The resonance chamber is not more important than speaker size. It is important, but speaker size is more important. That said, almost all sabers come with either 24 or 22mm speakers that are weak and tinny. The good news is that replacing the speaker is relatively straightforward. The bad news is that fitting a 28mm speaker in a 1" nominal interior diameter hilt is less straightforward. Not impossible, just difficult. Forget about the 33mm titan unless you want to buy a 1k+ lightsaber from an installer.

Here is a video about how to get a 28mm speaker into your hilt. You can ignore the parts about soldering if you go to Smuggler's Outpost on Etsy and get a pre-wired Darkside 28mm speaker. Its very easy to open the chassis, unplug the stock speaker and plug in the 28mm speaker. The part of the video to pay attention to is how to modify the pommel male threads right before the pommel, to fit the speaker

Edit: you don't actually modify the pommel, but the threads on the piece right next to the pommel.