Advice on cutting out more of a-pillar

[cpassmore1]

I did a test fit and test 'listen' of drivers in place (held in with blue masking tape) and they sounded forced and 'hollow' until I brought the low frequency cutoff to 1khz (high @ 5500hz). Driver is 4" Morel carbon nano mw4. Googling (AI) suggested I didn't have enough airspace behind the driver and that's what was causing the poor quality. I had my suspicions as I was building this I didn't have enough of an opening. Wondering if anyone has any knowledge on how damaging it would be to the vent being connected to the a-pillar facade if I was to cut out the green highlighted area. This is a relatively older version as I've cleaned up the fiberglass sanding and bondo but wanted to show shape and proportions. I haven't done any butyl on the inside but didn't feel any vibration in the panel when playing.

Thanks for any input.

 

[UNBROKEN]

When I had a-pillars I took those completely out and capped the vent coming out of the dash. It was like that for 100K miles…never missed them for a second.
You’ll always be chasing some imaging issues with pillars in these cars. The two of us that seriously compete with ST’s have both gone to dash mount…it’s sooo much better.