modiirq is probably going to work better for high frequency sweeps, though you can't control the Q at audio rate.
One thing that's important to remember is that when you stack up filters you're also stacking up any gain that those filters introduce. (e.g. if you have a Q of 1, you're going to introduce some gain. More sections = more gain) If you want a higher order filter that doesn't introduce gain, you might look at something like a Butterworth filter (you would need to cascade multiple filters for that)
