How Slow Duo is built

Two independent motors, a shell that stays quiet under load, and materials chosen for daily skin contact. This page is the engineering behind the range — written for buyers who have to justify the spec to a category manager.

Two motors, two zones

Most devices in this category take one motor and split its output. The result is a single rhythm travelling through two contact points — adjust one, and you have adjusted both.

Slow Duo runs two physically separate motors, each on its own drive channel. A low-speed motor is easier to control and easier to keep quiet: at lower RPM there is less rotor imbalance, less shell resonance, and less of the whine that buyers return units over.

PCB M1 M2 Battery Zone 1 — independent motor Zone 2 — independent motor SCHEMATIC — NOT TO SCALE Medical-grade silicone shell over ABS chassis

Schematic of the dual-motor layout: two motors on a shared PCB, one battery pack, one control surface. Structural dimensions differ between the three dual-motor models; the architecture does not.

What independent control actually changes

Pattern independence

One zone can hold a steady slow pulse while the other cycles through patterns. Ten patterns, applied per motor rather than to the whole device.

Intensity independence

Three intensity levels per motor. The pairing is yours to set, not a factory compromise between the two zones.

Low-end resolution

The speed range is weighted toward the low end, where most devices have two coarse settings and a jump. That is the range buyers use most.

Noise engineering

Acoustic performance in this category is decided by three things: rotor balance, the stiffness of the shell where the motor mounts, and whether anything inside is free to rattle. We address all three.

  • Motor selection. Motors are screened for balance at the assembly line, not just at the supplier.
  • Mount rigidity. The motor sits in a moulded cradle rather than against the shell wall, which stops the shell acting as a sounding board.
  • Internal clearance. Wiring runs are fixed in channels so nothing moves against the chassis under load.

Every model in the range is specified at 60 dB maximum, measured at 1 metre on the highest setting. Runtime and noise are tested on the same rig.

Test conditions we publish

  1. Distance1 metre from the device, on axis
  2. SettingMaximum intensity, continuous pattern
  3. RoomQuiet room, background noise below 30 dB
  4. SampleAverage of three production units per batch
  5. InstrumentClass 2 sound level meter, A-weighted

Request the noise test report →

Material safety

Skin-contact surfaces are medical-grade, hypoallergenic silicone. Silicone is non-porous: it does not absorb residue, and it can be washed with warm water and mild soap without degrading.

The internal chassis is ABS. It is light, dimensionally stable, and — importantly for a device that vibrates — it does not transmit sound the way a thin metal housing does.

Water resistance is IPX5 across the range: protected against water projected from a nozzle, suitable for cleaning and bathroom storage. It is not rated for immersion, and we do not claim IPX7.

  • Medical-grade silicone
  • Hypoallergenic
  • Non-porous surface
  • IPX5 water-resistant
  • ABS chassis
  • —

Certification claims are limited to certificates we actually hold. Verified wholesale partners can request the full document set, including material test reports for the silicone and ABS lots used in their order.

How we test

Every unit is batch-tested before shipment. Testing happens on production units drawn from the line, not on golden samples.

  • Incoming motors

    Balance and current draw checked on receipt. Out-of-spec motors do not reach assembly.

  • Assembly soak

    Each unit runs a full discharge cycle. Units that cut out early or overheat are pulled.

  • Acoustic sampling

    Three units per batch measured at 1 m on maximum setting, recorded against the 60 dB specification.

  • Runtime sampling

    Runtime measured at high setting on the same rig, recorded against the per-model figure.

  • Outgoing audit

    Charge level, mode count, button response and finish checked before packing.

    • Batch records are retained and can be supplied with wholesale orders. Ask our sales team →

    Want the full test pack?

    Noise readings, runtime data, material certificates and the current specification sheet for any model in the range — sent as a single PDF.

    Request the test pack