Re: Stereo floor monitor for vocalists?
There have been a couple of attempts at "two wedges, one box" monitors over the years, but now I can't recall who made them. They've all the problems with pairs of wedges with none of the positioning flexibility of individual monitors.
If your singers genuinely have a problem hearing themselves over the stage SPL, the music minister needs to be Music Director and declare the Noize UnJoyful®. I'm not sure why, but there is a huge disconnect between the "artistic" side and the technical side, and it's not just in houses of worship... But your singers and congregation are better served with stage levels are under control. If the music minister is the cause of the SPL... you have my sympathies; I've been there, quit that, didn't stay for the rending of garments.
If the problem is with the talent, i.e. timid singers with little experience, a good voice coach can help a great deal. The improvements will remain long after the Gear Acquisition Syndrome has done a couple of cycles, too. Spending money on the singers is good stewardship, and there is no reason those investments MUST be hardware.
Or are there other issues you hope to address with a different monitoring arrangement?
