A Great Hi-Fi Sound System for Everybody

Each member of a 100-piece orchestra produces multiple such sound waves from their instrument’s fundamental tones and overtones, and thanks to the uniqueness of each sound wave, as well as spatial clues from its timing, under the right conditions, our remarkable sense of hearing can distinguish each player.

Even more remarkable, then, is that a couple of small boxes in our living room, powered by an electric current and a magnet, can reproduce the orchestra’s sound with a fair degree of accuracy. Such is the magic of audio reproduction, but not every stereo system is created equal.

Today, it’s easy for a speaker to reproduce a sound that’s recognisable as an acoustic guitar; however, making that guitar sound exactly as it does in real life, preserving all the complexities of its sound, is extraordinarily more challenging. And tricking the listener into thinking that they are actually at a live concert is the Holy Grail of Hi-Fi. Critical listeners and audiophiles (enthusiasts for true-to-life sound) admit that this hasn’t yet been achieved, no matter how expensive the Hi-Fi sound system. But nor have Hi-Fi engineers given up the pursuit.

The most recognisable part of a Hi-Fi sound system is, of course, the speakers. Generally, these are rectangular boxes with a dome-shaped tweeter and one or two conical drivers, each attached to an electromagnet surrounded by a powerful, cylindrical magnet. A crossover array filters different frequencies of sound to the driver most adept at reproducing them. In a realm so dependent on changes in timing hundredths or thousandths of a second long, the piston-like driver array that compresses the air to create a sound wave, the crossover that manages the incoming musical signal, and the cabinet that houses and anchors it all, must be built to exacting standards.

Examining the opposite side of the signal chain, music originates from a source, a CD, a digital file saved locally or streamed over the internet, or a vinyl record. Each has its playback method, which operates differently. Still, the goal is the same: transforming a musical recording into an electric signal, whose ordinary sine wave is transformed into an analogue of the original sound wave. This electrical signal passes through an amplifier to boost its strength with an extra helping of power from the mains, which must avoid distorting the delicate, original signal. This boosted electric current finally enters the speakers. As mentioned above, the peaks and troughs of that electrical signal magnetise the electromagnet, causing it to move its driver back and forth, thus compressing the air in front of it precisely in the same manner that was done when the sound was initially recorded.

As we’ve discussed, translating sound into electricity and then back into sound is a remarkable feat of engineering. Translating that sound first into a discrete data format such as a digital file and then reconstructing the musical waveform from scratch is still harder.… Or so we hope.

The grooves of a vinyl record are a physical representation of the sound waveform, and a needle tracing the groove, attached to an electromagnet, generates an analogue electrical model of the sound in roughly the opposite manner as a speaker transforms the electrical signal into a sound wave. By contrast, a digital file contains no physical trace of the original sound wave. Instead, in the encoding process, that sound wave is sliced into tiny pieces, each slice is scored according to its amplitude, and then each value is recorded. In sequence, this data allows a digital to analogue converter (DAC) in a Hi-Fi sound system to reconstruct the electric representation of the waveform to feed the amplifier and speakers.

As the number of slices per second (or the sampling rate) approaches infinity, the digital waveform becomes closer to the original. Since most humans can hear a frequency of only up to about 20 kHz per ear, the 44.1 kHz sampling rate of a CD was deemed more than sufficient to simulate continuous music upon its invention and release to the market. However, we’ve since learned better since modifications done on a musical track in the mastering process can cause artefacts at lower sample rates, and sharply rolling off the sound data outside the range of hearing eliminates higher-order harmonics.

While not directly heard by the human ear, they are felt and contribute a sense of air and ambience to a well-recorded piece of music. As a result, a lot of the music for sale today is available in high resolution, meaning that it has a sampling rate higher than that of a standard CD — often up to 192 kHz. Such music typically also has a more considerable bit depth (24 bits vs 16 bits on a CD), reflecting the amount of data recorded per slice and directly reflects the dynamic range that the recording can capture, yielding an even more lifelike sound.

However, over the past four decades, we’ve learned that the consumer computer electronics we rely on to process such files — DAC chips, ethernet cables, power supplies — are shockingly ill-suited to the precision required to transform a chronological data string back into a realistic sound wave. Computers and the internet were designed to ensure that data arrives intact, with algorithms to account for and correct data loss, but without consideration for chronology and timing.

This is a problem because if a data packet from a music file is lost along the way, it doesn't help to go back and retrieve it; that moment in the music is passed, and the sound wave is disrupted. Such lack of continuity in the timing of the signal is called jitter and is a large part of why all-analogue sources such as turntables and reel-to-reel players have retained their popularity throughout the decades; purely analogue signals don't experience jitter. In addition, computer processors and power supplies are massive generators of electromagnetic interference, as is Wi-Fi and even wired ethernet cable, depending on the implementation. This also harms the integrity of the sound.

At the forefront is the Technics JENO Engine. Short for Jitter Elimination and Noise-shaping Optimisation, the brain of the SC-PMX802 counteracts jitter through proprietary technology to re-clock the incoming signal and push jitter into the high-frequency range, where it’s more benign, and upsamples the incoming digital music file to create a smoother presentation with a more gradual, and therefore more natural, high-frequency roll-off. Furthermore, the SC-PMX802 output is fully balanced, which means that electromagnetic interference is passively detected and scrubbed from the signal chain.

The SC-PMX802 can play standard high-res digital files and what many consider the ultimate audiophile digital format, DSD. But additional problems arise at the opposite end of the spectrum when playing a lower quality data stream in a compressed file format such as MP3, from CDs, or over Bluetooth (which itself is usually highly compressed). Compression creates a smaller file by removing sounds buried beneath other, similar sounds and not typically heard by a casual listener.

However, an attentive ear and high-quality stereo gear can quickly reduce sound quality than a lossless CD or high-res version of the same track. The compressed track will sound harsher, grainier, and less open since much of the data that gets scrubbed are upper harmonics of musical instruments and spatial, ambient cues such as the subtle echo of the recording space. The echoing shimmer of a cymbal crash often demonstrates this aptly.

But the SC-PMX802 has a solution for this as well, via its Re-Master technology. This analyses a musical track in real-time, looking for telltale high-frequency distortion and replacing it with equivalent but less distorted harmonic components. If you can’t always listen to lossless audio, this is the tool a true Hi-Fi stereo can’t be without.

Music is fundamental to the human experience because it is fundamentally a live art form. TV and film connect us to realities known and unknown. Few would argue against the notion that experiencing art live, in real-time as it’s being born, is the seminal way to enjoy art. For that reason, the ability to replay a live experience through a high fidelity system, and become fully immersed in the sonic world that the music or film inhabits, is a wonderful modern luxury.

Playback may sound simple, and the flood of inexpensive stereos on the market demonstrates how often it’s taken for granted. But reproducing sound well is fiendishly complex. That Hi-Fi luxury of true-to-life sound is now available to everybody, thanks to the technology-packed Panasonic’s SC-PMX802. This audiophile-grade mini Hi-Fi sound system can fit anywhere in your home. May it take your listening to new heights.