[LAU] How to run jack at 8kHz sr?

Hi list, I'm writing some signal processing algorithm for real time processing that has to run on a 8 kHz sampling frequency embedded device. My code is in C and I wrote a simple jack client for testing my algorithms. For now, I'm using a sample frequency of 44.1 kHz but I want to test the behaviour of my code at 8 kHz. With my sound card, is impossible to set jack to run at 8 kHz. It is possible in some way, to fake the 8 kHz sampling frequency (for example using plugins?). I've seen the Steve Harris Decimator, but it is not designed to run in real time. I've tried to put in jack-rack a low-pass (antialias) filter followed by the SH Decimator, but the result is (as expected) a 44.1 kHz signal with reduced bandwith and some "aliasing" (I don't think that what I get is alias -by definition- but some other artifacts). What can I do to test my algorithm at 8 kHz in realtime using jack? Thank you all :) -- a.