raise RMS

That's not quite as simple as it seems, as this is a sample-time measurement, and even altering the Window Width setting can sometimes make more difference than that. Which means, incidentally, that anybody else measuring this on a different system is likely to get a slightly different result anyway. Not only that, but you haven't specified whether it's the total or average value you wish to alter (by an imperceptible amount...) What's the context?