change it to chambered sir. most "bassy" sounding muffler i use was the FGK, i think all FGK chambered mufflers are "bassy" except for the Evolution Legalis R model.
or if you want to retain your current muffler, replace your stock resonator with this specs, 24" in body length with an inlet and outlet pipe size of 2.25" (oval design), this will "silent" your muffler from idle up to 3500 rpm but 3500 rpm till redline,

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any muffler shop can custom made this for you. price ranges from P1200 to P1500.