Originally Posted by Jamey Warren
Thanks for your feedback. I don't want to derail this thread but feel I should comment on your questions.
There is a way to measure overall SPL but this takes into account all frequencies and doesn't give a number that is very meaningful. What is more important is the difference in output between frequencies. If we pump pink noise into a headphone and measure the SPL and base our measurements on that, we still have to pick a frequency on the graphs which is the zero point.
We have considered providing the option to choose the frequency at which these headphones are compared but this is not an easy tool to build. This is essentially what you are doing when you photoshop the images like you have. You have simply chosen a different frequency for your reference point. If we were to zero the graphs at 100 Hz for example, this would in theory show you what the mid range and high end response is relative to the bass. The 1k frequency is chosen as it is an audio industry standard. From a consumers point of view, I can see how it would be beneficial to change this reference point.
For a different perspective, take a look at this difference graph tool which is supposed to show you the difference in frequency response from your reference headphone or one you may own, compared to one you're curious about.
HE-400 -> HE-500
Here's the other way around:
To me, this would mean that if the measurements are correct, our tools for displaying the data are working properly, and if frequency response were the main indicator of sound quality, that to make a HE-500 sound like a HE-400, you would need to boost 600-1.5kHz and to cut 1.5-7k, and finally boost 7-20k. In theory that is....