Recently, I purchased a Bartok Apex, and it quickly became evident that specific filter and mapper settings are crucial depending on the source data. I particularly dislike filters with pre-ringing as they sound unnatural to me and can cause smearing effects.
I discovered that Filter 5 introduces too many cycles of post-ringing, which results in an artificial brightness and overall auditory confusion.
I would appreciate it if dCS could introduce a filter with a slow roll-off characteristic, devoid of
pre-ringing and featuring just one cycle of post-ringing.
The operation of Filter 5 depends on which sample rate you are playing, but at higher sample rates may give the result you are after:
At 44.1kS/s, Filter 5 is asymmetrical with no pre-ringing but the trade-off is that it has to have more post-ringing to effectively filter out the unwanted stuff above 20kHz.
If Filter 5 was shorter than it is, so had less post-ringing, more Nyquist images would be reproduced by the system above 22.05kHz. Not only can these alias back down into the audible band (which is harmful to sound quality), your amplifiers and (probably) tweeters will likely still be trying to reproduce the out-of-band energy which is not a good thing.
All of this is a long way of saying Filter 5 is exactly as long as it needs to be to filter effectively, which is absolutely necessary for good performance.
When you are playing content with a sample rate of 176.4kS/s and above, Filter 5 is completely different. It has a Gaussian response, which has a slow roll-off and very little impact on transients. If you are playing higher sample rate content (176.4kS/s and up), give Filter 5 a try here as I wager it will be much more what you are looking for. Less impact on transients as a whole, with fewer Nyquist images removed as a result.
This type of filter can only be used on higher sample rates. The slower roll-off on sample rates of 44.1kS/s up to 96kS/s would let through too much out of band energy caused by Nyquist images, so would be harmful to sound quality.
I should note that the filters are stored per sample rate, so you could for example have your Bartók set to Filter 4 for 44.1kHz (the shortest symmetrical filter) to balance and minimise pre- and post-ringing, but have the system change to Filter 5 whenever you are playing a higher sample rate and can make use of the Gaussian filter.
Give Filter 5 a try specifically on some higher sample rate content and see what you think!
My system has advanced to a stage where I can readily discern differences between various filters and mappers on my Bartok. Based on my experience and evolving preferences, I have come to these conclusions:
When using a PCM source, I avoid upsampling to DSD64 or DSD128, as I find that the algorithm used in this process results in an unnatural sound quality. In contrast, my old Marantz CD player’s MMM DAC, which upsamples PCM to DSD256, delivers superior sound compared to the dCS DSD upsampling method.
DSDX2 works OK with a DSD64 source.
For 16/44.1 PCM, I recommend using DXD, Filter 3 and MAP3.
For DSD64, I suggest using DSDX2, Filter 5 and MAP3.
