• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

step response is a important part to show speed of speaker that is good enough for ITD. See measures

Status
Not open for further replies.
OP
B

bennybbbx

Addicted to Fun and Learning
Joined
May 27, 2020
Messages
568
Likes
105
Location
germany
Not this again.... it will tell you nothing without looking at your tweeter's band width. You're making up things again.
Use science, that will work way better.

the 1.5 cm measure is only the woofer. look here the compare of the kali lp6 step response and the iloud MTM. we all know that lower FR increase decay time of step response. But look at the results. the MTM have mor bass but much shorter decay time. the rise time of bass/mid can not see. But do you really think when can hear ITD that the kali can sound as good as the MTM or the other with shorter step response ? notice the Kali begin 100 µsec earlier

iloud mtm.jpg



step response iloud mtm.jpg
 

Wesayso

Member
Joined
Dec 30, 2021
Messages
74
Likes
144
Location
The Netherlands
the first step response have faster rise time as 2. on the 3. can nothing see about rise time. but look the speakers that are out in the world. on very much speakers see delay between tweeter and woofer. When all speakers look as 3 then i also agree step response is not usefull. but currently it can good see if a speaker have good time align and fast mid
You're not getting the hang of it yet huh? There we go again... assuming things without any knowledge of what it is you're looking at.

See Kimmosto's result for another example of excellent STEP behavior. Want to call something fast, his speaker is...
As is the 3rd example from Dunlavy's paper. The sooner you get that, the less prone you are to claim nonsense.

But... Never did I say that a speaker cannot sound good without that idealized STEP. Heck, I bet the Kef BrokenEnglishGuy shows sounds lovely.
So all of this is merely to get you to understand that STEP responses might not be as easy to judge if you don't know what kind of crossover is used or if it is taken inside a room etc.
If people want linear phase or not, is up to them, to discover their preference etc. That I like it says nothing, just my preference.
I wanted to test, I did test and I kept what I have because I like it. Or rather prefer it. Your opinion may vary. Your STEP result too ;).
 

Wesayso

Member
Joined
Dec 30, 2021
Messages
74
Likes
144
Location
The Netherlands
the 1.5 cm measure is only the woofer. look here the compare of the kali lp6 step response and the iloud MTM. we all know that lower FR increase decay time of step response. But look at the results. the MTM have mor bass but much shorter decay time. the rise time of bass/mid can not see. But do you really think when can hear ITD that the kali can sound as good as the MTM or the other with shorter step response ? notice the Kali begin 100 µsec earlier

View attachment 176491


View attachment 176492
So you have a peak before zero, in other words, you haven't even pressed play and the speaker is playing already and claim that it is faster or better? Is it reading your mind that it fires before you press play :D.

Try lining up the IR in these graphs, the timing on one of them is off, that is all. Clearly REW couldn't find the right pulse to line up the result.
Don't even think it has something to do with a faster speaker. What speaker can be faster than even you, pressing play? Nice STEP of the Iloud though, but that doesn't make it a good speaker yet, unless all other things are right too. Clearly both of the frequency curves you showed cannot be called 'behaved' if they vary more than 9 dB between 100 Hz and 10 KHz, although the blue one clearly does better than that (in both graphs).

It has been nice talking to you, but it didn't change much, did it? I'll call it enough wasted time for now. (clearly I'm a bit bored to still be at it)
Nice of Kimmosto to drop by, I'll take a deep bow for him as his software VituixCAD has helped me understand and learn more about my own array speakers and made it possible to create my frequency shading schematics. It's generous people like him that we should value and appreciate.
 
Last edited:

BrokenEnglishGuy

Major Contributor
Joined
Jul 19, 2020
Messages
1,238
Likes
680
You're not getting the hang of it yet huh? There we go again... assuming things without any knowledge of what it is you're looking at.

See Kimmosto's result for another example of excellent STEP behavior. Want to call something fast, his speaker is...
As is the 3rd example from Dunlavy's paper. The sooner you get that, the less prone you are to claim nonsense.

