astr0n0m1nus
New Head-Fier
You are correct in that the filler used in the gold upper helps reduce/tame the treble. However, with this upper filter in PB2, I find using blue or black lower filter significantly exaggerates the bass while overall sound clarity takes a hit. In fact even red bass for me is a bit much.I am confused , red and gold filters? Isn't gold for the least amount of treble and red is 3rd only less than blue and black.
Pairing with M15 I get the most balanced sound with silver/gold on OM and silver/pink on Semper , I am quite happy with this setup now.
Also I believe that the source may also have a part to play in influencing the overall choice of filters. For example, the Cayin E02 module with its saber chip is more analytical sounding while I am assuming that the AKM chips in M15 lean more towards a warmer presentation.