Okay, I just learned something... my modded L300 Limited actually has more subbass impact than my modded TH-X00 Purplehearts on this song, which I've heard many times (but not through several iterations of the new sealed pad mod on my modded L300 Limited):
This song really shows why I LOVE the STAX bass...besides that beautiful percussive midbass, there's that ~40hz centered large 'WUMP, WUMP, WUMP-WUMP' and 'WUMP-WUMP' drum impact starting around 47 seconds in that is absolutely TIGHT and precise yet also is felt as much as it's heard...STAX L300 Limited simply does it way better than the TH-X00 Purpleheart - tighter and more detailed yet with more lowend impact. Purpleheart is much messier/boomier and slower sounding. Both are equally full bodied sounding, though the Purpleheart does have more of a lingering resonating presence.
Now a few caveats to why this is the case for me:
1. On the STAX side, not using a STAX setup...using RME ADI-2 DAC as preamp to NAD C275BEE stereo amp and Mjolnir SRD-7. Have EQ setting of +3.5dB @ 57Hz with Q=1.2 and +1.5dB @ 82Hz with Q=1.3 on the ADI-2 DAC. My L300 Limited uses L700 pads and headband arc assembly and the pads are sealed to the frame with Loctite Fun-tak except for 2 segments at the rear-bottom of the inner channel.
2. On the TH-X00 side, it's running my most potent subbass pad setup, the Jmoney V3 lambskin with custom attenuators and plugged directly into the RME ADI-2 DAC headphone out. Subbass impact is a little below what the stock pads would be, but it does bass quality so much better along with overall better performance.
3. The pad sealing mod in combination with RME ADI-2 is the reason why the STAX is able to pull ahead of the TH-X00 PH at its own game of subbass impact. TH-X00 Purpleheart doesn't have the same level of subbass from the ADI-2 that it does with the Gustard X20U DAC and H10 amp they normally are used with.
And I came to comparing the Purpleheart subbass against the L300 Limited because after I got the pads sealed I started off with my modded HD58X with Yaxi Alcantara pads (which are a noticeable improvement over stock for the low end impact and punch) ... which were 'LOL Fail!' at subbass compared to the L300 Limiteds, then went to the Argons which were 'dang, farther behind in subbass than I remember!'... which got me curious on the Purplehearts...