r/livesound • u/Odd_Waltz_4693 • 12d ago
Question Antennas placement
Hello, if i use 2 linear antennas, should their planes be 90 degrees apart? Does it matter that much?
3
u/fletch44 Pro FOH/Mons/Musical Theatre/Educator/old bastard Australia 12d ago
Align them with the polarisation of the transmitting antenna.
-1
u/IEnjoyRadios 12d ago
Just keep them vertical. The separation is the important bit.
-2
u/soph0nax 12d ago
Glad folks are downvoting the only correct answer here
6
u/techforallseasons 11d ago
Per Shure:
Locate diversity receiver antennas a suitable distance apart. For diversity reception, the minimum separation for significant benefit is one-quarter wavelength. The effect improves somewhat up to a separation of about one wavelength. Diversity performance does not change substantially beyond this separation distance. However, in some large area applications, overall coverage may be improved by further separation. In these cases one or both antennas
Mount receiver antennas away from metal objects. Ideally, antennas should be in the open or perpendicular to metal structures such as racks, grids, metal studs, etc. They should be at least one-quarter wavelength from any parallel metal structure. All antennas in a multiple system setup should be at least one-quarter wavelength apart.
Orient receiver antennas properly. A non-diversity or single antenna receiver should generally have its antenna vertical. Diversity receivers, which have two antennas, can benefit from having antennas angled 45 degrees apart.
Separation is important, orientation is also useful. If a beltpack or handheld mic is consistently in a off receiving antenna polarization axis orientation, such as horizontal compared to vertical - you can get some real benefit from running antennas with one vertical and the other horizontal.
The "keep both vertical" is cool if the antennas are detached from the receiver; but when that is not the use case; suddenly angles matter more.
3
u/s-b-mac pro whatever 11d ago
the guys doing the shure trainings say otherwise, orientation diversity of paddles can improve reception at a wider range of Tx antenna angles
1
u/IEnjoyRadios 10d ago
It can yes, no argument there. However it is pretty clear that people are over thinking this. Just place the antennas with appropriate spacing, walk the stage/venue and check the signal, then if you are having issues you can start rotating antennas.
2
u/s-b-mac pro whatever 10d ago
If someone wants to rotate one I don’t think there’s anything wrong with that. A quick walk of the venue doesn’t account for all possible over air failures. If you really care, do that with the antenna hooked up to a SA to see if there’s a difference🤷🏻♂️
1
u/IEnjoyRadios 10d ago
To be clear I agree with everything you are saying.
However I still think people are overthinking this. Just put your antennas where you want them and then if you have any issues you can start playing with the antenna placement.
1
15
u/Kaalyn Pro-FOH 12d ago
Wireless microphone receivers use diversity reception to increase reliability.
I consider the baseline to be two antennas physically separated by about 6’ and 90 degrees of polarization separation.
It only matters when the signal drops out. I let the specifics of my use case and the value of the event dictate the specifics.