threshold and external speaker

Hi all ,still learning to drive the gp3000
I understand how to set the threshold with headphones , but my external speaker has a volume knob as well so in theory I could have the threshold flat out and adjust the speaker ,or max the speaker and adjust the threshold , both giving the same volume level but ,I suspect , different results .
Using the headphones the threshold is round 12 ish and so I left it there to use the speaker , but the knob got bumped last trip to 4oclock and I roamed around for half a day (still getting nails and ****) .When I noticed it and wound it back to 12 oclock and readjusted the speaker vol I had more ground noise and warbling .....
So , what is the best relationship for the threshold / speaker vol. ?
Thanks ,Brett

Hi Bbrook
The threshold is a fine balance point and should be set with the speaker volume initially at full.If set too high it will mask the signal,too low and the threshold will break up and you risk loosing a dropping signal.The correct setting for threshold would be the lowest smooth continuous threshold so that any small signal or murmur will cause a change in the threshold.The threshold is not a volume control,once set correctly you can then adjust your speaker volume.

Hi deutran thanks for that , I will have a play around next time I head north , It's got a lot more adjustments than my old diablo!! Thanks , Brett