Understanding Noise and Distortion
Noise and Distortion figures are fundamental to all other audio understandings. These two key terms relate to most other specifications you may read about, such as THD, SINAD, SNR, Dynamic Range, IMD, Crosstalk, etc.
Although much can be made about these and other performance metrics, there is a real, physical limit to what our ears and brains can hear. Better equipment does not always translate to better measurements, and more confusingly, better measurements do not always lead to better audio enjoyment.
Over the past decade, the audio industry has entered what some have described as the “golden age” of audio technology. In the simplest terms, noise and distortion are no longer concerns from affordable, well-engineered amplifiers and DACs. This certainly includes all JDS products, which consistently measure beyond the limits of human hearing, making them audibly transparent.
What is Noise?
Noise in audio systems refers to any unwanted sound that disrupts the clarity of your music. Noise can be part of the recording, but when we talk about Noise, we're referring specifically to sounds produced by your local audio equipment that are not part of the recording. This would include background hiss, hum at low or high-frequency, or electrical interference from external devices.
To better understand how noise level impacts audio quality, mute all audio and listen to the following Noise Floor demonstration at a high volume level.
Threshold of Noise Audibility
There is a certain measurement level below which you will not hear noise. We refer to this as the “noise floor.” Noise floors have improved dramatically over the past 20 years, such that nearly all high-performance headphone amplifiers and DACs exhibit exceptionally low noise levels. To give you ballpark figures, you may hear the noise floor of an amp rated 10 uV when listening to sensitive headphones, and some of the world's best noise floors hover around 1 uV. For comparison, Atom Amp 2's noise level is 1.3 uV (-117 dBV @ 13 ohms). You are highly unlikely to notice anything but silence from a JDS Labs amp.
What is Distortion?
Distortion refers to any alteration of the original sound signal as it travels through components of your audio system, such as software, amplifiers, DACs, and headphones. Distortion can appear in various forms, including harmonic distortion, intermodulation distortion, and clipping.
Total harmonic distortion (THD), along with Signal to Noise and Distortion Ratio (SINAD) are both comprehensive measurements used to capture the amount of distortion in a signal. Distortion contributions from JDS amplifiers exceed the limits of even the human ear, and have done so since 2011. Today, both measurements are no longer relevant for practical listening.
Dynamic Range
Dynamic Range refers to the difference between the noise floor and the maximum signal level of an audio device. A large dynamic range means the audio system can render details at a wide range of volumes.
The dynamic range of a DAC is also called its effective number of bits (ENOB), which is closely related to SINAD. When we know that SINAD is excellent, dynamic range must also be excellent.
Practical Considerations
- As long as your amplifier's noise level is below 2 uV, you're unlikely to notice background hiss. Remember, Gain settings directly impact noise levels.
- THD and SINAD measurements are insightful, but should not be a primary focus when investing in a modern amp and DAC. Choose equipment which suits your specific listening needs and preferences from a company you trust.
- Pairing your amplifier with a high-performance DAC ensures that your amp will receive a perfectly clean audio signal, free of Noise or Distortion.