But... Never did I say that a speaker cannot sound good without that idealized STEP. Heck, I bet the Kef BrokenEnglishGuy shows sounds lovely.
So all of this is merely to get you to understand that STEP responses might not be as easy to judge if you don't know what kind of crossover is used or if it is taken inside a room etc.
If people want linear phase or not, is up to them, to discover their preference etc. That I like it says nothing, just my preference.
I wanted to test, I did test and I kept what I have because I like it. Or rather prefer it. Your opinion may vary. Your STEP result too ;).
Imho i can't fully understand the step response and all of his impacts, talking about the speed is a very complex thing

i just supposed the step response from the R3 is not that bad at all lol, but i don't know if looking at the step response you can say if the woofer is fast or not
 

Wesayso

Member
Joined
Dec 30, 2021
Messages
74
Likes
144
Location
The Netherlands
For your post I'll come back to this thread :). You have the right idea. It is quite difficult to say anything useful about the STEP and speed etc.
What we see though is that the tweeter is firing in front of the woofer. (like most speakers that have a higher order crossover)
It doesn't lead to conclusions of being fast or slow. It's just how the crossover was chosen that makes a STEP look like it does.
In an ideal world, the woofer and tweeter would play at the same time, but that limits the type of passive crossovers one could use.
A first order crossover works, but offers hardly any protection for a tweeter. In this day and age, DSP can be used to do it, and still
offer enough protection for the tweeter. (prevent it from playing low notes) Then there is the woofer. Not all of them can play high enough and behave to use a first order. In other words, it isn't easy. Look up broken tweeter Dunlavy to see that even that tweeter had a hard time doing what it was asked to do.

There are a couple of other ways, but the whole point is what you already show you understand. Don't make uninformed claims about STEP responses because most of the time you'll be wrong. Just like Benny.

To (learn to) understand it one can look at crossover type, the order used, the frequency at which it is crossed etc. They all have their own effect on what the STEP looks like. Claiming to see one STEP being faster than the other based on hot air isn't recommended.

There are far more issues to solve for Benny, judging by his frequency curves. That Kali shouldn't vary 9 dB if it's placed properly.
(and measured at the right distance)
 
OP
B

bennybbbx

Addicted to Fun and Learning
Joined
May 27, 2020
Messages
568
Likes
105
Location
germany
So you have a peak before zero, in other words, you haven't even pressed play and the speaker is playing already and claim that it is faster or better? Is it reading your mind that it fires before you press play :D.

I choose in REW estimate IR Delay. and it set this. i let it in doesnt matter kali is so or so slower.


Try lining up the IR in these graphs, the timing on one of them is off, that is all. Clearly REW couldn't find the right pulse to line up the result.
Don't even think it has something to do with a faster speaker. What speaker can be faster than even you, pressing play? Nice STEP of the Iloud though, but that doesn't make it a good speaker yet, unless all other things are right too. Clearly both of the frequency curves you showed cannot be called 'behaved' if they vary more than 9 dB between 100 Hz and 10 KHz, although the blue one clearly does better than that (in both graphs).

It has been nice talking to you, but it didn't change much, did it?

when measure only the woofer/mid at 1.5 cm then the rise time of the woofer is show or did you not agree ?. Because for ITD need cycle to cycle between speakers phase precision of at least 40 µsec it should be fast. how should a speaker with a rise thime of 500 µsec produce such exact positions ?

here can read what step response show


I'll call it enough wasted time for now. (clearly I'm a bit bored to still be at it)

you tell me that i should look for speed of speaker at other display in REW. but this does not help because i am no speaker tester. I have only few speaker test. and with speed of speaker i mean the max frequency of the woofer/mid. easiest is when speaker developer tell this. currently speaker developer do only increase speed of the tweeter for HD audio and tell this. dali speakers have at 14 khz another tweeter that reach 38 khz. this does not help me. because when i add a lowpass filter on kali and other there can still hear that stereo width is small and reverb sound strange on kali. so there is to examine wy. only explain for me is that the woofer/mid is too slow.

there are people that think wide band speaker sound best. I notice when use a bass/mid that reach 15 khz it sound also good when use a tweeter
 

