I have some RedWirez IRs already, thinking of getting more for use with the Amplifire. I like that they have the mixIR online so you can blend several IRs into one easily. What I'm wondering about is their IRs that they have the "Tube Power Amp Filter" as an option to mix in your IRs. From what I can tell this mixes in their Speaker Impedance Curves in with standard cabinet IRs. This is what they say about these curves on their site: This update includes impulse responses of multiple speakers' impedance curves. These can be used to reproduce the effect that a tube amp can have on the frequency response of the speaker. Compared to solid-state power amps, tube amps have a high output impedance. As a result the connected speaker's frequency response will change, causing it to look more like it's impedance curve than when driven by a solid-state power amp. You may appreciate the more scooped tone, the added thump and sparkle. Has anyone used these curves along with traditional cab IRs? Do they add anything good to the mix? I'm thinking it might be redundant with the power amp sim already on the Amplifire - thoughts?