What is this called?

[2leftears]

I just want to understand how one balances the sound changes caused by the speaker diaphragm material against that caused by the ground box and that caused by the crystals especially after conditioning them in sunlight !

With a magnet.

 

[gregorio]

I wish. My high school physics course number 3 (waves/vibrations) included 7 pages worth of acoustics (the basics) in the textbook.

Ah, OK, not all school children then. In the UK it is a required part of the national curriculum for middle school children (pre high school), so at/by age twelve. It’s very basic acoustics though; what are sound waves, what is frequency (demonstrating a vibrating string/string instrument), what are echoes, plus the basic anatomy of the ears and how we hear. As it’s so basic, it’s all covered in just a few lessons. At high school the students (age 13) get to choose which subjects they study but at middle school it’s all mandatory, so all school children learn it.

I’m surprised if that’s not typical in other countries, don’t they teach the basics of how the human senses work?

G

 

[71 dB]

Ah, OK, not all school children then. In the UK it is a required part of the national curriculum for middle school children (pre high school), so at/by age twelve. It’s very basic acoustics though; what are sound waves, what is frequency (demonstrating a vibrating string/string instrument), what are echoes, plus the basic anatomy of the ears and how we hear. As it’s so basic, it’s all covered in just a few lessons. At high school the students (age 13) get to choose which subjects they study but at middle school it’s all mandatory, so all school children learn it.

I’m surprised if that’s not typical in other countries, don’t they teach the basics of how the human senses work?

G

I don't remember how much of this stuff was taught to us before high-school. I still have my high-school physics textbooks from the late 80s and that's why I was able to check how many pages there was in the curriculum. Possibly very basic things are taught before high-school level, but children forgot fast, especially if they don't find it interesting.

Schools are different in each country. In the UK languages are not so important I assume? I studied the minimum amount of foreign languages in school: English and Swedish. There is limited amount of time for lessons and every subject competes each other. Teaching more about physics means less time for biology, history or the arts. Within each subject, teachers can prioritise what topics are more important and how much time is spend on a particular topic such as basic acoustics. The curriculum may suggest say 2 lessons, but in reality the teacher may use only 1 lesson to save time for "more important" topics or even skip the topic completely!

In Finland children start school (grade 1) at age 7. Elementary school covers 6 years. Secondary school is 3 years. After these mandatory 9 years of comprehensive school comes high-school (starts at age 16). I have heard school starts at lower age in other countries, but 13 sounds young for high-school.

 

[Ghoostknight]

you’re also “tapping the membrane lightly”?

imo a somewhat large woofer can handle it if you are careful (preferably tap in the middle)

Sounds ideal for fidelity and presumably the stereo speakers have to be quite close together, so you can reach to hit both at the same time

Why would i need to do that? hearing it once is enough

Quite a dilemma you have there, do you tune to your silver coins, the copper in your amp/speakers etc or the Kevlar in your speaker membranes and, what about your ear drums/membranes, shouldn’t you be tapping those lightly too and tuning to that? How do you tune to all those different tunings at the same time, do you just pick one and then all your songs just sound out of tune with everything else?

Imo first we should agree that everything has its own resonant frequency or rather profile which is pretty unique to a specific element or composition of elements (think for example pressboard, where glue and wood form a somewhat new material with its own characteristics)

another thing is, you are right its a "dilemma" so to speak
i can listen to some clay songs and clearly hear some of resonances i hear from brick walls, literally everything in your room hit by soundswaves will make up your final room accoustics and coming from harmonic and unharmonic distortion in audio, people might also understand how some things can sound subjectively "better" than others (specially coming from harmonic vs unharmonic distortion in audio if we go by resonant profile of materials)

BUT the big thing here is, it only sounds obviously out of tune if you actually make a somewhat "loud" sound with the specific material everything else will probably pretty much part of your noise floor, tho to me it still feels like the "stuff that makes up the noisefloor" has some influence on sound

EDIT: what i should also mention here, not only are these material resonances part of your noisefloor but for example with each drum hit, a sound wave will hit them, literally making them vibrate/resonate to the music.... so its probably even more than a pure noisefloor issue

-----

one thing is definitely materials that make up your room, it heavly lies in your noisefloor, but imo it gets more intersting if we talk about speaker cabinet materials or membrane materials, or even isolation paltform and feet materials as these try to tend to vibrate the most
but also think for examples, crystals placed on the speaker cabinet...

 

[BS5711]

Every room is full of all manner of different construction materials and other hard and soft furnishings of all sorts of shapes, dimensions and using all manner of materials.

Technically they will of course all have a different response to the vibration from music pumped into the room from large loudspeakers, is that an audible response, of course you believe so because everything is audible to you.

