Fast Pace with Heavy Resistance/Low Reps?

In general, when working with heavy weight/low reps (1-6) do you have move the weight with as fast of pace as you can? The reason I am asking is b/c I have been working on wide-grip pull ups and I can only do 6-7 reps per set, yet I want to build a significant amount of muscle mass on my lats; therefore, I would like to do that exercise at a slow to moderate pace.

just do slow movement/negatives on the other back excercises you do in that workout. Also try doing the very last rep of pullups for a superslow negative, 60 secs even

Not absolutely addressing you, but a worthwhile read.