Im thinking about all the sighing that goes on over drivers with small xmax and its limitation of output.
i'm thinking of an instrument like a cello, how much is its xmax? They get pretty loud!
Or a violin? Heck a clarinet has an xmax of 1mm so an xmach of 2mm and they get LOUD! I know i played one.
Bass clarinet plays down to 35hz or so and has an xmax of 1.5mm, its horn loaded i know.
Hey im gonna do a horn resp layout of a bass clarinet. Its front loaded wit a back chamber of about 5cc, and s1 of 25mm2 and an s4 of about 5525mm2. As for the transducer properties its numbered stiffness bamboo reeds so pick a compliance and giver! I think the thing is about 1.5m long if my memory serves me.
i'm thinking of an instrument like a cello, how much is its xmax? They get pretty loud!
Or a violin? Heck a clarinet has an xmax of 1mm so an xmach of 2mm and they get LOUD! I know i played one.
Bass clarinet plays down to 35hz or so and has an xmax of 1.5mm, its horn loaded i know.
Hey im gonna do a horn resp layout of a bass clarinet. Its front loaded wit a back chamber of about 5cc, and s1 of 25mm2 and an s4 of about 5525mm2. As for the transducer properties its numbered stiffness bamboo reeds so pick a compliance and giver! I think the thing is about 1.5m long if my memory serves me.
Pleas quit speculating and go read real physics. Even a free program like WinISD will show you some nice and easy to understand charts.
You also need to consider the DISTORTION. This depends on motor design. Many drivers Xmax is way past their linear operation. Has it occurred to you that if it was only about Xmax that all speaker would be an inch across and eq'd to flat?
You also need to consider the DISTORTION. This depends on motor design. Many drivers Xmax is way past their linear operation. Has it occurred to you that if it was only about Xmax that all speaker would be an inch across and eq'd to flat?
Sigh.
Xmax is a value given to moving coil loudspeakers. It is simply an attempt to describe / indicate the linear operating range of the motor, or powertrain as it is probably more accurately described. However, there is no universal derivation.
Probably the most popular method, or at least the most consistent, is to measure a drive unit under load, and set Xmax as the point at which it reaches 10% THD.
An alternative method, which does not require measuring the driver, is to take the absolute value of the magnetic gap height minus the height of the VC winding & divide that by 2. Unlike the above, this does not set Xmax to any one particular value, since motor designs vary dramatically and this has a significant effect upon drive unit linearity. There have been several other suggestions for setting a value on linear operating range too, if memory serves.
As a general rule, manufacturers rarely state the method / criteria they used to establish the figure given in their datasheets. Therefore, IMO the exact numerical value listed should be viewed as part of a wider context, and it is arguably less significant than the general indication it provides, i.e. it may assist in narrowing down a list of possible options for a given application.
Xmax is a value given to moving coil loudspeakers. It is simply an attempt to describe / indicate the linear operating range of the motor, or powertrain as it is probably more accurately described. However, there is no universal derivation.
Probably the most popular method, or at least the most consistent, is to measure a drive unit under load, and set Xmax as the point at which it reaches 10% THD.
An alternative method, which does not require measuring the driver, is to take the absolute value of the magnetic gap height minus the height of the VC winding & divide that by 2. Unlike the above, this does not set Xmax to any one particular value, since motor designs vary dramatically and this has a significant effect upon drive unit linearity. There have been several other suggestions for setting a value on linear operating range too, if memory serves.
As a general rule, manufacturers rarely state the method / criteria they used to establish the figure given in their datasheets. Therefore, IMO the exact numerical value listed should be viewed as part of a wider context, and it is arguably less significant than the general indication it provides, i.e. it may assist in narrowing down a list of possible options for a given application.
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Not quite sure of what your asking.
im sure that within its xmax most drivers exhibit minimal distortion.
I know that the sound of a clarinet changes drastically if you overblow.
What aspect of physics would clarify my understanding, being specific.
Im also aware that most of the sound, 70% perhaps, is composed of harmonics.
Ah well i kind of forgot where that whole thread came from anyhow.
im sure that within its xmax most drivers exhibit minimal distortion.
I know that the sound of a clarinet changes drastically if you overblow.
What aspect of physics would clarify my understanding, being specific.
Im also aware that most of the sound, 70% perhaps, is composed of harmonics.
Ah well i kind of forgot where that whole thread came from anyhow.
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Not necessarily. As I noted above, there is no single definition for Xmax. One of the most popular ways requires the drive unit to be measured, and sets Xmax at point at which 10% Total Harmonic Distortion (THD) is reached. That is at least a consitent method, although note that a driver may be at anything up to 9.999% distortion below this point.
