M-Audio AV40 resonance(?) question

Apologies in advance for incorrect terminology.

I dug up my old AV40s and I’ve been noticing a weird resonance(?) at lower frequencies. Maybe not the right term, but for example, on this song, https://open.spotify.com/track/61cIo7tFo5XZAIkHASAZPN?si=dwatLCn_T3ucM-zdjN4juA, on certain bass notes (e.g., around 0:35), it seems particularly loud and kinda uncomfortably rings in my ears. I don’t really know what frequency it is, but lowering 64 and 125 (itunes built-in equalizer) seems to help some. I’m also an EQ noob as you can tell.

So can this be remedied without EQ? Moving the speakers further and closer to the wall seems fairly negligible (unless I need to be even further from the wall). Still hear it when I’m lifting the speaker in the air so don’t think my desk is causing it, and I did also buy foam isolation pads. Blocking the port in the back with my hand helps (is stuffing the port a viable solution?) Is there a way that I can better identify the offending frequency and use a crossover to get rid of it when I eventually get a sub?

Any enlightenment is appreciated. Thanks!

Is it new? i.e. Did it not happen previously?
How old are they?

They are quite old, more than ten years old? Took them out of storage. I don’t remember this problem. Did some more reading, could it be a room issue?

Speakers with foam surrounds can have the surrounds fail .
Take the cover off the front and inspect the driver, you might also want to gently push the driver in to ensure it’s moving freely.

Oh, good to know. Thanks, I’ll check it out!

They seem okay, as far as I can tell. I guess I’ll try to mess around with placement some more to see if it helps.

Yes they look fine

Ok thanks for the confirm!