> I'm not arguing for the sake of it. <
Of course, I know you're not, but much of what you are arguing is simply wrong. I am certain that Jeff Szymanski understands that a 1 ms pulse contains energy at 120 Hz, so maybe he'll pipe up and confirm it so we can avoid wasting yet more time on this. In the mean time I'll gladly carry on.
> the ringing starts at the upward transient <
You bet - the transient itself contains low frequencies. Just like dropping a book onto a table. Or the big bang, which had tons of LF content.
Stick a battery across your loudpseaker terminals and watch the woofer cone lurch forward. It doesn't matter if you leave the battery in place, or remove it after 1 millisecond. Either way, the LF energy that was present went through the crossover to the woofer's voice coil.
> why is it not possible an IMPACT of energy can cause ringing in an EQ at any frequency? <
It does, because the IMPACT itself contains low frequencies. So maybe we agree after all? Maybe now you can see that regardless of the pulse length, there is in fact low frequency energy?
> Please explain how you can get 100Hz, which smallest element is 10ms long in a 1ms pulse?? <
Okay, now I see where you're going wrong. Try to envision a small portion of a 120 Hz sine wave. Say, the first millisecond of the wave as it's just starting to curve upward. See what I'm getting at? The curve is what defines the frequency, not the absolute length! You don't need a full cycle for a frequency to exist, as evidenced by pink noise which often contains partial cycles at various frequencies.
Likewise, you can have a partial arc only a few inches long, but that belongs to a circle 60 feet in diameter.
> You don't need any frequency to excite a resonant entity at it's resonant frequencies. <
Yes, you do! Take a tambourine track and boost the bejeezus out of it at 30 Hz. Do you hear a change? I rest my case.
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