Change the spells on Restless Spirits so they can't just barrage you.

[Egon the Monkey]

I like the change to soundburst, but it's turned these monsters from what I remember back in the day as "an annoyance" into a horror.

• Previously, it did 1d8 damage, no save, 2 round stun on a failed will save. It was dangerous as it was a non-mind stun AOE, and a barrage did significant damage overall.
• Now it does 2d8+level (they're Bards, because some of their L2 spells are blocked by Blur due to being L1 for a Bard). Assuming these things have the  4-5 Bard levels a PC would need, that's triple the damage it used to be. Which means that old quests that have a lot of these suddenly have huge spikes of unavoidable damage, and encounters with these things are no longer balanced. I recall Jubal's for example being hard, but not due to "taking 99 damage in 1-2 rounds from a caster barrage that also stuns you"
• Twice on quests I've now seen an insulated party of level 7-9 PCs get sent to bleeding or dead by a barrage of 8-10 soundbursts. Combined with the fact they have another spell of mass knockdown to keep the healers pinned, it means they can trash your party on some good rolls and there's not really anything you can do about it.

I suggest splitting them into 2 monster types, with only the "elite" version using soundburst.