[Davesrose]

Quote:

Originally Posted by n2xe /img/forum/go_quote.gif This is why I asked where the data comes from. Particularly when the source of the data is boasting about spending more than $600 on snake oil. This one post by Bellsprout is really all my article was about.

humm.....no, HeadRoom conducts tests on headphones ranging from $20-$1000. Graphs don't indicate the cost of the headphone at all. And none of the headphones mentioned are $600

So a made up FRG is what your "article" is about?

There's no pseudo science going on here

Maybe you should ask Tyll to actually measure the SR80 if it's supposed to have a flatter FRG then any other headphone out there....it wouldn't be logical that it would follow the same sound signature as other Grados: which have emphasis in the upper mids.

I have the SR325i and my ears would say it's far from dead neutral.

Anyway, enjoy those CX-300s. I haven't listened to them myself. I just use what ever junkie street style earphones I have laying around for when I want portable audio. But maybe I'll read your impressions of buds if I ever decide to buy a pair.

 

[n2xe]

Quote:

Originally Posted by Davesrose /img/forum/go_quote.gif humm.....no, HeadRoom conducts tests on headphones ranging from $20-$1000. Graphs don't indicate the cost of the headphone at all. And none of the headphones mentioned are $600 So a made up FRG is what your "article" is about? There's no pseudo science going on here Maybe you should ask Tyll to actually measure the SR80 if it's supposed to have a flatter FRG then any other headphone out there....it wouldn't be logical that it would follow the same sound signature as other Grados: which have emphasis in the upper mids. I have the SR325i and my ears would say it's far from dead neutral. Anyway, enjoy those CX-300s. I haven't listened to them myself. I just use what ever junkie street style earphones I have laying around for when I want portable audio. But maybe I'll read your impressions of buds if I ever decide to buy a pair.

I was commenting on this - "Since joining Head-Fi, I've spent:
$653 ...and counting. bellsprout" And the straight line FRG he posted.

 

[Davesrose]

Quote:

Originally Posted by n2xe /img/forum/go_quote.gif I was commenting on this - "Since joining Head-Fi, I've spent: $653 ...and counting. bellsprout" And the straight line FRG he posted.

Bellsprout's straight line FRG was a very humorous joke: though EvilKing's was more obvious and ROTFL funny. The misspelling of "teh": classic

At least we're not attempting to be serious when we make up stuff......you probably don't trust bellsprout because he told you the difference between angular velocity and angular speed. I know, that impinges on your "juvenile narcissism" when it's shown that there isn't much cold hard science being used : on either your website or this thread.

Anyway, if you do want to actually talk about inexpensive headphones.....feel free to contribute to other threads. This one is getting very dead. Most audiophiles on here aren't total audio snobs. We might like more expensive gear, but most of us realize that cheaper stuff can sound pretty good too. There are verying levels of snake oil that some audiophiles subscribe to, and others don't. One good thing about this site is that there are a lot of members.....some do believe in the snake oil (expensive recables, CD-Rs, CD mats, etc), but others don't. It's good to have more opposing opinions, as someone may get a better informed decision on their next pair of headphones. As long as those opposing opinions are civil and aren't like the screaming heads political pundits that some "news" programs are deciding to air

 

[n2xe]

Quote:

Originally Posted by Davesrose /img/forum/go_quote.gif ...you probably don't trust bellsprout because he told you the difference between angular velocity and angular speed. I know, that impinges on your "juvenile narcissism" when it's shown that there isn't much cold hard science being used : on either your website or this thread.

I explained the difference between angular speed and velocity back on page 12. Frequency and angular velocity for a sine wave are the same thing.

 

[cribeiro]

Quote:

Originally Posted by n2xe /img/forum/go_quote.gif I explained the difference between angular speed and velocity back on page 12. Frequency and angular velocity for a sine wave are the same thing.

Yes, and you explained it wrong.

They are not the same thing. They deliver the same information in that simple and particular case, but they are different physical magnitudes.

And frequency is not the same as angular frequency, although they deliver the same information.

I know I am picky, but wouldn't you be picky if you were a filologist and somebody tells you that two words are the same because they mean the same in a particular case (just an example, maybe a native [English] speaker can find two words that fit here nicely)?

 

[Davesrose]

Quote:

Originally Posted by n2xe /img/forum/go_quote.gif I explained the difference between angular speed and velocity back on page 12. Frequency and angular velocity for a sine wave are the same thing.