Another purely mathematical method of providing a figure that can be called Xmax does not set it to a specific distortion figure at all, so unit X may be at 10% THD at the value obtained, while unit Y would be at 5% THD, and unit Z could be at 40% THD.
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your thought/question can be summed up as:
"how can a bass clarinet/cello produce 35Hz so easily while a speaker can't?"
well
one is a musical instrument
the other is not.
the musical instrument does not reproduce sound. It produces sound. The sound you hear is "distorted" (one would say). It can not produce any kind of sound. It can produce only that specific sound.
"how can a bass clarinet/cello produce 35Hz so easily while a speaker can't?"
well
one is a musical instrument
the other is not.
the musical instrument does not reproduce sound. It produces sound. The sound you hear is "distorted" (one would say). It can not produce any kind of sound. It can produce only that specific sound.
Geez, give him a break. He's just posting a theory, not spreading lies.
To the OP......
You need more excursion with small radiating surfaces, because they can't rely on the characteristics of the actual instrument.
Things like resonating of panels and such, like a piano. Sure, they are just strings but, they are exciting the whole instrument. This moves more air than the string itself.
Or like you said, the horn loading of a ummm......a horn
a titanium 'reed' in an oboe or clarinet would be a totally different instrument, but probably a great experiment, also likely a poor instrument. . The goals of an instrument and a reproducer are obviously at the opposite ends of an imagimary scale. One end being to maximise colouration and give timbre, colour tone etc. The other end being to minimise harmonic distortion.
cone excursion behavior can vary in the passband under transient conditions, from beat-tones between instruments or a bass instrument's fundamentals and harmonic content, enclosure type and its input impedance valley(s) placement/magnitude and Z below the passband. Sometimes a longer xmax driver such as W8-1772 will do less useful work and behave worse than say FE206EN as the Tangband has lower average impedance and draws more current below the useful range of the enclosure. I've seen drivers such as Nirvana Super10 in a 70 liter 41Hz tuned reflex go chaotic. Use of better loading such as a Karlson coupler will keep things under control longer.
one rough estimate of xmax is by the 70% BL point (Lc - Hg)/2 + 1/4(Hg) = x-max (70% Bl)
if a driver is seen moving much at a high overall rate then it can "gargle" which is highly disconcerting - even 15" coaxial will gargle on some material at modest listening levels.
one rough estimate of xmax is by the 70% BL point (Lc - Hg)/2 + 1/4(Hg) = x-max (70% Bl)
if a driver is seen moving much at a high overall rate then it can "gargle" which is highly disconcerting - even 15" coaxial will gargle on some material at modest listening levels.
yes, its horn loaded
try without, and blow just the mouth piece
you know it sounds like a duck
hmm, thinking about adding compressed air to a horn speaker
playing a horn instrument, the 'air blow' is always in the same direction
but when a woofer reproduces its sound it will move both back and forth to do it
funny stuff
playing a horn instrument, the 'air blow' is always in the same direction
but when a woofer reproduces its sound it will move both back and forth to do it
Well, the reed is the oscillating piece, just like the speaker driver. (creating compression and rarefaction)
The (air blow) is the power....it's constant.
Geez, give him a break. He's just posting a theory, not spreading lies.
To the OP......
You need more excursion with small radiating surfaces, because they can't rely on the characteristics of the actual instrument.
Things like resonating of panels and such, like a piano. Sure, they are just strings but, they are exciting the whole instrument. This moves more air than the string itself.
Or like you said, the horn loading of a ummm......a horn
What I am suggesting is there is considerable factual information available that will greatly help the OP instead of spending too much time arguing their point here. Just put in a little effort please. It is a very simple matter of physics to calculate how much air has to be moved to produce a given amount of sound at a given frequency. Even free tools will plot it. If you know your surface area, you can then calculate the displacement required. Instead, thread after thread is full of fine folks that are convinced that physics does not apply to them if they choose to have a different view. That is fine, believe what you will. I prefer to believe in physics that I can measure, model mathematically, and use reliably.
A speaker is not a reed instrument. They are using the internal air column as the radiating surface.
The old phrase is "you can lead a horse to water, but you can't make them drink".
