Despite our best efforts to describe what we hear, something will be lost in translation because we all hear differently. Furthermore, each of us can listen to the same recording at different times and, from session to session, hear different aspects of it. It may be useful, nonetheless, to identify sound characteristics in evaluating an audio system or component.

A term frequently used among audiophiles is hi-fi or high fidelity. Is the sound produced by an audio component an exact replica of the sound heard by the recording engineer? Perhaps only the recording engineer could answer that question. Another popular discussion among audiophiles is whether the equipment sounds “musical” or “hifi-ish”. “Hifi-ish” prioritizes sound quality over holistic enjoyment of a piece of music. Of course, the quality of the sound may get in the way of the holistic experience. A listener may disengage from a veiled recording played through poorly designed equipment. Overly bright sounds may be fatiguing. Hence, the characteristics discussed below straddle the “musical” and “hifi-ish”.

1. Sound Stage — Spatial information is crucial for listeners to imagine a live performance through the recording. Most concerts are amplified in some fashion. What a concert goer hears is not necessarily the performers themselves but loudspeakers controlled by the sound engineer. Ideally, the recording microphones would be placed where the engineer thinks the best sound is in the venue. An audio system with a good sound stage enables listeners to close their eyes and be transported to that sweet spot.

2. Timbre Accuracy — Our brain can decode subtle differences in instruments (Stan Getz’s tenor saxophone versus Scott Hamilton’s) and in voices (Frank Sinatra versus Frank Sinatra Jr. even though their voices are quite similar). A good audio system reproduces accurately not only frequencies but also complex harmonic structures. It conveys nuances in a realistic way, from the caressing pressure of the bow on a string instrument to the huskiness of a baritone.

3. PRaT (Pace, Rhythm, and Timing) — An audio system with PRaT makes listeners want to move with the music.

4. Clarity — Sound stage, timbre, and PRAT cannot be experienced with a muddled sound. Clarity enables listeners to enjoy a musical piece as a whole or to focus on the piece-parts.

5. Balance — With a balanced audio system, no individual part in a musical piece sticks out in an unnatural way. A soloist would be prominently featured; the supporting cast of performers would come into focus or recede at the right times.

Reviews of audio components often mention characteristics such as treble extension, deep and tight bass performance, or mid-range purity. These frequency-related qualities often reflect the listener’s preferences for certain sounds. That is why there is no such thing as the “absolute sound!”

Theories and opinions abound on vibration control for audio equipment: Is vibration control needed? If so, which products work best? Let’s start with how vibration affects sound quality.

Loudspeakers — To reproduce sound from a source, a moving component in the loudspeaker (a dynamic driver, a ribbon, an electrostatic panel) must vibrate and cause change in air pressure.  “Good” vibrations replicate the recorded signals.  But other characteristics of the loudspeaker (cabinet resonance, crossover components, driver specifications) may introduce unwanted vibrations.

Vibrations from loudspeakers are transmitted elsewhere through the air or to the floor through the stands, causing more vibrations in the listening environment. The aggregate effect can interfere with the listener’s perception of certain frequencies and processing of complex harmonics. It can also result in indirect reflections of low bass frequencies.

Other Audio Components — Vibration can create electro-magnetic fields around wires inside an audio component. It can cause the transport mechanism in a CD player to shake. In an analog setup, it can move the stylus in the record grooves in unexpected ways.

Evaluation Criteria

There are many vibration control approaches on the market. Some seek to isolate the components from vibrations in the environment while others try to channel vibration away from the components.  The material used ranges from soft iso-elastomers to hard metallic cones or balls.  To evaluate the effectiveness of a solution, we need to establish how to measure the results.

Accelerometers — Applying a vibration control device to a component should result in less vibration. The easiest way to quantify the difference is to compare signals from identical accelerometers, one mounted on the component with the treatment, the other on an identical component without the treatment. This test may be impractical because it requires two identical components operating under identical conditions except for the vibration control device.

An alternative way to quantify the difference is to mount one of the accelerometers on the component, the other on the shelf directly under the vibration control device. If the device does anything to the vibration, the accelerometer on the component should show less vibration than the one on the shelf.

A/B Listening Tests — The effect of reduced vibration on the sound quality should be verified in blind listening tests with multiple test subjects.

Vibration Control Methods

Spikes

The spike-based method encompasses any variety of feet used to support audio equipment.

Most audio components have rubber feet. Regardless of the material and durometer of the feet, their purpose is to cushion the chassis and lessen the vibration that can channel up from the rack shelf to the component.

Most speakers come with spikes that are typically made of metal (steel, aluminum, copper, bronze, etc.). Spikes couple the speaker cabinet to the floor and prevent the cabinet from moving with the drivers thus smearing the sound. They are also meant to channel vibration away from the cabinet, but this notion is often challenged.

Suspension

Suspension-based devices work like shock absorbers on cars.  The vibration transfer is reduced in both directions, to and from the component in question. The suspension can be air-based, spring-based, or both.  The stiffness of the suspension can be tuned to match the weight of the component to optimize performance.

Constrained-Layer Damping

Different materials have different resonances and affect vibration differently.  Judicious use of layers of different material to provide a base for components can reduce vibration across the frequency spectrum.

