ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 ... 7 8 [9] 10   Go Down

Author Topic: Combiner quality  (Read 13553 times)

John Sulek

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 447
  • Toronto Canada
Re: Combiner quality
« Reply #80 on: August 19, 2019, 03:58:11 pm »

Oh cool - I didn't know you had the Combine4. Good to know. And yeah, I'm definitely grabbing the CP Beam for whichever combiner I go with.

How far away is your antenna from the performers? I'll have the luxury of placing my rig side stage... I'm hoping that helps a bunch.

Height is your friend. Less salty water bags in the way.
Sometimes upstage pointing towards the downstage edge works best...all depends on the layout and what you can get away with scenic-wise.
Logged

Tim McCulloch

  • SR Forums
  • Hero Member
  • *
  • Offline Offline
  • Posts: 20983
  • Wichita, Kansas USA
Re: Combiner quality
« Reply #81 on: August 19, 2019, 04:01:38 pm »

IIRC the helical antennae have a beam spread of about 30 degrees.  An RF cannon may not be the best solution.  The domed helicals might be wider.

On most stages in a reasonable RF noise environment, better placement of Log Periodic antennae has more positive effect with fewer 'out of coverage' issues than a helical.  In high noise environments the helical may offer more advantages.

Height is your friend. Less salty water bags in the way.
Sometimes upstage pointing towards the downstage edge works best...all depends on the layout and what you can get away with scenic-wise.

^^^ THIS
Logged
"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

Steve Litscher

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 501
    • 608 Sound and Light
Re: Combiner quality
« Reply #82 on: August 19, 2019, 04:28:41 pm »

Thanks again guys - I'll definitely get the antenna raised as high as I can, and I'll check the coverage patterns of the CP Beam vs the domed helical.

Jason Glass

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 721
    • CleanWirelessAudio.com
Re: Combiner quality
« Reply #83 on: August 19, 2019, 05:40:02 pm »

IIRC the helical antennae have a beam spread of about 30 degrees.  An RF cannon may not be the best solution.

Antenna beamwidth is a largely misunderstood by too many users, IMHO.  First of all, the CP Beam beamwidth is 70.  This means that at 35 off-axis, the directional gain is 3 dB lower than on-axis.  Since the CPB's on-axis gain is 11 dBi, you still have 8 dBi of gain at that angle.  Then it's wise to deduct 3 dB for polarization mismatch loss between the circular polarized TX and randomly oriented linear RX.  This leaves you with gain at 35 off-axis that is roughly equal to an LPDA pointed directly at that position.  From that angle outward, gain doesn't just cut off.  It gradually decreases until minimums located approximately 120 to 160 off-axis, then shoots way up inside a hot lobe between 160 and 180.

If you overlay the polar pattern of a helical antenna such as the CP Beam or PWS HA-xxxx over a rectangular stage, you'll find that mounting it offstage of an upstage corner and pointing to the opposite diagonal downstage corner offers nearly ideal gain distribution to cover the stage.  You'll see that the highest gain on the axis points toward the most distant likely performer position while closer positions correlate with off-axis gain dropoff.

Henry Cohen

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 962
  • Westchester Co., NY, USA
Re: Combiner quality
« Reply #84 on: August 19, 2019, 06:13:03 pm »

Antenna beamwidth is a largely misunderstood by too many users, IMHO.  First of all, the CP Beam beamwidth is 70.  This means that at 35 off-axis, the directional gain is 3 dB lower than on-axis.  Since the CPB's on-axis gain is 11 dBi, you still have 8 dBi of gain at that angle.  Then it's wise to deduct 3 dB for polarization mismatch loss between the circular polarized TX and randomly oriented linear RX.  This leaves you with gain at 35 off-axis that is roughly equal to an LPDA pointed directly at that position.  From that angle outward, gain doesn't just cut off.  It gradually decreases until minimums located approximately 120 to 160 off-axis, then shoots way up inside a hot lobe between 160 and 180.

If you overlay the polar pattern of a helical antenna such as the CP Beam or PWS HA-xxxx over a rectangular stage, you'll find that mounting it offstage of an upstage corner and pointing to the opposite diagonal downstage corner offers nearly ideal gain distribution to cover the stage.  You'll see that the highest gain on the axis points toward the most distant likely performer position while closer positions correlate with off-axis gain dropoff.

