Due to "WAF" I had to mount my bookshelfs high on the front wall using small shelfs. I have them tilted down as far as I feel they can go without falling (maybe 12 degrees). When I stand I notice a slightly better sound so I believe I would benefit from a sharper angle. Is there any speaker mounts that can be tilted down 20 or more degrees? Something that will work in a living room. My speakers are the larger Athena AS-B2 bookshelfs