The EU-funded project VSAMUEL aims to record from up to 128 channels from animal multi-electrode experiments. This will put a significant load on data storage and retrieval. To decrease the file size of 16 bit, 25 kHz recordings, compression algorithms were investigated and compared. Due to the high entropy of the signal, entropy coding was discarded and instead a wavelet based coder implemented. Compression ratios of up to 1:20 were achieved, but on the cost of loss of spike events. This was quantified by a new spatio-temporal event detector, which takes the location of electrodes on our silicon probes into account.