beyondmyken,
With 35 years of testing of about every decoy setup known to man, I have found that a jake and a double hen setup has been the best producer. I set my jake (Avian) and a hen close together at 7-8 yards (max) and another hen right beside the blind. If the turkey totally commits it is a point blank shot. If he fades just a bit and does his little circle he will most times still be within easy range.
My close hen helps in that we often attract birds with simply scratching the ground (no calling). The sound from inside the blind goes well with the super close hen. This is a killer setup for call shy birds.
I called in 5 birds last year that never made a sound but still came in and pounded my jake. I use a gobble tube and a single cackle when I am hunting old birds or birds that have been pressured. I use this call combination one single time every 30-45 minutes (sometimes much longer and then I simply believe that the bird is just out of range but coming slowly. Less is a lot more when hunting turkey and the single most powerful tool in the turkey woods is patience.
I have posted this video before but if you have not seen it, it shows my setup in the first few seconds from outside and inside the blind along with a big birds response to the setup.
Listen close and you can hear the big bird spitting at the jake decoy.
http://www.youtube.com/watch?feature=player_detailpage&v=QkknrlJs2iM Good luck.