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Is my system only as good as its weakest link No. In fact, the playback system does not behave as a chain at all. Sure, a chain of events needs to take place to get sound, but really it’s a system and must be approached systematically. Like any complex system, the playback rig, and its environment, cannot be fully modeled without understanding of its components, relationships, and acoustics. This is not to say that devices sonically evaluated within any given playback system can only be done by those few with profound understanding. Here a some facts to consider. • Playback systems function as a system and any change within it will affect the final product.• We can never assume that an assembled array of playback equipment, or any single device is perfect. • The perfect recording does not exist. • There is no absolute sound. • Unless you are the producer, recording engineer, mix guy, and mastering man (rarely the same guy or even team) responsible for the recorded material, with a vast understanding and experience with your recording and playback systems, you can never know the recording’s nature and accuracy. (Show goer beware, if you roll in at a Zu demo, chattering about how you know what a particular recording is supposed to sound like... well lets just say it’s hard to take your comments seriously.) • A change anywhere within a system can and should impact the system’s performance. • Each person listens and physically hears differently. Like voices and fingerprints, none of us have the same physical hearing response. • All systems are different and a device under test will perform differently in them. • General listening specific assumptions can be made after a large enough sampling of systems and observers but it is only relevant to the state-of-the-art of playback systems within its sampled generation. (Loudspeakers that are known to sound good in today’s systems will generally sound bad when used within a system from the ‘40s. That is not to say a loudspeaker from the ‘40s will sound poorly in today’s systems.) • All devices will change over time. • People's emotions are easily fooled. Example: I have a system that is sounding really good, excellent detail, spot on stereophonic recreation, excellent attack, great tone, timing and texture. I then replace my loudspeakers with a different pair of loudspeakers. The system now has increased bass detail, deeper perceived sound-field depth and broader width but now sounds bright. Is the loudspeaker the source of the brightness? While I think I can say the increased bass detail could be attributable to the new loudspeakers and their reaction with the amplifying device, unless I know what brightness is and can define it as a particular frequency bandwidth and the distortion within that band—whether amplitude, harmonic, transient compression or so on—I cannot attribute the brightness to the loudspeakers or any other device within the system, at least not without further sampling of gear and time with the rig. The more knowledge regarding a system, the more accurate your hunch. It’s easy to present situations that cause a desired result. Both in oneself and in those you wish to influence. For the most part it’s quite easy to know performance changes relative to primary system attributes. Shades and gradients of primary and secondary attributes are much harder to wrap your ears around but it is usually within the secondary attributes that we find the details and magic we are looking for. In cable evaluation for example, observers are really trying hard to hear a difference because they believe the difference will be subtle. This compounds the potential for outside or psychological influence. If the observer has a predisposition to a model or brand being compared there will likely be subconscious events that will shape the outcome. Also, if a demonstrator wants to influence the observer there are several tricks he or she may use to produce the desired results. Those commonly used by industry types are: • The second set of listening of the same material results in increased awareness by the observer, particularly after a brief calm or distraction and so the second devise tested is usually psychologically perceived as the better sounding.• Observers usually relate a small increase in amplitude (1 - 3dB) to increased fidelity, especially in a room that has the capacity to damp high sound pressure levels. • Playback of recordings that are known to work with or against the bias. • Playback with equipment that works with or against the bias. • Observers are influenced by the demonstrator either before or after the played set. Combine this with the “second set” phenomenon and the demonstrator can easily direct the desired result. • Rumor, reputation, price and looks of the device. • The only way to know the performance of a device is to follow some semblance of scientific observation, within a large enough sampling of gear and people, with the observers keeping their notes to themselves until the completion of the study. A simple cable test could consist of two or more observers and a controller that have at least a basic understanding of musical acoustics and can accurately communicate using musical or scientific terms. The controller must not communicate anything to the observers during the test except the test number. There must be two cables to be observed. Three usually increases the level of complexity and duration to unusable limits in terms of information and listener fatigue. The controller must also account for any change in amplitude between the two cables prior to running the test. (Electrical characteristics of a cable influence power transfer between transmitter and receiver, even at line-level.) Observers are not allowed to know which cable is under test or know the device cycle. Then there is the very large topic about recorded material and how it factors in, but a song or two are selected and the set is played twice without change to the system. This is so the observers can listen to the music the first round and then take notes as she or he listens to the set the second time. The controller randomly changes between the two cables, sometimes leaving one cable in for multiple cycles and so on. The evaluation session should not last longer than an hour. |