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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Wireless and Communications => Topic started by: Brian Adams on November 06, 2019, 09:37:37 AM
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I normally use a UA844 to distribute my antennas, but I have a rental going out this week (local high school theatre), and I need to squeeze 3 receivers into a 4 space rack. This means I'll have just enough room in there for either a Furman or a distro, but not both. I'd like to have the Furman in the rack to manage the power and keep things looking clean, but this would mean I'd have to cascade all 3 ULXD units. I know this is theoretically possible, and people have done it, but I've never cascaded more than the recommended 2 units. What are the real-world negative implications of cascading 3 units, and are the disadvantages great enough that I should avoid doing this?
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Are they all the same frequency band? Generally the cascade outs are band-limited.
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Are they all the same frequency band? Generally the cascade outs are band-limited.
Yes, all of my ULXD is G50 band.
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I haven't noticed any significant ill effects in real-world use. If I were in a tough RF environment I might think twice, but for average uses with good antenna placement and SNR it seems fine.
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I haven't noticed any significant ill effects in real-world use. If I were in a tough RF environment I might think twice, but for average uses with good antenna placement and SNR it seems fine.
Thank you, Aram. This is exactly what I wanted to hear. I'd say this is an average environment, but I'll definitely be cautious in more challenging spaces. Thanks again!
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The literature says 2 units, but it also says you can do more if you don't mind potential issues.
Per Shure's website:
Note: The RF cascade ports continue to operate if more than two units are cascaded. However, the issue is RF signal degradation (IMD and RF noise)that will occur each time the signal passes through an RF cascade circuit. At some point, the RF signal will become too distorted/corrupted to be useful. Thus, Shure recommends the conservative approach to cascade only two units. No damage will occur if more than two units are connected in cascade.
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I need to squeeze 3 receivers into a 4 space rack...
Hi Brian,
We used to have 12 channels of ULXD as well. We cascaded the 1st two into one set of the front-mounted 1/2 wave antennas and let the 3rd unit use its own set.
On the smaller stages that we would play on (24'-36' x 12'-16') wee had excellent coverage just using the front-mounted 1/2 wave antennas.
Best regards,
Bob Charest
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If you really want to squeeze out as much performance as possible, cascade the A and B antenna chains differently.
Something like antenna A starts in receiver 1, then 2, then 3, but antenna B starts in receiver 3, then 2, then 1.
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I spoke with a Shure tech a while back, and he said a cascade of 3 is workable.
One suggestion I read was to use the middle frequencies on the 3rd unit, rather than ones at the high and low end.
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If you really want to squeeze out as much performance as possible, cascade the A and B antenna chains differently.
Something like antenna A starts in receiver 1, then 2, then 3, but antenna B starts in receiver 3, then 2, then 1.
An excellent tip!
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An excellent tip!
This is my standard way of cascading units too - also gives you the redundancy that loss of any single unit (PSU fail / turned off etc) only kills half the diversity to the downstream units.
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If you really want to squeeze out as much performance as possible, cascade the A and B antenna chains differently.
Something like antenna A starts in receiver 1, then 2, then 3, but antenna B starts in receiver 3, then 2, then 1.
i just remembered i used to do this all the time. i've no idea why/when i forgot this tip.
Ah, brain cells. how i miss thee...
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If you really want to squeeze out as much performance as possible, cascade the A and B antenna chains differently.
Something like antenna A starts in receiver 1, then 2, then 3, but antenna B starts in receiver 3, then 2, then 1.
Would this still work if you have 2 on one band and 1 on another? Curious and asking in case my distro dies. Or I could just cascade 2 and put the other on it's own antennas.
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Would this still work if you have 2 on one band and 1 on another? Curious and asking in case my distro dies. Or I could just cascade 2 and put the other on it's own antennas.
They must be the same band.
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They must be the same band.
(http://www.chicagonow.com/hippy-shakes/files/2019/06/rolling-stones-public-use-before-after.jpg)
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(http://www.chicagonow.com/hippy-shakes/files/2019/06/rolling-stones-public-use-before-after.jpg)
When someone mentions how much they love the Stones, I always ask them if they've heard of Brian Jones. Sadly, most are clueless.