Raw EEG signals with dry electrodes of NeuroSky system were compared to those with wet electrodes with Biopac system. FFTs were performed to compare signal characteristics of the EEGs, especially power spectrums. Results show that EEG signals of NeuroSky system are compatible to those of Biopac system. EEGs of Biopac system show a little bit more noise in low frequency bands. It may be caused by longer wires between electrodes and pre-ampliëers. e length of wires were 3 feet in Biopac system, while shorter than 10 inches in NeuroSky system. NeuroSky system also ëxes the wires so that they cannot move during EEG measurement. As a result, NeuroSky system is more noise-resistant. NeuroSky system may have an advantage when it is used in real living environment and consumer product applications. © 2009 NeuroSky, Inc. All Rights Reserved.