I need a pair of speaker mounts. These have caught my interest... http://www.partsexpress.com/pe/showd...ID=15077&DID=7 I plan to use them for a pair of JBL S38s. Do these look sturdy to you? My fear is they won't support the speaker or the clamp design may losen and the speker will fall. Can someone suggest a speaker mount if this doesn't look good. The JBLs weigh 28lbs. So a mount/bracket that can support at least 35 lbs would be desired. Any help would be appreciated. Thanks.