Outdoor audio: Stereo or mono?

@jay32267 - great advice. As much as I like where I have the speakers mounted now, I think my solution might just be to mount them closer together. I'm going to try doing a mono setup first to see if it solves the problem first, as it's the less invasive option. ...pushing 2000 watts though? dang! I'd be chased out of my neighborhood!

@americanaudiophile - coverage isn't a problem. The two 350s cover the entire yard just fine, it's just that one speaker can be heard much more clearly than the other, depending on where you're standing. My backyard is like a big rectangle, and no trees or obstructions. Garage in front of you, house behind you (or reverse), so it works well for sound as it's almost a stage-like setup. Thanks for the recommendation on the Sonance, I'll check them out if I decide to change speakers, but so far I'm very happy with the Yama 350s if I can get the sound distributed more evenly. I think I'd opt for a second pair first. -- And there's all kinds of ways to get mono sound

@madmatt30 - In really large areas, I'd agree that subs don't work outside, but my yard isn't huge and I've successfully used two subs in the past (not at the same time) on various occasions. This was before I had my newly installed system. These were just temp setups for parties and neither were large or outdoor subs. One setup I used was the Klipsch 2.1 Promedia system. This little sub pounded outside. Unfortunately it doesn't like my Yamaha receiver as I tried to repurpose the sub only and it wasn't happening. I also used an LG soundbar with wireless sub in the yard. It also sounded great. The only reason I installed my current system is because I was tired of putting up the soundbar and taking it down every time I wanted to listen to music on more than a bluetooth speaker in the yard, so it was time for something permanent. The point I'm trying to make is that subs have worked great for me outdoors in the past. Even subs not meant to be outdoors. Both of these were 6.5" drivers. The Polk I'm waiting to have delivered is 10", so I'm hoping it will give me even more punch (fingers crossed).

Just an update on this... After ordering and testing two subs, I am now in agreement that subs just don't work outside. Both subs have been returned. I also moved my Yamaha 350s to inside the garage (the little Yamaha 150s I had in there are also going back). I splurged and got 2 Polk Atrium 8s for the yard. Apparently much better bass response and known for producing high volume with this highs and lows (without the need for a sub). I chose to get these over the Bose Environmental 251s because many reviews mention muddy sound from the Bose as they try to get the lows and highs from the same drivers.