Why is 2 Channel better than multi-channel?

There is no reason why you can't enjoy both. It does take a substantial investment into multichannel to have a system that does both very well.

I have been struggling with this myself and have decided after listening to a limited number of SACD recordings that I am going to convert back to 2 channel and utilize my 5 channel amp to bi-amp my Linn Ninka's and call it a day. Most films I watch are just fine in 2 channel anyway

I'm a little late to the game here but could not resists weighing in. There is no doubt in my mind that a very good recording which is available in a 5.1 and 2.0 mix, is more enjoyable in 5.1 at any systems pricepoint over say 5K (or even a bit lower). For example, the Nordic 2L recordings come in 5.1 96/24 and 2.0 192/24 and the MCH mix wins hands down on any half decent surround system.

Think of it like this. You have say 20K invested in a good 2 channels system, and have 10K more to spend. Your options are upgrading your 20K 2 channels system to a 30K 2 channels system, or spend 10K on a center channel, pair of surrounds, 3 channel poweramp and active sub. Your 2.0 channel upgrade is deep into diminishing returns territory, while your 2.0 to 5.1 upgrade is a huge net system improvement. The issue is that because outside of the classical reportoire there are so few good native 5.1 mixed recordings available, many people in the audio crowd would understandable opt for the 2 channel upgrade anyway. However, this is not because a 2 channel 30K system is better than a 30K 2 channel system. It is because there is no content to enjoy the superior 5.1 system. Obviously for the movie crowd the equation is different.

So in my opinion you cannot discuss the relative merits of 2.0 and 5.1 without considering availability of content. Interestingly, the way audio is evolving it looks like legacy MCH high rez (i.e. SACD and DVD-A) is dead, future MCH high rez (i.e. Blu Ray music) is not really going anywhere, and 2 channel high rez may well have a future through 96/24 and 192/24 downloads. I personally love MCH high rez audio and this state of affairs frustrates me no end, but what can you do other than spinning your favorite MCH recordings over and over again....

This thread has progressed haltingly through nearly nine years of inconclusive debate. During that time much has changed in the world around us and in our narrow area of special emphasis.

My system has changed a lot since I first rendered an opinion on this subject and it is probable that the rest of us can say the same.

At present I have a two channel system comprised of big wooden horns and 15 inch woofers. The frequency response is narrow - (40 Hz. to 14Khz.) but the character and impact are very real and very impressive. I don't feel that I am missing anything.
To me the whole surround thing is an unnecessary gimmick, like 3-D.

As a dealer that almost uniquely, currently and continuously designs and sells (2) channel systems, I had to contribute to this forum. I have a lengthy list of clients that bought a (2) channel system from me that can attest to the superior attributes of their systems over a similarly priced multi-channel system. The most obvious advantage is buying such higher quality with a given budget, when buying such fewer items. The 2nd advantage is having fewer speakers. More, cheaper speakers do not sound better. When (2) speakers are set up properly in a well matched system, they merely represent the boundaries of a stage and then disappear. When your system sounds like a band or an instrument being struck in front of you, or like you are part of the scene in the movie, instead of sounding like a stereo (or speakers), you quickly get the idea of why it is so much better. I may not have read every response to this question and don't mean to repeat anything. It is just a question that I encounter and answer almost everyday. It's too bad that more dealers don't try to promote higher end (2) channel systems as an alternative to surround sound. Although, the current "norm" of multi-channel design provides a niche for me!