I have heard the Helix, owned the Focus 20/20s and now own the Whispers. From my experience, the bottom end of the 20/20s is unchallenged by any speaker I have heard except for the Helix. For example, in my room the 20/20s began to roll off at around 16 Hz with no help from a sub [exactly as the spec indicates]. When I listened to the Helix, I remember on one demo track feeling my hair vibrate before I could hear anything
now thats pressurizing the room! I have never experience that from any other home speaker.
I know what Chadnliz means about the Whispers though...I think he is referring mostly to the lack of deep bass. This is a bit odd when you consider it is up the model ladder from the 20/20s. Nevertheless, I like my Whispers more than my Focus 20/20s because of the improved imaging and sense of space. Things just got more real and believable with the Whispers. I have integrated some subs to get that bottom end back that I was used to with the 20/20s though. Doing it this way is much smoother and cleaner than turning up the Whisper Processor knob [IMO of course]. Now I have the 20/20s bottom end, and all the naturalness of the Whispers.
The Helix certainly seems more complicated and expensive to set up. I heard them in Macungie and they were fantastic...from my memory anyway. Besides the example above, I remember a huge, super wide soundstage that totally surrounded me [even behind me somehow]. Vocals just floated beautifully in the air. But this was in 03. Not that anything has changed since then, but it is a long time ago to remember this sort of thing.
The Helix requires all the amps because it has an outboard crossover/processor. There are not the standard internal crossovers for the tweeters/mids/woofers found in traditional speakers. I believe they also use an aluminum sub driver [like from the LF Xtreme Subwoofer] that has its own internal amplifier. At least this is my understanding, I could be wrong.