The digital filters in AKM chipset have always been a very interesting topic, I believe the Engineers who developed these anti-aliasing filters have nothing to do with the naming of the filters, quite often the explanation from R&D engineers are far too difficult to understand, and communicate in layman terms, so Sales and Marketing team has to develop names and illustration to term the hard science into selling points. So if you make any sense between what you read from the name of the filters to what you heard with your ears, don't be surprised, we have all gone through that stage at some point.
We used to have a lot of discussions on the AKM filters with the "older" DAPs when the DAPs were relatively simple and we didn't have extensive features such as Class A/AB, P/P+, tube/SS, .... , so filters were important features to shape the audio signature of your DAP. For those who want to understand the concept behind the digital filters of the AKM chipset,
@docholliday has compared the filters using digital audio reference signals and measured the filters in the studio where he works. He offered the best explanation I have come across. Yes, that was 2017 and the N3 was a $150 DAP based on AK4490. The discussion from
Post #3,492 to
Post #3,516 and
Post #3,623 to
Post #3,628 is a good starting point. AKM probably has changed some of the filter settings for different DAC chipsets, but the concepts remain the same IMHO.
