[NineRedTools]

So for a long time, I've wondered many things about headphones and sound. I have plenty of questions, and I'd love for my mind to be at ease from these as they have all been bothering me for a while.
 
Before I begin, I'd like to mention that I'm not an audio "noob", nor am I a bass-head, nor do I think all headphones sound the same. I love music and headphones, especially with hi-fidelity equipment. I'm asking these questions because I couldn't find an answer anywhere else online for most/all of them, and they just sort of pique my interest every time they come into my thoughts. It mildly frustrates me that I don't have answers.
 
1. When a headphone is playing a 20,000Hz sound, is the driver really moving 20,000 times a second?
 
2. If the highest most people can hear is about 22,000Hz, why are there headphones marketed at being able to produce sounds well over 35,000Hz?
 
3. I had a crappy pair of worthless blackberry earbuds. I decided to experiment. I started off by playing a 20Hz sine wave. Turning my amplifier all the way up caused the headphones to play this loud *tick tick tick tick* noise. What's actually causing the headphone to make this noise?
 
4. About those headphones again. I played a 500Hz sound extremely loudly. It sounded like clippers or something. Anyways, after laughing about the sound, I noticed they were smoking and it smelled of burnt plastic. Why?
 
5. I love headphones and music, and I've spent well over $500 on headphones, amps, and other sound-related things. I can certainly tell a difference between $20 and $200 headphones, but is it even harder to tell a difference between $200 and $500 headphones? Or $200 and $1000 headphones? I'm sure high-end headphones such as the HD800s and Audeze's are fascinating headphones, but is the price really justified? Do those headphones really make up for what you pay for them?
 
6. Do 1/4" jacks have any benefit other than durability over 3.5mm jacks?
 
7. Is there any noticeable quality degradation if I'm using 2 headphones in a splitter?
 
8. If I have a 1,000k FLAC file that's 3 minutes long, should it theoretically be about 180 megabytes? Why or why not?
 
9. What's that film-y, plastic thing that is on headphone drivers. Is that the cone? Membrane? Diaphragm? What is this thing for?
 
I guess that's all the questions I have.
 
Thank you, head-fi!

 

[billybob_jcv]

So for a long time, I've wondered many things about headphones and sound. I have plenty of questions, and I'd love for my mind to be at ease from these as they have all been bothering me for a while.

Before I begin, I'd like to mention that I'm not an audio "noob", nor am I a bass-head, nor do I think all headphones sound the same. I love music and headphones, especially with hi-fidelity equipment. I'm asking these questions because I couldn't find an answer anywhere else online for most/all of them, and they just sort of pique my interest every time they come into my thoughts. It mildly frustrates me that I don't have answers.

1. When a headphone is playing a 20,000Hz sound, is the driver really moving 20,000 times a second?

[COLOR=FF00AA]- Yes.
[/COLOR]
2. If the highest most people can hear is about 22,000Hz, why are there headphones marketed at being able to produce sounds well over 35,000Hz?

[COLOR=FF00AA]- Because Marketing Departments are an evil blight on the modern world. Just because the driver might respond in some way when fed a 35 KHz signal does not mean that driver actually sounds good at any other frequency.
[/COLOR]

3. I had a crappy pair of worthless blackberry earbuds. I decided to experiment. I started off by playing a 20Hz sine wave. Turning my amplifier all the way up caused the headphones to play this loud *tick tick tick tick* noise. What's actually causing the headphone to make this noise?

[COLOR=FF00AA]- It was probably the driver's voicecoil being energized and banging against the stops.[/COLOR]

4. About those headphones again. I played a 500Hz sound extremely loudly. It sounded like clippers or something. Anyways, after laughing about the sound, I noticed they were smoking and it smelled of burnt plastic. Why?

[COLOR=FF00AA]- You burned-out the voicecoil. The voicecoil is an electromagnet. When the sends power to the driver, the electromagnet is energized and that moves the "spider" that is attached to the speaker cone. The music signal is an A/C power signal that makes the voicecoil move. If you send high power signals that cause the voicecoil to be overdriven into distortion, you can damage it. Here's a general rule of thumb for anything run by electricity: The manufacturers fill all the components with smoke. The smoke is a vital part of every component. Once you let the smoke out, you can't refill it. All you can do is either send it back to the factory for more smoke, or throw it away and buy a new one... [/COLOR]

5. I love headphones and music, and I've spent well over $500 on headphones, amps, and other sound-related things. I can certainly tell a difference between $20 and $200 headphones, but is it even harder to tell a difference between $200 and $500 headphones? Or $200 and $1000 headphones? I'm sure high-end headphones such as the HD800s and Audeze's are fascinating headphones, but is the price really justified? Do those headphones really make up for what you pay for them?

