MarcAshken, i've got some good news...and bad news for you...
1st the bad news if you want that wide "barndoor" look you need to work on back width and shoulder width.....first..the bulk of your back work should be FREE WEIGHTS....NO MACHINES !!!! FOR SOMEONE WHO WANTS to be bigger,, free weight dumbells and barbells should form the block of your training and after you have gained all the size you want then you can incorporate some machine detail work....
for width chinups and pullups are one of the BEST to do....2 good chinup with bodyweight or added weight as you get stronger is MUCH BETTER than any lat pulldown machine can ever hope to be(this is because free weight exercises force your body to balance,stabalize and coordinate itself and so secondary muscles come into play whereas machines do all the balancing for you
other good back exercises which will give you width and thickness are deadlifts...barbell rows....1 arm dumbell rows
if you also put some mass on your shoulders that will also make you look much wider.....again NO MACHINES!!!!... do barbell presses or dumbell presses , dumbell side raises...upright rows etc..
p.s. sorry for the mini rant there but it's just that i don't want you to make the same mistake i did when i first started out...i've been a bodybuilder for 7 years but i wasted the 1st 2 years on doing machine work along with some free weights but once i did the research and began to ask questions and learn from those more advanced,i realized that you have to think of your body like a house.... BUILD A GOOD FOUNDATION FIRST (without that the house and your body will fail...you can always add the window dressing details later)....this is done by doing mainly compound exercises ex. squats, deadlifts, bench press , barbell rows ,barbell shoulder presses dumbell exercises etc.
do these things and your back will have no choice but to grow bigger and wider !!!!!!!!!!!!