Vandersteen 1C Tweaking distance to front wall


Hi
Looking for any experience and thoughts from Vandersteen owners on your setup distance to the front wall.

The back edge of my 1c's are currently about 23" distance to the front wall.
Speakers are 7.5 feet apart and i sit about 8.5 feet away.
At moderate volume  and with good recordings the sound is fabulous with good controlled full bass.

However I tend to listen a lot at low volumes late at night and listen to lots of older recordings as well. Both these factors contribute to the sound being a little lean sounding down low. I'm considering moving them back closer to the wall to tweak up the bass frequencies. 

Any thoughts or how far are yours from the wall ? thanks
michaelopolis
Many thanks. I've plenty of Amp power so no worries there. Tone controls sounds like a good option.
Backing them up to increase room gain is an option but will as noted effect imaging. Trying it is free.
thanks. I might have a play with positioning as you say it is free.
Literally talking about an inch or 2 at the most.
Backing them up start at 13 to 18 inches out also try a bit wider apart with just a bit of equal toe in and then play with tilt-back. like Tomic said it is free. Measure exactly each speaker's middle to your nose confirm they are both the same at your seating position.