I agree, 2.05 has superb definition, texture and timbre to its bass. While 2.00 just had more bass, both
mid bass and sub, not more bass extension, just louder bass all round, which caused a slight loss of texture and definition imo, but the increased bass can definitely be enjoyable if you have bass light phones or are a bass head or enjoy the bass impact etc. 2.00 really does have flat bass, meaning sub bass and mid bass are both level and not boosted , many people don't like this as it takes away from the mid bass impact, most people enjoy a slight mid bass boost over sub bass. Even Jerry Harvey tunes all his iems like jh13,16, roxx to have a midbass boost over sub bass as its the only way to communicate bass impact without sub bass rolling over it. I personally also prefer a slight mid bass boost over sub bass, but my iems take care of that (most but not all iems/phones naturally do have a slight mid bass boost), which is probably why I really like the bass on 2.05
But regardless, A DAP should have perfectly flat response, any coloration you want should be added by your iems/headphones, not the dap.
My main problem with 2.00 is actually the aspect I first loved most about it, its 3D presentation and vivid imaging. But after some serious listening, as awesome as the effect is, I have realized it is being unnaturally created by the tuning of the dacs/codecs and is not what a reference dap should be doing. I could also occasionally hear some channel mismatch, stereo image artifacts, image overlap and even
overly separated image, 2.00 was definitely altering the music presentation, sometimes it sounded really "cool" (but not reference), other times it sounded exceedingly fake. 2.00 was messing with the recording to create something else. Soundstage width left to right on 2.00 is compressed, Vocals would always be in the middle of your head and slightly compressed/overlaped in stereo image, while bass would kinda be behind my head and inflated/ with separated stereo image (causing the bigger bass imo), while treble would be on top of my head, and originate more from left/right rather than a coherent image. So mids=overlapping stereo image, bass and treble= overly separated stereo image, this was what was causing the "3D" sound, this is all my IMO though after comparing firmwares several times, and bear in mind I first liked 2.00 better!
To my ears 2.05 is close to perfection being dead flat in FR, while also having a nice wide and airy sound stage and the music presentation is now coherent and natural, sound is now as if its coming of a "stage" where all sounds originate from the same ground level but spread up through the air, and range from far left to center to far right. Slow roll is the only reference option imo.
