How to get an array control with Synth.get

I have defined a simple synth which has an array control argument and I wanted to use get method to get the freqs argument back, but instead I got only the first freq in the array. What should I do to get the whole array back?

a = {\[440, 550], 1), mul: \}.play;
a.get(\freqs, {arg ctl; ctl.postln});
// returns 440.0