This blog was originally posted on the VSSL website:

All sounds that the human ear can detect are essentially vibrations that, if visualized, appear as waves moving up and down at different speeds, or frequencies. The faster the wave moves, the higher the pitch. For example, bass frequencies, such as those you hear in a hip-hop groove, move very slowly, while higher pitches (treble), like the chime of a triangle, move very quickly.

Every pitch a music instrument plays has a core frequency measured in hertz (Hz), which is like a speedometer reading for the waveform. Hertz measures how many times (i.e., the frequency) a wave completes an up and down cycle in one second. If the wave moves up and down 50 times in a second, that’s expressed as 50Hz. The audio spectrum is the audible frequency range at which humans can hear and spans from about 20Hz to 20,000Hz. This range of frequencies can be effectively broken down into seven different frequency bands, with each having a different impact on the overall sound.

Equalization (EQ) is the process of adjusting the balance between frequency components within an electronic signal. EQ strengthens (boosts) or weakens (cuts) the energy of specific frequency ranges.


VSSL allows you to alter the Treble, midrange (Mid), and Bass in the normal EQ settings. From the VSSL app, click the hamburger menu in the top left and then click SETTINGS. Under the DEVICES list, you will see your VSSL unit(s). Click the unit you would like to adjust the EQ settings for. Under ZONE SETTINGS you will see the names of all your audio zones. You have to set the EQ settings for each zone, so click on any zone that you wish to alter. Near the bottom of the next screen, click the toggle switch for ENABLE EQ. Once that is enabled you can adjust the TREBLE, MID, and BASS as you see fit.

Altering the treble will affect the higher-end frequencies. Turning the treble up can give the effect of the instruments playing closer to your ears. Turning the treble down can open the sound and push instruments away to provide more depth.

Adjusting the mid-setting can be pretty touchy and have a quick impact on the sound you hear. Lowering the mid reduces the impact of the midrange frequencies and can take away the brittle sound of instruments. Increasing the mid boosts those midrange frequencies and can give things a metallic sound.
Turning the bass up or down will increase or decrease the impact of the low-end frequencies, which correspond to that thumping power you typically feel and hear from your subwoofer.
In addition to the standard EQ settings, you can also adjust the advanced EQ settings. To adjust the 7 bands parametric EQ to really fine-tune each zone of your audio system, click on ADVANCED EQ.

As you can imagine, sound quality is pretty subjective. What sounds right to one person may sound off to another. When adjusting the advanced EQ settings in the VSSL app, it’s important to know there is no correct EQ setting. Below is a breakdown of the frequency spectrum to help better understand which sound corresponds to each frequency range. It’s important to note that these are merely guidelines, not rules, to help you make a more effective adjustment. Your own auditory input will ultimately decide what you think sounds the most enjoyable.

Sub Bass (60Hz): This is the frequency band that comprises the thump of a kick drum or the Boom in a bassline. Too much and you’ll have flapping speakers with a flabby sound. Too little and the audio will never have enough weight or depth.

Bass: (200Hz): This EQ band adds punch in a snare while providing richness or “bloom” to almost anything. Too much makes things boomy or woolly while too little leads to thinking and cold sound.

Upper Bass to Lower Midrange: 500Hz: This frequency band is crucial for the warmth and weight provided by guitars, piano, and vocals. Too much makes things sound congested while too little leads to a thin, weak sound.

Midrange (1kHz): This is one of the trickiest areas to properly tune. This frequency range gives body and tone to many instruments. Too much leads to a hollow, nasal sound, and too little leads to a thin, harsh sound.

Upper Midrange (4kHz): This frequency range provides edge and bites to guitars and vocals that lead. Fine-tuning it can lead to aggression and clarity. Too much and your ears will hurt. Too little and the sound will come off as too soft or muted.

Presence/Sibilance Register (8kHz): This band adds clarity, openness, and life that is crucial for the top end of drums, especially the snare. Too much leads to a gritty or scratchy sound while too little yields a lack of presence and energy.

Open Air (15kHz): This frequency can add air, space, or sparkle. It’s nearly too high for most people to hear, especially in older people. Adding too much here will lead to an artificial sound that is hyped or fizzy. Too little and the sound becomes dull and stifled.

The bottom line is the default advanced EQ settings that come on your VSSL unit will serve most people just fine. If you are a true audiophile and love tinkering with the sound, then feel free to adjust the EQ settings as you see fit. EQ depends on your speakers and the environment of the listening room. It is tough to know how to set the EQ properly without hearing the sound. The best way to do it is to sit in the main listening position of the room and adjust the EQ levels for different songs and hearing the sound for yourself.