If you prefer the sound, for real or imagined reasons, with your pottery vase sitting 38.5cm from the left end of the glass table then do that.

Expecting others to believe this is a real thing that has meaningful application in home audio and asking them to discuss the matter with you is nonsensical.

I am clearly not the forum police but would this sort of conversation not be better saved for your mates in the tweaks forums ?

 

[bigshot]

A speaker is designed to produce a range of frequencies, not just one resonant frequency. Duh.

 

[2leftears]

A speaker is designed to produce a range of frequencies, not just one resonant frequency. Duh.

I think this is where Ghoostknight is getting themselves confused (or deluded).

Different speaker membrane materials do have a characteristic 'sound' to them, but this is when they break up, i.e, when the membrane itself is no longer considered a stiff material that moves in unison, but starts to flex in different vibrational modes.

Membrane materials and geometry are chosen/developed specifically to inhibit (stiffness) or control (dampen) such unwanted breakup behaviour. Those breakup resonance frequencies are (some of the) ones you hear when you tap your finger on a membrane, or rub it, and that is when paper will sound different from kevlar, or bextrene etc.

If such membrane breakup occurs to an audible degree during normal music playback, that would indicate a poor speaker design where the filter is not rolling off fast enough above the crossover frequency, or the crossover frequency has been chosen too high, such that too much high frequency content excites the membrane into internal vibrational breakup modes.

All membrane materials suffer from this breakup problem in theory, and therefore care needs to be taken during the design to control this unwanted behaviour. Examples of material where care needs to be taken with driver selection and bandwidth limiting are the classic paper cones, but also e.g. KEF's older bextrene-coned units such as their B200 driver.

When used judiciously, in good speaker designs, all these speaker cone materials function perfectly fine without any noticeable "paper", "bextrene" or 'kevlar" sound/colouration.

 

[gregorio]

imo a somewhat large woofer can handle it if you are careful (preferably tap in the middle)

So it’s always going to be out of tune with all your other drivers?

Why would i need to do that? hearing it once is enough

You would need to keep tapping them (according to your logic) because it you don’t then they no longer resonate. If you hit your silver coin (for example) hard enough with something solid and it’s free to resonate then it will resonate/ring at specific frequencies depending on the size of the coin. What happens though if you stop hitting it, does it magically hit itself, carry on resonating/ringing and break the laws of physics or does it stop resonating? If it stops, then how can it be in or out of tune?

Imo first we should agree that everything has its own resonant frequency or rather profile which is pretty unique to a specific element or composition of elements (think for example pressboard, where glue and wood form a somewhat new material with its own characteristics)

Everything does have “it’s own resonant frequency” but it is NOT “unique to a specific element or composition of elements”, it is unique to the amount and shape of the materials and in order to resonate it has to actually be free to resonate, and then of course it has to be hit with enough kinetic energy to actually cause it to resonate. What happens if you grip your silver coin tightly, how well does it resonate when you hit it then?

another thing is, you are right its a "dilemma" so to speak

Sure, being a deluded audiophile requires believing all sort of nonexistent things are both real and supposedly some sort of issue. The solution isn’t to go around hitting everything in your room and then having a dilemma about what to tune to, because it’s not possible to tune your system in the first place and secondly, it’s just insane. Presumably, you’re in the room when you’re listening to your speakers and according to your logic you must also have a resonant frequency, so do you sit listening to music recordings while hitting yourself? Maybe you should try hitting yourself a bit harder and see if you can knock some sense into yourself? The solution to your dilemma isn’t trying to tune your system to some BS you’ve invented, it’s to stop being delusional! Try learning some facts rather than just making up your own BS based on ignorance!

i can listen to some clay songs and clearly hear some of resonances i hear from brick walls

No, you CANNOT “listen to some clay songs” because there’s no such thing as a clay song or a copper song. You don’t seem to realise that just because you invent some crazy BS in your head, that doesn’t mean it’s actually real!

literally everything in your room hit by soundswaves will make up your final room accoustics and coming from harmonic and unharmonic distortion in audio …

Firstly, No, not “literally everything in your room”, if you put a silver coin somewhere in your room do you really believe your room now sounds of silver? Secondly, the “harmonic and unharmonic distortion in audio” has nothing to do with “your final room acoustics”, it also has nothing to do with resonant frequencies of “specific elements”! Your room acoustics are defined by the size and shape of the room, the reflective properties/absorption coefficients of the materials in the room, along with the angle of incidence of the sound waves and of the reflections. You don’t seem to have the first idea what room acoustics even is!

BUT the big thing here is, it only sounds obviously out of tune if you actually make a somewhat "loud" sound with the specific material …

That is not a thing at all, let alone a “big thing”. The only “big thing here” is how ignorant you are of acoustics and how you’ve seemingly convinced yourself of your own BS!

