Sorry to say that, but i guess both things is important. Out of date sound if you are using old cheap effects, or old guitar plug-ins, or old recording devices that bring you a lot of unwanted noise. I have no idea what gear you are using, but it sound no good. Well if you want an advanced answer just tell me what is it. What is your daw, what effects you are using, are they hardware ones, your soundcard or whatever you are using for recording. Because there is seems to be a big hole in some of this. I can just give a quick advise where to look, as WSO-MusicForMedia nicely said that you definitely need a fine studio monitors.