Thwack, thump, punch, bang, boom, and crash....all come from from the same thing....full-range response.
Transient response is impulse response, which is the sum of all frequencies together in time.
The measurement and data used to obtain an impulse response is the exact same measurement and data used to obtain frequency & phase response.
And when when impulse response is perfect, so is frequency & phase response.
Impulse, and frequency & phase, are just two different ways of looking at the same data.
So.... the definition of transient response is simply the range of frequency response.
(and vice versa).
It's part of what makes trying to talk about a limited-bandwith device's transient response difficult (a sub in this case).
It often gets more academic than practical imho. (But Pls know I do not mean to diminish the neat in-depth technical evaluations/contributions)
If we want thwack, thump, punch, bang, boom, and crash....we need a full-range speaker with the SPL capability throughout the range to pull off the combined transient sound.
Leave any holes in frequency response, we might get thwack but without thump, or punch without crash, etc, etc
Thanks for that,
So the initial transient peak (spike) is the sum of all frequency’s involved.
when these peaks are clipped by the low pass inductor is it just leveling one part of the thwack or the entire group of freq that make up the drum ‘sound’? Therefore affecting the signature of the decay?
Also, is it just an inductor that levels the peaks as in it wouldn’t affect the sub or is any low pass no matter the type going to clip the peaks?
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I think your last question gets to the heart of things...
Any type low pass removes frequency content and changes the sound of the original signal, if higher frequency content is present in the signal.
I prefer to say 'removes frequency content' than 'clip the peaks'.
Although if you are thinking in terms of an impulse response, removed frequency content does appear as a shorter impulse spike.
So the sub by itself is a low pass filter because it's not a full-range driver.
The inductor (or alternatively an active low pass), just restricts its bandwidth even further.
I mean really, what would a kick drum sound like, using just a sub, even without any kind of low pass filter...dead as hell, huh?
Ok thanks....I’m gettin a better grasp on it!
Would explain why I prefer the sound of the natural roll off in many designs Without a lp filter.
Seas makes a woofer that’s a replacement for the A25 ....A26RE4(H1411) that I might try in my next build.
would this (natural roll off) principle pertain to a sub if applied in a stereo ‘kick bin’ bottom configuration where vocal bleed and such wouldn’t matter?
Edit...of course driver choice would be critical.....something like the jbl 2226?
After thinking about it I suppose I’m just describing a woofer in a two way! lol
Would explain why I prefer the sound of the natural roll off in many designs Without a lp filter.
Seas makes a woofer that’s a replacement for the A25 ....A26RE4(H1411) that I might try in my next build.
would this (natural roll off) principle pertain to a sub if applied in a stereo ‘kick bin’ bottom configuration where vocal bleed and such wouldn’t matter?
Edit...of course driver choice would be critical.....something like the jbl 2226?
After thinking about it I suppose I’m just describing a woofer in a two way! lol
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No, your wrong. its a combination of 50hz and a few freqs beiow 150 hz. Youve filtersd out everything above. You should have shown the original drum waveform, but I guess that would not support your case.
Or even a low pass wall. Whats a kick drum sound like thru a wall? Any transients (snap) left?
Any technical discussion worth having should have technical knowns as a basis. Guessing from what people think they hear goes nowhere fast. This subject is full of pyhsics and math, and without a basic knowledge of those, ( like Fourier ) the discussion degenerates into... My dad can whip your dad.
Let's do some very simplistic math then.
My listening room has a rt60 of 0.5 sec at 50Hz and that is very good.
That means that a 50Hz tone takes about 20 cycles to diy out at my ears. (very roughly).
Now how many cycles does it take a subwoofer in an anechoic room to diy out? A lot less even with a sub that has very poor transient response.
Get your priorities straight.
If that’s a reference to my posts I’m just trying to correlate the math to the sound, and in turn how changes in the math will affect the end result(what you hear)......that is what this is all about anyway isn’t it?
Not your post, circlemans. Yes we need to corelate the math to what we hear. The math says that LPFing a transient will lengthen the attack. Or, a sub (lpf) will not reproduce the attack portion of the sound properly, wanting a sub with good transients is like wanting a tweeter with bass.
Aaaah......the allure of the full range speaker.
I’ve never heard a ‘good’ one, but I understand for the proper amount $$ they can be had?
If they were non linear, they would introduce harmonic distortion, ( right more math you Dont know). Sure there not perfectly linear but at these spls close enough for this discussion. If not, show me the measurements.
Edit: acoustic means in the air, Im not sure thats what he meant. But at any rate, it still means distortion, which are more sine waves, so why does fourier not work? ( how do we measure distortion? FFTs ) .
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At the distance we listen they are near enough linear, personally I wouldn't want to live in drum or a trumpet bell
@mountainman bob fwiw - here's what hornresp says for your LAB15 variant with regards to impulse. "Fullrange" = interesting - can sometimes use Karlson approach to get tiny cone excursion usable.
Without reading the comments, for a bass reflex with best transient response, use a large low tuned enclosure, and a shallow low pass slope on the crossover (2nd order). For best results in this area, if sensitivity isn't of utmost priority, use a lage woofer with a very low resonant frequency and large enough xmax, and tune for an extended bass shelf at -3 dB. This will greatly reduce mechanical power handling, so make sure you have plenty of cone travel available. Group delay will be a huge peak at the tuning frequency, but very low above that. I recall threads on AVS forum many years ago about this. For a simpler build, people were using Sonotube with a 15 or 18" mounted at the bottom on a circular MDF baffle with a large port at the top. Good luck and have fun.
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