G

 

[Ghoostknight]

Different speaker membrane materials do have a characteristic 'sound' to them, but this is when they break up, i.e, when the membrane itself is no longer considered a stiff material that moves in unison, but starts to flex in different vibrational modes.

break up is when things start to get "really worse" as distortion heavly increases (tho that doesnt mean no distortion exists at all before that)

think of a vibrating sheet of paper..... it will produce "material resonances" no matter what..... break up is when the movement gets so harsh that the membrane doesnt move (or RESONATE) uniformly anymore ..... but literally the "breakup" into smaller parts resonating radically will produce a new set of distortions (probably a much harsher/bad sounding distortion profile beside the overall rising distortion percentage)

also with most speakers we are probably talking like 2-10% distortion in "normal operation", i mean you guys can keep arguing whether its all "inaudible", to me the kevlar songs tests with my own speaker sound signature was enough of a test for me to believe in it

So it’s always going to be out of tune with all your other drivers?

in terms of such low level difference these will not sound out of tune... but for example the soft dome tweeter will have another sound characterisitic than the kevlar woofer, maybe a good match in the end, maybe not?

You would need to keep tapping them (according to your logic) because it you don’t then they no longer resonate.

dont you think a pretty short precise bass hit doesnt let the membran vibrate just like i do with tapping it? you just dont hear most of it actively as its drowned down by the main tone, THO imo the specific material characteristics still can be heared, just like a maple guitar neck sounds different to walnut or whatnot

If you hit your silver coin (for example) hard enough with something solid and it’s free to resonate then it will resonate/ring at specific frequencies depending on the size of the coin. What happens though if you stop hitting it, does it magically hit itself, carry on resonating/ringing and break the laws of physics or does it stop resonating? If it stops, then how can it be in or out of tune?

lets stay with the membrane example....

imagine a "pretty short precise bass hit" followed by another one .....
of course the second bass hit will change how the membran is "swinging out", does it mean the membrane does it in an completely random way? no .... it will resonate/vibrate just like kevlar usually does

dont get me wrong, you can literally hear the tone kevlar makes is a pretty "damp" mostly bassy one (the latter i suspect comes mainly from the cabinet)
and just because speaker manufacture try to minimize resonances it doesnt mean its a completely inhert material, just maybe more inhert than others
at that point it becomes a interesting question, do you rather take the most inhert material (which in the end still contributes to the sound somewhat) or maybe a material that is "a bit" less inhert but sounds more "harmonic" in the end

Everything does have “it’s own resonant frequency” but it is NOT “unique to a specific element or composition of elements”, it is unique to the amount and shape of the materials and in order to resonate it has to actually be free to resonate, and then of course it has to be hit with enough kinetic energy to actually cause it to resonate. What happens if you grip your silver coin tightly, how well does it resonate when you hit it then?

of course the silver coin will vibrate less if you grab it tightly, but im unsure what you are trying to say, its ONE variable under a dozens or more that will affect the endresult, and imo the material/element itself is just an variable as well, you are denying science yourself here

Firstly, No, not “literally everything in your room”, if you put a silver coin somewhere in your room do you really believe your room now sounds of silver?

No but it might in the end of the day be the one harmonic sounding thing in your room made out of clay(bricks), plasterboard and plaster

 

[bigshot]

If a speaker can produce a full range of frequencies without objectionable levels of distortion, it isn’t “breaking up”. Properly functioning speakers don’t have a “resonant frequency”. Duh again.

You can’t hear what the cone is made of. What you can hear is the dispersion characteristics, and that is as much a part of the room acoustics as it is the speaker. And room acoustics affect the response more than anything in the speaker itself.

 

[2leftears]

break up is when things start to get "really worse" as distortion heavly increases (tho that doesnt mean no distortion exists at all before that)

think of a vibrating sheet of paper..... it will produce "material resonances" no matter what..... break up is when the movement gets so harsh that the membrane doesnt move (or RESONATE) uniformly anymore ..... but literally the "breakup" into smaller parts resonating radically will produce a new set of distortions (probably a much harsher/bad sounding distortion profile beside the overall rising distortion percentage)

That confirms my suspicion you are confused as to the role (or not!) membrane material plays in the resonance characteristics. You really need to familiarise yourself with speaker driver design theory before floating all these ideas. I admire your perseverance and enthusiasm for all all your experiments, but presenting the pseudoscientific ideas behind it in a science forum isn't going to go down well.

