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Posts by briskly

Take the chatter over here.
Shouldn't that be a resonant filter? The hump is from the back EMF linked to the driver's mechanical resonance. Clamping the driver more or less makes it look like an RL circuit in the audio range.
Quote:I phrased that quite poorly. A Delta-Sigma DAC isn't necessarily restricted to a single bit and the output still operates by ZOH, albeit at a much higher rate than signal bandwidth.
To elaborate on a few concepts of sampling, informally: Just as you said, the sampling theorem does not assume sine waves, only a frequency representation(the existence of a Fourier transform). Sampling theorem invokes what is now called the Discrete-time Fourier Transform (DTFT) using discrete samples, impulses, to get a continuous spectrum. This DTFT representation does allow for the representation of sampled sinusoids as discrete spikes, but is not restricted to it. The...
The decibel is defined by ratio of power. Double pressure or voltage represents 6 dB. 10 dB SPL roughly relates to a change of perceived loudness at 1 kHz by a factor of 2, but represents 10x power and ~3.16 the pressure.Units of dB SPL and dBV reference a ratio compared to a certain value, generally 20 micropascals and 1 Volt rms.   Reminiscent of JJ Johnston's old tube/transistor amp comparison. The story starts before 20 minutes in.  
I think the stated goal was for acoustic impedance matching and managing wave diffraction. I don't know the dimensions of the slits well enough to evaluate if any meaningful impedance difference is to be had from it. There was the disassembly of the LCD-3F a while back that makes it all a bit questionable whether Audeze can achieve their started goals.With the limited driver excursion and volume displacement through the wide slits that LCDs used in their stators, I find it...
These types of measurements include the frequency response of the ear canal and the diffraction of the outer ear. If you had noticed from my previous post, there was a measurement of a headphone's response from inside the headphone paired with the subjectively determined response of the same headphone.The sound input before entering the ear should still be flat.
Our goal in this case of equalizing by ear is get a response that seems flat. Diffuse field response is not intended, but that is the result these tend to follow.Loudness adjustments will be needed when done by ear, especially as dependent on level. The middle and inner ear have compression mechanisms that increase the input range of sound, and also affect the transfer response when active. This is the response of the loudspeaker in the listening room used in the Harman...
Neutral curve has a simple answer: headphone insertion gain matched to or approximately close to the subject's diffuse field transfer function. You would get that using reference noise and sweeps. The problem is that people tend not to like that, which is what inspires all this research. Harman takes the position that a downward sloping response, from room absorption and LF bumps, in speaker listening seem more natural to listeners, and thus should be reflected in headphones.
Some measurements here. Link.   Competent enough, besides the slightly too high output impedance for some crossover fitted IEMs, at 3 ohms. Measurements are pretty typical for the line.
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