It's a mechanical example of a filter that only shifts the phase but not magnitude. The processing behind REW does something slightly similar, essentially "splitting" a perfect transient impulse into a swept sine wave. One of the advantages is that the energy is spread out over time, so it's not necessary to use a very high amplitude gunshot type of bang in order to get a broad spectrum measurement.
This is also why it's prudent to take flat, smooth-looking FR plots with a grain of salt. Speaker manufacturers rarely provide the accompanying phase plots, and when they do it's pretty much gibberish anyway, unless repackaged into something nicer like a waterfall plot.
That's what I say also but @hurrication states otherwise.
I wonder what he will bring to support his claim.
Oh gawd. It´s like cutting ones leg and arguing that it betters ones BMI. Can´t work in such isolated state with inductance for our case.
Yes, higher voltage basically increases "slew rate" of the signal so to speak, and to a point, everything in bass frequencies is to be compensated for. There is "no issue with higher inductance subwoofers" if we have enough voltage to feed em.
Ad absurdum, the best subwoofer would be piece of straight wire, and you where it goes. Can´t blindly follow lowest inductance.
Appealing from the position of authority does not work here at all btw... Give claim and facts, or it´s not happening.
Yes, higher voltage basically increases "slew rate" of the signal so to speak, and to a point, everything in bass frequencies is to be compensated for. There is "no issue with higher inductance subwoofers" if we have enough voltage to feed em.
Ad absurdum, the best subwoofer would be piece of straight wire, and you where it goes. Can´t blindly follow lowest inductance.
Appealing from the position of authority does not work here at all btw... Give claim and facts, or it´s not happening.
*edit
You know what, I changed my mind.. you guys have fun with trying to figure out this "kick science" thing
You know what, I changed my mind.. you guys have fun with trying to figure out this "kick science" thing
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Well, like I said, first time I heard it was either Meyer himself, or McCarthy. Whoever, through all they have written...how can you be so sure I mis-interpreted?
Yes we disagree.
First one appears to be our definitions of frequency response. Mine (and I'm certain the technically correct one) is that it includes both freq magnitude response and frequency phase response.
Yours apparently leaves out phase, which I think would cause you to have the opinion you do.
Yep, we are all aware of McCarthys reliance on phase alignment. Heck, I've been through 8 days of in person Smaart training, including a 2-day advanced session at RA headquarters learning the well established phase trace alignment method.
He suggests in your quote to use the impulse response to ballpark phase response.
Which is of course the 'delay finder' in Smaart, the 'estimator in Arta, the time to loopback or acoustic timing reference in REW....etc etc...or IOW, a simultaneous FFT determining the impulse response to be able to provide frequency response phase in a meaningful fashion. The fact the an impulse response is concomitantly made at time of producing frequency response is further evidence to me of the inseparable equivalency.
Anyway, another technique for time and phase alignment seems to be rapidly gaining popularity.... the use of time-domain wavelets.
Like SynAudCon has described. Crosslite+ is using a single wavelet for alignment, and it really does seem to be a better path than the phase overlay method.
Of course both methods will get to the same result if done properly, but I'm finding the single wavelet is easier and more immune to false phase traces from strong reflections than working directly in the real time frequency domain.
Which speaking of CL+..I need to hop to attend an instructional seminar being held in a few minutes.. (yes, i'm into this shite!)
That's sad; I, for one, approach every discussion with an open mind, always willing and eager to increase my knowledge. My loss, regrettably...
Nothing personal against you; I just didn't feel like going swimming in the jellyfish pool today. Even after posting klippel data to back up my notion, it still would have been squashed by the speculation and theory of some users. It's usually how that kind of thing ends up going.
You showed two different impulse responses, that's true, but we still needed the corresponding identical frequency responses..
But it has long been known that if the impulse response is different, the frequency response will be different and vice versa. Here we are only talking about a single source, not a multi-way configuration where this can vary.
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I did post the FR, which were within margin of error of each other, but decided against it and edited it out because you and I both know there would have been 3 more pages worth of mental gymnastics to try and pick it apart and invalidate it with different scenarios until it meets the criteria for the forum expert™ theory. I don't have time for that kind of waffling to defend klippel data; already been down that road plenty of times on this forum.
Just pretend I never commented here. Inductance is irrelevant, transient response is a myth, and every subwoofer sounds exactly the same if their FR is the same. Carry on. 👍
Just pretend I never commented here. Inductance is irrelevant, transient response is a myth, and every subwoofer sounds exactly the same if their FR is the same. Carry on. 👍
Whenever I see a thread with pages of replies, I always start from the very end and read up. The end is at times is the residue of final battle. "the forum expert™ theory" - pretty good.
I would also look at this challenge backwards. If you want chest kick, better know something about the chest that you intend to kick. Like I'm sure the chest cavity itself has a resonance and I'm sure there's a distribution of chest resonant frequencies across some population of humans. I'd bet it's a different frequency span for Americans, than for Europeans also.
