Forum » Znanost in tehnologija » invertiran zvok
invertiran zvok
problem ::
zanima me, če se je že kdo ukvarjal z invertiranim zvokom (saj ne vem če je taka oznaka pravilna). Gre za odstranjevanje hrupa na način, da v prostor pošlješ invertirano valovanje (zvok), tako hrupa človek ne sliši. Po TV sem gledal nek dokumentarec, da so to tehnologijo uporabili v nekem avtu, ki je zato za potnike popolnoma tih. Zunaj seveda ropota.
Zanima me, če lahko za tako tehnologijo uporabiš kar navadn fršterker in zvočnike.
Če ima kdo kaj več znanja ali kakšen link, bi bil hvaležen.
Zanima me, če lahko za tako tehnologijo uporabiš kar navadn fršterker in zvočnike.
Če ima kdo kaj več znanja ali kakšen link, bi bil hvaležen.
- premaknil iz Zvok in slika: CaqKa ()
glinik ::
O tem sem že nekaj slišal (za avto),ampak to je žal vse kar vem.Predvidevam,da ta tehnika ni tako enostavna.Se bo že kdo našel,ki bo kaj več vedel na to temo (al pa tud ne-kar je bol verjetno 
)
Lp
) Lp
CaqKa ::
to kar govoriš je zvok z nasprotno fazo.
verjetno bo kdo drug kaj več vedel.. pomojem je pa to tema za znanost in tehniko.
/edit: aja če boš iskal potem išči z nizom: "phase shift" ali pa nekaj podobnega.
verjetno bo kdo drug kaj več vedel.. pomojem je pa to tema za znanost in tehniko.
/edit: aja če boš iskal potem išči z nizom: "phase shift" ali pa nekaj podobnega.
Zgodovina sprememb…
- spremenil: CaqKa ()
BigWhale ::
Isci kaj na temo 'noise canceling earphones' recimo...
Preprosto vezje, ki 'obrne fazo' zvoku za 180 stopinj ce imas taksne slusalke, ki so kvalitetno narejene ti lahko naredijo skoraj popolno tisino okrog tebe. :)
Ostalih prakticnih uporab je pa bolj malo. Saj je problem v tem, da mora ta 'kontra' zvok priti v tvoje uho prakticno istocasno kot pravi zvok in iz priblizno iste smeri...
Preprosto vezje, ki 'obrne fazo' zvoku za 180 stopinj ce imas taksne slusalke, ki so kvalitetno narejene ti lahko naredijo skoraj popolno tisino okrog tebe. :)
Ostalih prakticnih uporab je pa bolj malo. Saj je problem v tem, da mora ta 'kontra' zvok priti v tvoje uho prakticno istocasno kot pravi zvok in iz priblizno iste smeri...
Thomas ::
Fentonov silencer - o tem smo že precej govorili na Slotechu. 
Man muss immer generalisieren - Carl Jacobi
TribesMan ::
Mislim da se te zadeve imenujejeo tudi "white noise". Mal poišči... So pa zanimive reči tole ja. Drgač se pa masovno uporabljajo na letalih.
LP
TribesMan
LP
TribesMan
Moj kompjuter dela: KVIIIIK ... KVIIIK ... KVIIIK.
Ko ga navijem dela: KVIKKVIKKIVKKVIK. :)
Ko ga navijem dela: KVIKKVIKKIVKKVIK. :)
BigWhale ::
Hm, white noise dobis, ce poslusas cel stadion ljudi na enkrat... ;)
Ali pa, ce na enkrat zaigras 30000 tisoc tonov na klavirju...
White noise je nekaj takega kot bela svetloba. Sestavljen je iz vseh mogocih frekvenc... :)
Ali pa, ce na enkrat zaigras 30000 tisoc tonov na klavirju...
White noise je nekaj takega kot bela svetloba. Sestavljen je iz vseh mogocih frekvenc... :)
TribesMan ::
Možno da sem se zmotil... 
LP
TribesMan
LP
TribesMan
Moj kompjuter dela: KVIIIIK ... KVIIIK ... KVIIIK.
Ko ga navijem dela: KVIKKVIKKIVKKVIK. :)
Ko ga navijem dela: KVIKKVIKKIVKKVIK. :)
Zmajček ::
To sm tud jest opazu enkrat k sem šu z avinom v ameriko, je mela biznis klasa posebne slušalke, k si lahko dal na en kanal (ostali so bli radijski al pa za TV gledat), pa da si mel kao čist tišino... žal jest nism bil v biznis klasi, da bi vidu kako ta stvar deluje.
The best way to get high is with adrenalin!!!
iskra ::
kaj pa recimo software varianta preko mikrofona? ... ko namreč odprem okno v sobi zaslišim veliko količino hrupa iz Tivolske ceste ... kup rešilcev, policajev in nestrpnih voznikov ... Se da to? Al je morda računalnik prepočasen? 
problem ::
No to s slušalkami, jaz prvič slišim, da bi pa to že uporabljal v avionu. Mene bi res zanimal domači poizkus, tako kot je zapisal iskra. Se mi zdi, da bomo neki skupi sestavil.
