ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 2 [3]   Go Down

Author Topic: Clearcom Freespeak II antenna sheilding improves audio.  (Read 6733 times)

Pete Erskine

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1201
    • Best Audio
Re: Clearcom Freespeak II antenna sheilding improves audio.
« Reply #20 on: April 26, 2017, 03:25:24 am »

What is actually causing the "stuttering"?
Do I take it these systems are not diversity and as such, the RF signals are subject to (partial) cancellation due to the out of phase signals reflected signal from the ceiling?

The multipath reflections cause out of time reception of several signals to the extent that the 1s and 0s cannot be distinguished anymore.  They are not diversity - this wouldn't fix the issue anyway.  Two solutions are better RX circuits and changing the kind of data which is sent.  The data type is fixed because of the licence to use DECT and cannot be changed,  Adding diversity as well as polarity diversity and extensive processing would probably help.

The new Bolero from Riedel does that and may work better (I have yet to try it myself).  Crewcom from Plyant (Coachcom) deals with it in a different way.  They made the data word be 3X linger with sane no if bits,  Now the multipath distortion is smaller in relation to the direct signal.  See the diagram below.
Logged
Pete Erskine
917-750-1134
www.bestaudio.com
peter@bestaudio.com

brian maddox

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1865
  • HeyYahWon! ttsss! ttsss!
Re: Clearcom Freespeak II antenna sheilding improves audio.
« Reply #21 on: April 26, 2017, 06:12:40 pm »

The multipath reflections cause out of time reception of several signals to the extent that the 1s and 0s cannot be distinguished anymore.  They are not diversity - this wouldn't fix the issue anyway.  Two solutions are better RX circuits and changing the kind of data which is sent.  The data type is fixed because of the licence to use DECT and cannot be changed,  Adding diversity as well as polarity diversity and extensive processing would probably help.

The new Bolero from Riedel does that and may work better (I have yet to try it myself).  Crewcom from Plyant (Coachcom) deals with it in a different way.  They made the data word be 3X linger with sane no if bits,  Now the multipath distortion is smaller in relation to the direct signal.  See the diagram below.

But Crewcom is not running on DECT if i understand correctly?  It's running in 2.4Ghz and/or 900Ghz?  Still a very cool idea for interference reduction, especially in that crowded space.

I'm assuming that in order to use something other than a legitimate DECT transmission within the 1.9GHz space would require approval from the FCC for a completely new use of that spectrum; something i am also assuming is slightly less likely than a sudden outbreak of aeronautical swine...
Logged
brian maddox
bdmaudio@gmail.com

'...do not trifle with the affairs of dragons...

       ....for you are crunchy, and taste good with ketchup...'

Pete Erskine

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1201
    • Best Audio
Re: Clearcom Freespeak II antenna sheilding improves audio.
« Reply #22 on: April 26, 2017, 07:32:29 pm »

But Crewcom is not running on DECT if i understand correctly?  It's running in 2.4Ghz and/or 900Ghz?  Still a very cool idea for interference reduction, especially in that crowded space.

I'm assuming that in order to use something other than a legitimate DECT transmission within the 1.9GHz space would require approval from the FCC for a completely new use of that spectrum; something i am also assuming is slightly less likely than a sudden outbreak of aeronautical swine...

This is not up to the FCC.  DECT standard is an international standard and cannot be substantially altered.  Advanced digital processing, both on the RF side and AF side is the only solution to make it work.  Possibly Riedel has solved it but I have not actually tried their system yet.
Logged
Pete Erskine
917-750-1134
www.bestaudio.com
peter@bestaudio.com

brian maddox

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1865
  • HeyYahWon! ttsss! ttsss!
Re: Clearcom Freespeak II antenna sheilding improves audio.
« Reply #23 on: April 26, 2017, 07:37:30 pm »

This is not up to the FCC.  DECT standard is an international standard and cannot be substantially altered.  Advanced digital processing, both on the RF side and AF side is the only solution to make it work.  Possibly Riedel has solved it but I have not actually tried their system yet.

So in order to alter DECT basically Old McDonald's entire farm would have to go airborne first.  Understood...  :)
Logged
brian maddox
bdmaudio@gmail.com

'...do not trifle with the affairs of dragons...

       ....for you are crunchy, and taste good with ketchup...'

Chris Johnson [UK]

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 446
Re: Clearcom Freespeak II antenna sheilding improves audio.
« Reply #24 on: May 04, 2017, 05:44:10 am »

This is not up to the FCC.  DECT standard is an international standard and cannot be substantially altered.  Advanced digital processing, both on the RF side and AF side is the only solution to make it work.  Possibly Riedel has solved it but I have not actually tried their system yet.

You'll get your chance soon, no doubt.

But yes, this is the key, and something we've spent years looking at.

