So I decided to play around with the 900S tips. Tried a smaller size soft rubber tip - and wow night and day difference! I kept going larger trying to get better isolation/seal the it struck me to go smaller.
I immediately felt the telltale "vacuum" for better word. I have been disappointed in bass. They are still not bass head OEM's but boy what wonderfully detailed and extended bass!!!
What do you mean by this? Using smaller tips for a deeper fit?