Linear Phase in Studio Monitors - the responses of Dr. Floyd Toole, Dr. Wolfgang Klippel, Andrew Jones, and James Croft

[OWC]

have you look on this page with the desktop web browser and not with mobile ?. there can comment or edit the page same way as in wiki. BTW: I have not create or edit this page. on this page stand too that step response show time. and the frequency a speaker can reach depend on the rise and fall time and the linearity of this. step repsonse is also important measure for hydraulic systems. for hydraulic systems there is no frequency diagram show

The step response or impulse response (same thing) is literally the same as a frequency response, just a different representation.
Practically speaking a step is a little difficult on a loudspeaker, unless you would like to first put a lot of DC on it and quickly switch it off.
Which I wouldn't recommend doing and is also not always possible with a capacitor in series.
So therefor we use impulse responses, but with some math they are interchangeable.

I have a background in physics, so I used to work with quite some hydraulic systems in the past (good old control theory systems)
The thing is, a frequency response just simply doesn't make sense for such a system, since it's not a point of interest.
An hydraulic system would also never work like a speaker on many frequencies, but just one impulse.
So in the end engineers are only interested in response times as well as how much shoot through there is (= Q factor).
There is no ideal step response for such systems, and by definition it's always a trade off between how fast you wanna switch things off, vs how smooth. With the disadvantage that a very "fast" system will shoot through and a very slow system will take forever to close a certain valve (or what have you)

For a slower system in sense of mass, the frequency response would just simply collapse, which is the same as a low pass filter.

Unless you mean the low frequency side of things, in that case an higher Q will just result in a peak (like said above) or have a very shallow output around the Fs (for Q < 0.707). Also the amount as well as the shape of the group-delay changes.

I find it a little strange to call that linearity, unless you call any kind of frequency dip or peak linearity as well?
In this case engineers don't really care about velocities or acceleration, but rather are interested in cone excursion vs max bandwidth (or peaks) vs lowest -3dB pont vs smooth crossover with roomgain vs a group delay that doesn't jump all over the place (sudden changes in GD can be audible).
So there is a trade-off again, although a good system should be between 0.5 < Q < 0.707
Much lower just doesn't makes any sense anymore and you will loose heaps of output, above 0,707 will give a peak in de frequency response.

Anyway, I don't really see the link between phase response and a certain impulse/step response.
Since there are many other things changing with the Q-factor as well.
The difference in group delay is also very small in practice.

Personal side note, is that I very often wonder what companies had in mind?
Looking at certain frequency responses and the lower-end looks totally awful, with sometimes an huge peak around the Fs = high Q factor.

I still find it a little strange that Toole never said anything about it in his books.
Because that is definitely audible unless room modes are far more substantial.

 

[bennybbbx]

As it has been said the frequency response plot is a more expedient representation for such, as an example for a moving object someone could show the acceleration time function to indirectly show the velocity (by integrating it), but its easier to read the velocity plot directly.


As above because often the representation in time domain might be more expedient, that doesn't mean there cannot be a frequency response plot:

instead that you write here, discuss in the hifi wiki and explain of step responses entry

this thread is about Linear phase. and ever mechanical device increase the lag time depend on frequency. so wy this should not minimize ?. this can minimize when for example for the woofer is used a speaker that can reach 20 khz too. (wide band speakers) or slight phase shifts. there are so many speakers so wy so many speakers have problems between tweeter and mid/ bass phase

I think i find the page you quote https://www.powermotiontech.com/hyd...21885043/the-importance-of-frequency-response

that stand on this page

With higher test frequencies, an attendant higher phase lag normally occurs, and the output amplitude changes. It is normal with any kind of machine that the output amplitude will be less able to keep up with the input amplitude with increasing frequency. That is, there will always be some frequency where the input command is vibrating so fast that the output cannot keep up at all. Therefore, the output amplitude tends to diminish with increased frequency, and the phase lag between input and output tends to increase.

 

[bennybbbx]

The step response or impulse response (same thing) is literally the same as a frequency response, just a different representation.

ok, then tell me in a frequency diagram the delay of tweeter and woofer/mid . can you do this ? . in a step response this can see

 

[thewas]

instead that you write here, discuss in the hifi wiki and explain of step responses entry

It doesn't work this way, if they make claims they should have some sources for them.

there are so many speakers so wy so many speakers have problems between tweeter and mid/ bass phase

And these can be better seen at the directivity plots.

that stand on this page

That quote writes that any device has a lowpass behaviour/limit, and now?

 

[OWC]

ok, then tell me in a frequency diagram the delay of tweeter and woofer/mid . can you do this ? . in a step response this can see

Delay in reference to what?
Delay in this case is always relative.

In theory it's possible to see I guess, but since there is so much going on in a step response, in practice it's just easier to look at the phase response and/or group delay.
Nowadays VituixCAD has a nice tool to do that for you.

In the end what counts is just looking at the off-axis response and directivity, because that is a result of misalignment.

Why so many speakers have issues with the crossover point, is just because of bad crossover design
Also a regular tweeter has a sudden jump in directivity (see Loudspeaker Handbook by Borwick)

 

[BDWoody]

when you quote text that say phase is not important, then of course the answer to this is same

We aren't going to rehash this every few weeks.