DVB C Tuner is 2 Needed for Dual tuner ?

[uscool]

Hi, im looking to buy a DVB C tuner for the Duo 2 , im wondering would 2 be needed to record 1 channel and watch another ? as cable seems different to sat , cable can be split using a splitter , i also see the Tivo box is 3 tuner, but only has 1 cable input

Thanks

 

[uscool]

the tivo has 3 inbuilt tuners , so guess would need 2 tuners , thanks