minimum impedance is 6 ohm, I'm running my own "Entropy" speakers with no less than 6 ohms. (Ribbon @ 6 ohms, 6 1/2 at 8 ohms, with only a 3.3 uf high pass for the ribbon. Audio grade metalized polypropylene cap.
No padding on the ribbon (round type, horn loaded)

response is well above and beyond...

I think the soundstage presented by the Onkyo is very wide and paroramic.
Tuning section leaves a little to be desired, yet these days reception is pretty good. I may add-on the HD component tuner module.

With my other receivers for comparison, the $320.00 was worth every penny. To my ears, this amplifier section is super. Very versatile tone adjustments.

I like the choice of 40hz sub crossover. I'm not using any sub for music, with the Entropy system. My center channel is also my own, made from Infinity 3"'s and Vifa 1" silk dome in D'Apolito. I like to call the center speaker, "Extropy"

I'm on this moment listening to my dad's (just passed) Pioneer SX-650 circa 1980, using FM and a turntable with magnetic cartridge. ( Audio Technica ). In a moment I'll switch on the Onkyo.

First the FM is clearer. ( a station about 60 miles away ). A CD in the DVD player is honestly perfectly clear and the dynamic range and the fre. resp. is great, wide, and deep. Pro Logic IIx sets up a very nice soundstage that extends through to the walls of the room, in other words, each channel can be clearly defined from anywhere in the room. Dolby sound with this receiver is excellent. I set up the Audyssey EQ which is very nice, and I switched it off for comparison, realized I need to reset it for the Entropy's. I set it up with my Big Brothers, which are 15" 3-way tower's, little brothers in back and baby in center.

I'd like to spend more on a receiver but ?I've never been able to afford more. In My Opinion the Onkyo is Audiophile grade equipment, and should be considered to always be just that. I cannot shake a stick at the sound. On the correct set of speakers.

The 80 watts rms @ 8 ohms in surround WRAT type amp, hit the room hard with my tower Big Brother speakers. The Entropy set is only 50 watt, and the Receiver allows the max volume to be limited, so someone not familiar with the equipment won't damage the speakers. The large set has a wattage rating a stage amp could handle, so 80 watts is nice enough 'headroom'. I have ideal neighbors...and am unlimited in my stereo usage.

The remote works on my RCA dvd player, and Panasonic Viera tv.

The lack of usb thumb-drive slot is ok, there are other options, but Onkyo could stand to add it on. Perhaps an add-on USB module, since they have the proprietary component slot on the rear panel, for HD tuner and Sirrus, etc.

The lack of sound modes like HALL, THEATER, JAZZ ,CLUb and all the other gimmick cheesy crap other receivers use is kind of cool, and the modes it does have are verstile and not confusing, even to an initiate.

I like the two assignable optical, and also two assignable coax digital inputs. The system auto-detects the component so for example two sources can use "AUX" like my computer, on optical digital, with a turntable on the analog rca jacks on the same AUX selection, so the amp will choose, and when both are on, the amp defaults to digital.

Zone 2 is limited to analog sources, unless I missed something in the programming options. The power and range on zone two is loud and clear.