You can unlink a Performance from a Price Profile and set specific capacities for that Performance only. See below for the different processes for General Admission and Reserved Seating.
General Admission
Select the Performances tab on your Event
Click Manage on the Performance you want to unlink
Scroll down and click Edit Capacity
Set the capacity for your Bands on this Performance by clicking the pencil icon next to the Band and entering the new capacity
This will then unlink it from the original Price Profile and create a new Price Profile for that Performance only
NOTE - this means that any changes on the original Price Profile won't pull through to this Performance.
Reserved Seating
You can do this in two ways: on the Performance page or in Box Office.
Performance Page
Select the Performances tab on your Event
Click Manage on the Performance you want to unlink
Scroll down and click Edit Capacity
Edit the seats and Bands as you wish on the new Performance-specific Price Profile. This will then unlink it from the original Price Profile
NOTE - this means that any changes on the original Price Profile won't pull through to this Performance.
In Box Office
Go to the Box Office page and select your Event and Performance
Scroll down to the pricing legend at the bottom of the page
Change from Add to Basket mode to Reband mode by clicking the price icon
Use the price legend and the Paintbrush to add or remove seats
Learn more - Guide: Rebanding Seats, Overview & FAQs: Price Profiles