For the audio they have two wireless handheld mics and a lavaliere going into a mixer, which is then connected to house speakers.
The mixer the contractor uses is a Mackie 1402-VLZ3 Fourteen Channel Mixer with 6 XLR Mic Inputs ($399.99) A nice little box with multiple inputs, and it even has sliders!
Given that the client typically only has three sources at their events (the three mics) they could get by with the Mackie 802-VLZ3 8-Channel Compact Audio Mixer ($199.99), even if it has knobs instead of sliders.
However, an eight-input mixer doesn’t mean eight individual inputs. The 802-VLZ3 has 2 mono lines and 3 stereo line inputs. So that’s really five channels, and if they decide they want to have a three person panel individually mic’d, plus a host mic and a mic for the audience, and they have a computer connected to the audio system (which they don’t usually do, but it’s perfectly possible that it could happen) then that eight channel mixer won’t be enough. So while it seems like it has ten more channels than are needed, the Mackie 1402-VLZ3 does seem the safe way to go.
The contractor is using the Shure SLX series ($599 for a wireless receiver and mic). These are in the pro-end of Shure’s line (though they have some “digital” models which are even more expensive.) Shure has several other systems, including:
Shure PG24 PG Series $299These two, and the SLX line, all include a Shure SM58 mic (or similar lavaliere mic, depending upon the package you buy), so the differences seem to be primarily in the range and number of channels in the base station:
Shure PGX Series $399
Now the client is using these in a medium sized room (about 100 people tops) in either a hotel room or in an office building. I don’t think that interference from other systems should be a major problem.
I think the PGX series is a good bet; sort of like Goldilocks and the Three Bears; 10 channels is too little, and 960 more than you need. Ninety seems enough to deal with interference 99% of the time.
Of course, one problem is that this isn’t really my field of expertise. I’ve been using a Sony wireless system for years, and never had a problem with interference. Checking the specs I see that Sony’s system claims to have 188 channels. If it were for my own use, I’d go with the PGX (or buy the Sony system.) But since it’s for someone else, the safest route might be just to tell the client that the contractor is using the SLX system, and that that’s what they should get. That way, if there are problems, I'm covered. But if I go and tell them to get the cheaper system, and then they have a problem one day, it’ll be my problem.
If you've had experience with any of these wireless systems, I'd love to hear from you.