Can I cut this with a track saw?

[Michael Kellough]

Clever!

And I did NOT realize you were cutting mdf as the picture you posted showed a nice piece of straight grain solid wood, which would be very suitable for cutting with a handplane.

 

[MTbassbone]

Won't there be a hole that needs to be plugged after this cut?

No the baffle a double layer of 18mm mdf. Also to be clear these pics are not mine. Another person found them on the net and in a response in an audio forum.