yes, in /etc/mpd.conf you can set the sample at something "static"
link for man page:
http://linux.die.net/man/5/mpd.confaudio_output_format <sample_rate:bits:channels>
This specifies the sample rate, bits per sample, and number of channels of audio that is sent to each audio output. Note that audio outputs may specify their own audio format which will be used for actual output to the audio device. An example is "44100:16:2" for 44100Hz, 16 bits, and 2 channels. The default is to use the audio format of the input file. Any of the three attributes may be an asterisk to specify that this attribute should not be enforced