Originally Posted by sloomingbla
I understand that, i just say they are educated guesses because those differences are there, but because of all the different thongs that can effect the sound (things like sound quality... Some headphones produce certain frequencies better than others obviously, which can influence how loud/dramatic the differences are percieved)
I basically am just saying, the graph wont tell you the differences in sound.
Not that you dont know that of course.
Wall of text incoming.
Well, actually there are measurements that can give you a more accurate representation of the sound.
Here's some videos that you (and other people) should watch. Very informative, bar some things he didn't go over.
Now, he didn't go over some stuff like step response, harmonic distortion, and impulse response, but those vids should show you that there are more to headphone measurements than just a frequency response chart.
There are three main websites that do measurements on headphones, Goldenears, Headroom, and Innerfidelity. All of them test with different equipment, and they test different aspects of the headphones. If all three of those websites reviewed the same pair of headphone, you should really get a good idea of how they sound, given you know how to interpret the graphs.
The things that Goldenears and Innerfidelity does different is the impulse response. Impulse response tests the speed of the drivers, and the higher and longer the ripple is, the slower the driver is, generally. You want the ripple to be a small and short as possible because that will determine the driver has good speed. The speed of the drivers help with the transparency, imaging, and soundstage performance.
Then you have Goldenear's step response, which is basically Headroom's and Innerfidelity's 50Hz square wave (it may be a different frequency, but they're bound to be in the same ballpark). Ideally, you want the square wave to look like a square, but there are many factors that make it look differently, as described in the aforementioned videos. Earpads are the main determiner. If you have poor sealing earpads, and clamping force isn't there to keep the headphones secure on your head, then you won't be able to get good bass performance, which means a poor square wave. The main reason why the LCD series has good bass performance is because their earpads seal very well around your ears, though the clamping force could be a bit more. Poor sealing earpads and a weak clamp will give you a steep square wave because you loose a lot of the pressure from the bass in those leaks.
Then, you have THD (total harmonic distortion). When you produce a sine wave at, let's say, 300Hz, headphones don't perfectly produce that frequency. There will be some other frequencies that are also being played, called harmonics. Generally, you want those harmonics to be a low as possible because you just want the harmonic of that one frequency played, not any others. This test basically measures the clarity of the drivers. It also measures the ability of the headphones to reproduce the sound at a given volume level. Usually, the louder the headphones get, the more distortion there will be. Having a low harmonic distortion is the ability to cleanly reproduce the sound without having interference from other frequencies. Now, THD is usually going to be a very low percentage, so these may only be noticeable by the measurements of audio equipment, and not noticeable by the human ear, but in some cases, if it goes above 1%, you might be able to hear it. Compare the 50 Hz harmonic distortion between the LCD2 and the D2000, and you'll see that there is much more harmonic distortion at the lower frequencies on the D2000 (going over 10% THD), whereas the THD on the LCD2 is pretty much under 1% throughout the whole range. Since the THD on the low frequencies is much lower on the LCD2, you will have a cleaner, less flabby sounding bass on the LCD2 than on the D2000, and that will stay the same the louder and the more power you pump through the headphones. The lower the THD can also cue you on how much power a headphone is able to handle. If the harmonic distortion is high in the lower frequencies, that usually means that the headphones can't take a lot of power, and/or they don't need a lot of power in order to be driven.
I didn't go over everything in the greatest amount of detail, but these resources should help out if you, or anyone else, is interested.
Innerfidelity - Square Wave Response
Goldenears - How Earpads Affect Sound
Goldenears - How to Read Measurements