Audio Musings by Sean Olive
Whole-body Vibration Influences Preferred Bass Equalization - Hydrogenaudio Forums

Ganske interessant. Forfatteren (jobber for Harman) har laget et system for å gjøre kunshode-opptak i bil, og så avspille dette med hodetelefoner.

Hva er hensikten? Å kunne gjøre blindtester effektivt med mange forskjellige miljøer uten å måtte bygge opp forskjellige platformer og sende lyttepanelet fra bil til bil.

Funker det? I følge powerpoint-presentasjonen ser det ut som om den "syntetiske" gjengivelsen korrelerer veldig bra med å faktisk sende lytterne ut i bilen.

Han har noen interessante tanker om generelle problemer med hodetelefoner, og det å bruke EQ for å kompensere for fravær av taktil bass.

Sitat Opprinnelig postet av Sean Olive
Yes, the lack of tactile information would be one reason for cranking the bass...But there are other reasons why you might need more bass in your headphones. There is much controversy right now about whether the standard diffuse field (and free-field) equalizations of headphones are valid. Gaëtan Lorho from Nokia gave a paper at the last AES Convention in Munich where he found listeners preferred a 3 dB bump at 3kHz in the headphones (first equalized to be flat) over the typical 10-13 dB bump at 3 kHz specified in the diffuse-field calibration target curve.

The other reason you may want more bass in your headpones is that stereo recordings are optimized over loudspeakers in rooms where there is typically some gain at low frequencioes from room modes/boundary/solid angle effects. These recordings are mixed and balanced by recording engineers with this room gain built-in to the playback chain. If you then play the stereo recordings back over headphones that don't have "room gain" built into the playback chain, the recordings will sound too thin or bright. Unless of course, it's a binaural recording, which already includes the room gain of the performance space.

Needless to say, I think there is a need for more psychoacoustic research in headphones, since no one seems to agree what the correct target curve should be.
The whole issue of headphone calibration, target curve and LF auditory-tactile sensory interactions is fascinating, and experimentally challenging. One of the big issues is that headphone performance -particularly LF response for in-ear and concha types - is very dependent on how well the phone seals and couples to the listeners' ears. So performance can vary widely among listeners depending on the type of phone. It is no wonder there is so much disagreement about sound quality, if these factors are not well controlled. And then there is the issue of "how to do a proper blind listening test on headphones"?

I hope to cover headphones in an upcoming blog posting. I'm starting to gather measurements on headphones, and hope to do some listening tests.