I have both and found them to exactly the same. The Sound Machine is a much better quality in terms of audio but that is by design. Make sure you are scanning often and have the antennas out and up at a 45 degree angle like this

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If you are having to transmit through people you will have problems, get the speaker up on a speaker pole as high as reasonably possible. Wear the pack in a shirt pocket or belt clip towards the receiver.