If I'm going to praise 5-channel stereo with a thread, I must praise LOGIC 7™ with a thread. 
http://www.lexicon.com/logic7/index.asp
http://www.hometheaterhifi.com/volume_13_3/harman-kardon-avr-340-receiver-8-2006-part-2.html
cheers!
http://www.lexicon.com/logic7/index.asp
http://www.hometheaterhifi.com/volume_13_3/harman-kardon-avr-340-receiver-8-2006-part-2.html
Testing with some music finally allowed me to experience Logic 7, and thus let me compare it directly with DTS: Neo 6 and Dolby Pro Logic IIx. I suppose I could have tested it with the two- channel soundtrack from any DVD as well, but since I rarely watch a film and select the two-channel audio track, I felt that music would be a better real world test for me. Sure, there are plenty of films that don't have a surround mix, but in those cases, I would rather watch it with its stereo track anyway (instead of extracting a surround experience where none was intended). I will also state for the record, that using the dedicated eight-channel input with some SACDs proved that the amplifier stages of the receiver were of excellent quality. I could not hear any clipping or distortion at high levels, and clarity and depth were still apparent at low levels.
I listened to several different types of music, employing the Logic 7, seven-channel music mode. I must say that in my opinion, Logic 7 surpasses the Pro Logic IIx and DTS:Neo 6 methods for creating surround from two channels of audio. I still think Dolby does an excellent job, but Logic 7 was a more realistic and natural sounding experience. One of the best examples of this during my listening was on the track "Can't Find My Way Home" from the classic album/band Blind Faith. In the instrumental passage towards the end of the track, there is a loud crash of a cymbal. While listening with Pro Logic IIx engaged, the sound came at me directly and somewhat harshly from the left surround speaker. With Logic 7 activated, the cymbal did not sound so directional; rather, it was woven more naturally into the left front part of the overall soundstage.
Generally, Logic 7 seemed to sound more true to the original source material while still providing an enveloping sound experience. It is a natural evolution in surround sound. Remember when you first heard a receiver that could create a concert hall effect and you were wowed? Well, now I would venture to guess most people completely ignore those faux venue creations since they carry with them the problems inherent in those very locations! Would you rather sit down to listen to music that has been artificially enhanced with reverberation that you didn't want in the first place? Of course not! Now surround formats such as Logic 7 and Dolby Pro Logic IIx demonstrate a more mature intent to subtly enhance the dimension and envelopment of the sound, rather than call attention to them as enhancement.
cheers!
