Last updated: November 2, 2026

Acoustic Doors · Last updated: 2 November 2026 · Jusen Doors Technical Team · Reviewed by Jusen Doors Engineering Team

ISO 10140 & Rw Ratings: Lab Sound Insulation Explained

What ISO 10140 measures

The specimen is installed between laboratory rooms and sound reduction is determined across frequency bands after accounting for receiving-room conditions. The ISO 10140 parts address test facilities, procedures and product-specific requirements. As with ASTM E90, careful lab mounting is central: an unrepresentative filler wall or permanently sealed perimeter can produce a result that says little about a functioning doorset.

Rw and spectrum adaptation terms

ISO 717-1 converts the measured curve into Rw and can provide spectrum adaptation terms C and Ctr. Rw(C;Ctr) says more than Rw alone when the noise source is speech, traffic or building services. A simple example format is Rw 38 (-1;-4) dB, where the traffic-adapted value would be lower. Buyers should ask which single number the project requirement names and avoid comparing a bare Rw from one supplier with Rw+Ctr from another.

Operability and seals decide door results

A door is not a fixed wall panel. Hinges, latch force, perimeter gasket compression, meeting stile treatment and drop seal operation determine whether test performance survives in use. Reports should state whether the leaf was locked/latched, which closers or seals were active and whether any additional tape or sealant beyond the product system was applied. For pairs, the meeting stile is often the critical leakage path.

Use lab Rw in a building prediction

Project calculations combine the doorset with wall area, junctions, vents and flanking to estimate field performance such as DnT,w or related national quantities. Increasing door Rw has diminishing value if the surrounding partition or a transfer grille is weak. National regulations may set door requirements directly or set whole-room separation targets, so the acoustic consultant should translate the target into a doorset specification.

Avoid the STC conversion shortcut

STC and Rw use different test/classification ecosystems, reference curves and frequency treatment. Products often report numerically close values, but no universal '+1' or '-1' conversion should be written into a purchase contract. If a project is specified in Rw, buy ISO evidence; if specified in STC, buy ASTM evidence. For a side-by-side explanation, see STC vs Rw vs OITC.

Specification checklist: what to confirm before ordering

• Rating system named in the specification (STC, Rw or a field metric), with no informal conversions.
• Laboratory evidence for the complete operable assembly, including frame and seals.
• Wall, junction, duct and other flanking paths reviewed with the door selection.
• Threshold or drop-seal detail coordinated with flooring and accessibility.
• Adjustment and seal replacement included in the maintenance plan.

Related guides

• ASTM E90 & STC Ratings: How Lab Sound Tests Work
• STC vs Rw vs OITC: Sound Ratings Compared (With Examples)
• How to Soundproof an Existing Door: 7 Methods That Work

FAQs

Is Rw measured by ISO 10140?

ISO 10140 provides the laboratory measurement data; the Rw single-number rating is calculated under ISO 717-1.

Can I convert Rw to STC?

There is no dependable universal conversion. Test or classify the product in the system the project specifies.

What do C and Ctr mean?

They are spectrum adaptation terms that adjust the single-number rating for different noise spectra; Ctr is commonly relevant to traffic-like low-frequency noise.

Data note: Figures described as typical, common or planning ranges are industry budgeting ranges with the stated assumptions. Building-code duties, tested scope and final quotations depend on destination, selected construction and order schedule.