[itistoday]

I'm trying to understand specifically how a single speaker (like earphones) is able to produce so many various sounds seemingly at the same time. I'm able to hear a bass drum and high pitched strings at the same time! How does this thing make so many different sounds at once?

[ManOfSteal]

Science.

[mitchell_pgh]

http://www.howstuffworks.com/speaker.htm

[Scifience]

Try here: http://electronics.howstuffworks.com/speaker.htm

[sugar_coated]

This is an excellent question! I think it must have something to do with vibration of carbon molecules of varying sizes in the speaker in response to electrical charge. I am not an expert though so I could be wrong.

[itistoday]

Originally posted by mitchell_pgh:
http://www.howstuffworks.com/speaker.htm

Try here: http://electronics.howstuffworks.com/speaker.htm

I read this a while back and it didn't answer my question if I remember correctly.

[mitchell_pgh]

Originally posted by sugar_coated:
This is an excellent question! I think it must have something to do with vibration of carbon molecules of varying sizes in the speaker in response to electrical charge. I am not an expert though so I could be wrong.

Gee willikers... I think you are right. You are very smart and obviously know much more then I do about the subject. All hale... sugar_coated... poster of the super sensitive.

[mitchell_pgh]

http://science.howstuffworks.com/hearing.htm

[Lefterer Guy]

No need to be so mean, Mitch.

[MacmanX]

Originally posted by itistoday:
I read this a while back and it didn't answer my question if I remember correctly.

Yeah, the problem is your question. Speakers are quite simple, and I assume basically everyone knows 'how' they work. What you really want to know about is the sound wave itself.

When we first learn about sound waves and speakers in school, we are generally not taught more than the very simple ideas of frequency, amplitude, and rarefaction. And to make it easier to understand, we are generally only taught with the example of a wave oscillating at one frequency at a time (often shown on an oscilloscope with simple frequency and amplitude dials).

Example:

Unfortunately, sound waves in real life are far more complex than these.

If you look at sound waves from music or normal speech, you will see they are very jagged (wiggly?) and variable. So, in the long oscillation of a 'bass' note you will get get many small fluctuations caused by shorter frequency waves hitting the microphone during the longer frequency wave.



All of these minute changes in pressure are picked up by the mic, converted into electrical impulses, then converted back in to air pressure waves by the speakers as described by the sites already mentioned.

Sorry, it would be a lot easier to explain on a blackboard, so you will just have to try to visualize what I'm talking about. Anyway, your question comes down how sound waves mix together to vibrate the mic (or your ear). The speakers just reproduce reproduce the vibrations. All the sound waves come pre-mixed.

Hope this helps a little (or at least gets you moving in the right direction).

Cheers!

[Sherwin]

It's important to note that speakers with single drive units will always produce what's called phase intermodulation distortion. i.e. while the speaker is trying to produce a long wave it's forced to "get out of shape" by being asked to simultaneously produce the short waves.
Thus it's always better to have multiple drive units - woofer, squawker, tweeter. A theoretically perfect speaker system would have thousands of drive units, each dedicated to a particular frequency in the hearing range. Real-World systems are always a trade-off.

[OreoCookie]

Originally posted by Sherwin:
It's important to note that speakers with single drive units will always produce what's called phase intermodulation distortion. i.e. while the speaker is trying to produce a long wave it's forced to "get out of shape" by being asked to simultaneously produce the short waves.
Thus it's always better to have multiple drive units - woofer, squawker, tweeter. A theoretically perfect speaker system would have thousands of drive units, each dedicated to a particular frequency in the hearing range. Real-World systems are always a trade-off.

Nowadays, most speakers are either two-way or three-way speakers. Two-way speakers either have a mid-bass unit and a tweeter or require a subwoofer. I have a good two-way system (Wharfendale 70th Anniversary) and while they lack some bass (not entirely unintended, I wanna be a good neighbor), their clarity (cello, bass, sax, etc.) is excellent.

[kikkoman]

A speaker produces a single composite signal. It is your perception of the sound that separates them into individual insturments.

[Mafia]

Originally posted by mitchell_pgh:
Gee willikers... I think you are right. You are very smart and obviously know much more then I do about the subject. All hale... sugar_coated... poster of the super sensitive.