Wesayso

Member
Joined
Dec 30, 2021
Messages
74
Likes
144
Location
The Netherlands
I choose in REW estimate IR Delay. and it set this. i let it in doesnt matter kali is so or so slower.
No, it isn't or wait.. what is your point here?
when measure only the woofer/mid at 1.5 cm then the rise time of the woofer is show or did you not agree ?. Because for ITD need cycle to cycle between speakers phase precision of at least 40 µsec it should be fast. how should a speaker with a rise thime of 500 µsec produce such exact positions ?

here can read what step response show
Thanks, I know what a STEP response is.
you tell me that i should look for speed of speaker at other display in REW. but this does not help because i am no speaker tester. I have only few speaker test. and with speed of speaker i mean the max frequency of the woofer/mid. easiest is when speaker developer tell this. currently speaker developer do only increase speed of the tweeter for HD audio and tell this. dali speakers have at 14 khz another tweeter that reach 38 khz. this does not help me. because when i add a lowpass filter on kali and other there can still hear that stereo width is small and reverb sound strange on kali. so there is to examine wy. only explain for me is that the woofer/mid is too slow.
Oh no, again something new. Now it is the extension you (would like to) see in this STEP response? The Frequency curve will show how high up the speaker is playing, not the STEP response. (blue wins again, the iLoud) do you test at 96000 sample rate? 44100 will limit what you get and you need to tell REW to extend it's upper frequency for a sweep. But again: why look at a STEP for this info?
there are people that think wide band speaker sound best. I notice when use a bass/mid that reach 15 khz it sound also good when use a tweeter
There are also people that think an extension to 40 KHz helps. I'm not one of them. I'm 54 years old, lucky if I make it past 14 KHz, bound to see it deteriorate further. I am extra sensitive at 6 to 8 KHz though, according to my last hearing test. As sensitive as the 2-4 KHz area. That makes me deviate from the average listener. Making me more prone to hear sharp Ssss and all that stuff.
 
Last edited:
OP
B

bennybbbx

Addicted to Fun and Learning
Joined
May 27, 2020
Messages
568
Likes
105
Location
germany
No, it isn't or wait.. what is your point here?

Thanks, I know what a STEP response is.

Oh no, again something new. Now it is the extension you (would like to) see in this STEP response? The Frequency curve will show how high up the speaker is playing, not the STEP response. (blue wins again, the iLoud) do you test at 96000 sample rate? 44100 will limit what you get and you need to tell REW to extend it's upper frequency for a sweep. But again: why look at a STEP for this info?

because in speakers the developer do not tell which FR the woofer/mid reach. but in step response can see if it can reach high FR or not. maybe it is not clear what i mean with rise time. the time between arrows i mean for the woofer/mid. a half period need for rise time around 400 µsec on kali. this *2 mean 800 µsec. so this speaker can reach around 1.2 khz good. but faster is better

rise time (2).jpg



There are also people that think an extension to 40 KHz helps. I'm not one of them. I'm 54 years old, lucky if I make it past 14 KHz, bound to see it deteriorate further. I am extra sensitive at 6 to 8 KHz though, according to my last hearing test. As sensitive as the 2-4 KHz area. That makes me deviate from the average listener. Making me more prone to hear sharp Ssss and all that stuff.

the s is in the range of 7-11 khz.
 
Last edited:

Wesayso

Member
Joined
Dec 30, 2021
Messages
74
Likes
144
Location
The Netherlands
How fast that rises is depending on the crossover used and at what frequency it is set at. What do you want to read into it?
Do you know the crossover order of the Kali? Do you know at what frequency? If you do, you could compare it to a simulated speaker with the same settings. Then you might actually learn something.

Look up stereo cross talk to know/learn why the S can be a problem. Especially around 7 KHz.
 

witwald

Senior Member
Forum Donor
Joined
Jul 23, 2019
Messages
335
Likes
293
... I want only show that with a shorter step response stereo width and transients are better and so it is useful to see step response. and when there is a speaker below 1000 euro with rise time less than 300 µsec and 6.5 inch woofer I buy it and test. Kali is 6.5 inch have much slower step response, less transients and stereo width. And I want show that the FR have not much influence to step response.
It's not possible to show that the frequency response has not much influence on the step response. That's because they essentially represent the same thing. Once you know the frequency response of a linear system, you can obtain its step response, and vice versa.

