Couch cushions too soft
My wife and I purchased a relatively inexpensive loveseat about a year ago. Almost immediately, we noticed an uncomfortable sag to it. I added a piece of 1/2" plywood below the cushions. This helped somewhat at first, but now seems to almost make matters worse.
I am wondering if perhaps the cushions themselves are too soft. They are obviously foam, approximately 6" thick -- but while they appear perfectly fine when unused, they very quickly collapse under even my wife's slight frame. Is there any way to "reinforce" that soft foam with a firmer material? If so, how and with what?
Or would we be better off replacing them entirely?