Short answer: Somfy guide spec 12 25 09 prints four sound classes for roller shade motors: 38 dBA for Sonesse ULTRA 50, 42 dBA or less for Sonesse 30, 47 dBA or less for Sonesse 50 and 55 dBA or less for LT50 RS485. Schedule a class per room, name the motor family that meets it, and specify the tube hardware that keeps the installed shade quiet.
A shade that hums through a board meeting is a callback, and the owner remembers it longer than the price. The fix costs nothing at spec time. Pick the sound class per room, match it to the load, and lock the install details into Part 3. For most quiet commercial rooms on SDN, that motor is the Sonesse ULTRA 50 DC RS485 (1134022).
Free spec package
Somfy shade motor noise classes: 4-sheet drawing set
- SMD-01: acoustic class schedule with torque, speed and source per class
- SMD-02: tube ID sections at 1:1 and a motor-in-tube acoustic detail
- SMD-03: SDN riser by acoustic zone plus conductor and wiring schedules
- SMD-04: 3-part guide spec language, BOM and submittal checklist
The four Somfy sound classes in guide spec 12 25 09
Somfy's guide spec for motorized shade operators carries a note to the specifier in each motor section: motor selection is also based on roller shade quietness. Then it prints one sound line per motor. Four numbers cover the whole roller shade range.
| Sound class | Somfy family | Guide spec section |
|---|---|---|
| 38 dBA | Sonesse ULTRA 50 AC and DC | 2.2 C, 2.3 C, 2.3 E, 2.4 B, 2.4 C |
| 42 dBA or less | Sonesse 30 DCT, RTS, RS485 | 2.2 A, 2.3 B, 2.4 A |
| 47 dBA or less | Sonesse 50 RA, RTS, RS485 | 2.2 B, 2.3 D, 2.4 D |
| 55 dBA or less | LT50 RS485 | 2.4 E |
Copy the class line as Somfy prints it. The 38 dBA line reads "ultra-quiet". The other three read "or less". Those words matter in a bid review, because a competing motor has to meet the same line.
Read the rating basis before you promise a room level
Somfy's 500 Series and Low-Voltage databooks state the test basis under every sound figure: ISO 3741 / NF 31022, in dBA referenced to 1 pW, at nominal torque, without the end product. That is a sound power rating of the motor on a test stand. No fabric, no tube, no brackets.
The occupant hears the whole shade. A loose drive wheel, a tube that rubs, or a bracket on a hollow wall adds noise the motor rating never saw. Our rule: never write a room decibel target for the shade system. Write the motor class, then write the installation items that protect it.
Match the class to the room and the load
Quiet has a torque ceiling. Each class comes with a load range, so the shade size decides which class you can deliver.
- 38 dBA, Sonesse ULTRA 50. 120V AC: 6 Nm at 24 rpm, 0.95 A. 24V DC: 4 Nm at 10-25 rpm, 1.5 A. Boardrooms, bedrooms, studios.
- 42 dBA or less, Sonesse 30. 24V DC, 2 Nm, 10-28 rpm, 0.8 A. Private offices and smaller windows.
- 47 dBA or less, Sonesse 50. 120V AC, 6 Nm or 10 Nm, 32 rpm. Open office and classrooms with heavier shades.
- 55 dBA or less, LT50 RS485. 120V AC, 15-35 Nm. Atria and lobbies where the shade is the size of the wall.
Our rule: if the shade in a 38 dBA room needs more than 6 Nm, split it into two shades before you drop a class. The fabricator sizes torque; you protect the acoustic line in the spec.
Pick the protocol inside the class
The 38 dBA class comes in four versions, so the control system never forces you out of the quiet class.
- SDN on low voltage: Sonesse ULTRA 50 DC RS485 (1134022), powered from an SDN PowerConnect panel (1871026) with 10 motor ports and 240 ft per motor run.
- SDN on line voltage: Sonesse ULTRA 50 RS485 120V (1002566), 6 Nm at 24 rpm.
- RTS on low voltage: Sonesse ULTRA 50 DC RTS (1134023) on a Somfy 24V supply, 240 ft max at 14 AWG.
- RTS on line voltage: Sonesse ULTRA 50 RTS 120V (1002562).
Down the ladder, the Sonesse 30 RS485 (1241144) shares the PowerConnect panel with the ULTRA 50 DC, so a floor can mix 38 and 42 dBA rooms on one SDN power system. For heavier SDN shades, the Sonesse 50 RS485 6 Nm (1002286) and Sonesse 50 RS485 10 Nm (1002287) hold the 47 dBA line.
