The concept of Harman curves is not widely known, even among audio professionals. However, it is an important tool for understanding how different speakers and headphones reproduce sound. In this article, we will take a deep dive into Harman curves, exploring what they are, how they are used, and how they can help improve the sound quality of your audio setup.
What are Harman Curves?
Harman curves are a set of measurements that are used to quantify the accuracy of a speaker or headphone’s frequency response. They were developed by Harman International, a leading audio company, and are based on extensive research and testing.
The main goal of Harman curves is to measure how closely a speaker or headphone’s frequency response matches a “target curve”, which is a theoretical ideal for how a speaker should reproduce sound. The target curve is based on extensive research on how the human ear perceives sound and takes into account factors such as room reflections and the listener’s position.
The target curve is divided into several areas, each corresponding to a specific range of frequencies. These ranges are:
Low frequencies (20 Hz – 200 Hz)
Mid-low frequencies (200 Hz – 1000 Hz)
Mid-high frequencies (1000 Hz – 6000 Hz)
High frequencies (6000 Hz – 20,000 Hz)
Each of these areas is further divided into several sub-ranges, each with their own target curve. The target curves for each sub-range are based on extensive research on how the human ear perceives sound and take into account factors such as room reflections and the listener’s position.
When a speaker or headphone’s frequency response is measured, it is compared to the target curve to see how closely it matches. The closer the curve is to the target curve, the more accurate the speaker or headphone is considered to be. This allows audio professionals to identify any issues or inconsistencies in the speaker or headphone’s frequency response, and make adjustments to improve its sound quality.
It’s important to note that Harman Curves are not a standard for audio products and some manufacturers may not use it as a reference. However, it is widely used in the audio industry as a reference tool to measure the accuracy of a product’s frequency response.
How are Harman Curves Measured?
Measuring a speaker or headphone’s frequency response using Harman curves is a multi-step process that involves conducting a series of tests in an anechoic chamber. An anechoic chamber is a room designed to eliminate reflections and other external factors that can affect sound quality.
The first step in measuring a speaker or headphone’s frequency response using Harman curves is to set up the speaker or headphone in the anechoic chamber. This typically involves positioning the speaker or headphone at a specific distance from the microphone, as well as at a specific angle.
Next, a series of sweeps are played through the speaker or headphone at different frequencies. A sweep is a sound that gradually changes in frequency over a specific period of time. During the sweep, a microphone is used to record the sound levels at each frequency. These measurements are then used to create a frequency response curve for the speaker or headphone.
It’s important to note that the microphone is positioned at various positions around the speaker or headphone to account for off-axis response of the speaker or headphone. This is because the human ear perceives sound differently when it comes from different directions.
Once the frequency response curve has been created, it can be compared to the target curve to see how closely it matches. The closer the curve is to the target curve, the more accurate the speaker or headphone is considered to be.
It’s also worth noting that to obtain the most accurate measurements, many factors must be taken into account, such as the microphone’s calibration, the anechoic chamber’s conditions, the measurement techniques and more.
In summary, measuring a speaker or headphone’s frequency response using Harman curves involves conducting a series of tests in an anechoic chamber, where the speaker or headphone is placed at a specific distance and angle, a series of sweeps are played through the speaker or headphone at different frequencies, and the sound levels are recorded at each frequency. These measurements are then used to create a frequency response curve, which is then compared to the target curve to see how closely it matches.
How Harman Curves are Used?
Once a speaker or headphone’s frequency response curve has been measured using Harman curves, it can be compared to the target curve to see how closely it matches. The closer the curve is to the target curve, the more accurate the speaker or headphone is considered to be.
Knowing the accuracy of a speaker or headphone’s frequency response is important for several reasons. Audio professionals use this information to improve the sound quality of the speaker or headphone, and also to help ensure that the speaker or headphone is consistent across different listening environments.
One of the main uses of Harman curves is for audio product development. Audio manufacturers use Harman curves as a reference to ensure that their products have accurate frequency response. By comparing the product’s frequency response to the target curve, manufacturers can identify any issues or inconsistencies, and make adjustments to improve the product’s sound quality.
Another use of Harman curves is for audio system setup and tuning. Audio professionals use Harman curves to optimize the positioning of speakers or headphones in a listening environment. By measuring the frequency response at different positions, professionals can identify the optimal position for the speakers or headphones, which can help to reduce reflections and other external factors that can affect sound quality.
Additionally, Harman Curves are also used by audiophiles and enthusiasts who want to measure and improve the sound quality of their audio systems. By measuring the frequency response of their speakers or headphones, they can identify any issues or inconsistencies, and make adjustments to improve the sound quality of their system.
In summary, Harman Curves are used to measure the accuracy of a speaker or headphone’s frequency response, and to compare it to a target curve. Knowing the accuracy of a speaker or headphone’s frequency response is important for audio professionals and enthusiasts to improve the sound quality of the speaker or headphone and also to help ensure that the speaker or headphone is consistent across different listening environments.
How Harman Curves Can Improve Sound Quality?
Knowing the accuracy of a speaker or headphone’s frequency response can help audio professionals and enthusiasts improve sound quality in several ways. One way to improve sound quality is by identifying and correcting any issues or inconsistencies in the frequency response. For example, if a speaker or headphone has a peak or dip in its frequency response at a certain frequency, this can be corrected by adjusting the speaker or headphone’s crossover or equalization. A crossover is a device that divides the audio frequency spectrum into different bands, and sends them to different speakers or drivers. An equalizer is a device that allows the user to adjust the balance between frequency components within an audio signal.
Another way to improve sound quality is by optimizing the positioning of the speakers or headphones. By measuring the frequency response at different positions, audio professionals can identify the optimal position for the speakers or headphones, which can help to reduce reflections and other external factors that can affect sound quality. Additionally, positioning the speakers and headphones in the correct angle can also improve the off-axis response of the speakers, making the sound more consistent for different listeners.
Moreover, Harman Curves can also help to improve the sound quality of a surround sound system by ensuring that each speaker reproduces its corresponding frequency range accurately. This can lead to a more immersive and realistic surround sound experience.
In summary, Harman Curves can help improve sound quality by identifying and correcting any issues or inconsistencies in the frequency response, optimizing the positioning of speakers or headphones, and improving the consistency of the sound across different listening positions and environments. Additionally, it can also help to improve the overall audio system setup and tuning.