This article goes through what each block on that page does, what the defaults are in current firmware, and how to change things without cooking a set of motors. RPM filtering has its own article on this site, so here I assume it is either already running or that you know why it isn't. Defaults below are taken from the Betaflight 2026.6.2 source code and the Betaflight wiki. If you run a different version, check the numbers in your own Configurator or with get in the CLI.
The order of the filters
Gyro filters come first. Everything that leaves the gyro passes through them, and the filtered signal feeds the whole PID controller. D-term filters come second and only act on the D term, which is calculated from the already filtered gyro signal.
D needs its own filtering because it reacts to the rate of change. According to the Betaflight wiki, D amplifies high-frequency noise by roughly 10 to 100 times, which is why D-term cutoffs sit much lower than gyro cutoffs.
Two kinds of filter appear on the page:
- Lowpass filters let low frequencies through and attenuate everything above a cutoff. They work on all noise, wherever it sits, but they add delay across the board.
- Notch filters cut a narrow band around one frequency and leave the rest alone. Less delay, but they only help if the noise sits where the notch is.
The defaults in Betaflight 2026.6
| Setting | CLI name | Default |
|---|---|---|
| Gyro Lowpass 1 (dynamic) | gyro_lpf1_dyn_min_hz / gyro_lpf1_dyn_max_hz |
250 / 500 Hz, PT1 |
| Gyro Lowpass 2 (static) | gyro_lpf2_static_hz |
500 Hz, PT1 |
| D Term Lowpass 1 (dynamic) | dterm_lpf1_dyn_min_hz / dterm_lpf1_dyn_max_hz |
75 / 150 Hz, PT1 |
| D Term Lowpass 2 (static) | dterm_lpf2_static_hz |
150 Hz, PT1 |
| Dynamic notch | dyn_notch_count, dyn_notch_q, dyn_notch_min_hz, dyn_notch_max_hz |
3 notches, Q 300, 100-600 Hz |
| Filter sliders | simplified_gyro_filter_multiplier, simplified_dterm_filter_multiplier |
100 (1.0x) |
"Dynamic" lowpass means the cutoff moves with throttle. At low throttle it sits at the minimum, so there is more filtering, and it rises towards the maximum as you add throttle. The dyn_expo settings (default 5) shape that curve.
These defaults are deliberately safe. They are meant to fly a dirty or slightly damaged quad without burning anything, so most clean builds have some room to filter less.
The sliders: start here
At the top of the filter section sit two sliders, "Gyro Filter Multiplier" and "D Term Filter Multiplier". They don't add a separate filter. They scale the default cutoffs. In the code the multiplier is applied directly to the defaults, so 1.2x on the gyro slider gives Gyro Lowpass 1 at 300-600 Hz and Gyro Lowpass 2 at 600 Hz. Moving left lowers the cutoffs and filters more. Moving right raises them and filters less.
Gyro settings are global. D-term settings, the D-term slider included, belong to the PID profile, so a second profile can have different D filtering.
What the wiki says about each slider:
- Gyro slider to the right reduces delay and can help with propwash, but the wiki adds a warning in capitals to be careful: too little filtering can mean a flyaway on arming or burnt motors. Move it left if the quad has a frame resonance, worn bearings, damaged props or comes back with hot motors.
- D-term slider - the default suits most builds. Moving it left cools the motors at the cost of some propwash handling. Moving it right is not recommended, because it can cause grinding on arming, resonance and overheating.
The 4.3 tuning notes add that many quads with RPM filtering fly fine with the gyro slider all the way right. Without expert mode the Configurator limits the slider range, and the note under the sliders says that range should suit most builds and beginners.
One trap: while a slider is on, it owns the numbers. If you type a value into Gyro Lowpass 1 or any D-term field and then touch the slider, your value gets overwritten. To set cutoffs by hand, turn the slider off first. In the CLI, get gyro_lp and get dterm_lp show all the relevant values at once.
Gyro Lowpass 1 and 2
Gyro Lowpass 1 is dynamic by default. According to the wiki it can usually be turned off on 4.3 and newer when RPM filtering is running, unless your gyro has no internal hardware filtering. Without RPM filtering, leave it on.
Gyro Lowpass 2 is always static and has a second job: anti-aliasing. When the PID loop runs slower than the gyro is sampled, for example a 4 kHz PID loop with an 8 kHz gyro, Lowpass 2 removes noise that would otherwise fold back into lower frequencies. The 4.3 tuning notes give these rules:
- At an 8 kHz loop there is no aliasing issue.
- At 4 kHz keep Lowpass 2 on. If you turn it off, Betaflight falls back to averaging pairs of gyro samples, which works but filters less.
