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  Setting up a stereoOK. You’ve finally decided it’s time to do it right. Time to put together a hot two-channel setup and enjoy all the wonderful benefits associated with a great stereo system. Where do you start? How do you get where you want to go? There aren’t many books to read or advice to follow that can truly help you figure this out. One excellent piece of reference material is Bob Harley’s Complete Guide to High End Audio. It is well written and has a lot of good advice.  We would suggest that setting a system up is a little like raising a child for the first time. There aren’t any schools for this, there aren’t any real answers that are right because every situation is different. Most parents or future parents rely on advice from friends and relatives. So too is setting up a high end system. You rely on every scrap of input you can lay your hands on and hope for the best.In our travels We travel around the world setting up systems for people and helping them with their setups when we visit our dealers and distributors of PS products. On these visits, we run into a everything imaginable from wonderful sound to less than stellar setups. Great equipment is usually in place, good power management, good loudspeakers, cables and all the necessary gear for a great performance. But the owners are not thrilled with their systems. They know they can be better, they’ve heard better. We usually leave their homes with the customers feeling wonderful about their systems again. What did we do? How did we do it? In these next weeks we will begin sharing our perspectives on system setup with you. Our hope is that you can glean some valuable information from these articles and apply them to your own setup.  Keep in mind that this is a generalized viewpoint and, just like raising children, every system, every room, every situation is entirely different. None of this is gospel, it is just a simple set of guidelines designed to help you get the most out of your two-channel audio system. Terms Perhaps it is best to start this series with improving our level of communication. There are many Audiophile terms used in conversations and this article set will be no different. To ensure we are all on the 'same page', so to speak, we’ll begin this series with defining our terminology and how it applies to your system. Tonal Balance Tonal balance is the art of achieving a balance or neutrality of volume between tones. If one tone or frequency is louder, softer, more apparent than another tone, then you do not have accurate tonal balance. This is tricky to try and explain in words. The problem is, what is correct? You could suggest that all one  needs to further define proper tonal balance is to listen to live music. However, that is flawed. It is flawed because in nearly every live music venue, tonal balances are never perfect. The stage or the hall where live music is being played is not a perfect place and therefore the tones of certain instruments or voices will be altered.To further exacerbate the problem, the human ear very quickly adjusts and compensates for these tonal imbalances and one tends to not notice them when one listens to live music. It is actually easier to recognize tonal balance problems in a stereo system than it is in a live music venue. Variety of program material in a consistent setting is the reason. As an example, if you play five different recordings of live music in the consistent space of your home, tonal balance differences caused by your system will be easier to identify because each of the recordings will consistently have one or more tonal areas emphasized or de-emphasized. The chances that this was a consistent error made by five different recordists is slim to none. Therefore, the most likely culprit is your system or some component in your system. Soundstage The recreation of live space, or the recreation of the recording space.  Every recording (with the exception of pure electronic music) was made in a space. The recording process picks up reverberant cues and ambient information of the space it was recorded in and the stereo system will attempt to playback these cues in such a way that the listener believes he/she is reliving that same space.Very few systems ever get the soundstage to be right. This is one of the most difficult tasks for anyone trying to setup a system and perhaps the most elusive of them all. Depth Boy. Here’s a can of worms. There’s more opinions on this subject than you know what. Here is our opinion. Depth is the ability of the loudspeaker to reproduce accurate distance from the recording microphone. That distance should appear from behind the loudspeaker’s drivers. As a person or an instrument gets closer to the microphone that is recording it, the sound will have less 'depth' and will appear to come from the speaker itself. If the recording is very close-miked the sound can actually appear in front of the loudspeakers. Most Audiophile recordings and well made recordings don’t close mike the sound sources and therefore have a lot of depth. During the course of these articles we will go into great detail on the subject of depth and present plenty of examples of music you can use to achieve 'proper' depth.  Width The ability of the loudspeaker to create an image that extends beyond the outer left and right boundaries of the loudspeakers when the program material supports it. Center image The phantom third channel. Many people think of a two-channel system as having three distinct channels or places where sound appears from. This phantom center channel is the product of an equal and identical sound source coming from both the left and the right loudspeakers. Our contention in this article is that this is incorrect. There is no phantom center channel, there is no center image. Properly setup a well balanced two-channel stereo system should produce a virtually seamless presentation that extends from one side of the room to the other side of the room. The only reason that there should ever be an obvious 'center channel' is when a recording engineer placed a center voice or instrument too close to the microphones. What we normally consider as a center channel is really a recording error. Phase and polarity For the purposes of this article we will suggest these two items are essentially the same (although they are not, technically speaking). Phase in this context will be defined as the difference or lack of difference between the left and right channel speaker driver motion in an absolute sense. As you know, loudspeakers generate sound that we hear because of the back and forth movement of the speaker drivers. This back and forth movement pressurizes the air and moves our personal hearing mechanism. We hear this pressurization of the air. If the same signal comes to both loudspeakers at exactly the same time, and the two loudspeaker drivers are moving at exactly the same rate and time, then the air will move in concert with the drivers. However, if the two drivers are out of phase, then each moves in an opposite direction from the other. This causes the sound to de-pressurize or cancel and you lose sound pressure or volume.  Standing Waves Groups of high and low pressure waves that build up in a room. There are no standing waves without a room. A graphical view of a standing wave is easy to produce. Take a glass of water and set the glass atop your loudspeaker. Put on some music with lots of heavy bass and crank up the music. While it is playing, look at the water inside the glass. Note that there are ripples in the water caused by the speaker’s vibration. The ripples will appear to stand still and in many cases not be obviously associated with the sound. The air in your room can act the same as the water in the glass. As your speakers pressurize the air in the room, standing waves bunch together in much the same way as the water in the glass did. Typically these standing waves gather at the boundaries of the room and the corners. The problem with standing waves is that they create tonal imbalances, especially in the bass. Standing waves create interference patterns that will either boost some frequencies while attenuating others. This has a lot to do with why one room sounds better than another. Standing waves are bad. Point of first reflection The point at which the sound from your loudspeaker first hits a wall or room boundary. Now that we have some of our terms defined we can all be on the same page with respect to our level of communication. In our next installment, we will begin by learning how to choose the room or how to deal with the room we have chosen to place the stereo system. Stay tuned for more! |
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