The WEIRD Paradox of Sound Waves | Destructive Interference

[@ODDRISER]

Those animations are so incredible. Great video. Definitely earned my subscription.

[@NexusAcademy]

Thanks so much :)

[@garethb5729]

I already subbed bro. Humour and delivery was on point.

[@NexusAcademy]

Thank you very much!!

[@kirtichandnani8037]

Such visual explanations make learning difficult concepts so easy 👌🏾👍🏼

[@NexusAcademy]

Thanks for the feedback!

[@NexusAcademy]

Thank you all so much for subscribing, liking, and even just watching!!! I can't thank you enough for supporting my channel :) Check out my previous upload about a simple but INCREDIBLE camera trick you can achieve with a guitar: kzbin.info/www/bejne/bH-lg5emlMiHaLM

[@Sciencedoneright]

Awesome as always!

[@NexusAcademy]

Thank you! :)

[@puneetmithra]

Very informative and interesting, look forward to more of such videos. 👍

[@NexusAcademy]

Thank you, that means a lot :)

[@yesway]

Thank you. Myself and my crew of schizophrenic aliens from outer space liked that!

[@NexusAcademy]

Haha this earthling appreciates you 🖖

[@vershakukreja5545]

Very well explained

[@NexusAcademy]

Thank you!!

[@vershakukreja5545]

Great video WOW

[@NexusAcademy]

Thank you :)

[@m3lemable]

Thank you it is so informative

[@RomanTheEternal]

Thank you bro

[@Parthkumar_vekariya]

What cause my Bluetooth headphones generating sounds of songs without connecting to any of my devices. I have read that this is kind of interference of frequency, or is it? Could you explain please? I am curious?

[@NexusAcademy]

Hmm interesting! I've never experienced this before, but I can tell you it's not related to acoustic interference. Do you have other Bluetooth devices nearby that could be operating on the same frequency?

[@OrbvsTomarvm]

thanks 👍🏻

[@NexusAcademy]

Thanks for watching :)

[@Fadingbeat]

A friend asked me how I am, I said "like a sine wave" and ended up in here.

[@donniumar4840]

it’s better to use 1 pcs speaker,,,?

[@stephenxadonai]

Nah, he most likely created inverted waves through both speakers

[@kemmuannisa8451]

SO BETTER USED 1 SPEAKER TO GET GOOD QUALITY SOUNDS....?

[@NexusAcademy]

Whether you use one speaker or two shouldn't matter as far as sound quality is concerned. In many cases, two speakers are actually preferred for a stereo effect. I'm sorry if I'm misunderstanding your question!

[@kemmuannisa8451]

@@NexusAcademy i mean for mono better use 1 pcs speaker

[@NexusAcademy]

Oh ok, I see! My answer is still basically the same. Unless you're listening to a steady tone like a sine wave, using two speakers doesn't diminish the volume or reduce sound quality. So it just comes down to your volume preference. Two speakers would simply give you a higher volume than one speaker.

[@donniumar4840]

so better used 1 pcs speaker?…

[@NexusAcademy]

Hi! If you're asking about destructive interference messing with your ability to listen to audio, that's not going to be the case with a two-speaker system. I'm guessing you're referring to the experiment I performed at the beginning of the video. That demonstration only applies under very specific circumstances where you have a consistent, pure tone and you're located in a zone of destructive interference. If you have music, speech, or other inconsistent audio playing out of two speakers, you will not experience any reduction in volume. Hope this helps! Let me know if you have any other questions :)

[@abueloraton]

YOU NEVER SHOWED HOW TO FLIP THE WAVES!!!!!!!!!!

[@NexusAcademy]

Hey! So I left that out because it's more of a technical consideration, and I just wanted to cover this on a high level without getting too complex. But since you ask, there are certain audio editing programs that can take the waveform and essentially flip it, so that every *_peak_* is converted into a *_valley_* with equal & opposite amplitude, and every *_valley_* is converted into a *_peak_* . So basically, what was previously a high-pressure region turns into a low-pressure region, and vice versa. Hope that makes sense; let me know if I can clarify further!

[@abueloraton]

@@NexusAcademy Yes, but how is this done? With a time delay that synchronizes peaks with valleys of the same sound? It's the same sound!

[@NexusAcademy]

That's a good follow-up question! Yes, a time delay that synchronizes the peaks of one track with valleys of another would work for something with a _repeating pattern_ such as a sine wave (as I demonstrated in my video). So if you offset two copies of the same sine wave so that they look like 5:18, they'll cancel out and neutralize. But if you have a more complex audio track that *_isn't_* just made of a simple repeating pattern (like speech or music), then you have to use software in order to create the inverted waveform. Imagine a speaker cone vibrating in and out to produce sound (like in this image: animagraffs.com/wp-content/uploads/loudspeaker/suspension.gif). When you tell the program to invert a waveform, the audio editing program would basically tell the cone to go *in* where the original wave would have made it go *out*, and vice versa. So then every high-pressure region will be replaced by an equal and opposite low-pressure region. Here is a great video by The Action Lab explaining it in a different way: kzbin.info/www/bejne/j53PnZhjetZnm80 Let me know if this makes sense to you!

[@abueloraton]

@@NexusAcademy No. It doesn't, because the computerized programs synthesize everything inside their software: if you were to listen to the combination of sounds and their inverted wave forms in monaural, you would still notice a cancellation! It's not dependent on speakers or stereo system; it's all programmed inside its software. That's why I have to ask you how the waves are flipped and what it really means in practice: how are these waves flipped? I know they are flipped and cancel each other but, what is the process? How does it translate to flip a sound wave? The only thing I can think of is a micro delay.

[@NexusAcademy]

Oh wow! After reading your comments more carefully, I realized I totally misunderstood your question and gave you a response that was partially irrelevant. Sorry for the confusion, and allow me to try again! Active noise cancellation (ANC) _does_ rely on speaker output, but it doesn't work by _digitally_ flipping the waveform like an audio editing program would. Instead, as you mentioned, it simply uses a phase shift. An amp outputs the same frequency as the incoming noise in real-time, but shifted over by ~1/2 period to effectively create the inverted waveform. That's why ANC only works well for consistent tones with a repeating pattern (like a sine wave), as opposed to more abrupt sounds like speaking or clapping. Thanks for your thoughtful question, and I hope this answer is a bit more satisfactory!