Going Where Angels Fear to Tread, We Propose Two Additions to the Thiele-Small "Canon" of Driver Parameters

[lrisbo]

Can you explain post #21 in light of no difference between mass of cones and it's "speed", in this case bandwidth.
Because I can't get around a restriction to the statement. E.g. BL changed otherwise bandwidth (and sensitivity) will in fact change. I'm not sure where to draw the line between a woofer and a compression driver, even though TS don't apply to compression drivers, yet no idea why the same rules wouldn't apply for mass, force etc.
Curious.

I don’t know much about compression drivers so I am luckily unaffected by that in this context. sound pressure in the listening position (aka far field) is proportional to the cone acceleration. increasing Bl and lowering Mms increases acceleration for the same electrical drive level. hence sensitivity goes up. There is no inherent bandwidth limit other than after cone break up the cone is not accelerating like a piston and sensitivity goes down (after a potential spiky resonance)

 

[jan.didden]

@jan.didden I was a bit direct, to try and get this thread not going off the rails, sorry if that meant I came across pushing a bit.

Yeah, that's true, but not entirely sure about the not starting signals part. Most signals die out gradually for sure, but a kick drum, timpany or equivalent is fast in it's attack.

Didn't feel pushed at all.
On fast attack: look at the waveform. It sounds fast to our limited understanding, but in terms of signal rise time, it's leisure.
As noted before, your attack time or rise time is ultimatily limited by the bandwidth limit.

Lots of examples on this forum of people testing their stuff with suddenly starting tone bursts with zero rise time and then complaining that the system can't handle it. It doesn't have to handle that because it never happens in real life!

Jan

 

[mbrennwa]

Agree, then again, iirc it was said it could be added to the pdf, as is done on sites with EBP. It's just a rough estimate and helps in filtering, nothing more, nothing less.

Then just filter for your preferred Mms/Sd ratio. No need to claim a new "addition" to the Thielle-Small parameter set.