Slow roll off filters used in dac side (playback) improve impulse response ( this I understand ),
if the low pass filter cut off frequency is lower than the mirror image frequency since the image frequency is pushed higher when oversampling is used?
I read this information about aliasing in slow roll off filters in Ayre acoustics white paper.
This leads to spectral images (a.k.a. aliasing)...
The problem is that if you leave the ultrasonic image frequencies in, they could cause intermodulation distortion in equipment down-stream, and then become audible, and objectionable. The other "problem" is that without an anti-image/reconstruction filter, the waveform looks awful on a scope and people start to think that digital audio ruins the signal - whereas the part within the range of human hearing (ignoring intermodulation distortion during playback) is fine even without a reconstruction filter.
Are audio DACs constrained in the peak output voltage?
Werner0 I tried minimum phase with all pre ringing and it did sound a little brighter,
QuoteAre audio DACs constrained in the peak output voltage?I don't know enough about how real-world audio DACs are made, but I would assume the analog-output is not hard-limited. ...I assume good audio DACs can properly reconstruct inter-sample overs.
has anyone got a definitve answer.
The question posed by the OP is why images wold occur in the transition band of a slow roll off filter in a DAC system that uses oversampling.
The OP is asking why the image is not shifted away from the transition band by the oversampling process.