Just heard the 608, 708 and 808 today at Fry's where they set up the 808 tonight. In my quick 5 to 10 minute test, they sounded similar. The 808 did have a little bit more power ie the volume control was about 3 dB lower for about the same loudness. Luckily, all were connected to Polk's LSi25 floorstanding speakers, at 4 ohm. I have the LSi15s, so I am familiar with the sound.
All three sounded good, clean, tight. The 608 and 708 sounded extremely close, and the 808 had a bigger sound, more base, but perhaps less clean (?).
Inspite of what I have read on these forums, all of them performed fine with 4 ohm speakers even at high volumes. I couldnt hear any distortion, or clipping etc. I set them for 5 channel stereo in Music mode.
I also compared them to Denon's 791 and 891. Those two sounded identical, no difference at all ! Unfortunately, they were in a different room, with different speakers (8 ohm this time). Not sure if they were set up wrong, but they sounded just a little bit thinner than the HK 1600/2600/3600 set up in the same room. I have the HK635 currently, so I know its sound.
I am impressed by these new Onkyos. Even the 608 could play these 4 ohm speakers at fairly loud volume, at about -10dB setting, leaving enough headroom for high dynamic range peaks.
Originally Posted by abc5
yes the weight difference is big, everything else specwise seems to be the same. really dont know what the weight is that the 708 is missing, or the 808 gains.