The data that is recorded during the experiment by the workstation, is filtered. We are using a 64 Channel programmable Filter/Amplifier System from Frequency Devices Model 9064. The actual filters a 8-Poles 6-Zero Constant Delay Low-Pass Filters whose cutoff can be set from the workstation.
The company address is:
Frequency Devices
25 Locust Street
Haverhill
Massachusetts
01832
Tel: (508) 374-0761
Fax: (508) 521-1839
The following links contains specs of the filter and its transfer function: