| My question is how will someone know - just by listening, not measuring - what's caused by the headphone impedance mismatch and what's caused by the inherent resonances in the hearing system? |
I only just barely understand the concept of acoustic impedance as it is (too much math!), so I cannot provide a good technical reply to this. There are ways to test for this though. The best way I can think of would be to use a pair of studio monitors that you know to have a flat output, and a pair of headphones that you know to have a flat output (such as STAX, for example.)
Use the SineGen program with both the speakers and the headphones and note where the perceived amplitude of the sound increases. With the speakers, the sound will be more or less uniform, with an increase around 2.5-3kHz due to the pinna. If the speakers are truly flat, there will not be any sharp peaks in the upper mids or highs. With the headphones, however, the response will start to become increasingly jagged above 2kHz, with a sharp peak in the 5-8kHz range. You can verify the presence of the problem by taking the headphones off, placing them on the desk and turning the volume up to where you can hear a 1kHz tone clearly. If you run the frequency sweep again, it will suddenly appear to be much
more uniform in amplitude. Put the headphones back on, and the problem comes back.
The human auditory system does not normally create such a large peak in that specific frequency range. It can only be due to the unnaturally close coupling of the headphones to the ear canal and eardrum. When I listen to music on my studio monitors, it does not have the exaggerated high frequency energy that it does when I listen with my headphones unequalized, even though my headphones have a technically flatter response.
| thanks to the OP for the Electri-Q equalizer. good program =)|
i still havent gone through what you hvae said in full detail but i will give it a bash. i dont know much about EQ just yet in intricate detail. i just clicked the "analyser" button and set it to output and then equalized based on the output graph it gave me.
Unfortunately, the analyzer does not know what you are hearing, so equalizing based on what it tells you does nothing. If you are interested, you should start with SineGen as soon as possible and see what you can find out.