You might also think about carrying a mouth reed. Of the bear we have killed calling I think ten were called in using a Larry D. Jones Green reed elk diaphragm. Not sure but I think that is now what Point Blank calls their Knock Down Double. In each case I started off with a soft lost calf call and began increasing desperation. After about ten minutes I started thrashing the brush and began bawling using the same reed. Starting off bawling loud and frantic, moving to winded and weak, and then finishing the setup with gurgled bawls with some spacing between. Besides the bear we've killed doing this we probably spooked twice as many when we gave up too early and stood up to move to a new location...Doh!!
My other bear call is a super raspy double reed jackrabbit call. I open up the reeds to give rasp without a lot of back pressure. But not so much it breaks out when I want desperate volume. I use long breath calls more like a fawn in distress than the short bursts of a rabbit. This is my call of choice in the High Cascades.
We have killed only a dozen or so bear calling. Maybe screwed up on another 20 or 25 over the past 30 years. So take my experience for what it's worth. I think we have a few on this site that have called a lot more bear than I have.