance control. SPL rises between mechanical resonance in the upper bass and highest frequencies, natural 'contour' effect occurs and sound becomes better than with transistor amplifiers with low output impedance.
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What parameter is responsible for bass control then? Why does the bass sound tighter with some amps than with other amps?
For example, NC*** amps sound tighter than ucd*** amps. Is it because of 10x lower impedance of NC series or because of something else.
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L-pad or series resistor affects circuit impedance not device(load) impedance.
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Becouse loudspeakers are perfectly happy being current-driven, when impedance peak is properly managed it becomes non-issue. Unfortunately, these techniques are very rare among DIY'ers and hardly even manufacturers would like to handle that, becouse of struggles of applying motional feedback over entire playback system. Motional feedback, as any kind of loop control, is essential in order to manage end-point response linearity (mechanical resonance and BL nonlinearity control - speaking in audio language) issues. It is big obstacle in in-depth understanding proper sound reproduction using non-perfect loudspeaker drivers. I know that I've just entered uneven ground for many, sorry for that.
Can you enlighten us by naming some well-known manufacturers that have successful products based in motional feedback (not involving special motion sensors on the drivers)?
You didn't. So for those of us who don't have those special drivers, what's wrong with using the voice coil and amplifier to control the driver?
Nothing, we're doing it like that for decades and we are happy. I am using voltage drive, too, becouse of its simplicity. It is just simplicity which is paid with not having 100% available performance out of the technology and wisdom in our disposal novadays. That is why I will still be convinced that we are blocking ourselves from innovations sticking with usual technical habits.
Mr. Erath's circuit used the current to the woofer for feedback and circuit control. But it didn't work with ribbon tweeters and the such. Only drivers with voice coils.
This all started from you claiming "And the myth that damping factor has any positive effect on sound quality should fall like old walls"...
I know that. Thinking about damping factor in terms of its necessity in providing better sound quality is that mind blocking thing.
L-pad and series resistor between the amp and driver results in higher Qes because part of the output current dissipated as heat and not to drive the speaker. And yes, the driver becomes "slower" because it starts to ring more around Fs.
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Yes, I know your way of arguing by now, but thanks for the link anyway.
You start with an open (but clearly condescending) question ("why would that be", "so you think", etc.), and then go round and round with any argument you can pull out, with short answers, attacking and mocking all along.
And here your final argument is that it is a "generalized claims not based on reality" to say than an amplifier has low distortion because at some point it will reach 100% distortion.
Big news: that is true for any amp on any load (including ncores), be it voltage limited or current limited (in the case of current limitation it might just enter protection mode, or simply burn, which are different forms of 100% distortion...).
My advice to you: if you don't agree with something/someone then say it clearly, not with a mischievous/oriented question but with opinions/facts.
You can also choose to let people express opinions that are different than yours, or even learn something (one can dream).
You start with an open (but clearly condescending) question ("why would that be", "so you think", etc.), and then go round and round with any argument you can pull out, with short answers, attacking and mocking all along.
And here your final argument is that it is a "generalized claims not based on reality" to say than an amplifier has low distortion because at some point it will reach 100% distortion.
Big news: that is true for any amp on any load (including ncores), be it voltage limited or current limited (in the case of current limitation it might just enter protection mode, or simply burn, which are different forms of 100% distortion...).
My advice to you: if you don't agree with something/someone then say it clearly, not with a mischievous/oriented question but with opinions/facts.
You can also choose to let people express opinions that are different than yours, or even learn something (one can dream).
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Thank you for the advice. In return, here is my advice to you - try to avoid (incorrect) broad generalisations like "Distortion always goes down with impedance".
I guess you didn't learn anything from the link I provided. Oh well... Ad hominems are just too convenient for people who run out of rational arguments.