It all depends on your taste. Personally, I like to let the hops be in the spotlight and use very little crystal. From a non-personal taste perspective, 20% crystal is sometimes mentioned as the upper limit of the grist for a pale ale. At 1.5 lbs and .5 lbs that's where you would be at. What I do is look back at previous recipes and compare my impression with what was in it. If you tend to like more crystal it may work well for you, if not, you might want to cut back.