You could try and read a book on speaker driver design, but it would be pointless, because they are full of maths, materials science, acoustic science, and measurements. In these books they don't experiment tapping membranes to check the speaker material is sympathetic to the music material being played...

dont get me wrong, you can literally hear the tone kevlar makes is a pretty "damp" mostly bassy one

"damp" . There's a new one for the audiophile phraseology book...

 

[71 dB]

Properly functioning speakers don’t have a “resonant frequency”.

Not in the ways Ghoostknight says. Speakers do have resonances, but in properly designed speakers those resonances are controlled and even beneficial! For example in ported speakers the bass response has been extented downwards using intentional and carefully tuned Helmholtz-resonance of the speaker cabinet.

 

[gregorio]

in terms of such low level difference these will not sound out of tune...

So you’re contradicting yourself now.

but for example the soft dome tweeter will have another sound characterisitic than the kevlar woofer, maybe a good match in the end, maybe not?

Now that’s true. I find that dome tweeters tend to sound a bit brighter/higher pitched than Kevlar woofers but I always thought that was just me imagining things. Interesting that someone else has noticed this different sound characteristic.

dont you think a pretty short precise bass hit doesnt let the membran vibrate just like i do with tapping it?

You’re joking right? I suppose it stands to reason that if you don’t really know what sound and acoustics are then you also wouldn’t understand how drivers work. The answer to your question is “no”, can’t you hear the difference between your driver reproducing a bass hit and you tapping the driver membrane?

imagine a "pretty short precise bass hit" followed by another one .....
of course the second bass hit will change how the membran is "swinging out", does it mean the membrane does it in an completely random way? no .... it will resonate/vibrate just like kevlar usually does

And that confirms you don’t understand how drivers work! The driver indeed does NOT move “in an completely random way” but it also doesn’t move according to how Kevlar resonates, it moves/vibrates according to the voltage swings in the analogue audio signal, that’s why it’s called analogue, because the voltage swings in the analogue signal are analogous to the physical movement/vibrations of the driver/sound wave.

you can literally hear the tone kevlar makes is a pretty "damp" mostly bassy one (the latter i suspect comes mainly from the cabinet)

So your speaker cabinets aren’t made of solid silver, they’re made of Kevlar? Make up your mind! According to your logic; if the bassy/tone “comes mainly from cabinet” and it’s “the tone Kevlar makes” then your speaker cabinets must be made of Kevlar, because if they were made of say wood or MDF, then surely the tone coming from the cabinets would be the resonant frequency of wood or MDF, not Kevlar.

of course the silver coin will vibrate less if you grab it tightly, but im unsure what you are trying to say …. you are denying science yourself here …

No, I’m not denying science, I’m denying your BS/fallacious use of science! Did you watch the video? If so, how did you miss the fact that the bells were suspended and therefore free to resonate/ring, then hit with a hammer to actually make them resonate? And therefore …

No but it might in the end of the day be the one harmonic sounding thing in your room made out of clay(bricks), plasterboard and plaster …

1. Are the bricks “your room is made out of” suspended so that they’re free to resonate (as the bells in your video were) or are they stacked and mortared together and,
2. Are you hitting those suspended bricks with a hammer to actually make them resonate (while you’re playing music)?
3. If your answer to both the previous questions is “yes” then you still wouldn’t be getting brick resonances when playing music recordings because your room/house would just collapse into a heap of rubble! lol

BTW, trying to defend crazy with self-contradictions and false analogies doesn’t work, it actually has the opposite effect and just makes you look even more crazy!

G

 

[castleofargh]

If a speaker can produce a full range of frequencies without objectionable levels of distortion, it isn’t “breaking up”. Properly functioning speakers don’t have a “resonant frequency”. Duh again.

You can’t hear what the cone is made of. What you can hear is the dispersion characteristics, and that is as much a part of the room acoustics as it is the speaker. And room acoustics affect the response more than anything in the speaker itself.

As @71 dB said, strictly speaking every object and every air volume shaped by it, has frequencies that will shake it(or the air) in phase and create resonance. It's not limited to tuning forks and the crystal glasses.
But obviously the material alone was never going to determine a fixed resonance, that much is understood by all but one dude in the thread. Of course, if we're all wrong and Ghoosty is correct, forget about speaker designers, it's multibillion industries that want to hire him for his revolutionary way of handling geological surveys. All those so-called experts pretending that you need seismic, electromagnetic, gravitational, aerial and spatial imagery, lots of mining and sampling over wide areas, then narrow down the search area, etc. When in reality you just need to play music and listen for the frequency of the material you want. Problem solved!

I have him on ignore, so I'm typically missing out on his creative self delusions, but taking this entire thread in one go right now is quite a ride. It would seem like the fix for audio is to put silver coins in a "grounding" box to retune music to 432Hz or something.
Me reading the thread: