ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1] 2  All   Go Down

Author Topic: Wireless analog point-to-point: oddity in the specs  (Read 3203 times)

Joseph D. Macry

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 420
  • Austin TX
Wireless analog point-to-point: oddity in the specs
« on: December 04, 2015, 10:03:00 am »

I've been considering using Listen Technology's assistive listening components to do point-to-point audio. Specifically purpose is to send a mix from a portable audio cart into an installed system in a Gym. There are no mic/line jacks so trying a wireless solution that is cheaper than Shure P9T-to-UR4+.

The oddity: Listen Tech's LT-800 transmitter and LR-100 receiver are available in 72MHz and 216MHz varieties. I assumed the 216MHz would have better specs. BUT: frequency response specs say
216 MHz - 60Hz to 10KHz (+/-3dB)
72 MHz - 50Hz to 15KHz (+/-3dB)

Whadya make of that?

Link to transmitter: http://www.listentech.com/shop/product/stationary-rf-transmitter-72mhz/
Logged
Joseph Macry,
Austin, TX

Scott Helmke

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1410
Re: Wireless analog point-to-point: oddity in the specs
« Reply #1 on: December 04, 2015, 10:17:51 am »

Neither one is going to sound especially hifi - emphasis is on low cost and reliability, not sound quality. 
Logged

John Sulek

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 421
  • Toronto Canada
Re: Wireless analog point-to-point: oddity in the specs
« Reply #2 on: December 04, 2015, 10:24:07 am »

I've been considering using Listen Technology's assistive listening components to do point-to-point audio. Specifically purpose is to send a mix from a portable audio cart into an installed system in a Gym. There are no mic/line jacks so trying a wireless solution that is cheaper than Shure P9T-to-UR4+.

The oddity: Listen Tech's LT-800 transmitter and LR-100 receiver are available in 72MHz and 216MHz varieties. I assumed the 216MHz would have better specs. BUT: frequency response specs say
216 MHz - 60Hz to 10KHz (+/-3dB)
72 MHz - 50Hz to 15KHz (+/-3dB)

Whadya make of that?

Link to transmitter: http://www.listentech.com/shop/product/stationary-rf-transmitter-72mhz/
more deviation allowed in the fm band would be first guess
Logged

Tim McCulloch

  • SR Forums
  • Hero Member
  • *
  • Offline Offline
  • Posts: 20516
  • Wichita, Kansas USA
Re: Wireless analog point-to-point: oddity in the specs
« Reply #3 on: December 04, 2015, 12:04:57 pm »

I'd contact Listen and ask them.  As to any technical reasons, I'll leave that to Henry or the manufacturer but I'd guess that for listening assistance bottom and top octaves can be sacrificial as they don't significantly contribute to intelligibility.
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

David Sturzenbecher

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1614
  • So. Dak.
    • Sturz Audio
Re: Wireless analog point-to-point: oddity in the specs
« Reply #4 on: December 04, 2015, 12:08:02 pm »

I am pretty sure what you are trying to do is also illegal. Those frequency bands are specially reserved for ADA hearing assistance. Proceed with caution.


Sent from my iPhone using Tapatalk
Logged
Audio Systems Design Engineer
Daktronics, Inc.
CTS-D, CTS-I
AES Full Member

Joseph D. Macry

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 420
  • Austin TX
Re: Wireless analog point-to-point: oddity in the specs
« Reply #5 on: December 04, 2015, 12:53:08 pm »

I am pretty sure what you are trying to do is also illegal. Those frequency bands are specially reserved for ADA hearing assistance. Proceed with caution.


Sent from my iPhone using Tapatalk

Interesting thought, David. Must look into that.
Logged
Joseph Macry,
Austin, TX

Tim McCulloch

  • SR Forums
  • Hero Member
  • *
  • Offline Offline
  • Posts: 20516
  • Wichita, Kansas USA
Re: Wireless analog point-to-point: oddity in the specs
« Reply #6 on: December 04, 2015, 04:25:22 pm »

I am pretty sure what you are trying to do is also illegal. Those frequency bands are specially reserved for ADA hearing assistance. Proceed with caution.


Sent from my iPhone using Tapatalk

Have receivers available for the intended use. So long as signal distributed contains the full program  I don't think the subsequent additional use infringes on the assistance.
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

Cailen Waddell

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1428
Re: Wireless analog point-to-point: oddity in the specs
« Reply #7 on: December 04, 2015, 06:35:04 pm »


Have receivers available for the intended use. So long as signal distributed contains the full program  I don't think the subsequent additional use infringes on the assistance.

We use our assisted listening receivers with a small powered speaker when odd rooms become dressing or production offices at our PAC.  That said, there are laws about the minimum percentage of receivers required to be available vs number of seats - if you pull receivers in a system and don't have the minimum available you could open yourself to liability (unlikely) if you ran out of receivers. 


Sent from my iPhone using Tapatalk
Logged

Keith Broughton

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 3167
  • Toronto
Re: Wireless analog point-to-point: oddity in the specs
« Reply #8 on: December 05, 2015, 08:55:24 am »

I've been considering using Listen Technology's assistive listening components to do point-to-point audio. Specifically purpose is to send a mix from a portable audio cart into an installed system in a Gym. There are no mic/line jacks so trying a wireless solution that is cheaper than Shure P9T-to-UR4+.

The oddity: Listen Tech's LT-800 transmitter and LR-100 receiver are available in 72MHz and 216MHz varieties. I assumed the 216MHz would have better specs. BUT: frequency response specs say
216 MHz - 60Hz to 10KHz (+/-3dB)
72 MHz - 50Hz to 15KHz (+/-3dB)

Whadya make of that?

Link to transmitter: http://www.listentech.com/shop/product/stationary-rf-transmitter-72mhz/
You are sending the sound to a GYM  :o ...what difference are those relatively minor differences going to really make?
Logged
I don't care enough to be apathetic

Henry Cohen

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 915
  • Westchester Co., NY, USA
Re: Wireless analog point-to-point: oddity in the specs
« Reply #9 on: December 05, 2015, 12:47:34 pm »

I've been considering using Listen Technology's assistive listening components to do point-to-point audio. Specifically purpose is to send a mix from a portable audio cart into an installed system in a Gym. There are no mic/line jacks so trying a wireless solution that is cheaper than Shure P9T-to-UR4+.

The oddity: Listen Tech's LT-800 transmitter and LR-100 receiver are available in 72MHz and 216MHz varieties. I assumed the 216MHz would have better specs. BUT: frequency response specs say
216 MHz - 60Hz to 10KHz (+/-3dB)
72 MHz - 50Hz to 15KHz (+/-3dB)

Whadya make of that?

It's a result of FCC rules regarding occupied channel bandwidth limits. More band width for deviation is (was, actually, as only legacy certified products can still be manufactured in 72MHz IIRC) available for 72MHz systems compared to newer 216MHz systems. Since these assisted listening products are manufactured under the permitted use rules for "auditory assistance communications" ( 47CFR Part 95.1009(a) ), it's only the voice frequency range that's of interest, thus the narrower frequency band.
Logged
Henry Cohen

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

ProSoundWeb Community

Re: Wireless analog point-to-point: oddity in the specs
« Reply #9 on: December 05, 2015, 12:47:34 pm »


Pages: [1] 2  All   Go Up
 



Page created in 0.049 seconds with 24 queries.