speaker placement

[aqus]

I have build the denham speakers and have a few questions about placement.
I do realize this is not the best setup but trying to the best with what I have.
The room is 14x12.
I know speakers are too close to back wall, But since I am using a subwoofer and cutting the frequency to the mains at 80hz with a crossover does it still make much of a difference on back wall placement?
If I push them almost all the way back to not be too close to them I am wondering if the pc monitor will hinder the sound as it will probably bounce from back of screen. Or is it better to make stands which will be slightly higher than the monitor and tilt them down towards ears?

[---k---]

These graphs hopefully will explain it:

https://www.htguide.com/forum/showthread.php?t=34016&

[bvbellomo]

Are these ported or sealed? Your ears are probably your best judge, but you can also measure. Even if you don't have a calibrated microphone, measurements can still show the difference between positions.