MiniSEED volumes (waveform data records without accompanying parametric information, like station location, etc.) need a dataless SEED volume (metadata headers) in order for a user to extract data using rdseed. This is enforced by rdseed to ensure proper extraction of the waveform data. Here is an extract from the rdseed manual about how to put these two files together in order to get at the data:
The user can specify that station configuration and responses be taken from another SEED volume. This will allow for two possible scenarios to be accomplished. First, if station information is found to be in error, the user can use the headers from another SEED volume that is known to be correct. Second, if the SEED volume is a "data-only" volume (miniSEED), the user can use a "data-less" SEED volume and the "data-only" SEED volume to extract the desired waveforms. So you say, "How do I do this?" The environment variable ALT_RESPONSE_FILE should be defined with its value being the path name of the SEED volume from which responses should be taken.