Have you seen the step responses of amplifiers with a flat wide-band frequency response? They have a very fast rise time, subject of course to their –3dB frequency response limits at low and high frequencies. A loudspeaker behaves in a similar manner, albeit we have multiple sources of filtered sound being blended together, but the the concept is the same.

You mentioned that you think that shorter step response leads to better stereo width and transients. That seems to indirectly imply that we should all be listening to tweeters exclusively!
 
Last edited:

Wesayso

Member
Joined
Dec 30, 2021
Messages
74
Likes
144
Location
The Netherlands
Glad to see someone taking over (lol)

I looked up my source for the Dunlavy papers, in case anyone is interested in it. I know I was, he has been a great inspiration to me and my personal project. Anyway, without turning another post into a long-winded rant: Dunlavy paper attached in post #282.
That thread contains a wealth of papers and data on several Dunlavy speakers. I hope some might be interested in it.
 

witwald

Senior Member
Forum Donor
Joined
Jul 23, 2019
Messages
335
Likes
293
Because in speakers the developer do not tell which FR the woofer/mid reach. But in step response can see if it can reach high FR or not.
Why would the designer need to tell us the frequency response of the woofer/midrange driver? In the loudspeaker itself, the driver's response is lowpass filtered, so it's not easy to determine the natural frequency response. If you can perform a step response measurement on the woofer/midrange, it should be easy enough to just carry out a frequency response test to determine it's upper frequency limits.
Maybe it is not clear what I mean with rise time. The time between arrows I mean for the woofer/mid. A half period need for rise time around 400 µsec on kali. this *2 mean 800 µsec. So this speaker can reach around 1.2 kHz good. But faster is better
You would get the information that you require much more easily from a frequency response test (e.g. gated chirp, MLS, etc.). Although faster is indeed better, it needs to be kept in mind that controlling cone resonances is also an important factor in the design of a driver. In the end, if a woofer/midrange had a textbook Butterworth 2nd-order roll-off at low frequencies and high frequencies, its so-called speed is simply related to its high-frequency cutoff. The latter is then itself filtered by the low-pass filter, so any inherent extra "speed" is simply filtered away. Importantly, the driver's frequency response curve should be as smooth as possible for the most accurate reproduction possible.

Of course, step response measurements of a loudspeaker system can be handy for a number of reasons. It is often possible to discern the polarity of the tweeter connection relative to that of the woofer. It's also possible to check relative driver offsets on the baffle to the listening position.
 

witwald

Senior Member
Forum Donor
Joined
Jul 23, 2019
Messages
335
Likes
293
I just supposed the step response from the R3 is not that bad at all lol, but I don't know if looking at the step response you can say if the woofer is fast or not
It's pretty much impossible to look at a step response and say if a woofer is fast or not. Woofers that are "fast" don't really exist. They couldn't reproduce "slow" low-frequencies if they were (just ask a tweeter).

Assuming the woofer is a linear device, its time domain performance is entirely defined by its frequency response function, which is normally low-pass filtered in a multiway loudspeaker system. As you drop the low-frequency cut-off point, the woofer's step response just gets longer and longer. There's nothing special about that; it's just the electromechanical physics of the driver design at play.

These sorts of concepts were all covered by Small in his journal papers on low-frequency alignments for woofers, way back in the 1970s. A vented-box enclosure fitted with a woofer with a –3dB point at 50Hz with a 4th-order Butterworth alignment has a longer step response than a closed-box enclosure with the same cut-off frequency but having a 2nd-order Butterworth alignment.

The transient response described above is simply embodied in their respective frequency responses. A mathematical analysis can clearly explains/describe why a sealed enclosure has a better transient response. In that sense, the sealed enclosure is "faster" for the same cut-off frequency, because the response settles more quickly. However, if you look at the differences between the respective time-domain waveforms, they are not that large. See the plots below:

1641260878698.png
 

BrokenEnglishGuy

Major Contributor
Joined
Jul 19, 2020
Messages
1,238
Likes
680
It's pretty much impossible to look at a step response and say if a woofer is fast or not. Woofers that are "fast" don't really exist. They couldn't reproduce "slow" low-frequencies if they were (just ask a tweeter).