JerKoJ ::
V novem ŽIT sta dva kratka članka na to temo - stran 5 in 7.
Posebaj prvi je zanimiv, ker obravnava blaženje hrupa z
nasprotnim nihanjem na osnovi piezo keramičnih vlaken.
Drugi govori samo v obliki reliefa, da se zvok čim manj
odbije.
lp
jernej
Posebaj prvi je zanimiv, ker obravnava blaženje hrupa z
nasprotnim nihanjem na osnovi piezo keramičnih vlaken.
Drugi govori samo v obliki reliefa, da se zvok čim manj
odbije.
lp
jernej
BigWhale ::
Googlajte za 'noise canceling earphones'. Ugh,... Par let nazaj je bil tudi en clanek na to temo na /. Samogradnja, kako nardis take slusalke in kako se jih uporablja... vse...
:)
:)
CaqKa ::
pomojem bi potreboval samo en ultra hiper hiter čip za phase shifting.. to bi brane2 kaj več vedel?
Brane2 ::
Za te stvari se uporabljjo DSPji, ki iz posebej postavljenih mikrofonov zajeti signal obdelajo in preračunajo potreben odziv "antizvočnikov".
Bojim se, da za tole ne boste našli rešitve "v prahu" (dodati vodo) .
če se prav spomnim, je pri teh zadevah težava v tem, da antizvočnik ne more ustrezno predvideti vseh sprememb v okolju, pa tudi z danes dosegljivimi zvočniki ni mogoče skenslati zvoka povsod, ampak v samo omejenem majhnem obsegu.
Stvar bi se mogoče obnesla, kot je že nekdo reku, kot kak dodatek slušalkam in to je več ali manj vse.
V glavnem, dvomim da boste kaj našli in se niti ne bi trudil kaj dosti iskat...
Bojim se, da za tole ne boste našli rešitve "v prahu" (dodati vodo) .
če se prav spomnim, je pri teh zadevah težava v tem, da antizvočnik ne more ustrezno predvideti vseh sprememb v okolju, pa tudi z danes dosegljivimi zvočniki ni mogoče skenslati zvoka povsod, ampak v samo omejenem majhnem obsegu.
Stvar bi se mogoče obnesla, kot je že nekdo reku, kot kak dodatek slušalkam in to je več ali manj vse.
V glavnem, dvomim da boste kaj našli in se niti ne bi trudil kaj dosti iskat...
Zgodovina sprememb…
- spremenil: Brane2 ()
BigWhale ::
Dve minuti Slashdot searcha. Poglej tam v enem komentarju link na NoiseBuster slusalke...
Pet minut googla
Sest minut googla
Ma tko blazno tezko in komplicirano ne more bit... ;) Nevem zakaj bi rabil nek silen DSP, tuka ljudje govorijo vecinoma o phase inverterjih... Afaik moras fazo invertirat in ne premaknit. Razlika je pa precej bistvena.
Ja, v prostoru je to bolj tako tako. Na slusalkah pa deluje in ljudje pravijo, da precej dobro. :)
Pet minut googla
Sest minut googla
Ma tko blazno tezko in komplicirano ne more bit... ;) Nevem zakaj bi rabil nek silen DSP, tuka ljudje govorijo vecinoma o phase inverterjih... Afaik moras fazo invertirat in ne premaknit. Razlika je pa precej bistvena.
Ja, v prostoru je to bolj tako tako. Na slusalkah pa deluje in ljudje pravijo, da precej dobro. :)
Brane2 ::
Po tistih dveh minutah Slashdota sem v tretji minuti nasel na njem vsaj en odgovorv threadu z vsaj malo soli:
Don't take my word for it. Record some and run it through your favorite MP3 player, with a reasonably sized FFT filter going in realtime. Watch the FFT display jerk spasmodically. Even the wiggling isn't as regular as you think; if you could do an FFT of the FFT, you'd see that. It's noise, it really is, and even if it sounds to your ear like it's "the same" noise, your computer hears it as anything but.
For extra bonus points (and to really enhance your understanding of what noise really is!), open that noise recording in a sound program. Zoom in really tight, until you can see one wave cycle (from 0, to max, to 0, to min, back to 0 again. It may cross 0 a few times in that span, so eyeball it. You can't really be wrong, so it's not that big a deal, as long as the two ends meet up when you're done.) Copy that sound for 1 or 2 seconds worth, and play it. (Copy and paste it twice, highlight that, copy and paste again, and duplicate that; you'll be into seconds in no time.) Take a moment and ask yourself what you expect this to sound like. Then play it. Is that what you expected? Still don't believe me? Take a larger snippet, three or four waves.
Noise is really, really dynamic, and you can't predict what it is going to do next.
Oh, and there's no such thing as noise cancellation, by the way, only cancelling certain sounds at certain isolated locations. That's why you need two headphones, one dedicated to each ear, to cancel noise. A single microphone cannot cancel noise for two ears across a set of frequencies, period, especially if it doesn't know where those ears are.
