Greetings to all!
First, please me if this has been discussed here or elsewhere. Could not find anything satisfactory though.
1. Does the mechanical integration of a whizzer have a definite order of crossover? Would it be similar to a 6 dB slope to a tweeter which a single capacitor demonstrates?
2. Does it entail a definite amount/degree of phase shift? Would it be similar to a
what a single capacitor ("1st order" slope) demonstrates?
3. Are there any manufacturer datasheets which disclose phase response of such whizzer based wide band drivers? Or any actual measurements of any such drivers?
It would be greatly helpful if somebody can share something useful on these questions. 🙏
Thanks in advance....
sujat
First, please me if this has been discussed here or elsewhere. Could not find anything satisfactory though.
1. Does the mechanical integration of a whizzer have a definite order of crossover? Would it be similar to a 6 dB slope to a tweeter which a single capacitor demonstrates?
2. Does it entail a definite amount/degree of phase shift? Would it be similar to a
what a single capacitor ("1st order" slope) demonstrates?
3. Are there any manufacturer datasheets which disclose phase response of such whizzer based wide band drivers? Or any actual measurements of any such drivers?
It would be greatly helpful if somebody can share something useful on these questions. 🙏
Thanks in advance....
sujat
If response is (iir dsp) linear(ized) then the phase should be linear too.
I would say 6 and 6db filters and acoustical separation of bass and tweet can have more phase issues but its all implementation in the end.
Phasing irregularities above 5khz don't play a role any more. Dispersion and distortion is more audible
I would say 6 and 6db filters and acoustical separation of bass and tweet can have more phase issues but its all implementation in the end.
Phasing irregularities above 5khz don't play a role any more. Dispersion and distortion is more audible
Loudspeaker drive units are essentially (essentially) minimum phase devices, so the phase response follows the FR; if you see a deviation in one, the other will follow, since they're inherently connected. So in order:
Not really. In theory it's 2nd order but in practice the mechanical & acoustic interactions with the coil, main cone, suspension & other components vary wildly with the design, so there is no fixed consistent slope you can separate out & track that applies to every drive unit with sub-cones until it eventually reaches a given point (also depending on the design).
Per above: the overall phase response of a drive unit basically follows the frequency response, & since there is rarely a total transition in emitting surface from the main cone to the sub-cone, the electrical analogue isn't especially useful here.
Also per above.
Scott, thank you for your detailed and comprehensive response as always. It gives me a fair idea now.
(Your post somehow doesn't show the "quote" feature.)
I wonder then, with so much of mechanical & acoustic interactions with the coil, main cone, suspension & other components, how does such a driver sound (like many experts endorse/describe) more seamless & coherent than 2-way or more elaborate designs which use electrical crossover components? Coherent in what aspects?
This is not an expression of a doubt, but a genuine, passionate interest in this very intriguing contraption! As i see it, with a single wide-band driver.... as with everything else, the simplicity is the greatest luxury!
Thanks in advance.
(Your post somehow doesn't show the "quote" feature.)
I wonder then, with so much of mechanical & acoustic interactions with the coil, main cone, suspension & other components, how does such a driver sound (like many experts endorse/describe) more seamless & coherent than 2-way or more elaborate designs which use electrical crossover components? Coherent in what aspects?
This is not an expression of a doubt, but a genuine, passionate interest in this very intriguing contraption! As i see it, with a single wide-band driver.... as with everything else, the simplicity is the greatest luxury!
Thanks in advance.
The once well-known whizzer-less 4" JX92S by Ted Jordan, has published or measured phase chart (Jim Griffin?), essentially ruler flat. I haven't studied whizzers' phase, sorry. Most of my "fullrange" arsenal are whizzer-less. In principle, I can compare any driver against JX92S as "standard", just by listening to them together playing frequency sweep.
I don't really know, since 'seamless' and 'coherent' don't have a technical definition, so to a point, people tend to call them what they like & it varies from person to person. Being point sources no doubt helps (and probably a large amount of what's liked is because of that), but I don't necessarily find all wideband drivers automatically superior than a quality 2-way or visa versa. Depends on the design. There are some widebands I find completely unlistenable for instance, due to a fairly rotten axial and / or power response, gain peaking at problem frequencies, blanking off-axis etc. Equally, there are some fairly poor multiways out there -usually ones either built to a budget, or some form of extreme philosophy that pursues one aspect over everything else.
Many people use fullrange drivers how they were constructed. With no special optimization.
Keeping in mind that electrically today a lot can be done to make them sound linear with modern dsp and careful on axis and off axis measurements. Even careful designed classical networks make them sound much better like in "Let's dance" speaker from "Don Highend".
There can be done some things mechanically bringing these drivers to a more acceptable sound level:
Damping the basket on both sides reducing first loud reflections through the cone and diverse cone treatments.
Some expensive fullrange drivers are already very sophisticated leaving not much space for further improvement but are rarely part of the listening experience of most hifi users.
Keeping in mind that electrically today a lot can be done to make them sound linear with modern dsp and careful on axis and off axis measurements. Even careful designed classical networks make them sound much better like in "Let's dance" speaker from "Don Highend".
There can be done some things mechanically bringing these drivers to a more acceptable sound level:
Damping the basket on both sides reducing first loud reflections through the cone and diverse cone treatments.
Some expensive fullrange drivers are already very sophisticated leaving not much space for further improvement but are rarely part of the listening experience of most hifi users.
I now see the picture quite better, from what you have described.
Thank you, Scott!
I recall having read this mention from you on a couple of other threads. I am a bit "shy" of implementing a surgery on a driver (scalpeling off the dust cap without disturbing the whizzer)!
Thank you for the useful suggestion again, Dave. 🙏
Please forgive me for asking how quantifiably "essentially minimum phase" are speaker drivers. Simple/dumb (math) questions: How does speaker grille (which changes very high frequency response) change the phase response? How do speaker placement and toe-in, listening position and ear angles, etc., change the phase response? All phase response can be reverse-modelled from measured-at-ear frequency response, at least in principle/to what extent?
It would be really helpful to have real-life examples/demonstrations of this "law", as well as counter-examples showing where/when it broke down.
Well, I'm sure you're familiar with the Fourier transform where a function of time is expressed as a function of frequency; moving coil drive units are generally taken as minimum phase devices in their piston & for practical purposes most of their TL (resoant) operating ranges, so the phase response is inherently connected to the frequency / amplitude response. That's why accurate extraction of minimum phase response works (or can work -the key word there being 'accurate' since that's it's not always the case 😉 ) via an HBT, Bohdan's IHBT &c. -for the latter see https://www.diyaudio.com/community/threads/automatic-extraction-of-minimum-phase-response.374898/ & the links he provides, which are more comprehensive than I could hope to do.
Diffraction & external effects can become modifiers, but you'll note I said 'loudspeaker drive units' not 'loudspeaker systems'. To use the grill as an example, if we ignore other aspects & just assume an acoustic damping effect on the HF however, you can expect the phase to continue following the frequency / amplitude response.
Diffraction & external effects can become modifiers, but you'll note I said 'loudspeaker drive units' not 'loudspeaker systems'. To use the grill as an example, if we ignore other aspects & just assume an acoustic damping effect on the HF however, you can expect the phase to continue following the frequency / amplitude response.
These get in to the room. Phase would not be of much interest.