Keep It Down, Please
Earphones let you listen to music almost without outside interference, and they also often have the capacity to deliver very high sonic volumes. Be careful not to go overboard with the decibels - which can be easy with certain models such has intraaurals, which can easily attain very high levels, even with a portable player. I should remind you that the maximum tolerable exposure to noise (even if you think of it as music) is one hour per day at 94 dB(A) and only 15 minutes (yes, per day!) at 100 dB(A). Beyond that you can do irreparable damage to your hearing.
Testing And Evaluation Methods
As for my previous articles on earphones, I made acoustical measurements on the earphones I tested, except for certain models that are hard to test. I used the same techniques and protocols. I used the DAAS32 audio analysis system with a Neutrik artificial ear and suitable microphone. For earbuds and intra-aural earphones, which can't be tested on an artificial ear, I have built my own coupling system.
Note that my measurement system is calibrated and that the volume values in dB SPL are absolute levels (re 20 micropascals) for a voltage of 1 V at the earphone input. That means you can also compare the sensitivity of the earphones - keeping in mind, however, that impedance is not taken into consideration. That, by the way, explains why you may not get the full benefit of high sensitivity with all media players. How well a player handles reduced impedance and a relatively high current requirement can play a role.
For listening, I used a system equipped with an E-MU 1820 professional sound card - first of all for its quality, but also because it has a headphone jack with a hardware adjustment, capable of providing a high level with no faults in the signal. Finally, this card has a sophisticated virtual mixing board with inserts for numerous parametric equalization filters, which I use during listening to correct the response (in general as a function of the response curves I record) in order to see how the earphones perform if I apply suitable corrections. Sources are either the original tracks or else tracks compressed using a lossless compression system (FLAC). I did additional listening tests on a PC equipped with a Creative X-Fi Elite Pro sound card to get the benefit of the CMSS-3D Headphone system for creating virtual spaces. Finally, I used a small Creative MP3 player to check how the earphones behave with a lightweight device in terms of the volume level possible without distortion and any other problems.
Many models have scores that are identical or very close. That doesn't indicate an absence of an opinion on my part; but if there are no clearly identifiable shortcomings, the choice is a matter of personal taste, and by definition that's up to you!
- Processor: Athlon 3000+
- Memory: 1 GB DDR
- Sound card: E-MU 1820
- OS: Windows XP Home SP2
- Foobar 2000 (software)
- Creative Zen Nano Plus 512 MB (MP3 player)
- DAAS32 audio measurement system
- Neutrik 3282 artificial ear
- Neutrik 3381 microphone
- DIY adapters for intraaural earphones