Smaller endcaps and tone?

[OutofShape]

Has anyone noticed a difference in tone by using a smaller diameter endcap (i.e. 5.56/6 mm) on the end of their 30 cal suppressor? Again, discussing tone not decibel reduction. I have 30 cal cans but am stepping down to 6.5 mm and down and am wondering if it warrants the investment of buying a bunch of endcaps.