I'm jumping into the deeper end of TS and looking to find some transient response information but this is very hard to come by and does not look like they are included in the original T/S parameters.
My understanding is that transient response is the time it would take for a note/signal to go from 0-100 and back to 0. I have seen some impulse response graphs that are supposed to help, but no T/S parameters.
So I had a thought that a loose approximation is at least possible. For instance we have the BL which is the 'motor strength' which is like the muscle of the speaker, then we have the MMS, which is the mass of the moving parts. Then we have the CMS, which is the strength of the suspension system, surround and spider. Between these we should be able to find SOME approximation of the ability of the BL to pull along the MMS and the CMS, right? The question is what are the equations.
The MMS is weight, the BL is strength, so lower weight and higher strength would be amazing, then we have CMS and something about CMS is that I cannot confirm is higher is tighter or looser suspension? So in a perfect world we would have high BL, low MMS and a medium CMS (so that the speaker doesnt rip itself apart?), or loose CMS. But is lower number looser or tighter?
I am currently compairing a 5 1/4 sub to a 10" sub and it looks like the 5 1/4 would be "faster" a .248 vs a .13, sound about right, right? Keep in mind I am simply looking at response rates not SPL. This does not take into account CMS, which is the X factor in this. Has anyone else tried to do this?
My understanding is that transient response is the time it would take for a note/signal to go from 0-100 and back to 0. I have seen some impulse response graphs that are supposed to help, but no T/S parameters.
So I had a thought that a loose approximation is at least possible. For instance we have the BL which is the 'motor strength' which is like the muscle of the speaker, then we have the MMS, which is the mass of the moving parts. Then we have the CMS, which is the strength of the suspension system, surround and spider. Between these we should be able to find SOME approximation of the ability of the BL to pull along the MMS and the CMS, right? The question is what are the equations.
The MMS is weight, the BL is strength, so lower weight and higher strength would be amazing, then we have CMS and something about CMS is that I cannot confirm is higher is tighter or looser suspension? So in a perfect world we would have high BL, low MMS and a medium CMS (so that the speaker doesnt rip itself apart?), or loose CMS. But is lower number looser or tighter?
I am currently compairing a 5 1/4 sub to a 10" sub and it looks like the 5 1/4 would be "faster" a .248 vs a .13, sound about right, right? Keep in mind I am simply looking at response rates not SPL. This does not take into account CMS, which is the X factor in this. Has anyone else tried to do this?
TS parameters have nothing common with transient response, as you defined it - it depends heavily on the high frequency response (TS parameters are describing only the low frequency response).
Do not focus on Mms, BL and Cms. If you want "fast bass", you need low Qtc parameter (0.5 to 0.7) for sealed enclosures and low Qts parameter (0.35 or lower) and low group delay alignment for vented/bass-reflex enclosures.
Do not focus on Mms, BL and Cms. If you want "fast bass", you need low Qtc parameter (0.5 to 0.7) for sealed enclosures and low Qts parameter (0.35 or lower) and low group delay alignment for vented/bass-reflex enclosures.
the QTC parameter is said to have a preferential reading for sealed/vented enclosures. That may help a bit but why ignore motor strength and moving mass? Do you have anymore insight.
You are referring to filter transient response with regards to the woofer rolloff, its damping and slope. You can arrive at these in different ways from various ranges of T/S, which makes it a little difficult to know how to respond to this question. Have you considered the efficiency/bandwidth product of a speaker? fs/Qes suggests an application, for example below 50 may suit a closed box.
(Could this be better served in another subforum, such as subwoofers?)
(Could this be better served in another subforum, such as subwoofers?)
Qtc parameter is property of sealed enclosures only. Vented enclosures do not have Qtc parameter.
You can not conclude anything useful by analyzing Bl and Mms parameters in isolation from other parameters.
If you want the best transient response (without overshoot) in the low frequency band, sealed enclosure with Qtc=0.5 is the only way to go.
It’s not necessarily just for subwoofers. Transient response can be just as important in any speaker. The post was about transient response in general not necessarily subwoofers.
Ok fair, I’m getting used to the TD parameters.
I see what you are saying about the QTC in the enclosure. But without buying 2 drivers and building 2 enclosures and then listening and/or measuring there is no way to chose one driver over the other.
Why is BL/MmS useless? I see very little on this good bad or otherwise.
^^ I agree, it's just a matter of going where the knowledge is for each particular question. Let us know if you change your mind.
The Acceleration Factor is an indicator of a speaker's ability to respond to an impulse. It is calculated as follows ; Gamma = BL/Mmd . The units are given as ms^-2 A^-1 (Metres per second per second per Ampere).
You don't need to build and listen to, it is known that Qtc=0.5 is transient perfect (no overshoot).
How to choose one driver to another? Because TS parameters usually are known (spec-sheet or tested), just run simulation of both drivers and compare.
Because high ratio Bl/Mms usually means no low bass. Complete box simulation with WinISD, VituixCAD (or something similar) is the only way to go.
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Isn't this covered in Dan Wiggins' article about 'Woofer Speed'? And the answer is low inductance:
"Mass isn't the problem - inductance is. So if you want faster transient response, ignore that moving mass parameter that some manufacturers push - look at the inductance!"
"Mass isn't the problem - inductance is. So if you want faster transient response, ignore that moving mass parameter that some manufacturers push - look at the inductance!"
Related (i just had to dig this out for another thread (on another forum): https://adireaudio.com/wp-content/uploads/2018/12/Adire-Audio-Woofer-Speed-by-Dan-Wiggins.pdf
dave
Edit: i see andesonix beat me to this paper.
T/S parameters are only relevant at the frequency of the drivers resonance. It doesn't describe anything else which mean it is only used for dimensioning of box wrt. bass behaviour. A transient response is a wideband affair while box tuning using T/S params is a small band affair.
//
Room screws stuff up. A wild card. Probably the most important part of your hifi but the hardest to change.
dave
dave
If this is your answer to my question in post 14, than it not negate the importance of loudspeaker with tight, precise bass. Even in rooms with bad acoustic good loudspeakers will sound better than bad loudspeakers.
It does not, it just says that you need to consider your room when designing or choosing your loudspeakers.
dave
dave
Besides the obvious smart choice of small loudspeaker in small room instead of big, bass heavy floor-stander (or big, powerful speaker in a big room), and bearing in mind that particular room acoustic may influence our choice (of loudspeaker) regarding other speaker characteristics - like dispersion in mid or high range, I fail to see how room acoustics will change the fact that loudspeakers with tight, precise bass always sound better than loudspeakers with soft, imprecise, floppy and "one-note" bass.
The Dan Wiggins white paper is more to do with promoting a 6.5'' speaker and his theory is not substantiated due to his faulty treatment of Newton's second law . That paper should be ignored.
This topic should be moved to the speaker forum section.