440 vs 432 Hz: The Two Crystal Singing Bowl Tunings Explained

In sound healing, we talk about healing frequencies. Being in the presence of crystal singing bowls is soothing, deeply relaxing and in many ways restorative. If you go deeper into the research about healing frequencies, you might come across the debate around 440 Hz and 432 Hz tunings. 

In music, there is a standard tuning so if an orchestra is playing, all the instruments are in the same pitch. For a long time, 432 Hz was popular. But then in 1955, 440 Hz was chosen as the official standard tuning. So, that’s what we aim for when creating I Know This Girl crystal singing bowls but because they are handcrafted, they all come out at a unique frequency. It’s like they have their own personality! 

The reason some people are interested in deviating from the musical standard is that 432 Hz is believed to be more relaxing and healing. So, how should this impact the way you choose crystal singing bowls?

What are hertz in crystal singing bowls?

The first thing I want to clarify is what we mean by hertz (abbreviated as Hz). This is how we describe the different frequencies of crystal singing bowls and other instruments too. What it is actually measuring is the number of vibrations per second. Imagine a guitar string. When it’s played, it vibrates. It’s the same with crystal singing bowls. They vibrate when played with a mallet. Larger bowls tend to vibrate more slowly. They have a lower frequency and deeper tone. On the other hand, smaller bowls vibrate faster. Their frequency is higher and so is their tone. 

Each frequency is related to a musical note which is why we describe the different singing bowls as an A note, F note, D#, for example. It’s easier than saying 440 Hz (A note) or 390 Hz (G note).

How are crystal singing bowls tuned?

The second thing it’s important to know is that there is variation in the tunings of crystal singing bowls because they are handmade. We can’t adjust the pitch like you would do on a guitar. Instead, we measure the variation of the pitch in cents. A true tone measures zero cents. Most bowls are either above or below the true tone. For example, E+5 or F-20. This is something we consider when building a collection because sound baths sound better when all the bowls are plus or minus and the level of variation is within 20-30 cents. The human ear can’t tell the difference when it’s only a 20 cent variation or less. 

I’m highlighting this now because even though 440 Hz matches an A note, not all A bowls will be exactly 440 Hz. We’ll need to test it to see the pitch and how close it is to the true tone. 

What is a 440 Hz frequency?

440 Hz is the standard tuning frequency for modern instruments, at least in the West, so all instruments play in the same pitch. However, this only relates to the A note. The other musical notes are all different frequencies. A G note is approx. 390 Hz, for example. The idea is that if you get the first note aligned, the rest will follow. 

For crystal singing bowls, 440 Hz is the A bowl, specifically in the 4th octave. Although there is likely to be some variation because they are handmade instruments and the tuning can’t be changed. If you want to be precise, look for a true tone or zero cents A0 4th octave bowl. Variation within 20 cents will be close enough. The rest of your crystal singing bowl collection, or at least the bowls you play with your A bowl, will have to be within 20 cents of true tone too. And all in either plus or minus cents for a harmonious soundscape.

What is a 432 Hz frequency?

432 Hz is still an A note in the 4th octave, just a slightly different frequency. As it is a lower frequency, it’s a slower vibration and a more relaxed pitch. Some people believe it has spiritual connections. That is, it is natural, supports harmony and is connected to the body and the earth. With only 8 Hz between them, the difference isn’t really noticeable to the human ear. I find 432 Hz is a warm tone and 440 Hz is brighter but the difference is so slight.

Again, if you would like to be precise, it’s possible to test different A bowls and find one at or close to the 432 Hz frequency. As I Know This Girl bowls are tuned to the 440 Hz frequency, a 432 Hz bowl would be around A-30 cents. When building out the rest of your collection, remember that your bowls will need to be minus cents and within 20-30 cents of -30.

What about the 528 Hz frequency?

When I was talking to Kim, the host of our New Forest showroom, she brought up that there is a third frequency people often ask about. As a trainer in sound healing and crystal singing bowls, Kim really knows her stuff so here is a direct quote from her. 

“Within sound healing, we also sometimes see what is described as 528 Hz-based tuning. This is slightly different because rather than referring to A (4th octave) being tuned to 528 Hz, it generally refers to C (5th octave) being set at 528 Hz. If the other notes are calculated using standard modern Western tuning, that puts A (4th octave) at around 444 Hz, so the whole scale sits slightly sharper than standard A=440 tuning.”

“528 Hz is also one of the frequencies in what is now commonly known as the modern Solfeggio frequency system, where it has become associated with things such as transformation, love and healing.”

How much does frequency impact sound baths?

None of these tunings are better than the other. You don’t need to pick a side. When you’re in the room playing a sound bath, the numbers don’t matter.

Of course, you want the bowls to harmonise and we look at the frequencies and cents to make that happen. But during a sound bath, it’s the feelings, sensations and connection that make up the experience. In the room, participants absorb the vibrations of the bowls. When you play multiple bowls, the vibrations of the different singing bowls layer on top of each other to create a new combined frequency.

What matters in that moment is how you play the bowls, creating a soothing soundscape that guides people into relaxation and restoration. Also, your intentions are super important. Crystal singing bowls are made of quartz crystal. This is a mineral that amplifies energy. As you play, the energy you bring to the session will be amplified through the vibrations. So will the energy of the participants. I go into more detail about this in a blog dedicated to intentions and crystal singing bowls. 

How to find the right bowl for you

Ultimately, it’s up to you. You know which crystal singing bowls are meant to be part of your collection. You feel the draw from within you. The main numbers you need to think about are the cents. The cents need to be aligned for the bowls to sound harmonious. The power of the vibrations comes from you when you sit down to play. 

I share the key questions we ask clients when they are looking for new bowls in our free guide to choosing crystal singing bowls. Read it to understand how the process works and then book a consultation at one of our showrooms. We also offer online discovery calls for those who can’t make it to a showroom. Our sound practitioners help you build an attuned singing bowl collection, considering frequencies, cents, notes and what you are intrinsically drawn to.