Should I be able to hear a 4Hz difference in my speakers?

Not much down there generally but there can be.

This shows it well:

https://sanfranciscoaudiophilesociety.com/interactive-frequency-chart-by-independent-recording-network/

You probably need a very beefy high power high current amp into the little Totem’s to have any chance of much that can be heard happening at 28hz. Most amps will probably say uncle first. If the room is smaller rather than larger, that will also help greatly. Those little guys have to do a lot of work to deliver 28hz so the the amplifier has to be able to make up for that. Basic physics....

Good news is Totem is one of the best at getting a lot of very good quality extended sound out of a smaller box (if you provide a suitable amp)  so you have a winner there no matter what.

Good question!

28-32hz - you might be able to feel rather than hear the bass in that range a bit more if a) its in the recording b) the rest of your system has good response down to below 28hz and c) the room acoustics support it, but probably a very marginal difference that may be hard to determine at best.

Many instruments can produce sound in that range, including synthesizer, tuba, bassoon, harp, organ, and piano.

So even if in the recording to start with, speaker response low enough to reproduce it alone does not mean you will hear it.

You can always run test tones through your system and see what happens.