String Gauges
 

I may sound like a noob, but I really don't like the output of my higher strings on my 5 string ibanez sr305 (D and G strings) because I don't get enough sound out of them playing live through a PA mixer. A normal 5 stringed ibanez bass is gauged with .045 .065 .085 .105 .125 gauged strings. I may just buy some singles of strings but i was thinking of raising the D and G string gauges and leaving the rest the same, so it'd be: .050 .070 .085 .105 .125

Is there anything wrong with this? Or should I move all the strings up in size?

I don't think there's anything wrong with trying heavier strings, but I'm not sure what you'd accomplish, either. If by output you mean volume, then I wouldn't jump to conclude the strings are the issue. ...but maybe you didn't mean volume?

Sounds like pickup adjustment should be tried first. If not, I'd try lower tension G and D strings.

+1 for the pickups. They should be closer under the thinner strings.
The output should be consistent with all controlls set to their neutral positions.

I meant volume when I said output. And ya I've been thinking its the pickups too, but I should lower the tension on the G and D strings or do the opposite?

I would not go for fatter strings. Yes they do have a little more material moving about in the magnetic field of the pickup(s). But: A a stiffer string has less amplitude, due to more tension. So that makes more material, but less movement. I have had many brands, kinds and sizes of strings on my cheap Ibanez GSR200EX, but the output accross the board has always been fairly even.

The few times I've been to jams and I can't get any sound out from the thinner strings on my bass guitars, usually it's the amp setup where they cut out the highs as their preference.