Again, don't take my word for it, draw it. Draw equally-spaced concentric circles emanating from a point. Draw equally spaced concentric circles of the same size emanating from another point. The distance between the two concentric circles is the frequency, and let's say one circle's lines is the bottom of the signal, and the other the top. The places where the circle touch the sound is canceled (in this hopelessly perfect little world where nothing is interfering with the sound). In the middle of each of the little quadrangles you build, the sound is doubled. You'll see it's impossible to complete and totally cancel the sound unless the two sources are exactly the same... which is not surprising because that's equivalent to preventing it in the first place!
And lest ye think that you can put your ears at two of the meeting points (again, totally and completely ignoring the sound's interaction with the environment)... draw another set of circles using the same sources, but multiplying the distance between each concentric circle by, say, 8/7s. And 1/3. And 87/34s. And everything in between. All at once.
Please try these things before trying to pick them apart; human intuition and wave phenomena are notoriously poor bedfellows.
Don't take my word for it. Record some and run it through your favorite MP3 player, with a reasonably sized FFT filter going in realtime. Watch the FFT display jerk spasmodically. Even the wiggling isn't as regular as you think; if you could do an FFT of the FFT, you'd see that. It's noise, it really is, and even if it sounds to your ear like it's "the same" noise, your computer hears it as anything but.
For extra bonus points (and to really enhance your understanding of what noise really is!), open that noise recording in a sound program. Zoom in really tight, until you can see one wave cycle (from 0, to max, to 0, to min, back to 0 again. It may cross 0 a few times in that span, so eyeball it. You can't really be wrong, so it's not that big a deal, as long as the two ends meet up when you're done.) Copy that sound for 1 or 2 seconds worth, and play it. (Copy and paste it twice, highlight that, copy and paste again, and duplicate that; you'll be into seconds in no time.) Take a moment and ask yourself what you expect this to sound like. Then play it. Is that what you expected? Still don't believe me? Take a larger snippet, three or four waves.
Noise is really, really dynamic, and you can't predict what it is going to do next.
Oh, and there's no such thing as noise cancellation, by the way, only cancelling certain sounds at certain isolated locations. That's why you need two headphones, one dedicated to each ear, to cancel noise. A single microphone cannot cancel noise for two ears across a set of frequencies, period, especially if it doesn't know where those ears are.
Again, don't take my word for it, draw it. Draw equally-spaced concentric circles emanating from a point. Draw equally spaced concentric circles of the same size emanating from another point. The distance between the two concentric circles is the frequency, and let's say one circle's lines is the bottom of the signal, and the other the top. The places where the circle touch the sound is canceled (in this hopelessly perfect little world where nothing is interfering with the sound). In the middle of each of the little quadrangles you build, the sound is doubled. You'll see it's impossible to complete and totally cancel the sound unless the two sources are exactly the same... which is not surprising because that's equivalent to preventing it in the first place!
And lest ye think that you can put your ears at two of the meeting points (again, totally and completely ignoring the sound's interaction with the environment)... draw another set of circles using the same sources, but multiplying the distance between each concentric circle by, say, 8/7s. And 1/3. And 87/34s. And everything in between. All at once.
Please try these things before trying to pick them apart; human intuition and wave phenomena are notoriously poor bedfellows.
Thomas ::
Imel sem zadevo na ušesih, leta nazaj. Nekako "90%" hrupa v resnici skensla.
Man muss immer generalisieren - Carl Jacobi
CaqKa ::
hehe tukaj pa mpeg kompresija ne pride do izraza.. oziroma njena slabost pride do izraza...
ta kompresija ni dobra za demonstracijo tega efekta :)
90% pomojem res zaduši... kaj več je pomojem težko dosečt.. potem bi potreboval preveč mikrofon pa mašinerije za vse skup sprocesirat.. pomojem.
ta kompresija ni dobra za demonstracijo tega efekta :)
90% pomojem res zaduši... kaj več je pomojem težko dosečt.. potem bi potreboval preveč mikrofon pa mašinerije za vse skup sprocesirat.. pomojem.
.:joco:. ::
Čisto tako, teoretično.
En zvočnik priklopiš normalno, drugemu pa enostavno zamenjaš + in - kabla.
Jih postaviš tesno skupaj in greš 7 metrov stran.
Kaj slišiš?
En zvočnik priklopiš normalno, drugemu pa enostavno zamenjaš + in - kabla.
Jih postaviš tesno skupaj in greš 7 metrov stran.
Kaj slišiš?
"Is science true?"
You don't get it.
Science is the process of trying to find out what's true.
You don't get it.
Science is the process of trying to find out what's true.
.:joco:. ::
Še tole. Malce off topic (ampak res čist malce!)
Naj nekdo pove, ali sliši interferenco na stereo slušalkah?
klink
Naj nekdo pove, ali sliši interferenco na stereo slušalkah?
klink
"Is science true?"
You don't get it.
Science is the process of trying to find out what's true.
You don't get it.
Science is the process of trying to find out what's true.
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