32-Bit Float Is Everywhere Now, and It Still Won't Save a Bad Lav Placement

You now get 32-bit float on €110 recorders and mid-price wireless kits, and it has largely ended one kind of audio disaster: digital clipping inside the recorder. It does nothing about the rest. Headroom is not the same as quality. The capsule, where you put it and what it rubs against still decide whether the dialogue is usable.

What 32-bit float actually fixes

Most float devices run two analogue-to-digital converters at different gains and combine them into one file. The Zoom Essential recorders work this way, and so does Sennheiser's Profile Wireless. The file format can represent a theoretical 1,528 dB of dynamic range, according to Sound Devices. That is far more than any real sound needs.

The useful number is the one that sits underneath. In a separate test, Sound Devices quotes 142 dB for the MixPre II's converters, and concludes that with float the recorder is "practically only limited by the dynamic range of the microphone itself." It added 40 dB of gain to a track recorded far too low, and the result matched a properly gained take.

Read that the other way round and you have the point of this article. Float takes the recorder out of the equation, so the mic and its position become the weakest link. When you raise a quiet float recording, you raise the room and the capsule's self-noise along with the voice. And a capsule or preamp pushed past its own limits distorts before the converter ever sees the signal.

Where the float file lives in a wireless kit

On most wireless systems, the 32-bit float file is the transmitter's on-board backup. It is not the signal that reaches your camera. The clue is in the safety features. RØDE's Wireless PRO has a safety channel 10 dB lower than the main one, "in case the signal is too hot and clips the camera input", as Newsshooter's review explains. Sennheiser lets you switch off float recording and use a Safety Channel 6 dB lower instead. Nobody builds safety channels for a feed that cannot clip.

What the current kits actually offer:

• Sennheiser Profile Wireless gained 32-bit float in firmware V4.1.0 in May 2025, when the one-channel kit launched at $199/€199.
• DJI Mic Mini 2 (28 April 2026, €89 for the two-transmitter kit) has no internal recording at all, so there is no float backup. It records 48 kHz/24-bit and protects you with automatic limiting.
• DJI Mic Mini 2S (global launch 4 August 2026, from €189) adds 32-bit float internal recording on about 14.5 GB of storage. The quoted 28 hours of recording time is for the default 24-bit mode, so float has to be switched on. Check it.
• RØDE Wireless GO (Gen 3) and Wireless PRO transmitters can now connect directly to an iPhone without a receiver, in merged or split mode. The phone gets a live stream. Your safety copy is still the on-board file, and only if recording is turned on.

What float cannot touch: placement

Every one of these problems is recorded perfectly in 32-bit float, which is exactly why float doesn't fix them.

• Distance. In free field, direct sound drops about 6 dB each time the distance doubles, while the room noise stays where it is. Here is our own worked example: a lav that slides from 15 cm to 30 cm from the mouth loses about 6 dB of voice against the room. That is the same as the background getting twice as loud. Float captures that worse ratio with total accuracy.
• Tone. DPA's measurements show that a chest position substantially cuts the 2–4 kHz range where consonants live, and needs a 5–10 dB boost around 3–4 kHz to compensate. Below the chin there is "a massive reduction of consonant frequencies." The forehead is the least obstructed position, and the cheek keeps 2–4 kHz better than most. You can EQ the loss back, but you boost the noise in that band along with it.
• Head turns. A chest lav stays put while the head moves. When talent turns to the side, level and brightness drop together, and no amount of headroom brings back sound that never reached the capsule.
• Rustle. Fabric on the capsule is a mechanical noise at speech level, inside the speech band. Float records it as cleanly as the words.
• Self-noise. If you normalise quiet dialogue, the capsule's own hiss becomes the floor. Quieter capsules are arriving: RØDE says its Sonaura MEMS capsule reaches 11 dBA self-noise in a 4 × 5 mm package, and it debuts in the Lectrosonics L1 lav. That is a manufacturer figure we have not seen tested independently.

A routine for float-equipped kits

1. Turn on on-board recording and confirm the format is 32-bit float, not the default. Check free storage and battery before the first take.
2. Set the camera feed for the edit, not for safety. Peaks around −12 dBFS on the camera track, with the safety channel on if the kit has one. The float file is your insurance. The camera track is what the editor will actually use.
3. Place for tone first. Use the sternum, clear of fabric, on the side the talent will favour. Our rule of thumb is a hand's width, roughly 15–20 cm, from the mouth. For costume or period work, use the hairline or forehead.
4. Do a movement test on headphones before you roll. Have the talent cross their arms, turn their head both ways and sit down. If you hear the capsule, move it.
5. Keep the on-board file clean. Our rule: noise reduction and limiting may go on the camera feed for quick-turn jobs, never on the safety file, and never on both. If processing is baked into both, you have no clean copy.
6. Check sync on the first take when you record straight to a phone over Bluetooth. Line the clap up against picture before you trust the rest of the day.

The decision rule

Float means you can stop fearing the gain knob. Spend the time that saves on mic position, because that is now where nearly all the remaining quality comes from. Buy float on the transmitter if you shoot alone, unattended or run-and-gun. If a kit lacks it, as the Mic Mini 2 does, rely on its limiter and set conservative levels. And when a take sounds thin, distant or scratchy, don't blame the bit depth. Move the mic.