METHOD	PROS	CONS
Spikes	• Provide a firmer base for the speaker or component. • Reduce vibration transfer by isolating the bottom of the speaker cabinet or component chassis from the surface it rests on.	• Even when the difference in vibration can be measured, improvements tend to be small. • The spike material will have its own resonance that can affect the final result.
Suspension	• Can be tuned to suit the application and optimize performance. Reduction in vibration can be measured as the suspension is tuned.	• Can be difficult to balance and level. • When not configured properly, can cause the supported component to be unstable.
Constrained-Layer Damping	• Simple to design and manufacture, once the combination of materials and construction technique has been selected.	• The materials used may have their own resonance that can affect results, depending on the applications. • The thickness of the base adds to the overall height of the component.

Theory vs Practice

Although spikes are meant to channel vibration away from the speaker cabinet to the floor, tests using accelerometers have shown similar vibration between the accelerometer the floor and the one on the cabinet.  This may be because the spike transmits vibration in both directions.

We find that a suspension-based approach works for most audio components. Gingko Audio’s Cloud platform combines the suspension provided by rubber balls with the rotational movement of the balls on dimples in the platform base.  The Cloud platform works great for turntables and similar components. But it does not work at all for speakers because it wobbles under the load, especially when the speaker plays music.

A constrained-layer approach requires careful design, testing, and measurements to ensure positive results across different components.  As an example, Gingko Audio’s ARCH is a multilayered band in a curved shape that acts as a leaf spring, turning vertical vibration energy into horizontal vectors under load. The choice of materials and construction technique must take into account different component weights.

Theories and measurements aside, if the listener can hear the effects of a vibration control device and concludes that they yield more enjoyment of the music, then it is the “best” device for his/her application.  Not everything works well in all situations, so by definition, the “cost-effective” device is one you can return and get your money back if you are not satisfied with its performance.

Write to us at gingko@gingkoaudio.com with your specific needs and we will recommend the right solution for you.

There are five broad categories of components in an audio system: Source, amplification, loudspeaker, connections, and accessories.

Source

Source components decode the information that has been encoded on storage media (vinyl records, CDs, etc.) and reproduce the original recording of the musical performance. High fidelity, or hi-fi, denotes how faithful the reproduction is to the recording. On live recordings, listeners can recognize not only the individual sounds of the instruments but also where the instruments are located in the three-dimensional space of the venue. On studio recordings, listeners can hear the final mix and sound stage intended by the recording engineer.

Flaws in a source component cannot be corrected by another component later in the chain. A good source should make a good recording sound good and a bad recording sound bad. A bad source may make a good recording sound bad or a bad recording sound better, i.e., more “musical sounding”, but it is still a bad source.

Amplification

Amplification components boost the sound signal. A preamp takes a low signal from a source, boosts it to standard voltage level, and outputs it to an amplifier. The amplifier boosts the signal to an even higher level to drive components in the speaker that, in turn, reproduce the recorded sound. The preamp also serves as a control point for adjusting the volume, inserting frequency equalization to the signal, and switching between different components as the source of the signal.

Loudspeaker

Loudspeakers are designed to have a distinct “voice”: The designer will have tweaked the speaker’s components (drivers, crossovers, cabinet) to reproduce what they deem as the sound of the original recording. Two designers may use similar physical parts (capacitors, inductors, resistors, etc.) yet create two entirely different voices. Furthermore, listeners may love one design and loathe the other, depending on the sound they were seeking.

Connections

Whether wired or wireless, the connections between audio components can have a significant effect on the reproduced sound. As inherently passive components, connections should be as transparent as possible. Using connections to tune the sound to one’s liking (tempering a “bright” sound or boosting the high frequencies of a “dull” sound) is masking a problem that should have been fixed elsewhere in the audio system’s chain.

Accessories

Sturdy racks or stands provide a stable base for a system’s components. Tweaks such as vibration control, when applied correctly, can optimize the system’s performance. On the other hand, a turntable dust cover can cause vibrations that are picked up by the stylus riding on the record grooves. Though often overlooked, accessories can enhance the overall sound – or ruin it.

Allocation of Audio Budget

We are often asked how important is a particular piece of equipment relative to the entire audio system. In other words, what percentage of an audiophile’s budget should be allocated to each type of component? Below is a suggested rule of thumb.

Type of Component	Allocation	Rationale
Source	30%	A bad source cannot be corrected with another component or treatment down the chain
Loudspeaker	30%	The choice of loudspeaker is so personal that skimping on the cost may lead to wrong choices.
Amplification	20%	Amplification needs to match the choice of loudspeakers, e.g., more power for less sensitive speakers.
Connections	10%	Cables cannot make bad components sound better but they can make good components sound worse.
Accessories	10%	Accessories can eliminate or reduce bad effects from the environment on the system components.

One may argue that since the preamp is the control center of the system, it should warrant a larger portion, something like 20% by itself. A listener who puts a high value on the bass performance of a speaker may argue for a beefier amplifier capable of controlling the speaker’s drivers for a tighter and more powerful bass.

In summary, putting together an audio system should start with understanding the listener’s preferred sound and priorities in achieving that sound. Contact us at gingko@gingkoaudio.com for help with the journey.