Keep the installed shade close to the rating
Somfy's 500 Series databook says it plainly: free play between the accessories and the tube must be minimized to keep the motor quiet. Put these items in Part 3 and on the shop drawings.
Acoustic install rules from Somfy's databooks
- Tube inside diameter over 47 mm for Sonesse 50 and ULTRA 50; over 31 mm for Sonesse 30
- Crown adaptor between motor and tube for concentric operation
- Drive wheel and pin end screwed in place on ULTRA 50 RA, RTS and RS485
- Drive stop and screw 9910004 tightened to 1.5-1.8 Nm
- No soft clip drive wheel adaptors on Sonesse 50 or ULTRA 50
- ULTRA 50 DC on Somfy power supplies only, to keep the UL listing
Keep one motor family per elevation
Speed is part of how a room sounds. Somfy's 500 Series databook lists Sonesse ULTRA 50 AC at 24 rpm and Sonesse 50 at 32 rpm. Put both on one window wall and the hems arrive at different times, every time.
The DC motors give you a lever. Somfy lists Sonesse ULTRA 50 DC as adjustable from 10 to 25 rpm and Sonesse 30 from 10 to 28 rpm. Our rule: one motor family per elevation. If an elevation must mix DC families, set both to the same speed and record it on the submittal.
The LT50 line in the guide spec carries the same idea: the shade contractor uses the same motor torque for all roller shades.
Write the acoustic class into the spec and the submittal
Add four items to Section 12 25 09 and the acoustic question gets settled at the bid table.
- Part 1 submittals: product data per motor stating sound level and test basis, and a product schedule listing each room, its class, the motor model and the set speed.
- Part 2 products: the class lines from sections 2.2 to 2.4, the rating basis (ISO 3741, dBA ref 1 pW, nominal torque, without end product), and motors tested to CAN/UL 325 and CSA C22.2 No. 247.
- Part 3 execution: the install rules above, flexible cords per NFPA 70 Article 400, and grounding per NFPA 70.
- Warranty: Somfy's non-prorated motor and control warranty, five years from date of manufacture, per guide spec 1.9.
Attach the current Somfy product page or spec sheet for each motor SKU in the submittal. Somfy's current published data governs, and the reviewer sees the number at the source.
Take the spec package to your submittal
Somfy acoustic class drawing set, 4 sheets
- Class schedule with sources for every number
- Editable 3-part guide spec language
- BOM and submittal checklist
FAQ
Which Somfy roller shade motor is the quietest in the guide spec?
Sonesse ULTRA 50. Somfy guide spec 12 25 09 lists it at 38 dBA ultra-quiet in the wired, wireless and digital network sections, in 120V AC and 24V DC versions.
Does the Somfy dBA rating include the shade fabric and tube?
No. Somfy rates motor sound per ISO 3741 / NF 31022 in dBA ref 1 pW, at nominal torque, without the end product. Tube fit, drive, idler end and bracket change what the room hears.
Can Sonesse ULTRA 50 DC RS485 run on SDN PowerConnect?
Yes. Somfy lists the SDN PowerConnect panels as accessories for 1134022. PowerConnect 1871026 has 10 motor ports, and Somfy sets 240 ft per motor run.
Why do two quiet shades on the same wall stop at different times?
Speed. Somfy's 500 Series databook lists Sonesse ULTRA 50 AC at 24 rpm and Sonesse 50 at 32 rpm. Keep one motor family per elevation, or set adjustable DC motors to one speed.
Sources: Somfy guide spec 12 25 09 on ARCAT (note to specifier, sections 1.9, 2.2 to 2.4, 3.3); Somfy 500 Series databook, Sonesse 50 and Sonesse ULTRA 50 AC and DC (speeds, torque, sound test basis, accessories, wiring); Somfy Low-Voltage databook, May 2019 edition, pp. 4 to 8 (Sonesse ULTRA 50 DC and Sonesse 30 torque, speed, tube ID, sound test basis); somfysystems.com product pages 1134022, 1134023 and 1871026; Somfy press release, April 12, 2016, Sonesse ULTRA 50 motor range.
Ryan Towns writes the Somfy Integrator Guides for ShadeMotorsDirect, an authorized Somfy distributor. Questions on a spec or a retrofit: 859-414-6872 or colin@shademotorsdirect.com, 8:00 AM - 7:30 PM ET.
