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[Mac Kerr]

Shure has leveraged the DECT spec to attempt something similar to what you are describing with the MicroFlex Series which combine RF mic transmitters [beltpacks, handhelds, etc.] with mono receivers [each of the transmitters has a mono 1/8" output on it].  It works.  But it does NOT sound as good as true professional RF systems.  I worked with a company that bought a bunch of this instead of more traditional RF systems and tried to use them in a production environment with mixed results at best.  I'm sure they work swimmingly in installed conference systems, which is what they are designed for.  But they don't hold up in critical listening situations.

Any word on additional latency due to the network audio distribution model on both the send and receive with DECT?  We don't notice it on comms, where FSII sounds pretty good, and Bolero sounds better, but we can turn down the side tone. IEM use would be turning up the return.

Mac

[Henry Cohen]

Well, bummer. That sucks. And is stupid.

Bummer, yes. Stupid? Depends on your perspective. From that of the OEM's, it's likely not seen as a high enough sales volume product to justify the R&D and tooling at this time. But if demand grows, someone will no doubt attempt to fulfill the niche.

[Henry Cohen]

Any word on additional latency due to the network audio distribution model on both the send and receive with DECT?  We don't notice it on comms, where FSII sounds pretty good, and Bolero sounds better, but we can turn down the side tone. IEM use would be turning up the return.

FSII, Bolero and Roameo sidetone is generated locally in the pack, so there's only AD/DA conversion latency involved (pretty minimal these days), no TDMA RF.

[Scott Holtzman]

Not a RF guru, but I would expect having receiving antennae that close to a transmitter would be a serious engineering challenge....
Never mind separation of the radios in the beltpack.
Chis.

Actually with a few Mhz of separation a transmitter and a receiver can share the same antenna.  The device is called a duplexer and very common in commercial radio systems.

In a digital system you simply turn the transmitter on and off, buffer  bit of data then transmit again.  The latency is manageable and improves as bandwidth is increased and more data can be transmitted per frame.

[Chris Hindle]

Actually with a few Mhz of separation a transmitter and a receiver can share the same antenna.  The device is called a duplexer and very common in commercial radio systems.

In a digital system you simply turn the transmitter on and off, buffer  bit of data then transmit again.  The latency is manageable and improves as bandwidth is increased and more data can be transmitted per frame.

Thanks for the info Scott.
My radio "knowledge" comes from quite a while back in the last century.
So, it is a real possibility if someone will pony up the $$ to make it happen.
It would be quite convenient to a lot of performers....
Chris.

[Jason Glass]

Actually with a few Mhz of separation a transmitter and a receiver can share the same antenna.  The device is called a duplexer and very common in commercial radio systems.

In a digital system you simply turn the transmitter on and off, buffer  bit of data then transmit again.  The latency is manageable and improves as bandwidth is increased and more data can be transmitted per frame.

IMHO, this is what most high end RF mic and IEM systems will look like in the not too distant future.  Similar to Freespeak and Bolero, where all devices are wirelessly connected to one network and audio data can flow from any point to any point.  The devices can be input, output, both, and likely even multichannel.

Sent from my mobile phone using Tapatalk

[Tim McCulloch]

Actually with a few Mhz of separation a transmitter and a receiver can share the same antenna.  The device is called a duplexer and very common in commercial radio systems.

In a digital system you simply turn the transmitter on and off, buffer  bit of data then transmit again.  The latency is manageable and improves as bandwidth is increased and more data can be transmitted per frame.

Even at 500mHz a resonant tank duplexer would be like carrying a small SCUBA tank on your back.

[brian maddox]

Any word on additional latency due to the network audio distribution model on both the send and receive with DECT?  We don't notice it on comms, where FSII sounds pretty good, and Bolero sounds better, but we can turn down the side tone. IEM use would be turning up the return.

Mac

When i used these, it was a typical broadcast situations, so a Lav and an IFB.  In that situation, because the IFB doesn't seal the ear if i dialed the Lav back into the IFB you could 'hear' the latency but it wasn't a huge deal.  But testing the things out with headphones sounded pretty weird.

I don't know what the actual latency is on these devices.  But even if the audio quality was sufficient [and it is admittedly pretty close], the latency is too much to be usable for an IEM situation.

[Pete Erskine]

FSII, Bolero and Roameo sidetone is generated locally in the pack, so there's only AD/DA conversion latency involved (pretty minimal these days), no TDMA RF.

there is an existing wireless mic using tdma with extremely low latency (<3ms worst case) which could do bidirectional communication.  Because of the mechanics of the system the return leg would be very low bandwidth and not suitable as an IEM but maybe as an IFB.

The system is Alteros and uses TDMA to put 24 channels of wireless mic with best audio quality on a single carrier network, albeit 500 MHz wide band width and extremely low power - way less than 1 mW.  so low that the entire carrier is lower than the normal noise floor.  Extremely specialized SAs are needed to see this carrier which is about 6 GHz center.

Alteros, particularly the husband wife engineering team, Jackie and Bob Green has said that the technology could do bidirectional with the limitations listed above.

Because of those limitations it will probably never be implemented.

that being said TDMA on a transceiver like Bolero/Freespeak/CrewCom might be tweaked to have barely acceptable music quality and latency...

Isn't it just easier just to put a TX on the left and a RX on right of the person?  why is that so objectionable?

[Tim McCulloch]

there is an existing wireless mic using tdma with extremely low latency (<3ms worst case) which could do bidirectional communication.  Because of the mechanics of the system the return leg would be very low bandwidth and not suitable as an IEM but maybe as an IFB.

The system is Alteros and uses TDMA to put 24 channels of wireless mic with best audio quality on a single carrier network, albeit 500 MHz wide band width and extremely low power - way less than 1 mW.  so low that the entire carrier is lower than the normal noise floor.  Extremely specialized SAs are needed to see this carrier which is about 6 GHz center.

Alteros, particularly the husband wife engineering team, Jackie and Bob Green has said that the technology could do bidirectional with the limitations listed above.

Because of those limitations it will probably never be implemented.

that being said TDMA on a transceiver like Bolero/Freespeak/CrewCom might be tweaked to have barely acceptable music quality and latency...

Isn't it just easier just to put a TX on the left and a RX on right of the person?  why is that so objectionable?

For the vast majority of entertainment uses, wireless is *unnecessary* from a number of angles.  Can wireless make things musically better?  No, but it can allow the performer to go places they might not otherwise go while playing.... but really, that's about it.  Wireless mics, wireless guitar, IEMs are all about *visual* stuff for the most part.  IOW, music does not inherently require that wires be eliminated.  Yes, there is a huge, very huge desire to cut the cords but it's typically an ego or psychological thing not based in either musical or technical necessity.

{optional repeat story}
A couple of years ago we provided for a RibFest gig where the "radio station band" (someone on their way up) insisted on loading the stage at 9am, pretty much pig-fucking the rest of the day and bands using the Showmobile.  So much stuff on stage the radio station emcees were given a 2 x 4 ft space in the extreme DSR corner and 2 SM58 on straight stands.  The promoter was the venue, and one of their people came up to me and wanted to know were the wireless mics were for the emcees.  "Why do they need wireless?  There is literally nowhere they can go on stage." "But, they're RADIO PEOPLE!" she exclaimed.  "Well if you really want wireless they're $100 each when ordered day of show, plus a $50 delivery charge, who is authorized to sign the change order?"  "$250 for wireless?"  "Yes, and you need to tell me NOW so I can have them delivered in time."  "Uh... never mind."

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