This article proposes a characterisation of the double-reed in quasi-static regimes. The non-linear relation between the pressure drop $\Delta p$ in the double-reed and the volume flow crossing it $q$ is measured for slow variations of these variables. The volume flow is determined from the pressure drop in a diaphragm replacing the instrument's bore. Measurements are compared to other experimental results on reed instrument exciters and to physical models, revealing that clarinet, oboe and bassoon quasi-static behavior relies on similar working principles. Differences in the experimental results are interpreted in terms of pressure recovery due to the conical diffuser role of the downstream part of double-reed mouthpieces (the staple).
