"If you only knew the magnificence of the 3, 6 and 9, then you would have the key to the universe."
Widely attributed to Nikola Tesla
Tesla was famously fascinated by these three numbers. This app turns the idea into its structure: three binaural beats at 3, 6 and 9 Hz (Ground, Create, Calm), and Solfeggio tones whose digits add up to 3, 6 or 9. For example, 528 → 5+2+8 = 15 → 1+5 = 6.
It's an organizing idea and an inspiration, not a scientific claim.
Volume70%
BinauralAmbient
Ambient bed
Sleep timer
Fades out gently, then stops. Starts counting when playback starts.
Quick sessions
Saved mixes
Save a combination you like and bring it back in one tap.
Your practice
How do you feel right now?
Optional. Saved only on this device.
Daily reminder
Adds a repeating event to your calendar app. Nothing is sent anywhere.
Only one preset plays at a time — the highlighted group below is whichever preset is currently selected. Picking a tone in a dimmed group just saves it for later; hit the Play button above to hear it.
3 Ground
6 Create
9 Calm
Do not use while driving, operating machinery, or walking near traffic.
Design a sequence of presets and tones to play back-to-back, hands-free — build it once, then hit start.
Ready-made sessions
Preset
Tone
Duration10 min
Do not use while driving, operating machinery, or walking near traffic.
Evidence-based options for attention and an overactive mind — separate from the Solfeggio/Tesla tones elsewhere in this app. Evidence for all of this is early and mixed, not proven treatment.
β Focus
★ Our recommendation: pair this with the White Noise ambient bed (Presets tab) — white noise has the strongest evidence of anything in this app specifically for ADHD attention.
16 Hz beta binaural beat. White/pink noise showed a small but real, statistically significant effect on ADHD-related task performance in a 2024 meta-analysis of 335 participants — beta rhythms are separately linked to alert, focused concentration.
θ Calm — Theta
6 Hz theta binaural beat, kept clean here — no Solfeggio overtone layered in, unlike the "Create" preset elsewhere in the app which shares this same beat. A small pilot study found theta beats increased calmness and stress resilience under a stress test. Good for winding down a racing mind.
α Calm — Alpha
9 Hz alpha binaural beat, kept clean here — no Solfeggio overtone layered in, unlike the "Calm" preset elsewhere in the app which shares this same beat. Alpha rhythms are associated with relaxed, settled alertness — a gentler option than theta if you don't want to feel drowsy.
Please read before using: this is not a diagnosis, treatment, or substitute for professional care for ADHD or any condition. If you have epilepsy or a history of seizures, talk to a doctor before using any binaural-beat or rhythmic audio tool — rhythmic stimulation can, rarely, affect seizure activity. Use caution if you have severe anxiety, panic disorder, bipolar disorder, or PTSD. Not intended for young children or use while driving or operating machinery.
Do not use while driving, operating machinery, or walking near traffic.
Before you listen
3·6·9 is a relaxation tool. Please read this once.
Never while driving or operating machinery, heavy equipment, or anything that needs your full attention. These sounds are made to relax you and can cause drowsiness.
Not near traffic. Don't wear headphones while walking, cycling, or anywhere you need to hear your surroundings.
Seizures. If you have epilepsy or a history of seizures, talk to a doctor before using binaural or rhythmic audio. Stop if you feel dizzy, unwell, or uncomfortable.
Protect your hearing. Keep the volume low to moderate.
Not medical. This is not a medical device or a treatment for any condition, and it is not intended for young children.