diff --git a/htdocs/openwebrx.js b/htdocs/openwebrx.js
index 4f4d090..752b533 100644
--- a/htdocs/openwebrx.js
+++ b/htdocs/openwebrx.js
@@ -2433,7 +2433,8 @@ function secondary_demod_update_channel_freq_from_event(evt)
     if(typeof evt !== "undefined")
     {
         var relativeX=(evt.offsetX)?evt.offsetX:evt.layerX;
-        secondary_demod_channel_freq=(relativeX/$(secondary_demod_canvas_container).width()) * (if_samp_rate/2);
+        secondary_demod_channel_freq=secondary_demod_low_cut + 
+            (relativeX/$(secondary_demod_canvas_container).width()) * (secondary_demod_high_cut-secondary_demod_low_cut);
     }
     //console.log("toset:", secondary_demod_channel_freq);
     if(!secondary_demod_waiting_for_set)