Festival change voice server

Hi I have installed festival

but have a issue of not being able to change from the default of voice_kal_diphone …

I have installed this voice voice_cmu_us_slt_arctic_hts but how do i use it with festival --server command .

I know i can use it normally by just doing switch in cmd pressing festival than from there pressing (voice_cmu_us_slt_arctic_hts) but how do i do this when in server mode when i pressing festival --server how do i use that voice ?