Use a model M51 for the highest degree of
grade silencing for areas requiring “hospital quiet”
noise reductions. The M51 is presently the top-of
the-line silencer without resorting to multiple
silencers in series or custom designed silencers.
Use a model M41 for quiet residential
background noise is relatively low and “critical”
grade silencing is required.
Example: For truly quiet residential areas
ambient noise levels are very low and the sounds
of birds singing and the soft hum of air conditioning
units may be the noticeable noise features.
Use a model M31 in residential areas where
background noise is present but not objectionable.
In these areas, installation of an M31 on an engine
exhaust is intended to bring the noise level down to
match the ambient noise levels.
Example: In a quieter residential areas
main traffic areas and away from constant noise
M21 – Good Chamber Type
Expected Attenuation is 17 to 20 dBA
Use a model M21 in residential and light
areas where background noise is relatively high
and constant and the need for higher degrees of
silencing is minimal.
Example: In residential neighborhoods
traffic or light industry with relatively constant
background noise. Residents in these areas are
typically accustomed to the noise or make some
efforts to shield themselves from the ever present
background noise . Use of an M21 can keep engine
exhaust noise within existing noise levels.