The Bass Enhancer audio object allows to enhance the signal level of the low frequency components for better listening experience. The is achieved by generating harmonics for the low frequency components of interest and attenuates the higher harmonics after retaining the second harmonic alone. This is to avoid interference with the higher frequency components of the original signal.
The Bass Enhancement audio object is popular in the consumer electronics industry where good bass quality is expected from small or flat speakers. Bass performance is lacking in these speakers due to physical limitations and cost constraints. Bass Enhancement solutions are based on the psychoacoustic phenomenon where the human auditory system can perceive fundamental frequency from its higher harmonics. This is done with non-linear operations to generate harmonics that enhance bass virtually.
The audio object splits the signal into low pass and high pass based on the tunable set cut-off frequency. The harmonics are generated for the low-pass signal.
Input & Output:
The input gain scaling is applied on both the channels. The algorithm then separates the high pass signal based on the cutoff frequency set for both the left and right channels. Also, the left and right channels are merged, and the resultant mono signal is applied to the low pass filter.
The process of generating harmonics and attenuating higher harmonics are done only with the mono signal. This is done to reduce computing complexity. Bass Enhancer uses the same coefficient set for both left and right input channels. So, the output high pass filtered left and right channels will have same outputs if the input left and right channels are same.
Bass Enhancer have 3 audio outputs: High pass filtered Left, High pass filtered right, and Low pass filtered with harmonics shaping enhanced mono. The number of input channels is 2 and the number of output channels is 3.
The input channel order is:
- [1] Left
- [2] Right
The output channel order is:
- [1] Left (High pass filtered)
- [2] Right (High pass filtered)
- [3] Enhanced Mono (Low Pass with harmonics shaping)
Use case: This object can be deployed wherever a Bass Enhancing effect is required in the audio pipeline.
Bass Enhancer Properties
Below table describes about the Bass Enhancer audio object properties and functionality.
| Properties | Description |
| Display Name | Display name of the Bass Enhancer audio object in signal flow design. It can be changed based on the intended usage of the object. |
Mode
There are no mode available for Bass Enhancer audio object.
Additional Parameters
The Bass Enhancer audio object doesn’t have any additional parameters.
Tuning Parameters
| Parameter | Description | Data Type | Default | Unit | Step Size | Range |
| Bypass | BassEnhancer AO bypass On /Off | int | 0 | None | None |
0 – Bypass Off 1 – Bypass On |
| InputGain | Gain to be applied on the Input signal (in DB) | Float | 0.0 | dB | 0.01 | -30.0 to 6.0 |
| FcLplnp | Cut-off frequency for Low pass and High pass filters | Float | 250 | Hz | 0.01 | 10.0 to 1000.0 |
| DistOdd | Distortion Factor Odd | Float | 0.1 | – | 0.01 | 0.0 to 0.5 |
| DistEven | Distortion Factor Even | Float | 0.1 | – | 0.01 | 0.0 to 0.5 |
Control Parameters
| Parameter | Description | Range | Default |
| BassEnhancerEnable | BassEnhancer AO On/Off |
0 – Disable 1 – Enable |
1 |