It is the tyre size that is the culprit here in my opinion, i have 205-65-15 in my Civic and LM703 205-65-15 in my Crown.
I personally believe you should stick to the stock size for better comfort. 185-65-14 or 185-60-14 would be better.
Bumps are bumps, you would feel them when you drive over them no matter which ever tyre you put.