Quite right, Xmax is not standard, and I have seen Xlin numbers. Sometimes it is where the driver is sort of usable, sometimes it is when the former slams into teh pole piece.
you can infer from the actual value what it is about.
if you see a 1mm value for a large full range speaker you can guess it is for the displacement where the speaker remains linear.
if you see a 20mm value for a small woofer (say 8"?) you can be pretty sure it's the physical movement possible, with sound quality suffering
I seem to recall writing something about this above... Depends what you mean by 'linear.' Using one method of setting a value to Xmax, it means anything less than 10% THD. With other methods, there isn't even a specific distortion value attached to the figure obtained -it could actually be anything from a very small figure to a very large one. The point is, distortion will still be present within the supposed 'linear' region (however it's defined), and there will not necessarily be an abrupt transition from low to high THD levels beyond that given length. Granted, irrespective of the method used to put a value on Xmax, you'll likely be better off staying within it, but it's a fairly nebulous concept anyway & is useful more as a general guide than anything else.
Depends what you mean by 'linear.' Using one method of setting a value to Xmax, it means anything less than 10% THD. With other methods, there isn't even a specific distortion value attached to the figure obtained -it could actually be anything from a very small figure to a very large one. The point is, distortion will still be present within the supposed 'linear' region (however it's defined), and there will not necessarily be an abrupt transition from low to high THD levels beyond that given length. Granted, irrespective of the method used to put a value on Xmax, you'll likely be better off staying within it, but it's a fairly nebulous concept anyway & is useful more as a general guide than anything else.
X-travel (amplitude) and frequency are inter-related.
A bass driver could be around 1mm to 10mm of amplitude when reproducing bass signals loudly.
A mid driver could be 0.1mm to 2mm, when loud.
A treble driver could be 0.01mm to 0.1 when loud.
Yes, 0.1mm of one way travel @ 10kHz would be VERY loud.
A bass driver could be around 1mm to 10mm of amplitude when reproducing bass signals loudly.
A mid driver could be 0.1mm to 2mm, when loud.
A treble driver could be 0.01mm to 0.1 when loud.
Yes, 0.1mm of one way travel @ 10kHz would be VERY loud.
You're not kidding.
Depends how much cone area you have really, and as Andrew notes, the frequency in question. Moving coil loudspeakers are inherently quite inefficient, although you can make a more or less dramatic improvement in this via horn loading over some portion of its BW.
It's possible to make driver behaviour reasonably linear at large deflections -not easy, but possible. FMD & AMD (often labelled as doppler distortion) can become an issue though at large deflections, depending on the BW covered by the drive unit in question. Can. It can also be overstated. All other things being equal, as frequency drops, you're better off with a larger cone if you need to maintain efficiency. Trouble is, those other things are never equal.
Depends how much cone area you have really, and as Andrew notes, the frequency in question. Moving coil loudspeakers are inherently quite inefficient, although you can make a more or less dramatic improvement in this via horn loading over some portion of its BW.
It's possible to make driver behaviour reasonably linear at large deflections -not easy, but possible. FMD & AMD (often labelled as doppler distortion) can become an issue though at large deflections, depending on the BW covered by the drive unit in question. Can. It can also be overstated. All other things being equal, as frequency drops, you're better off with a larger cone if you need to maintain efficiency. Trouble is, those other things are never equal.
you described in more detail my position, thanks
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about what andrew said, of course amplitude is related to displacement and frequency, that is why displacement is mostly irrelevant at high frequencies, xmax is important only in the bass region and that is why i glossed over the fact (the fact that amplitude is related to displacement and frequency)
Hell, 440Hz is painfully loud at less than 0.1mm with the 12" CF AN (certainly less. a rough estimate. ) I'd say 0.1mm at 10KHz wouldn't be just loud, it would be a weapon. You could possibly cut through steel with it.
after the test now my ear is ringing. Something good came of it though, i found out that the room is bristling with resonances. dammit.
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about what andrew said, of course amplitude is related to displacement and frequency, that is why displacement is mostly irrelevant at high frequencies, xmax is important only in the bass region and that is why i glossed over the fact (the fact that amplitude is related to displacement and frequency)
Hell, 440Hz is painfully loud at less than 0.1mm with the 12" CF AN (certainly less. a rough estimate. ) I'd say 0.1mm at 10KHz wouldn't be just loud, it would be a weapon. You could possibly cut through steel with it.
after the test now my ear is ringing. Something good came of it though, i found out that the room is bristling with resonances. dammit.
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I dressage totally. If you could actually RECORD a piano, a good speaker system should be able to reproduce it just as well as a good guitar recording. OK, we are short on those too. I use female voices for final voicing on my speakers. Usually Joni Mitchel or someone like that. If you get her right, Julian Bream will sound right.
I bet you are thinking that because speakers are the weakest link in the chain by far, some of the trade-offs are so far biased that you don't get a overall good result. Maybe with a really bad cheap speaker, but when you start to build a decent one, if they are better at one thing, they will be better at everything. This being the single driver thread, every design here is severely limited and no single driver can ever reproduce the piano. I have not heard one reproduce a guitar either.
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