BIOPAC® Systems, Inc. Logo

Filter Multiple Channels at Once

Filtering Channel Dialog

Filter Multiple Channels at Once allows FIR, IIR, or Comb Band Stop filters to be selectively applied to a single EEG channel or to multiple EEG channels at the same time. Use AcqKnowledge Analysis > Electroencephalography > Filter Multiple Channels at Once to easily select multiple channels and apply filter parameters for concurrent processing. After selecting desired channels, click OK to open a new dialog to specify how channel data should be filtered.

Different frequency parameters and default Q settings are enabled in this dialog for each specific Filter Type as selected from the drop-down menu at the top of the dialog. The filtering options are like options detailed in Transform > Digital Filters, except they are only applied to the channels selected in the preceding dialog. Unlike in Transform > Digital Filters, if Comb Band Stop is selected from the Filter Type menu here, the software will not permit a range of frequencies; the default option is all up to Nyquist.

The final three checkboxes further define how processing should be applied:

Filter Entire Wave(s) is equivalent to checking the Transform Entire Wave checkbox used by Transform > Digital Filters.

Duplicate Channels Before Filtering will make a copy of the channel data being recorded and apply selected filter options to that copy to preserve the original input data and selected channels.

Show Filter Response is only available with certain filters and will open a new graph window to plot how the filter is attenuating energy as a function of frequency. This graph only tracks one copy of the filter response since the filter is applied to all channels of selected data.


This feature is available in AcqKnowledge 5.0.6 and above; Upgrade AcqKnowledge if needed.

Spotlight On
free BIOPAC webinar

Ergonomics & Fatigue Series Part II: Cognition & Neuroergonomics

Learn about the tools you can use in neuroergonomics research such as fNIRS, EEG with cognitive state detection, and eye tracking.

You Will Learn:
– Data analysis for fNIRS, EEG, HRV, and eye tracking (including pupillometry, saccades)
– How to perform experiments in VR
– Automation and standardization
– Tips and tricks for getting optimal data quality
– Demonstration
Join Live
December 1st
8am PT / 11am ET

Register Now
Latest News

New Citations | BIOPAC in Ergonomics

Whether using specialized equipment, performing repetitive tasks, or simply going about our daily work routine, the effects of design in our environment as well as the tools we use and the way we use them can impact our health, work performance, and quality of life. Here are a few studies that have recorded and analyzed […]

EDA Guide Available

BIOPAC’s comprehensive EDA Guide provides an introduction to Electrodermal Activity (EDA or GSR) and details topics including: EDA Complex: SCL, SCR, tonic, phasic, specific SCR, non-specific SCR Participant Prep & Electrode Placement Data Recording tips Automated EDA Analysis Routines Digital input to Stim Events Stim-Response Analysis Derive Phasic EDA from Tonic Event-related EDA Analysis Locate […]

Read All
Request a Demonstration
Request a Demonstration