From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Noise complaints regarding the non-resonant silencer on the 20/25HP model.
| Identifier | ExFiles\Box 104\2\ scan0077 | |
| Date | 13th March 1933 | |
| LID{A. J. Lidsey} X8230 Hs.{Lord Ernest Hives - Chair} [REDACTED] from Mx.{John H Maddocks - Chief Proving Officer} See me Mx{John H Maddocks - Chief Proving Officer}7/T13.3.33. HS{Lord Ernest Hives - Chair} NON RESONANT SILENCER - 20/25HP. There are two features which are noticeable on this Silencer as fitted to Production chassis which we feel may be a source of complaint - (1) "Spitting" at closed and small throttle openings on retard - when this takes place it is much more audible than with the previous type of silencer. (2) Contraction noises when cooling down. Both these features were quite marked after we had effected the changeover of the exhaust system on Air Vice Marshal Longmore's car. Mx{John H Maddocks - Chief Proving Officer} [SIGNATURE] | ||