I would also look at this challenge backwards. If you want chest kick, better know something about the chest that you intend to kick. Like I'm sure the chest cavity itself has a resonance and I'm sure there's a distribution of chest resonant frequencies across some population of humans. I'd bet it's a different frequency span for Americans, than for Europeans also.
Not only that, but the entirely subjective personal assessment of the phenomena can never be properly quantified, just as people prefer white wine to red; Porsche to Ferrari; brunettes to blondes...
The frequency amplitude response alone is not equivalent to the impulse response. Both the amplitude and phase vs frequency are required to transform from frequency domain back to time domain. Maybe that is the missing link in this discussion, which ties back to perception of group delay at low frequencies - change in the phase angle as a function of frequency.
Wait, what? Were you saying that you need a tweeter to feel bass chest kick???
When speaking of rise time and "speed", it should be specifically expressed what kind of speed are we talking about. With AC signal we obviously know that low frequencies rise much slower than high frequencies and that induction causes impedance to rise (resist current) towards higher frequencies. However, this is not to be mistaken with higher voltage. One more picture (Windows Calculator):
Blue is sin(x), green is 10sin(x) and red is sin(10x). Blue and green are the same frequency, they have equal rate of cycles, but different magnitude. Green and red rise about the same rate (for a brief period), but they have different magnitude and frequencies. Red and blue match only for the magnitude. Induction (a specific amount) would not resist the green or blue, but would resist red.
Bringing this to context, I got a feeling that @hurrication was talking something about this. I can not think of any other reason to bring inductance on the table. Thanks @tmuikku for your post, by the third picture anybody should understand what's going on.
Blue is sin(x), green is 10sin(x) and red is sin(10x). Blue and green are the same frequency, they have equal rate of cycles, but different magnitude. Green and red rise about the same rate (for a brief period), but they have different magnitude and frequencies. Red and blue match only for the magnitude. Induction (a specific amount) would not resist the green or blue, but would resist red.
Bringing this to context, I got a feeling that @hurrication was talking something about this. I can not think of any other reason to bring inductance on the table. Thanks @tmuikku for your post, by the third picture anybody should understand what's going on.
JukkaM, you make a good argument for not using the word "limit", which was used earlier when someone said that inductance limits slew rate. In fact it is only relative.
As far as the other point, a tweeter is necessary for giving bass it's due impact. I accept that this is not the same as saying "chest kick".
As far as the other point, a tweeter is necessary for giving bass it's due impact. I accept that this is not the same as saying "chest kick".
@JukkaM I never mentioned tweeters anywhere, I'm just confused where you assumed I mentioned tweeters, since we're in a thread about subwoofers.
Inductance is a main contributor to a subwoofer's time domain performance, regardless of frequency. We can see this by looking at the difference in phase angle of an impedance sweep. While most are only familiar with inductive rise with frequency, I am trying to point out that there is a quantifiable difference in time domain performance of a subwoofer in its passband outside the scope of inductive rise. I posted some of my impulse and step response klippel results for a subwoofer i'm developing, back to back with and without shorting rings that changed the inductance, and it showed that the motor with lower inductance had a faster impulse and step response. The second reply I edited out was the Klippel measured FR of both woofers that showed them having near identical FR within the typical margin of error based on noise floor, as woofers having different FR due to inductance was the counter argument.
You're on the right track with your illustration, but instead of isolating each wave and only looking at that, send all three of those signals you illustrated through a subwoofer at the same time. That's where inductance comes in to play. As I mentioned earlier, IMD (intermodulation distortion) is where we see the time domain characteristics of low inductance play out. Woofers with better time domain performance due to lower inductance will naturally have better IMD, and that is what we hear as "transient response".
https://www.klippel.de/know-how/measurements/nonlinear-distortion/multi-tone-distortion.html
https://www.klippel.de/know-how/measurements/nonlinear-distortion/intermodulation-distortion.html
Inductance is a main contributor to a subwoofer's time domain performance, regardless of frequency. We can see this by looking at the difference in phase angle of an impedance sweep. While most are only familiar with inductive rise with frequency, I am trying to point out that there is a quantifiable difference in time domain performance of a subwoofer in its passband outside the scope of inductive rise. I posted some of my impulse and step response klippel results for a subwoofer i'm developing, back to back with and without shorting rings that changed the inductance, and it showed that the motor with lower inductance had a faster impulse and step response. The second reply I edited out was the Klippel measured FR of both woofers that showed them having near identical FR within the typical margin of error based on noise floor, as woofers having different FR due to inductance was the counter argument.
You're on the right track with your illustration, but instead of isolating each wave and only looking at that, send all three of those signals you illustrated through a subwoofer at the same time. That's where inductance comes in to play. As I mentioned earlier, IMD (intermodulation distortion) is where we see the time domain characteristics of low inductance play out. Woofers with better time domain performance due to lower inductance will naturally have better IMD, and that is what we hear as "transient response".
https://www.klippel.de/know-how/measurements/nonlinear-distortion/multi-tone-distortion.html
https://www.klippel.de/know-how/measurements/nonlinear-distortion/intermodulation-distortion.html