so, sigpack/freqshift~ is based on a ladspa plugin, and I think it's supposed to be a frequency shifter just like pd vanilla's extra complex-mod~ object, am i right? But it sounds really "worse"/more distorted, so is it really supposed to be like that?
I guess if someone has this plugin, a test could be made to check how the original works... try it with a sinusoid and you'll be able to hear how sigpack/freqshift~ really distorts it.
here's the original plugin ( bode shifter 1431 http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html#id1431 )
cheers