Hi-Fi Myths and 3TIUM Truths

The evolution of Hi-Fi is quite similar to evolution of democracy with the audio equipment specs resembling the human rights declaration. Just like everyone was unique until Sam Colt made us equal. Any declaration is worthless against a technological breakthrough. The same principle applies to Hi-Fi. The best sounding audio equipment never has the best specs, but has some hidden secrets instead. Read on to see how deceiving a specification could be.

The audio reproduction industry standardized the specs to compare the products theoretically. Standard parameters include THD, frequency response, output power and many others. Ironically, the Hi-Fi standards came out in the era of Elvis and Beatles, when the quality of audio recording and reproduction fell dramatically. Equipment producers then pushed studios to replace tube amplifiers with transistor rivals and chose characteristics, by which transistors outperformed tubes. The marketing hypnotized consumers that synthetic sound of transistor amps is closer to the original because of lower harmonic distortion compared to tube-driven sound. Similarly, many expensive speakers with super linear frequency response sounded dull, with no audio scene depth, whereas some radios from 1940s sounded quite deep in spite of being mono with limited bandwidth. The myth about linear frequency response as a primary measure of quality was quite audible and even inspired Amar Bose to establish his now well respected global corporation. The specs have little to do with sound quality nowadays, just like half a century ago. In part because the parameters are measured in an artificial manner and in part because some important characteristics are intentionally omitted. Let's demystify current situation in the audio industry.

Myth 1: Output Power

First, let's convert Chinese 1000 Giga watt written on the box for promotional purposes into electric power, defined in physics. The math is fairly simple: divide the "P.M.P.O." (Promotional Microsecond Power Outage) by 12 for respectable Hi-Fi brands or by 66 for Chinese clones. For example, when a 50ny home theater says it is theoretically capable of producing 1000W for one millisecond on Mount Kailas with aid from an alien spacecraft, it means that in such home theater all amps together are capable of delivering maximum 88W of relatively undistorted electric signal to purely resistive load. Speakers are naturally inductive with extremely nonlinear impedance and main resonance, lowering the high fidelity power even further. This is how some 2X6W vacuum tube amps sound cleaner and louder on sensitive acoustics than many "100W" stereos. Chinese watts evolved as a marketing tool to put mediocre products on the same shelf with the quality equipment. Two countries have always rated their amplifiers' output accurately nonetheless: Nazi Germany and Soviet Union. Hitler could execute anyone responsible for the incorrect specs and the Soviets, due to centrally governed economy, had no sales people to inflate the numbers. The RMS ratings could be as deceptive as P.M.P.O. for the same reason: marketing. The specified RMS may imply partial clipping mode (10% THD), loading one channel at a time, purely resistive load and other tricks that take the numbers far from how the RMS power is rated by engineers while the sales people are away. In general, divide the officially rated RMS power by Euler's number (2.718) for branded products and there will be the real high fidelity output the amp is capable of handling. The bottom line is that many systems rated with the same RMS output power may have it threefold different in reality.

Myth 2: Linear Frequency Response

The trick is in using manufacturer's anechoic chamber for measurements. The chamber, where the measurements are taken, is far from real room where the audio system will perform, just like Earth surface is a bit away from the space vacuum. Therefore, Space Horses in Vacuum is the proper name for all equipment, rated in anechoic chamber. Any room distorts lower octaves as a multi-frequency discrete resonator up to room's Schroeder frequency. Anechoic chamber is the only exception, providing resonance-free listening, but its every visitor feels a light post-concussion syndrome, so home owners are highly discouraged from turning their living rooms into anechoic chambers. The important moment is in real room the upper bass always masks out the lower bass. For instance, in a typical room of 220sq.ft. the main room resonance is at 92Hz and all frequencies lower than that would be masked out by 92Hz intermodulation, often causing an expensive subwoofer to sound like a cheap boombox without the feel of lowest vibrations going through the body. The worst booming happens when room resonance meets speaker's resonance, but these cases are rare. The room distortion is well heard during a grenade explosion sound or kettle drums play. In accurate reproduction, even at lower listening volume explosion's lowest vibes go in you, like you feel it with your whole body, not just the ears. The survivors of a real grenade/mine explosion know that literally vibrant feeling and only the system capable of replaying all the vibes within a living room may be rated as High Fidelity. Nevertheless, the mainstream speakers typically reproduce the grenade explosion like a sledgehammer with a couple of firecrackers dropped hard on a laminated floor. In general, the great Hi-Fi sounds great at any sound volume whereas the poor quality audio subconsciously prompts you to turn it louder in hope that speakers need more power to sound right.

