the nice thing about a highbanker is you can buy a kiddie pool and run all kinds of tests in the back yard.make lead shavings of different sizes paint them neon pink......

make a batch of mud as close as you can get to your diggin sites mix in the lead(if you want to be really authintico make sure you dry that mud as much as possible and it must have rocks in it dry it on a 4x8 sheet of plywood) then dig that break that and feed it into your banker......what comes out the other end vs what stays in the box may just change what you think youve been doin.....

? everyone......i bet you wont want to go through all this and if you do it once you may be so educated as to not need to do it again..........R your possible results if you run a stock banker like you see in the videos....loss of some maybe alot of your gold........so combined with what i saw in the above posts short boxes are no good for production,and retention of fine gold.......Damper like hoser mentioned.......try to know if gold is comin out of the end......i believe if your geared for the finest of gold you wont have to worry about the bigger stuff.....throw some split shot through your banker if its not in and staying in the very front of your rig you are losing gold........with longer boxes you can run different angles per box to tune recovery by size......classify down from box to box automated like use your hydraulics if ya catch my DRIFT.....

and make it work for you.....losing big material runnin a more classified slurry and let the slurry get a chance to settle out...just watch what happens.