Speak low

Your choice of loudspeakers is one of the two most important factors which shape the sonic design of your dream home audio system; the other is the acoustic treatment of your music room.

There are thousands of loudspeakers available on the market today, with prices ranging from P10, 000 to more than a million pesos a pair. Aside from the price and the WAF (wife acceptance factor), you’ll have to contend with a myriad of "advertised" tonal characteristics of each brand and make: brighter sound, powerful mid-range, good deep bass reproduction, among others. In short, finding the right speakers that will satisfy your sound preferences will involve a lot of thinking and several consultations with experts and audiophile friends.

But are there hard and fast rules to make an easy decision?

Sound is perception. It is how our brains interpret air vibration through our ears. Our sense of hearing has a very wide audible range. A person with healthy ears can distinguish anything from a whisper (in a sound-proofed room) to the sound of the loudest rock concert; the latter being 10 billion times louder than the former, giving you a dynamic range of 100dB.

In our last column we also discussed that highly sensitive speakers require less power to make them work properly. Thus, speakers with sensitivities of over 100 dB can be driven at ease by amplifiers with a low power rating. Only a few modern-day speakers can offer over 90dB; most are below that range. Loudspeakers with a sensitivity rating of 91dB will need an amplifier which has 130 watts in power to reproduce sound without distortion. Since low-watt amplifiers are more often cheaper than those which pack enormous power, just think of the savings you would have if you could have speakers with a sensitivity rating of over 100dB!

Some claim that sensitivity rating has no bearing on sound quality. To them, "branded" means the "very best speakers" which may have low sensitivity ratings. I respect their opinion, but I beg to disagree. Highly sensitive speakers offer a wider dynamic range, which is a vital gauge of the system’s quality to record or reproduce information for human perception. In audio, dynamic range is often used by sound engineers to describe the ratio of the loudest possible undistorted sound to the softest. Wider dynamic range also gives your system more headroom to reproduce music without ear-piercing peaks and distortion. Picture several children playing trampoline indoors; no matter how high they jump, there is no chance that their heads will hit the ceiling with ample headroom.

While playing soft music, for instance, your amplifier may be only cruising along, churning out only a few watts. But for loud explosions, such as in Tchaikovsky’s 1812, crisp percussion and loud horns in big bands and other music which contain dynamic passages, your system will need extra power. With limited headroom, these dynamic passages will figuratively hit the roof, degrading the sonic quality of your system. Highly sensitive speakers can easily be driven by low powered amplifiers to produce 10 times the speakers’ average power to faithfully reproduce these passages; and an immensely powered amplifier can do the same with low sensitive speakers.The most important factor to consider is your speakers’ ability to reproduce low level information. Can your speakers speak low?

Low-level musical information embraces the widest possible collection of musical sounds. These include, but are not limited to: the harmonics that recognize instruments and allow them to sound "musical" or natural; the delicate, immediate changes in dynamics and their concentration and emphasis (also known as micro-dynamics and dynamic shading), enabling musical "expression" to be sensed, heard and felt; the sense of ambience and liberty, which affords the listener to both hear and "be there," and the intricacy and division, or absence of homogenization, of all of the above that reduces "boredom" and "listener fatigue."

If your speakers are unable to reproduce low-level musical information, the danger is that you will be forced to fill the gap with your brain. This subconscious effort causes "listening fatigue." (This article assumes that the speakers are going to be placed in an acoustically treated music room.)

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More about speakers and room treatment in my next column.

For comments and suggestions, please e-mail me at vphl@hotmail.com.