You can wallmount the speakers.....instead of regular length screws....put longer ones with maximum head size (which fits in the key slot) ...this will tilt the speakers to some extent (10-25 degrees) which will be enough for bass to come out....try it with one speaker first and once mounted, play some real bassy songs / movie effects to check...
He may have a solution for you where the speakers can be kept on a wall bracket
( swivel ) than drill and mount.
That would be a better looking solution too and that will avoid drilling etc..
Also if and when you decide to sell the speakers then a speaker used normally sells for more than something thats drilled.
Regarding sound - that depends.. this is a smaller dimension speaker and if the room is small it may not afftect too much though it wount be the same as something thats positioned on stands.
But at home.. some or other compromise is on the menu for all of us ( atleast most of us )
What a coincidence. Just an hour back I ordered clamp based speaker mounts from iShopinternational. They had the 50% offer going on so was able to save on shipping. I wanted to wall mount my BS22 bookshelves which are rear ported. They do not have any wall mount option. Since I wanted a long term modular solution I ended up purchasing these mounts.
Dali provides four small self sticking plastic distance pieces to wall mount their Zensor 1 speakers. I have them mounted with one screw of suitable length. Maybe you can stick something similar on the backs of the speakers as per your requirement.
Afraid, I cannot provide pics as I am not at home.