Myth 3: Total Harmonic Distortion (THD)

Audio systems are typically rated with total harmonic distortion (THD) parameter as a subset of intermodular distortion (IMD), rated for high end audio. Intermodular distortion is measured when all oscillating processes in the system run steadily. However, the real audio signal, such as percussion attacks, sheer guitar riffs or emotional vocals are, in essence, the continually transient signal having very little in common with steady oscillation. Therefore, intermodular and harmonic distortion ratings, shown in specs, do not represent much of the real audio distortion picture. That is exactly why many people nowadays prefer vacuum tube amplifiers despite their substantially higher THD compared to semiconductor-based rivals. The major transient distortion source is not in semiconductors. It is in the enormous amount of low quality transistors combined on a monstrously engineered integrated circuit (IC). Just like in the bleeding edge technology a team of few gurus outperforms any corporation, because a big organization with dominant low quality labour simply cannot succeed in things that require expertise, accuracy and clarity of perception. The low-quality contributors often contribute noise, distortion, time lags, phase outs and lack of transparency. On a silicon chip it's just the same. The great old Fisher TX-1000 had only seven quality transistors on board whereas modern IC-based power amplifiers have hundreds. In spite of Fisher's highly distorting electrolytic output capacitor, the signal fidelity of the seven-transistor circuit is notably higher compared to STK, left alone TDA integrated amps. That's what happens when trying to fit a thousand uniform yet poor quality components in a high density place hoping they will compensate each other's flaws. Complex control loops make the measured parameters up to the highest standard, but the real output quality is enormously low due to uncontrolled and unmeasured processes. The manufacturers pretend that THD, IMD and frequency responce nail the Hi-Fi system quality numerically, leaving consumers to hear that those three characteristics have little in common with sound reproduction quality nowadays.

Myth 3.14: Bass Distortion is Barely Notable by Human Ear

Good subwoofer drivers typically offer 12% THD below 50Hz measured by engineers for engineers and kept secret from advertisers and the public. The impressive speaker size, monstrous electromechanics, high inductive currents and few other factors contribute to inevitable sound distortion. Because a human ear can barely notice the bass distorted by one fifth, such distortion rate is considered good by the mainstream manufacturers. The assumption is medically true until after ten minutes of listening, when the brain signals that it is tired of something being not right. We may not note every waveform distortion, but we do hear distorted waveform envelope. True undistorted bass is best valued in cello, pipe organ, bag pipes and piano performances. Therefore, when coming back from a concert, do not try to play its professional recording on a home theater as the 5.1/7.1 equipment may end up tossed the hard way. 3TIUM heart takes a special care of bass distortion, making, among other things, a recorded listening of low pitch instruments that produce important overtones indistinguishable from live performance.

Myth 4: Bass Phase Coherence is Unimportant

This myth comes from the truth that a human ear is unable to localize the bass source. In essence, the bass must play in tact with higher frequencies to reproduce the sound as it was during the recording. Therefore, we can't localize the bass itself, but we do hear coherent bass interference with the mid range. This phenomenon is easily notable in jazz, easy listening, or orchestral music. The bass coherent with mid range makes the air breathe. You feel every inch of space in the room the recording was made. You also hear if the audio scene had been artificially staged by offsetting phase for every separately recorded source. Examples of poor phase coherence are modern 5+.1 home theaters, where audio scene depth is delivered artificially by tickling the ears from several locations by synthetically filtered and offset sounds, like the air-rubber strings holding the audio scene. Great examples of phase coherent systems are German radios made in 1930s. One big open-box speaker made of special wood with large quality driver in it, complemented with vacuum tube amp containing the current feedback circuit still is one of the best configurations for bass and mid range audio reproduction in terms of phase coherence. This is why many audiophiles prefer older Hi-Fi to modern flat sounding synthetic 7.1 "high end" stuff.

Myth 5: Active Speakers Are Better Than Passive

The truth is that Chinese active speakers are typically better than Chinese passive speakers. For properly designed, built and tuned passive speakers being worse is a myth. Properly designed passive filters, besides the filtering, linearize the reactive artifacts in speakers and only take 1-2dB of extra power, which is a fair trade for not having too many wires towards each speaker or the cancer-causing Bluetooth/Wi-Fi radiation. Two wires for each speaker is to this day the most elegant and ecological installation option. About benefits of using a good two-wire audio cable, read Myth 5.2. In general, for an audio system taking advantage of the concept devised in Nazi Germany and depicted on the left, it does not matter if speakers are active or passive. The amplifier + speakers synergising circuit will bring the capabilities of both to their best.

Myth 5.2: Different Cables Sound Different

For passive acoustics, it is actually true unless there is a special circuitry neutralizing capacitive, inductive and damper effects in speaker wires. Our testing ruined a common myth that wires made of pure gold are the best. Without the compensatory circuit, wires will contribute to the sound. The same circuit compensates reactive artifacts inside the speakers. That is why active speakers could also sound dull without impedance- and damper-compensatory circuit, as if they had some bad wires. Reverse intermodulation distortion (RIMD), compared against traditional IMD, indicates how accurately the reactive speaker currents are dampered. The RIMD is measured by applying one sine wave to the input and the other to amplifier's output on a resistive load, just like it is measured for radio transmitters. But again, the compensatory ciruit with concept thereof on the left is mandatory for any system that claims to be Hi-Fi.