IEM Sensitivity, Frequency response & Impedance

Impedance is an "AC-resistance" (audio is an AC signal.) In the most basic terms, if you have a voltage across a resistance, you get current flowing, and you dissipate power in the resistive load.

Headphone sensitivities are what count for "loudness," they tell you how loud a headphone will be for a certain power level. So a lower-impedance headphone won't necessarily be easier to drive to an equivalent level. You need both sensitivity and impedance to get a handle on that.

You can get an impression of how a headphone will sound from a frequency response graph but there are many other variables to take into account and it's probably a better idea to try it out yourself before making a decision based on a FR graph. If you are focused on bass response, looking for the headphones with reduced low frequency responses (relative to the higher frequencies) would be a good starting point.

Edit: The idea behind multiple drivers is that it's easier to get the overall FR that is desired by using more drivers. I think this is a valid theory (see speaker crossovers.) However, whether it results in a FR that is unattainable by less drivers could be debatable.

You actually want an increased low frequency response relative to higher frequencies for a increased bass response.

Also impedance and sensitivity will not tell you the sound quality of a headphone. More drivers doesn't mean better sound, its possible, but doesn't mean its better. More drivers means more crossovers which means its overall a lot more complicated to design.

Certain tonal qualities are actually pretty specific to certain frequency ranges. Check out this glossary of terms and you can get a better idea of how to interpret some things in a frequency response graph.

http://www.head-fi.org/forum/thread/220770/describing-sound-a-glossary

Here's another great site that shows how different frequencies affect sound.

http://www.independentrecording.net/irn/resources/freqchart/main_display.htm

From what I read it sounds like he wants reduced bass.
 

Quote:

Originally Posted by brconner 

You actually want an increased low frequency response relative to higher frequencies for a increased bass response.

 

Also impedance and sensitivity will not tell you the sound quality of a headphone. More drivers doesn't mean better sound, its possible, but doesn't mean its better. More drivers means more crossovers which means its overall a lot more complicated to design.

 

Certain tonal qualities are actually pretty specific to certain frequency ranges. Check out this glossary of terms and you can get a better idea of how to interpret some things in a frequency response graph.

 

http://www.head-fi.org/forum/thread/220770/describing-sound-a-glossary

 

Here's another great site that shows how different frequencies affect sound.

 

http://www.independentrecording.net/irn/resources/freqchart/main_display.htm

 

 

Quote:

Originally Posted by WaiY 

I've read reviews on both the 535s and W3s I think I really like the sound of them (no pun intended!). I got this idea that as with headphones (which have higher impedance than IEMs), the 535s and W3 should have a much bigger soundstage than the IE8s. Am I right? If so I'd definitely want a pair of either.

 

On another matter, can someone explain to me what specs indicate good quality IEMs, I've no idea when looking at Sensitivity (loudness?)and Frequency response (the bigger the range, the bigger the soundstage?) etc.

I think that the soundstage will get a lot wider with more neutral headphones/IEMs.

One possible explanation is that usually the lower frequencies in a recording are much less separated (L-R) than the rest of the spectrum. Because the IE8's definitely make the lower end 'stick out', soundstage and stereo imaging suffers.

edit: some 'graph' info (relative dB difference in the frequency response between 500 Hz and 100 Hz)

IE8: about +9 dB

SE535: about +3 dB .. so a lot less hyped bass