DUDE!
i'm okay with only having one speaker in the door as long as it works well. and as luck would have it...all of my speakers sound great for being 17 years old.
i will be changing to a 2 speaker door panel set up in May...so, i won't have an odd-ball set-up like i've got now.
check out these panels i just went and took pictures of. interesting eh? lol