Assuming the woofer is a linear device, its time domain performance is entirely defined by its frequency response function, which is normally low-pass filtered in a multiway loudspeaker system. As you drop the low-frequency cut-off point, the woofer's step response just gets longer and longer. There's nothing special about that; it's just the electromechanical physics of the driver design at play.

These sorts of concepts were all covered by Small in his journal papers on low-frequency alignments for woofers, way back in the 1970s. A vented-box enclosure fitted with a woofer with a –3dB point at 50Hz with a 4th-order Butterworth alignment has a longer step response than a closed-box enclosure with the same cut-off frequency but having a 2nd-order Butterworth alignment.

The transient response described above is simply embodied in their respective frequency responses. A mathematical analysis can clearly explains/describe why a sealed enclosure has a better transient response. In that sense, the sealed enclosure is "faster" for the same cut-off frequency, because the response settles more quickly. However, if you look at the differences between the respective time-domain waveforms, they are not that large. See the plots below:

View attachment 176545
And what about with a Impulse response graph?
With that kind of graph can you say if the woofer stops quickly it's a fast woofer or something like that?

Talking about Speed and Time it's a very complex thing
 

witwald

Senior Member
Forum Donor
Joined
Jul 23, 2019
Messages
335
Likes
293
And what about with a Impulse response graph?
The impulse response graph and the frequency response graph (magnitude response and phase response) are interchangeable via the Fourier Transform. If you have an impulse response graph, you can compute the frequency response graph from it, and vice versa.
With that kind of graph can you say if the woofer stops quickly it's a fast woofer or something like that?
The difficulty here is that the so-called "speed" of a woofer is related to the type of enclosure (e.g. vented, sealed, passive radiator) and the tuning of the enclosure in which it is mounted. The choices of these parameters result in a particular transient response for any given woofer+enclosure combination. In general terms, the lower the order of the low-frequency roll-off of a woofer+enclosure combination, then the woofer transient response will die away more quickly, so the woofer in such an enclosure could be described as being faster.

With vented enclosures, we have a few parameters to play with that can affect the transient response. Say we have a classic Thiele B4 alignment with Fb = Fs = 50Hz for a woofer with Qts = 0.383, Fs = 50Hz and Vb = Vas/1.414, producing an F3 = 50Hz. We can now increase the enclosure volume to Vb = Vas, and lower the vent tuning frequency to Fb = 0.95Fs and we will have an F3 of 0.88Fs. This produces a response with a small depression above Fb (0.5dB or so), and the transient response will take a little bit longer to die away.

In the above example, the woofer itself is not any faster per se; it has exactly the same electromechanical parameters (Thiele–Small parameters). However, the transient response of the system is affected by the enclosure volume and vent tuning. Therefore, in the smaller enclosure the woofer might be regarded as being "faster", while in the larger enclosure it might be regarded as being "slower", even though the larger enclosure is appropriately tuned. In a careful measurement of the two sets of transient responses, there may not be all that much difference between them.

To be able to provide a fair comparison between low-frequency alignments, one needs to normalize the transient response by the low-frequency cut-off frequency. That's because for a given low-frequency alignment the transient response shortens as we increase the cut-off frequency.

In the end, the idea of "fast" bass is really just someone's choice of low-frequency cut-off frequency. The "faster" the bass, the less extended the low-frequency output will be.
Talking about Speed and Time it's a very complex thing
You're not wrong!
 
Last edited:
OP
B

bennybbbx

Addicted to Fun and Learning
Joined
May 27, 2020
Messages
568
Likes
105
Location
germany
How fast that rises is depending on the crossover used and at what frequency it is set at. What do you want to read into it?

also same answer for @witwald

How fast it rise depend on the Crossover and the driver speed. both together give the rise time result. Or do you think the crossover frequency is the only part that influence the rise time and a speaker driver have no or few rise time influence ?. logically a mechanical device have more influence rando,m phase errors because there need move masses. if there is no problem with speed of a driver system wy should build 3 way systems ?. for sound quality it doesnt help when 20% of rise time depend on crossover 80% on driver speed or 80% depend on crossover and 20% on driver speed. it is same slow and cause lots phase shift and lag