[turtle777]

Originally posted by mitchell_pgh:
Gee willikers... I think you are right. You are very smart and obviously know much more then I do about the subject. All hale... sugar_coated... poster of the super sensitive.

seconded.

-t

[itistoday]

Originally posted by MacmanX:
Yeah, the problem is your question. Speakers are quite simple, and I assume basically everyone knows 'how' they work. What you really want to know about is the sound wave itself.

When we first learn about sound waves and speakers in school, we are generally not taught more than the very simple ideas of frequency, amplitude, and rarefaction. And to make it easier to understand, we are generally only taught with the example of a wave oscillating at one frequency at a time (often shown on an oscilloscope with simple frequency and amplitude dials).

Example:

Unfortunately, sound waves in real life are far more complex than these.

If you look at sound waves from music or normal speech, you will see they are very jagged (wiggly?) and variable. So, in the long oscillation of a 'bass' note you will get get many small fluctuations caused by shorter frequency waves hitting the microphone during the longer frequency wave.



All of these minute changes in pressure are picked up by the mic, converted into electrical impulses, then converted back in to air pressure waves by the speakers as described by the sites already mentioned.

Sorry, it would be a lot easier to explain on a blackboard, so you will just have to try to visualize what I'm talking about. Anyway, your question comes down how sound waves mix together to vibrate the mic (or your ear). The speakers just reproduce reproduce the vibrations. All the sound waves come pre-mixed.

Hope this helps a little (or at least gets you moving in the right direction).

Cheers!

Thank you, this was really helpful

[MacmanX]

Originally posted by itistoday:
Thank you, this was really helpful

I'm really glad that made some sense to you. It's really easy for me to explain (quite in depth) when talking about it and chalking it up, but it's a bit of a struggle for me to write an explanation. It's not that I'm a poor writer. I'm just more of a visual thinker (and teacher). Anyway, let me know if have anymore questions.

Cheers!

[MacmanX]

Originally posted by Sherwin:
It's important to note that speakers with single drive units will always produce what's called phase intermodulation distortion. i.e. while the speaker is trying to produce a long wave it's forced to "get out of shape" by being asked to simultaneously produce the short waves.
Thus it's always better to have multiple drive units - woofer, squawker, tweeter. A theoretically perfect speaker system would have thousands of drive units, each dedicated to a particular frequency in the hearing range. Real-World systems are always a trade-off.

You're right that it's a trade off, but not a terribly poor one given our sense of audio perception. Also, music is generally mixed to sound good on your average two or three drive unit. Don't forget that a music studio is designed to eliminate things like overtones that are so important in live musical sounds.

However, this is a good thing! When the recorded tones are played on your home system, the waves reflect off the surfaces in your room producing overtones specific to your listening space. Now, most of us don't have listening rooms, and I probably couldn't tell the difference if I did, but it does allow audio purists to get a close approximation to having the instruments playing 'live' in the room.

If you had a sound system with thousands of drive units (in order to play every little tone and overtone perfectly), you would then need a sound dead room to listen to them. Otherwise, your room would produce unwanted over-tones and wouldn't sound like it would live.

Quite frankly, most people (myself included) are happy enough as long as the music is reproduced clearly (no buzzes or distortion) . Anyway, it's far cheaper to build a few sound studios and mix the music for cheap speakers than it is for everyone to have sound rooms and thousand-drive units.

Anyway, you're perfectly right. I just wanted to explain why �ber-systems aren't necessary before the audio trolls show up!

Cheers!

[Sherwin]

Originally posted by MacmanX:
Anyway, you're perfectly right. I just wanted to explain why �ber-systems aren't necessary before the audio trolls show up!

Yeah, no worries. I was just backing up your wave explanation with a little about why there's usually more than one driver.

And hey, what kind of crappy studio doesn't mix to also sound good on single-drive units?!?

[sugar_coated]

Originally posted by mitchell_pgh:
Gee willikers... I think you are right. You are very smart and obviously know much more then I do about the subject. All hail... sugar_coated... poster of the super sensitive.

By the way, sarcasm is the cheapest form of humor!