I have a Denon 3803 receiver and looking at the following Klipsch speakers RF-35 (Fronts); RC-35 (Center); RS-35 (Surround). Will these Klipsch speakers provide adequate sound for HT?
Sure. Pretty much any functioning speaker will provide "adequate" sound for HT. Speaker sound varies significantly, and you should go listen to the MANY brands out there. Klipsch is in a somewhat unique camp in terms of the sound of their speakers, which is often characterized as a "you either love the Klipsch sound, or you hate it." I myself, hate it, and would not enjoy owning a pair of their speakers for music. For strictly HT,, I would find them perfectly enjoyable, but I might strongly prefer another brand. I can't tell you whether you'll like klipsch or not, or another brand or not. You need to go listen to as MANY brands out there as possible, STRONGLY preferable from a specialty retailer over a cheesy BB/GG type chain store. As to whether Klipsch and Denon would blindly work fine for HT, absolutely.
BTW, Klipsch speakers are very efficient, and thus should be able to reach extremely high SPL off your denon with no problem at all. Still, how speakers SOUND is the most important aspect, and you may find that klipsch is perfect for you. You should still take the time to go listen to them thoroughly, along with the many other well-regarded brands out there.
Chris basically pointed everything out. I myself own 2 pairs of Klipsch speakers (1 set of speakers on my computer, and another for my HT) and I love them. There sound is unique usually because they are a little bit more heavy on the vocals than other speakers, although they do maintain a nice amount of midrange and bass... something you will notice if you take a good listen.
As for the reciever, yes it will work perfectly fine. Try to demo those speakers on a Denon reciever close to what you have... if you like it then get it.
But like Chris said, Klipsch is usually characterized by "You either love Klipsch sound, or you hate it." Give them a listen though, I think there Reference series is excellent. Not to mention powering those speakers won't be a problem. Your reciever it turned up all the way would make your ears bleed with those speakers.
I have the 3803 and rf7's and I'm in the love camp.I have also owned more expensive speakers that I hated,but were highly rated(sold at huge loss).I actualy never owned a pair of Klipsch before the 7's,I went to buy a 3k pair.After I heard another guy audition the 7's I was like WOW.Its the first set of speakers I ever owned that I like more now than when I bought them.