The Klipsch are entirely inadequate for what you're attempting.
Exactly what are you wanting to achieve? Interested in 5.1 surround movie playback outdoors? That's three front speakers, two surrounds and a subwoofer system. This is ideal and can be very impressive, however not entirely necessary.
1.) Two channel, full range stereo playback, no subs.
2.) Two channel playback with separate subs/woofer cabinets and tops per side. Similar to a live sound scenario for bands/clubs etc, with sub/sat crossover and amps. There are many mfrs that facilitate this quite easily with minimal gear.
Then you move into more Home Theater techniques, primarily bass management. If you're not familiar with bass management, it's occurs in your receiver or pre/pro (possibly disc player), it takes the low frequency signals from your speakers, and combines that with the LFE (low freq effects) signal, and sends it all to the subwoofer system. That's quite the simplified version, as it becomes more complicated with the various choices of control etc.
3.) 2.1 Stereo, bass managed with sub system. An AVR/Receiver based system.
4.) 5.1 full bass managed playback, as commonly found in homes. Due to the rigors of outdoor HT, you'd likely have more than one sub due to the lack of natural boundary loading from walls, etc.
What you would need?
In addition to being an audio enthusiast since the 70's, I've been involved in live sound reproduction in every sized venue up to stadiums. I currently own what is often considered the biggest bang for the buck loudspeakers for this type of use you're describing. They are QSC's K series
, K-8, K-10, and K-12. These are 8", 10", and of course 12". These things are extraordinary, and ideally suited for what you're describing. They powered (1,00watts each), their response is contoured w/on-board EQ'ing, they possess every connectivity feature you can imagine, and you can simply plug an Ipod right into them and jam, use them in a full blown HT system, or anything in between. They really are amazing.
Yes, you could get by with simply the K-12 per side with no subs. It would likely impress you with their capability. But they can't overcome the physics inherent to outdoor playback of low frequencies. For any kind of decent impact associated with movie playback, music playback, you're going to need some subs. Yep, it be ok without htem, but it'll lack the fun factor that accompanies contemporary soundtracks.
The QSC's are outstanding. Mine are K-8's, and I use them for my four surrounds (7.1) in my HT. Upon initially buying them, I un-boxed them and set them and set them up for a listen. I ended up using them extensively for my three front LCR's for a few months. I had merely temporarily did this, to perform some simple comparos, and they blew me away. I've since moved on to the much more expensive Seaton Catalysts for LCRs, but the K-8's perform amazingly well amidst some tough competition. The 8, 10, and 12 inch versions all use the same amps, power, and HF driver, they simply match the coverage angle of each sized woofer with three different waveguides/horns at the crossover with three different horns.
Yes, there's less expensive options for you to take, but the K-12s (or any of the K series) would be an outstanding set of mains for an outdoor system.
Is this an option for you budget wise? A pair of these.
Is there more in the budget for the needed subwoofer system? A pair of K-12's and subs?
Full blown 5 QSCs and two subs? (LCRs all QSC K-12s, two QSC K-8s for surrounds, + subs)
That's ideal, expensive.
Best of luck