- At 2 kHz a 500 Hz PT1 Lowpass 2 is essential.
- Most clean 4 kHz quads fly well with Lowpass 1 off and only Lowpass 2 at around 500 Hz. On a clean build with RPM filtering the wiki allows a single Lowpass 2 anywhere from 500 to 1000 Hz.
Filter type matters too. PT1 is the default and has the least delay. The 4.3 notes give PT2 about 60% more delay than PT1 and PT3 roughly double. Biquad was removed from the gyro lowpass options and replaced by PT2, but it is still available for the D term.
The dynamic notch
The dynamic notch uses a sliding Fourier transform to find the strongest noise peaks on each axis and places notch filters on them, updated continuously. It is good at following resonances that shift with throttle or come and go.
Four values control it:
- "Notch Count" - how many notches per axis. With RPM filtering, the wiki recommends 1-2. Without it, 4-5 (the 4.3 notes suggest 3-4). Each notch adds delay, so fewer notches mean a sharper quad, but hotter motors if a real peak goes unfiltered.
- "Q factor (x100)" - how narrow each notch is. Higher Q is narrower and adds less delay. A very low Q makes the notch wide and adds a lot of delay. The 4.3 notes suggest about 300-450 for freestyle quads with RPM filtering, and 120-150 when running 3-4 notches without it.
- "Min Frequency [Hz]" and "Max Frequency [Hz]" - the range in which the notch looks for peaks. Keep the minimum as high as practical. The 4.3 notes give 200 Hz as an example. Slow quads and X-class builds work better with a maximum of 350-400 Hz.
Without RPM filtering, the 4.2 notes give a rule of thumb for the maximum: about 70% of no-load motor speed in revolutions per second. Their example is a 2000KV motor on 6S, roughly 48,000 rpm unloaded, which works out to around 560 Hz.
The DShot RPM filtering wiki page says that when RPM filtering is on, the dynamic notch can drop to a single notch, and the Configurator from 4.3 does this automatically when you enable RPM filtering. The motor noise is then handled by the RPM filter, and the dynamic notch is left to catch frame resonance.
Static notches
"Gyro Notch Filter 1" and "Gyro Notch Filter 2" are fixed notches, off by default. Use them only for a resonance that stays at the same frequency regardless of throttle, typically a frame or camera mount resonance. In a Blackbox spectrum it shows up as a peak that stays at the same frequency across the whole throttle range.
The wiki's guidelines:
- Set the centre on the resonance and the cutoff 10-40% below it. The cutoff sets the width.
- Avoid going below 100 Hz.
- Treat the second static notch as a last resort.
The 4.3 notes add that a well-placed static notch can beat the dynamic notch on a fixed frame resonance. If you add one, you can usually drop the dynamic notch count by one.
There is also a "D Term Notch Filter" with the same logic, plus a separate lowpass on yaw. Most builds never need to touch them.
D Term Lowpass 1 and 2
D Term Lowpass 1 is dynamic by default, and the wiki does not recommend switching it to static. Lowpass 2 is static and is usually set near the upper end of the Lowpass 1 range, which is how the defaults are set: 75-150 Hz dynamic plus 150 Hz static.
The wiki is firm on one point: the D term needs at least two first-order filters (two PT1) or one second-order filter. Turning off both D-term lowpasses to "free up" the quad is a quick way to hot motors.
If you change anything on the D side, change it a little at a time with the D-term slider.
A sensible order of work
- Get the hardware clean first: tight screws, straight props, good bearings, a soft-mounted flight controller if the frame needs it. Filters can't fix a bent prop for long.
- Turn on RPM filtering if your ESCs support bidirectional DShot.
- Record a Blackbox log at a rate of at least 2 kHz, which the 4.3 notes recommend for filter work.
- Look at the gyro spectrum. To tune the dynamic notch, the notes suggest one log with the dynamic notch off, then setting the min and max to cover the peaks you see with about 20 Hz of margin on each side. Fly again with the notch on and raise Q as far as it still keeps the resonance under control.
- Move the gyro slider right in small steps. After every short flight, touch the motors. Warm is fine. Too hot to hold means go back a step.
- Leave the D-term slider at 1.0x unless the motors run hot, in which case move it left.
Two more pieces of advice from the tuning notes: don't paste an old diff from previous firmware into a new version, because names and defaults change between releases. And if Blackbox shows more high-frequency noise at full throttle, lower the dynamic lowpass expo or the upper cutoff instead of filtering harder across the whole range.
When to stop
The warning signs are the same every time: motors noticeably hotter after a minute of flying, a rough grinding sound or twitching on arming, or oscillation that appears suddenly at high throttle. Any of them means you have gone a step too far. Go back one step and fly that setting for a few hard packs before trying again.