Otherwise, you need to buy a SWM16 depending on how many other receivers you have.
The HR34 is 5 tuners. DVRs are 2 tuners, regular receivers are 1 tuner.
That would let you use the HR34 and 5 other DVRs (or 6 if you have one run on single tuner).
SWM16 are around $70-80 on ebay, much more at retailers.
Directv would probably do it for the cost of a service call, possibly free depending on your account.