The response is peaking

Your box gives a Qtc above 1.0, which means the response rises before it falls. At Qtc = 1.0 the bump is about 1.25 dB; at 1.2 it is around 2.4 dB; at 1.5 it is over 4 dB and centered close to fc.

What this sounds like

A single emphasized region rather than extended bass: often described as one-note, or boomy on some tracks and thin on others. The resonance is underdamped, so it also takes longer to settle after a transient. Unlike a broad tonal tilt, it is frequency-specific and tends to become obvious on material with a moving bass line, where some notes bloom and others do not.

It is worth saying that a modest peak is not always wrong. A Qtc of 1.0 in a small stand-mounted speaker, crossed to a subwoofer, is a normal engineering choice. It is the values well above that which cause trouble.

What to do about it

The box is too small for this driver. In order of effectiveness:

1. Make the box bigger. Qtc scales with \sqrt{1+V_{as}/V_b}, so volume has to grow substantially to move it much: halving Qtc's excess is not a 10% change.
2. Add stuffing. Worth 10–20% of effective volume. Useful for trimming, not for rescuing.
3. Choose a different driver. A lower Qts driver reaches a sensible Qtc in the box you actually have. This is the real fix when the gap is large.
4. Vent it, if the driver suits a vented alignment, though a high-Qts driver usually does not.

What will not work is equalization alone. You can flatten the peak electronically, but the excursion and the settling behavior stay as they were, and you have spent amplifier power fighting a resonance rather than removing it.