OK, even though I don't have an engineering background or physics background, I've now read enough about angular velocity vs angular speed to know it's not the same thing. They may have a coorelation, but they don't mean the same thing. Here's what you said in page 12:

Quote:

Originally Posted by n2xe /img/forum/go_quote.gif Angular velocity is rotational speed (and amplitude) over time. http://www.answers.com/topic/angular-velocity

even answers says that angular velocity is: "The rate of change of angular displacement with respect to time".

Wikipedia says: "In physics, the angular velocity is a vector quantity (more precisely, a pseudovector) which specifies the angular speed at which an object is rotating along with the direction in which it is rotating." Even this non-physics person sees the coorelation between the two, but that they don't mean the same thing.

 

[n2xe]

Quote:

Originally Posted by Davesrose /img/forum/go_quote.gif OK, even though I don't have an engineering background or physics background, I've now read enough about angular velocity vs angular speed to know it's not the same thing. They may have a coorelation, but they don't mean the same thing. Here's what you said in page 12: even answers says that angular velocity is: "The rate of change of angular displacement with respect to time". Wikipedia says: "In physics, the angular velocity is a vector quantity (more precisely, a pseudovector) which specifies the angular speed at which an object is rotating along with the direction in which it is rotating." Even this non-physics person sees the coorelation between the two, but that they don't mean the same thing.

The frequency of a sine wave is its angular velocity. The rate of change of angular displacement is zero because there is no variation in the angular displacement over time. This is exactly what I've been saying all along and even the physicist agreed that in the special case I described, I am correct (again).

 

[cribeiro]

Quote:

Originally Posted by n2xe /img/forum/go_quote.gif The frequency of a sine wave is its angular velocity. The rate of change of angular displacement is zero because there is no variation in the angular displacement over time. This is exactly what I've been saying all along and even the physicist agreed that in the special case I described, I am correct (again).

If by "the physicist" you mean me, your statement is far from reality. I actually said the opposite, as every other person who can read will acknowledge.

EDIT: sorry, I forgot the sarcasm... You are wrong (again).

 

[Davesrose]

Isn't it like saying 1cm is equal to 1cm cubed? They can never be equal, because they're different units of measure.

Anway, since we're also on the subject of real science.....isn't a soundwave not a true infinite linear sine wave? A soundwave has a decay because of differences in air volume and reflection off of objects. Am I in the ballpark cribeiro?

 

[Daroid]

Angular speed and angular velocity is the exact same measurement, at least in electronics. They're both measured with respect to time in a periodic signal, here sin(t). When wikipedia uses the word "speed", speed is also with respect to time (duration of periods).

EDIT: I didn't read any other pages but this last page... Looking back from page 12, it's one man nitpicking the other. We're discussing omega i hope, and not f.

Davesrose,
I think i know what you meant. In theory yes, but one could argue it is not so for a zero amplitude signal (0*sin((omega)t+theta) ) because signal information is lost, and can thus can't be scaled, delayed, etc. Music is created from multiple sine waves with different amplitudes, phase and frequency. Since amps are made with semiconductors, the signal will be distorted in one (measurable) way or another.
The decay will happen when energy isn't transfered from the speaker cone to the air molecules.

 

[cribeiro]

Quote:

Originally Posted by Davesrose /img/forum/go_quote.gif Isn't it like saying 1cm is equal to 1cm cubed? They can never be equal, because they're different units of measure. Anway, since we're also on the subject of real science.....isn't a soundwave not an infinate linear sine wave? A soundwave has a decay because of differences in air volume and reflection off of objects. Am I in the ballpark cribeiro?

Nice try..., but no, sorry. Don't worry!! You can anyway enjoy your great gear while I envy you nastily

Probably because you have better ears, also. Hey, that is not fair!! I have just realized you have corrected your post while I was writing...

And you are right in part (even a bit more, after your editing).


Should I?... Oh, man... I love physics so much that I can't stop myself now...

It is not really like saying 1cm is equal to 1cm cubed, but it seems you got the point.

You are right, a sound wave (any physical wave, for that matter) is not an infinite linear sine wave (and I think "sine wave" suffices, it is infinite by definition. And "linear"... we could talk for hours about what is meant by that). A sound wave can be described to a certain (good) degree by a linear combination of sine and cosine waves. But it is a frequent mistake to mix up reality and model. Nature is very complex, and our descriptions are limited, simplified... Sometimes, the description matches the reality so well, that we are tempted to say "yes, nature behaves like this" (many physicist do, Einstein included... I think the more brilliant you are, the easier it is to believe it...). But it actually doesn't. I am a theoretician, so I would love to find out that it actually does

....

