Is Room treatment different for Horn Speakers?

The last few days these Speakers have really blossomed. Bass right now is good. I hear some what I call "frequency specific resonance",.. I was wondering if a little dispersion would help. I understand other Cornwall owners mod their speaker horns with Dynamat, but I don't want to go there just yet.

Duke, atmosphere, rego, actually everyone above, thanks for the comments. I have the speakers as far apart as I can get them... I will try to toe them in so they cross in front of me. These speakers do sound good when I set at my desk in the corner. I am really enjoying these Cornwalls, I believe with some tweaking (acoustic and otherwise) these could be very very good. 

I have horn speakers and am in the process of considering a bass trap in the corner right net to the speakers.  I have had good luck with Vicoustic Acoustic.  

Horns may need much less toe in than conventional speakers.