Yes, for the first two rounds, you vote off 3 songs and the lowest three songs are eliminated, isn't that how it's supposed to work?
From the album survivors that I've seen, any amount of saves/offs can work for each round. But once the votes are counted, only one or two songs with the lowest scores are eliminated. It doesn't matter how many save/off votes the participants were allowed for that round. I've never hosted one of these, but the way you are doing it makes sense... Killing off six songs in the first two rounds just seems like a bit of overkill.