When mastering audio, the low end is considered correct when it sounds balanced, tight, and punchy without being too boomy or overpowering the other frequency ranges. To determine this, you can use a combination of techniques, such as using a spectrum analyzer to visualize the frequency content, using a reference track for comparison, and listening to the audio on various playback systems. Additionally, adjusting the levels, equalization, and dynamic processing of the bass frequencies can help you achieve the desired low-end balance.
To make the low end tight and punchy, you can use several techniques:
1. Equalization (EQ): Use a high-pass filter to remove unnecessary low frequencies and boost the mid-bass frequencies for punch.
2. Compression: Apply dynamic processing to reduce the volume of the loudest bass frequencies and increase the volume of the quietest, resulting in a tighter, more consistent low end.
3. Saturation: Use subtle harmonic distortion to add warmth and weight to the low end, making it sound more punchy.
4. Stereo Imaging: Utilize stereo widening (minimally) and stereo field enhancement techniques to create a spacious low end that adds definition and impact to the mix.
5. Sub-Bass Synthesis: Synthesize sub-bass frequencies using a synthesizer or sample library to reinforce the low end and add more punch.
Note: It’s important to not overdo any of these techniques as too much processing can result in a muddled and overbearing low end.