I do compare of headphone and 1.5 khz lowpass. faster rise time as kali. i am not sure if kali have 24 db or more. see the measure of woofer only also here https://www.audiosciencereview.com/forum/index.php?threads/kali-lp-6-review-studio-monitor.17978/

I am only sure that steep crossover sound not good. i do tests with DSP 24 18 12 and 6 db. 24 db sound not good in reverb and room. more as 24 i have not test. but i guess it sound worser because of much phase shifts and lag. the JBL use 6 db crossover

Look up stereo cross talk to know/learn why the S can be a problem. Especially around 7 KHz.

The longer and more dominant S or F happen mostly (maybe 95% ) of early reflection reverb that is used in mixing or record and make the voice fuller. record dry it is not so much. most use a desser a little but this reduce transient. too much reduce sound not so good. most people like reverb. the s get longer and spread in stereo a little. I like the s when i use a target curve with - 2 db on 10 khz.
 
Last edited:

Wesayso

Member
Joined
Dec 30, 2021
Messages
74
Likes
144
Location
The Netherlands
I figured as I still had some spare time, I could go "one on one" with Benny for another night or I could spend the time cleaning up that Dunlavy paper. I chose the latter, see attachment. No offence meant, Benny, I just figured that document would benefit more people.
Thanks to Google for their free OCR software in Google Drive -> Docs.

So here's: Loudspeaker Accuracy by John Dunlavy

(I have to chuckle about the passages about "A wide "sound stage" :D, I don't disagree however, Toole might have a different opinion)
 

Attachments

  • Loudspeaker Accuracy - John Dunlavy.pdf
    865.6 KB · Views: 52

witwald

Senior Member
Forum Donor
Joined
Jul 23, 2019
Messages
335
Likes
293
How fast it rise depend on the Crossover and the driver speed. Both together give the rise time result.
You are quite correct when you note that, when they are combined together, the crossover and the driver produce a rise-time result. Such a combination of course produces a bandpass frequency response function. The frequency response function, for a linear system, embodies the rise-time result, as well as the response of the given bandpass system to different transients. Consider an example.

Say we have an 6.5-inch woofer, tuned to provide a certain bandpass frequency response function in combination with a low-pass filter network. It will produce a certain response to a transient, whose rise-time it will be possible to measure.

We now create another system comprised of an 18-inch woofer, which has exactly the same-shaped frequency response function as that of the 6.5-inch system. The moving mass of the 18-inch woofer will generally be much greater than that of the 6.5-inch woofer. However, when we input the same transient into the 18-inch system as we input into the 6.5-inch system, we will find that both systems will have the same rise time. In the common parlance, the 18-inch woofer will be just as "fast" as the 6.5-inch woofer. Hence, this example illustrates the somewhat mythical nature of driver "speed". Any such "speed" is simply related to the frequency response of whatever linear system is under test.
Or do you think the crossover frequency is the only part that influence the rise time and a speaker driver have no or few rise time influence?
No. See the example above of a composite woofer+filter system. Of course, any woofer in and of itself is a bandpass system, usually with a quite variable, non-flat frequency response in its passband.
Logically a mechanical device have more influence random phase errors because there need move masses.
At first glance, it all might sound very logical, but the mathematical model of the mechanical device provides us with insights into its behavior. When one device has the same frequency response as another device, then their rise times, etc., will all be the same irrespective of their different masses, stiffnesses, dampings, etc. That's where Thiele and Small made great inroads into the understanding of low-frequency response functions for woofers, and by analogy the same approaches work also when characterizing the performance of tweeters.
If there is no problem with speed of a driver system why should build 3 way systems?
It seems that the so-called "speed" issue is front and center in your interpretation of the various parameters that affect the performance of a multi-way loudspeaker system. As the example I provided above (hopefully) demonstrates, there is no "speed" associated with any given driver. It's how it is integrated into a system, which is typically made up of low-frequency woofers and their enclosure alignments and crossover filters and other (equalized) driver responses that determines the rise-time when tested with transients.
For sound quality, it doesn't help when 20% of rise time depend on crossover 80% on driver speed or 80% depend on crossover and 20% on driver speed. It is same slow and cause lots phase shift and lag.
I know that I am repeating myself here, but the rise-time depends entirely on the frequency response of the system. For example, when tested with a step input, a loudspeaker system that has a perfectly flat (ideal) bandpass response that is –3dB at 30Hz and 15kHz will have a slower rise time than will a bandpass system that is –3dB at 60Hz and 15kHz, all other things being equal.

