The velocity response of the
Streckheisen STS-2 seismometer used at the IRIS station in Borgarfjöršur
has a passband from about 40 Hz down to at least 
Hz
(Figure 2).
Poles:
Zeros:
The Streckheisen STS-2 geophone has a leading factor (A0 in the
ah header) of 5.699996 
and its gain (DS in the
ah header) is 360.0 V/m/s. Information
on the poles and zeros of the STS-2
seismometer comes from Pete Davis, pdavis@yin.ucsd.edu.