Latency. Analog is instant. Digital take time. Usually this is so minimal it's imperceptible, but poor overall
system design can with a large number of
network hops and/or A/D (analog-to-digital) and D/A conversions can make it a problem, particularly if you're running in-ear monitors (which I assume you aren't).
My recommendation is that for this number of systems, go with something that has a digital transport such as the ULXD quads. The quads have Dante transport natively built-in, which is very convenient for the number of cables you need to worry about if you have a
console with Dante functionality. If you don't, just keep in mind that more A/D and D/A conversions is bad.
An example of a poor
system design would be taking the analog outputs of the receivers, spitting them analog into a signal
processor I/O frame, which then has to turn the signal into Cobranet to talk to another
DSP frame, and then gets translated back down to analog somewhere before hitting your
console. Each conversion adds
latency. Too much
latency and people will become discombobulated that their voice coming out of the their mouth is noticeably delayed when it plays back into their in-ears.
The ideal design is that you either go analog straight into your
console off of the receivers, or go Dante off of the receivers into your Dante
network, and in as few
network hops as possible, get your receivers talking to your
console via Dante. More
network hops may force you to turn up the
latency for your Dante
network.
Let's say you put 7 quads in a rack. You minimize your
latency by having all 7 quads
plug into a
network switch dedicated for Dante, and then having your
console plug into that
switch. Or go from that
switch on-stage to a
switch near your
console, and hook your
console up to that. You will unnecessarily add
latency into your
system by connecting the Dante connection up to your first quad, then looping it through that quad into the next, and into the next, and into the next. This will transmit audio, but by the time you get to the 7th receiver, it your digital audio signal has to hop through the first 6 receivers and 1 or 2
network switches before hitting your
console.
---
As for RF transmission and integrity, modern digital wireless systems have substantial improvements in reducing drop-outs and interference due to inter-modulation. If you do what Wireless Workbench tells you to when you log into your wireless receivers and perform an RF scan and frequency coordination, you should not encounter much in the way of issues. You can also actively
monitor your wireless systems and see an error log of interference or RF overload (for example, if your transmitter ends up right next to your antenna or you use active antennas and turn the antenna
gain up too high).
Generally when I get phone calls for non-functional wireless systems these days, it's a broken mic
element, or someone turned off the receivers in addition to
power sequencing the
system down, and didn't realize that they then needed to flip the
power switches on their receivers back on (got that
call this morning).
Calls about drop-outs or interference are few and far between, both in our installed systems and when we rent equipment out.
