Originally Posted by ap1
In DACs digital reconstruction filter is what most influences sound.
...in days gone by. Particularly true when they were analog filters.
If you get a DAC where you can choose one of several filter algorithms, you will understand the importance of it.
Again, true only if you do sighted evaluations.
Different DAC manufacturers use different filters. In most cheap devices they use whatever comes inside D/A chip, but some use their own implementation either in DSP or FPGA.
Actually, the reconstruction filters in good chips are these days, outstanding.
Providing options is a tacit admission that none of them must be sonically transparent, while sonic transparency is relatively easy to obtain.
If you look at the tech specs of most DACs with filter options, at least some of the filter options are just fixed-tuned equalizers by a different name.
This is most important for 44.1 and 48 kHz sampling frequencies. For 88 kHz and upper sources filter artefacts are high in ultrasonic range and thus almost negligible for listening experience.
Actually, that is also true for 44.1 and 48 KHz. The actual practical limit of hearing the kinds of artifacts that good DACs have is pretty much over by 16 Khz, so there is an effective perceptual dead band that is from 7 to 12 KHz wide.
Fletcher-Munson predicts that the hearing of a very good listener is upwards of 25 dB down as low as 16 KHz and falling into a far deeper hole:
The following is a FFT analysis of what an advocate of ultrasonic content in music James Boyk shows as an example:
it is significant to note that by 15 KHz, even for this extreme example, the average spectral content of the music is 3 major divisions or 37.5 dB down.
Put these two facts together and we find that any possible artifacts of digital filtering are weighted by an immense 50 dB of loss by 15 KHz. If we look at the artifacts themselves, we often find that they are all above 20 KHz and are far smaller than full scale. Then we have to add the additional losses due to masking. Put it all and we find a perfect explanation for why the audibility this sort of thing is so low as to be vanishing.
Of course you have to avoid the hype and do good listening tests to know this from your own personal experience.