For a multi-way loudspeaker system, be it 2-way or higher, there is phase shift being added into the summed response. Also, geometric offsets between the drivers will affect the phase response due to differential time delays between the outputs of the drivers. However, these are generally of a not very great magnitude, and the available literature indicates that they do not affect the sound quality; there are much more important design factors to consider.
I am only sure that steep crossover sound not good.
Hmmm. That's a subjective impression and it runs counter to the experience of others. Steeper crossovers bring many benefits to the listening equation when implemented in multi-driver loudspeaker systems, such as minimizing the driver interaction region through the crossover.
I do tests with DSP 24 18 12 and 6 dB. 24 dB sound not good in reverb and room.
When one changes the order of the crossover filtering, there is also a requirement to adjust the responses of the drivers to get the summed responses identical. Did you try and do that? If so, how did you accomplish it? If the summed responses were not identical, then what you were hearing would have been down to differences in the magnitude frequency response curves, no more, no less.
More as 24 I have not tested. But I guess it sound worser because of much phase shifts and lag. The JBL use 6 dB crossover.
Which JBL uses a 6dB/octave crossover. Certainly none of their powered studio monitors, I expect.

A 6dB/octave crossover is quite difficult to implement well, as there is a very large transition band through the crossover region. This means the drivers need to be very well behaved to get a nice and flat on-axis summed frequency response. These first-order crossovers are popular in some circles due to their perfect time domain response, but that comes at the expense of off-axis radiation patterns that may not be as well controlled as desired for applications in a typical listening room. The tweeter especially has to have excellent low-frequency power handling and excursion capabilities, as it is called upon to reproduce quite low frequencies at relatively high levels.

@bennybbbx Have you tried implementing a high-order crossover using FIR filters? These can attain a very steep roll-off, but with entirely linear phase response, manifesting as a pure time delay. Summing the FIR-filtered low-pass and high-pass responses should produce an almost-ideal loudspeaker, affected only by the low-frequency and high-frequency roll-off shapes of the low-frequency and high-frequency drivers that make up the overall system. However, there is likely to be a step-like response in the loudspeaker's directivity at the crossover point, as the transition region would be only tens of hertz wide.
 
Last edited:
OP
B

bennybbbx

Addicted to Fun and Learning
Joined
May 27, 2020
Messages
568
Likes
105
Location
germany
We now create another system comprised of an 18-inch woofer, which has exactly the same-shaped frequency response function as that of the 6.5-inch system.

and for @Wesayso too. Of course this give same rise time in step response. If we know the max frequency -3 db of the mid/bass is the best. but in speaker test we did not know the max frequency of the bass/mid driver or did you know this from the kali lp6 ?. so what can speaker testers other do to show something that let conclusion to max freq -3 db. and the FR is not so much influence. most speakers of same inch have very simular bass range. I show with my tests clear that 5 db more increase the step response by 5%. but the decay time can also ignore and only look at rise time. The step response is good to see more. and for DIY build speakers and people that can hear ITD, i suggest to try a Bass/mid system that can reach 15 khz - 3 db and compare to a system that reach only 5 khz - 3db. maybe come to same conclusion as i get. And thats maybe also the reason that people think wide band speaker sound better in depth of field transient and . maybe it is a bad choose also to use low crossover frequency of 1.5 khz and steep filter. this give alot of additional phase shift in the ITD range upto 1.3 khz. when use a crossover with 2.5 khz as most do, then the phase shift in the range upto 1.5 khz is less and it have in general faster rise time. the curve of the rise time depend on phase shifts too. with phase linear filter there get a more straight and not so much roundet curve. and step response also show the time align of tweeter and mid good.
 
Status
Not open for further replies.
Top Bottom