[COLOR=FF00AA]- Audio is not a linear ROI model. As you spend more, the differences become smaller and smaller. At the top of the mountain (summit-fi) all of the gear is very, very good. There is no such thing as "best" in audio, at the top, there are simply different shades of "great".[/COLOR]

6. Do 1/4" jacks have any benefit other than durability over 3.5mm jacks?

[COLOR=FF00AA]- No, not for consumer use. For pro audio, where there might be long runs of heavy gauge wire, a 1/4" connector can accept larger diameter wire. However, for really long runs, balanced, locking XLR would be the way to go.[/COLOR]

7. Is there any noticeable quality degradation if I'm using 2 headphones in a splitter?

[COLOR=FF00AA]- Yes, it can. Splitting the signal lowers the signal level, which can compress the signal dynamics and force the amp gain to be higher, thus also increasing the noise level.[/COLOR]

8. If I have a 1,000k FLAC file that's 3 minutes long, should it theoretically be about 180 megabytes? Why or why not?

[COLOR=FF00AA]- It depends on the amount of the compression achieved. FLAC is lossless, but it is still compressed. It is analogous to a Zip file. The bit patterns in the file determine how much compression can be achieved.[/COLOR]

9. What's that film-y, plastic thing that is on headphone drivers. Is that the cone? Membrane? Diaphragm? What is this thing for?

[COLOR=FF00AA]- I'm not sure which film-y plastic thing you are referring to. If you mean the part directly inside the ear cup, then that is probably the speaker cone. However, not all headphones have speaker cones - only dynamic headphones. There are several other technologies used: Planar Magnetic, Balanced Armature & Electrostatic - and there are others. Dynamic is the most common.[/COLOR]

I guess that's all the questions I have.

Thank you, head-fi!

 

[MindsMirror]

1. Yep
 
2. It's mostly just a marketing strategy. Many people think that higher spec numbers will always mean better sound. Or maybe they made the headphone, and when they measured it, it just happened to be able to produce up to 35KHz, so they put that on the spec sheet.
 
3. Nothing good.
 
4. If you have a powerful amp, it could drive a lot of current through the headphones, and they could get hot, just like the filament in a light bulb which gets so hot that it glows.
 
5. Only you can answer this one.
 
6. I don't think so.
 
7. Yes. If your amp doesn't have a very low output impedance, the frequency response of each headphone could be altered by the other. Distortion created by one headphone driver can feed back to the other headphone. Try it yourself, plug two headphones together with a splitter and tap on the ear cup of one of then, the sound will travel through the splitter to the same ear in the other headphone. The amp will also be working harder, which will increase its distortion.
 
8. No. Bits and bytes are not the same. 1000Kbits/s = 125KBytes/s. 125kB/s times 180 seconds equals 22.5MBytes.
 
9. I think you would call that the membrane or diaphragm. I guess they probably use a thin filmy plasticy material because it's light so it can vibrate quickly (up to 20000 times per second!) without requiring a large amount of energy.

 

[NineRedTools]

Thanks! These are really good answers, exactly what I had hoped for. I appreciate it!

 

[tomb]

Here's a general rule of thumb for anything run by electricity: The manufacturers fill all the components with smoke. The smoke is a vital part of every component. Once you let the smoke out, you can't refill it. All you can do is either send it back to the factory for more smoke, or throw it away and buy a new one...

 
 

 
 
 

6. Do 1/4" jacks have any benefit other than durability over 3.5mm jacks?
- No, not for consumer use. For pro audio, where there might be long runs of heavy gauge wire, a 1/4" connector can accept larger diameter wire. However, for really long runs, balanced, locking XLR would be the way to go. 

After that memorable comment above, I hate to disagree with any of that post.

  However, there are rules of physics and materials involved here.  3.5mm jacks simply have less contact area compared to the size of the crystalline structure in the metal.  1/4" jacks have been know to be just fine after 50+ years.  3.5mm jacks on the other hand, can go bad in 6 mos.  Not saying they all do that, but the potential is there.  When you have a diameter of the plug that small, the geometrical mathematics of the contact between the plug surface and the jack spring is very, very small.  Eventually one of two things will happen: 1) the spring will give up the ghost and lose tension upon the plug surface, or 2) the contact surface will corrode enough that electrical contact is lost.  Gold-plating will help some, but #1 will win out, eventually.