milosz
500+ Head-Fier
- Joined
- Aug 17, 2009
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Quote:
Well, then I wonder what accounts for the differences in perceived LF sound quality between headphones? Your thoughts- ?
The impulse response shows that and if there really was a severe issue in the transient response at LF, it would show right up in the impulse response because of the rather long decay time at low frequencies (that's the ringing stuff in the mid-highs which is not particularly straightforward to see in an impulse or step response due to fast decay).
The one thing you may be alluding is the fact an electrostatic transducer is working in stiffness region below the first resonance (which is ~50Hz for the 009) while a traditional dynamic transducer operates in piston motion in that range. So, conceptually, you could raise the point of some form of distortion / compression effects. But in practice, this shape of the transducer has nothing to do with the pressure wave that results from it. Be it a piston or a stretched diaphragm like and estat or ortho, they all drive a small acoustic space which is again in stiffness controlled region (no acoustic modes in the earcup cavity there) and you get uniform pressure across the earcup.
This may be hard to visualize so have a look at this, it is a contour plot of SPL inside and outside a stat headphone (not the 009 but conceptually it's the same thing) at the fundamental resonance frequency (60Hz here) where the diaphragm, earcup cavity, ear pad, and frame (assumed rigid here) were all modeled. You can clearly see the diaphragm fundamental resonance but the SPL in the earcup is basically homogeneous (and will remain like that until 1kHz or so, e.g. until it can sustain standing waves):
Well, then I wonder what accounts for the differences in perceived LF sound quality between headphones? Your thoughts- ?