Updated: Nov 30
Defining the Low End
What we can hear as low end usually ranges from 20Hz to 250Hz. The full physical range (0Hz-250Haz) encompasses the frequencies we feel more than hear, and it plays a pivotal role in shaping the character and energy of a track. The low end in music is the foundation and the driving force.
The Physics of Low End
Understanding low end begins with the physics of sound. It's crucial to recognize that as we move from the source of a low-frequency sound (a sub-bass synth or a kick drum) into a listening environment, the wavelength of these frequencies becomes incredibly long. This has a profound impact on how we perceive low frequencies depending on where and how we're listening.
- In a room: when listening in a room, sound waves bounce off walls and interact, leading to reinforcement or cancellation of certain low frequencies. This room mode phenomenon can make bass sound uneven and lead to muddy mixes if not addressed properly.
- With headphones: with headphones, we lack the room acoustics, so we're exposed to the raw, unaltered low-frequency content. This can result in hearing more detail and clarity in the low end, but it's essential to ensure it translates well in other listening environments.
- In Open fields: in open spaces, there are no room acoustics to consider. The low end propagates freely, allowing us to hear the purest form of these frequencies.
Perception of Low Frequencies
The brain plays a significant role in how we perceive low frequencies. It processes and decodes the sub and low frequencies differently from higher frequencies. This often results in us feeling low frequencies more than hearing them. When mixing and mastering, it's essential to consider this perceptual aspect, as it can affect the perceived balance and clarity of your mix.
Addressing Phase Issues in Mixing
Mixing low-end-heavy instruments, like bass and kick drum, can present challenges related to phase issues. When two signals of the same frequency are out of phase, they can cancel each other out. To combat this, consider these solutions:
- Time-align instruments: adjust the timing of bass and kick to be in phase, reinforcing each other rather than canceling.
- Frequency splitting: use EQ to divide frequencies. Let the kick dominate the sub frequencies, while the bass guitar focuses on the upper bass.
- Parallel processing: apply parallel compression to the low-end instruments separately. This maintains the punch while controlling phase issues.
Cut When Necessary
Many mixers advocate for a high-pass filter on every channel. However, it's important to note that not all tracks need a low cut. If an instrument doesn't produce low frequencies that are audible or impact the instrument's balance, there's no need to filter. Trust your ears and apply low cuts only when necessary.
Low End in Mastering
In mastering, treating the low end is just as vital. The excessive use of low cuts can negatively affect the mix's perception, energy, and phase. Consider these solutions for a balanced low end:
- Use gentle filters: apply gentle 6dB per octave low cuts. Steeper cuts can cause phase issues and a perceived loss of energy.
- Find the sweet spot: whether you are in a room or using headphones, train yourself to know your listening environment so that identifying low frequency phasing becomes a natural practice.
Engineer's Tip: Training Your Ears
Recognizing low-end issues takes practice. Train your ears to distinguish between muddiness, phase problems, and the sweet spot. Listening to professional mixes and using reference tracks can help sharpen your low-end perception.
The low end is the soul of your music. Understanding its physics, perception, and potential issues is vital. By addressing phase problems, avoiding unnecessary low cuts, and mastering with care, you can create tracks that resonate deeply and consistently in any listening environment.