Interestingly, this is something that makers of mobile phones implicitly understand and they have been dealing with this for a lot longer than us lowly comms folk! If you think the multipath issues are bad getting 50m to your DECT antenna, wait until you try and go 250m to the nearest cell tower...
Logged
Riedel Communications

David Cheramie

  • Newbie
  • *
  • Offline Offline
  • Posts: 1
Re: Clearcom Freespeak II antenna sheilding improves audio.
« Reply #25 on: February 12, 2018, 09:53:19 am »

These BBQ Pizza trays eliminated the fluttering we got when initially setting up here at the UNLV Thomas & Mack Center.  The roof here is a dome and, while not excessively high, does reflect back down to the floor all RF.  The aluminum screen is not grounded, just mounted above the antenna.  I'm thinking about suspending another 8" below to make essentially a doughnut pattern and keep reflections from going down when the antenna is mounted higher than 20' from floor.  The fluttering mostly would have gone away once an audience fills the arena but on this show there is virtually no audience -- most of the stadium is empty.



Hello, I am going to set up a Freespeak II system in NRG stadium for a large event in March, All I need is coverage around the stage and surrounding floor area.  The Stage moves to the center of the arena for the performance.  Should I place these ants possibly under the Metal stage?  We will still have BTR and RAD there for other facets of the show and I want to do some experimentation.  Any hints are certainly appreciated.

Thanks,

DC
« Last Edit: February 12, 2018, 12:03:37 pm by Mac Kerr »
Logged

Collin Donohue

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 80
Re: Clearcom Freespeak II antenna sheilding improves audio.
« Reply #26 on: June 08, 2018, 02:29:00 pm »

Just a quick little revival to this thread... I'm curious if anyone has tried putting antennas up near the ceiling of an arena?  In other words, if given access to catwalks in an arena, would putting the antennas within 20-30' of the ceiling in a venue with a 120' ceiling do any good?  Yes, there is real potential for signal loss just due to the distance, but would putting the antennas as close to the ceiling as possible be a solution?  We have a show in a few months where I'd much rather use our FS2 system, rather than wrangle 4 BTR systems.  We've got a couple of network switches with fiber modules, so using house fiber to get the signal up there shouldn't be an issue... at this point it's just a matter of reducing the reflection issues.

So... antennas approximately 100' up, approximately 120' ceiling, and all users on the floor.

Thoughts?
Logged

Mac Kerr

  • Old enough to know better
  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 6208
  • Audio Plumber
Re: Clearcom Freespeak II antenna sheilding improves audio.
« Reply #27 on: June 08, 2018, 02:43:33 pm »

We've got a couple of network switches with fiber modules, so using house fiber to get the signal up there shouldn't be an issue...

Will FS transceivers work through a network switch? My understanding is that they will not.

Mac
Logged

Henry Cohen

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 812
  • Westchester Co., NY, USA
Re: Clearcom Freespeak II antenna sheilding improves audio.
« Reply #28 on: June 08, 2018, 03:26:10 pm »

Will FS transceivers work through a network switch? My understanding is that they will not.

Correct; the currently shipping FSII transceiver is not IP and will not work with Ethernet equipment. The new IP transceiver will work over standard Ethernet switches but requires the IVC-32 card and an Eclipse HX frame. Should be shipping in the very near future.
Logged
Henry Cohen

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

Pete Erskine

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1201
    • Best Audio
Re: Clearcom Freespeak II antenna sheilding improves audio.
« Reply #29 on: June 08, 2018, 10:07:42 pm »

Just a quick little revival to this thread... I'm curious if anyone has tried putting antennas up near the ceiling of an arena?  In other words, if given access to catwalks in an arena, would putting the antennas within 20-30' of the ceiling in a venue with a 120' ceiling do any good?  Yes, there is real potential for signal loss just due to the distance, but would putting the antennas as close to the ceiling as possible be a solution?  We have a show in a few months where I'd much rather use our FS2 system, rather than wrangle 4 BTR systems.  We've got a couple of network switches with fiber modules, so using house fiber to get the signal up there shouldn't be an issue... at this point it's just a matter of reducing the reflection issues.

So... antennas approximately 100' up, approximately 120' ceiling, and all users on the floor.

Thoughts?

We tried ceiling antennas in a venue with bad multipath.  Made no difference because now the signal was bouncing off of the floor,  For venues with slight dropped packets the new firmware V1.07 is truly magic.  Even in good venues people talking while moving are jittery... this 1.07 fixes that totally.

The firmware is not officially released.


For fiber remote antennas use a combination of 2 media converters. The antenna connection is not actually only network-it is a combination of network and 422 data. 

Using this kluge of media converters you can remote antennas over fiber..

Another way:
Using FSII-SPL splitters you can use 2 splitters and split the 5 antennas between two locations.  Cat5 to 1st FS-SPL (outputs 1-2-3-4 turned on) and fiber to second FSII-SPL (only output 5 turned on)





« Last Edit: June 08, 2018, 10:15:52 pm by Pete Erskine »
Logged
Pete Erskine
917-750-1134
www.bestaudio.com
peter@bestaudio.com
Pages: 1 2 [3]   Go Up
 


Page created in 0.034 seconds with 18 queries.