Now, you can have test tones on a cd, which "are" (that means, can be described to a very good degree by) sine waves, and play them on your hifi. What comes out of the loudspeaker "is" a sine wave and decreases its amplitude because it propagates in all directions (think of two concentric spheres: the total wave energy going through each of them is the same, but the outer one has less energy per surface unit). On top of this decrease, attenuation comes from the fact that a sound wave propagates through a material, which presents some "friction" to the wave, causing scattering and absorption which attenuates the wave. Of course differences in air density (you meant density, right?) and reflection off objects influence not only to attenuate, but also distort the original wave.

As Daroid points out, there are many other places where distortion of the original, recorded "sine" wave occur, like the coupling cone-air (there is a good reason for horn loudspeakers to exist!), or even an electrical connector with impedance mismatch (he knows this probably better than me...).

And BTW, this is not basic stuff anymore*, I would really thank that some specialist proof read this.

---
Daroid, about "speed" and "velocity" being the same measurement in electronics, that is exactly what I mean. They are different physical magnitudes, but might contain the same information (measurement) in particular cases.

Something very important, though: angular velocity depends on time. Think of turning a vertical wheel with some heavy weight at one point. When the weight goes upwards, I turn the wheel slowly, when it goes downwards, it goes damn fast... The angular velocity changes... But I nevertheless manage to keep the frequency constant (inverse of the time needed to make a complete turn).

-----------------------------
*I would be fit in this topic if I specialized in applied physics, but I did it in particle physics, where all waves are transversal, while sound waves are longitudinal and thus behave somewhat differently (for example, they cannot be polarized).

 

[tbritton]

The original article really was about gear rip-offs, and the great value one can get if one shops for the quality currently available for a low price.

The following thread is discussing some bargains to be had today.

http://www.head-fi.org/forums/showpo...00&postcount=4

Terry

 

[Daroid]

Good example with the turning wheel with weights. That would indeed be catastrophic if they were the same measurement, or one mistook one for the other in a design process.

Currently i'm studying transmission lines and reflection with (ideal) cables, but not enough yet to discuss much, other than there always will be a reflected signal depending of the cable length and frequency...

 

[n2xe]

Quote:

Originally Posted by Daroid /img/forum/go_quote.gif Good example with the turning wheel with weights. That would indeed be catastrophic if they were the same measurement, or one mistook one for the other in a design process. Currently i'm studying transmission lines and reflection with (ideal) cables, but not enough yet to discuss much, other than there always will be a reflected signal depending of the cable length and frequency...

There will always be a reflection if the line is not terminated with the transmission line's characteristic impedance. Using what I'm most familiar with, 50 ohm cable common in RF work, a 50 termination at the end of the line will not produce a reflected wave but anything else will. It's not dependant on frequency, line length or prop velocity per se. I guess it's a matter of degree and what you are willing to tolerate. With digital signals, you can pretty much ignore reflections for anything shorter than 1/8 wavelength (electrical i.e. propagation velocity of the cable). For RF work, it's important to have matched lines and loads for anything putting out appreciable power. In many applications, it doesn't really matter much.

Many Amateur Radio guys get really hung up about matching antenna impedance to the line that's driving it but in a lot of situations it doesn't hurt you. Then again, in some situations you can blow up a transmitter with a bad match and big reflections.

 

[n2xe]

I think I can see why the CX-300 gets a lot of mixed reviews. Some people love them and some say it's too bassy. I don't find it to be too bassy and after looking at the FRG you folks provided I was really wondering why.

Again, we were debating my assessment of several headphones but keep in mind, that's with an iPod as the source. I usually listen to the CX-300 with my 4th Gen 20GB iPod and that makes a huge difference.

4th Gen iPod use a class A output amp with capacitors to remove the DC bias. I measured the output impedance vs frequency on that iPod this afternoon. Because of the output capacitors, the output of the iPod starts climbing above 5 ohms at 800 Hz to about 45 ohms at 20 Hz. All things being equal with 16 ohm CX-300, you get a 9dB drop in signal at 20 Hz (about -3dB at 100 Hz).

Those of you listening to CX-300s with a source that has a direct coupled push-pull driver are going to get a lot more bass than you will with a 4th Gen iPod. Just for kicks, I plugged into my iPod Shuffle (direct coupled, push-pull output) and there is a significant difference.

Since the SR-325i has 32 ohm impedance, the difference is not as pronounced.