Standard vs. Premium Silencers

When specifications call for a “Premium Grade Silencer” there can be confusion as to the definition of a premium grade silencer. Premium grade does not necessarily refer to a chamber-absorption silencer; a silencer that has chambers and tubes but also the inclusion of acoustical pack material to attenuate high frequency noise.

Each style of silencer – both chamber and chamber absorption – has a standard grade and a premium grade. The defining characteristics are different for each.

For chambered silencers – often called reactive – the difference is in the volume of the silencer. For Stoddard Silencers’ discharge silencers the D12 series is the standard grade silencer while the D13 series is the premium grade. Chambered silencers are for blowers operating below transition speed (see separate specification sheet for a definition of transition speed). The D13 has more volume and different internals that cause its attenuation to be greater than the D12. Thus the D13 is a premium grade while the D12 is our standard. For the intake silencers we only use the L41 series which is a premium grade silencer.

For chamber-absorption silencers the difference is the volume of the silencer plus the thickness and length of the acoustical packing section. Chamber absorption silencers are used on blowers operating above transition speed. Stoddard Silencers’ standard grade intake silencer is the L63 series while the L61 is the premium grade intake silencer. Stoddard Silencers’ standard grade discharge silencer is the D32 series while the D33 series is the premium grade.

One last note worth mentioning; in the 6” pipe size silencers and smaller there is minimal difference between the standard and premium grade silencer. For that reason, unless specifically asked for by the customer, Stoddard Silencers only makes the standard grades in 8” pipe size and larger.

If you have further questions about the construction of Stoddard Silencers’ silencers and/or filters please call the factory at (847) 223-8636, send us a fax at (847) 223-8638 or send us an email at