Thanks to all for much useful information. I have one last theory to verify. I am quoting a post from a different forum on the topic that seems plausible but that is up for your verification:
"the real clue in how quick a driver sounds is its voltage sensitivity. This is largely determined by three things.
Motor force product (BL) * Radiating area (Sd) / Moving mass (mms) = Gamma
The 8" Scan-speak I referred to earlier has a Gamma value of 60 and a voltage sensitivity of 86dB/2.83V
The 15" ATC SB75-375SC has a Gamma value of 127 and a voltage sensitivity of 91dB/2.83V
The 31" Fostex FW800HS has a Gamma value of 198 and a voltage sensitivity of 96dB/2.83V
"
Herman
"the real clue in how quick a driver sounds is its voltage sensitivity. This is largely determined by three things.
Motor force product (BL) * Radiating area (Sd) / Moving mass (mms) = Gamma
The 8" Scan-speak I referred to earlier has a Gamma value of 60 and a voltage sensitivity of 86dB/2.83V
The 15" ATC SB75-375SC has a Gamma value of 127 and a voltage sensitivity of 91dB/2.83V
The 31" Fostex FW800HS has a Gamma value of 198 and a voltage sensitivity of 96dB/2.83V
"
Herman
The assertion:
..is an pure audio-myth and has nothing to do how human hearing perception evaluates the fidelity of different detailed../or the so called audibly "fast driver"assertion of/ ..reproduced sound events from loudspeakers in a arbitrary listening environment.(Sorry for my bad? English)
Read all about the speculative 'wanna be an audio expert'- low tech babble here:
Driver Illusions
Loudspeaker drive unit cone acceleration - [English]
Loudspeaker drive unit cone acceleration - [English]
To understand why this is 'pseudo science' you need dive deep into psycho-acoustics/music and why not join the AES.:
Psychoacoustics - Wikipedia, the free encyclopedia
Diana Deutsch's Web Page
b 🙂
FYI: Loudspeaker drive unit cone acceleration - [English]
deals too with:
' Motor force product (BL) * Radiating area (Sd) / Moving mass (mms) = Gamma'
b🙂
deals too with:
' Motor force product (BL) * Radiating area (Sd) / Moving mass (mms) = Gamma'
b🙂
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bjorno, thank you for the informative reading material! In short, this information confirms my somewhat crude idea of the driver's dynamics ability.
I've learned a lot.
Thank you,
Herman
I've learned a lot.
Thank you,
Herman
Hi,
The "speed" of a subwoofer has very little to do with driver sensitivity,
and much more to do with the bass alignment, integration and large
scale linearity.
Regarding the bass alignment, nothing beats the transient response
of a lowish Q sealed box. Two of the chosen drivers in a stuffed
5 cuft box should be fine, with the option of added low boost.
Mount them on opposite faces for force cancelling.
rgds, sreten.
The "speed" of a subwoofer has very little to do with driver sensitivity,
and much more to do with the bass alignment, integration and large
scale linearity.
Regarding the bass alignment, nothing beats the transient response
of a lowish Q sealed box. Two of the chosen drivers in a stuffed
5 cuft box should be fine, with the option of added low boost.
Mount them on opposite faces for force cancelling.
rgds, sreten.
I'm with bjorno, a certain amount of confusion in this thread. Discussion should have ended long ago with Fletcher-Munson post. If the sound changes with the volume, you've got distortion*.
F-M is a reality although all but universally overlooked in system design. No getting around it except to always play music at the same level and that has to be the same level as the mixing studio. To make music sound right, you must have "loudness" compensation. To achieve that, you need to find an old pre-amp with a complex four-pot-section loudness circuit AND coordinate your playing levels to the right points on the curve of the volume control**.
Simple as that. But can't be done any other way.
BTW, "room gain" is a factor worth thinking about only if you play music in well sealed propane containers or very small well-sealed cars. Even there it is hardly a major factor in bass response... and hardly matters in real-world rooms made of plaster or wall-board.
*OK... you record the speakers at different levels and then play back to your ears at a constant volume.
** You must have some kind of volume control, not an L-pad of course, further downstream. Such as bi-amping.
F-M is a reality although all but universally overlooked in system design. No getting around it except to always play music at the same level and that has to be the same level as the mixing studio. To make music sound right, you must have "loudness" compensation. To achieve that, you need to find an old pre-amp with a complex four-pot-section loudness circuit AND coordinate your playing levels to the right points on the curve of the volume control**.
Simple as that. But can't be done any other way.
BTW, "room gain" is a factor worth thinking about only if you play music in well sealed propane containers or very small well-sealed cars. Even there it is hardly a major factor in bass response... and hardly matters in real-world rooms made of plaster or wall-board.
*OK... you record the speakers at different levels and then play back to your ears at a constant volume.
** You must have some kind of volume control, not an L-pad of course, further downstream. Such as bi-amping.
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