I observed something unusual! (Maybe because I faced it for the first time) I hadn't used my sp2k since about a week back then, so when I turned it on for listening, the battery drained quicker than usual and followed the same behaviour for 2-3 cycles. It's working optimally now.
I suggest you use the: Nature(1st), and Traditional(6th) because they are most different.
- For vocal: choose some Chinese or Katie Melua song ( lots of air, breath): Nature sound more airy and flow of air feelings, the consonant sound is faster. Traditional sound more intimate, voice are more dense, less air but more visible of voices.
- For piano: I often listen to La Campanella, Grieg Sonata. Nature sound better attach, note are faster on attach, more solid on high note, the low register show better stopping of note. Traditional: note are more round and thick, the low register show thicker texture and the stopping of note is slower/blurring. The feeling of melody, the unity of two melody of left and right hand is different between the two filter.
It hard to describe but for tradition, you can feel the sound at the center of the note. When in Nature, you can feel the attach more sooner, at the beginning of note, it is just micro part of second.
- For sound stage: The Traditional seem better render the image and draw close relation ship between fragment between frequency. The Nature sound stage seem scattering, diffuse detail, however, the better impulse response make treble seem have to contrast. You can choose some orchestral with large scale and high dynamic: Mephisto, For season( I have lots),
- Some harpsichord tracks show good example of texture, composition of tone( I have some J.S Bach)
- Some track which have drifting of string like "Moonlight on spring river-dali3", the Nature show better clarity and separation for each note of consecutive phrase.
- For drum: listen to some track of Telrac, Burmester collection CD, some track in The Lord of The Rings OST, which have high dramatic melody.
Nature more hard, physical feeling of strike.
Traditional: attach is blur, texture have more thick.
This impression base on my own listening experience, I have do some A/B listening on my own carefully to confirm my impression.
I also conduct some searching about these issue but hardy did any information has been found about the impression. There are some highlight info about measurement between filter implementation.
Tradition(sharp roll off): better performance, noise filter out, however, there are no between frequency domain. Its pre, post ringing may make the sound less clarity, especially in tiny detail level.
Nature(slow roll off): phase shift, best impulse response ( quick attach)
But the gear precision level can affect the perception, if your gear have very long decay in certain frequency ( EA lengendX- bass driver ) for example, too long decay make it impossible to hear the different of start/stopping note in certain frequency.
Hope that can help.
Changing the filter name to straightforward terms makes more sense than trying to decode those silly names lol. I’ll keep the fancy filter names with FW 1.22 as I find them “exclusive” to AK DAPs where as all other DAPs have the same slow/fast filter name on their list