Center Channel

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There is a very good article concerning the need for a center channel by Richard Hardesty.  His article inspired me to think further about the necessity for a center channel.  The point of my comments here isn’t to totally convince the reader that there is no need for a center channel, but merely to present some further issues concerning a center channel speaker beyond those mentioned by Mr. Hardestry.  It is important to admit that I do NOT have a center channel speaker nor do I intend to implement one in my system.  My comments are obviously biased against the need for a center channel.  However, recent electronics have almost created a need for the center channel.

 I believe the need for a center channel and surround sound is merely a placebo attempting to bring the live experience into the listening environment after years of slowly degenerating components at the consumer level.  Years ago Altec, Harmon Kardon,  JBL, Pioneer, Marantz, Heathkit made some darn good stuff.  These components were available to the common consumer at common stores.  The sonic presentation of these components was relative good and clean.  It was quite possible for the common guy to go to the local electronics store and purchase relatively clean electronics.  The imaging was very present and respectable.  Today there is a gross dichotomy and most consumers are never exposed to anything producing clean sound.  “Back in the day”, things were a little different.

As time moved forward consumers became quite engrossed with things like Watts Per Channel, Total Harmonic Distortion, Signal to Noise ratio (etc. etc.), and the manufacturers rose to the objective challenges.  They also realized that a grossly decreasing number of consumers actually attended symphony events or cared about reproducing the live event.  A smart consumer could brag about how many watts he/she had in their system and how clean it was because of the lack of distortion printed on some sheet of paper. 

There are two problems with this.  First, any tube guy with $500 today can purchase an used/old piece of tube gear that will always sound cleaner than a $500 piece of used/old solid state gear.  This happens in spite of the generally higher even order distortion of the tube gear.  Any tube guy knows that higher levels of even order distortion are relatively insignificant.  While I am not a tube guy, I have heard this phenomena and tend to agree.  Second, American consumers have progressively listened to less live un-amplified music.  There is little reference for what accurate production is, so the consumer can easily turn to a sheet of specifications to determine the quality of a particular piece of stereo equipment.  The consumer is oriented totally towards READING about how “good” a piece of equipment is.  The obvious outcome is that manufacturers obliged, and built wonderful specification sheets.  They didn’t build wonderful sound.

Eventually the sound became so muddy/harsh that the ears could audibly localize the sound and everyone could audibly locate their speakers.  Imaging was gone, so was quality.  Surround sound attempts to return imaging to the listener, but the quality is still not present.

Digressing… I will admit that initial studies about the ideal system configuration in the early years of stereo/quad (etc) revealed that a 3 channel setup was the best.  I will also agree that if quality recordings were done in this format that I would buy them.  The harsh reality is that most recordings are junk.  If a recording engineer can’t get a 2 channel recording correct then how could they possibly get something in 5,6,7 channel correct?  I consider only about 2% of recordings as well done.  I am not a recording expert, but do have a system that will easily resolve good clean recordings.  It will also easily resolve very nasty recordings.  Most are quite nasty.

Most consumers have never heard a really good 2 channel system.  Those who have will agree that a very nice center channel image is present.  This also works very well when watching movies.  The image can have nice depth of field and makes watching movies in 2 channel very pleasing to my ears. 

There are two reasons to purchase a center channel home theater system. One is to experience a fidelity placebo for clean sound.  The other is if the listener is sitting in an extreme off axis position.  This is very valid, however, there will still be phase problems due to the off axis position. 

If the center channel and side speakers are adjusted in-phase for the center listening position they will not be in-phase for those listening off axis.  This is also true for those listening off axis with 2 channel.  My point is that having a center channel does not completely eliminate phase problems.  It does reduce their effects somewhat due to the relatively close proximity of the speakers.

 

 

 

The above example depicts what happens when the system is phase adjusted for the center listener.  The phase is perfect for him/her, but this leaves the listener on the right side with phase errors.  The arrival of the wave front from the right speaker is not in phase with the arrival of the wave front from the center channel speaker.  This will cause distortion.

My intent in this illustration is to convey that systems with center channels have phase problems with off axis listeners TOO.  There is a common misconception that center channel speakers will completely eliminate these problems, but this is not so.  Surround sound systems with center channel speakers still have phase problems and the associated distortion.

Many folks, including me, are quite happy without the use of a center channel speaker. This is primarily because I am cheap.  I have about $5000 in a decent clean 2 channel system, and have a wonderful center image.  This is primarily because my system is quite clean.  Probably the most common question I get when friends listen to my system is, “So what do you use for a center channel?”  I do have a false grill in the entertainment center below my TV where a center channel could rest ( concealed). 

My response to this question is often vague.  Sometimes I nurse the conversation a little and ask them to describe what they are hearing and where the sound is really coming from.  All are quite shocked when they realize that I don’t have a center channel.  The most common remark is "everything is so clear."

This is a sad phenomena but one that most folks haven’t experienced.  Good 2 channel can sound very pleasant when watching movies.  Good sound from 2 channel is also much cheaper than good sound from 6+ channel (i.e. surround sound).  Many of my customers mention the desire for a center channel before purchasing my speakers.  After purchasing my speakers the desire for a center channel strangely disappears.  Hmmmmm....