Tried searching regarding the following but couldn't find any relevant info.

I have a room and the rear wall is a large wardrobe. A couple of questions:

1) Does the wardrobe define the borders of the room or should any measurements be taken, taking into account the depth of the wardrobe also?

The wardrobe will not have any clothes, just some cables etc and the doors will definitely stay closed.

2) Is it wise to install standing bass traps at the back inside of the wardrobe? Has anyone taken any measurements to indicate if this is an efficient approach vs installing the bass traps standing outside of the wardrobe (which I'd like to ideally avoid).

Had a post similar to this....it sounds like it will be most beneficial to put bass trapping on the doors if the wardrobe (closet?) vs the back, because it will be more effective as frequencies will get trapped twice....once on tje way im, and again on the way out.

I got some owen cornings 705 on the way to do mine up here very soon.

fill it full of rockwool and you'll have a swell bass trap!