THIS  ^^^^^^^^^
Logged
Henry Cohen

CP Communications    www.cpcomms.com
Radio Active Designs   www.radioactiverf.com

Bob Charest

  • Lab Lounge
  • Hero Member
  • *
  • Offline Offline
  • Posts: 815
  • Westbrook ME, USA
    • Bob Charest Band
Re: Combiner quality
« Reply #85 on: August 19, 2019, 08:50:58 pm »

THIS  ^^^^^^^^^
Yes, for sure. The attached pic shows how we did this from the upstage corner aimed at the downstage corner opposite.
« Last Edit: August 19, 2019, 08:53:14 pm by Bob Charest »
Logged

Rick Earl

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 316
Re: Combiner quality
« Reply #86 on: August 20, 2019, 09:49:48 am »

Reviving this thread with the hope of finding someone who is/has used the PSM 1000 system with the RF Venue Combine4 system.

I've got 4 channels of PSM 1000 and am about to pull the trigger on a combiner. There's good info in here, but I wasn't able to extract any real world experience/advice about the RF Venue Combine4.

Heading out on a USA tour, smaller theaters (2500-ish cap). Want to make certain I have a stable, reliable combiner and would prefer to not break the bank (if possible). Even with deep discounts, the Shure PA421B is still nearly 3x more than the RF Venue...

Thanks in advance.

I have been using the Combine 4 with Sennheiser EW-300 and a CP-Beam for a couple of years now with no issues.   Inside, outside, close to stage and almost 80' from stage.  One group on campus uses it 3 times a week for rehearsals for 2 1/2 hours a day.   I would say it is reliable and as quiet as the EW-300's on their own. 
Logged

Steve Litscher

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 501
    • 608 Sound and Light
Re: Combiner quality
« Reply #87 on: August 20, 2019, 02:13:38 pm »

Thanks again everyone, and Jason/Bob thanks for the extra detailed info. Much appreciated!!

I talked to Don from RF Venue yesterday and learned *a ton* from him. I pulled the trigger on a RF Venue Combine4 with CP Beam today and will get everything racked-up and ready to test within the next few weeks. I'll let you know how it goes, but based on what Don shared, I'm thinking this will be a winning combination.

Nathan Riddle

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1798
  • Niceville, FL
    • Nailed Productions
Re: Combiner quality
« Reply #88 on: August 20, 2019, 04:14:53 pm »

Thanks again everyone, and Jason/Bob thanks for the extra detailed info. Much appreciated!!

I talked to Don from RF Venue yesterday and learned *a ton* from him. I pulled the trigger on a RF Venue Combine4 with CP Beam today and will get everything racked-up and ready to test within the next few weeks. I'll let you know how it goes, but based on what Don shared, I'm thinking this will be a winning combination.

What all did you learn?

---

To answer your earlier question. I've had a few configs.

1/2 wave antenna at foh (50ft from stage) on 2x mipro 909digital
1/4 wave antenna farm on 4x ew300's G50 band side stage
1/2 wave side stage with 100ft LMR400 (generic) & combine 4
1/2 wave side stage with 25ft RG6U (RF venue) & combine 4
Helical with 25ft RG6U (RF venue) & combine 4

Helical resulted in best RF performance the above list also coincides with performance from low to high.

It also is inversely proportional with band complaints.
Logged
I'm just a guy trying to do the next right thing.

This business is for people with too much energy for desk jobs and too much brain for labor jobs. - Scott Helmke

Jason Glass

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 721
    • CleanWirelessAudio.com
Re: Combiner quality
« Reply #89 on: August 20, 2019, 05:34:56 pm »

Helical resulted in best RF performance the above list also coincides with performance from low to high.

It also is inversely proportional with band complaints.

 ;D ;D ;D ;D ;D  The most important metric known to every Monitor Engineer.   ;D ;D ;D ;D ;D

ProSoundWeb Community

Re: Combiner quality
« Reply #89 on: August 20, 2019, 05:34:56 pm »


Pages: 1 ... 7 8 [9] 10   Go Up
 



Page created in 0.061 seconds with 24 queries.