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[Ike Zimbel]

Anyone had any experience with how the Sennheiser AVX 1.9GHz wireless  system coexists with 1.9GHz comms? Does it take up a time slot? If so, if you knew you had an AVX system in play, would that limit you to, say, 49 Bolero packs instead of 50 in one space?

[Russell Ault]

Anyone had any experience with how the Sennheiser AVX 1.9GHz wireless  system coexists with 1.9GHz comms? Does it take up a time slot? If so, if you knew you had an AVX system in play, would that limit you to, say, 49 Bolero packs instead of 50 in one space?

I have zero experience, but given that Sennheiser recommends no more than 8 simultaneous AVX systems in North America I'd guess that each TX-RX pair uses half the time slots in a single DECT channel, or 10% of the total North American DECT spectrum (I'm ASSuming that the recommended maximum is 8 and not 10 in order to leave ~20% of the spectrum vacant to accommodate AVX's opportunistic frequency hopping).

Put another way, I'd expect one AVX system to use the spectrum of at least 5 Bolero packs, but with the automatic frequency hopping I wouldn't be totally surprised if you had to knock a whole Bolero antenna offline in order to keep one AVX system happy (although at that point you might be able to run two of them).

-Russ

[Ike Zimbel]

I have zero experience, but given that Sennheiser recommends no more than 8 simultaneous AVX systems in North America I'd guess that each TX-RX pair uses half the time slots in a single DECT channel, or 10% of the total North American DECT spectrum (I'm ASSuming that the recommended maximum is 8 and not 10 in order to leave ~20% of the spectrum vacant to accommodate AVX's opportunistic frequency hopping).

Put another way, I'd expect one AVX system to use the spectrum of at least 5 Bolero packs, but with the automatic frequency hopping I wouldn't be totally surprised if you had to knock a whole Bolero antenna offline in order to keep one AVX system happy (although at that point you might be able to run two of them).

-Russ

Well, I have up to nine AVX systems in the building, and 33 Bolero packs and, so far, everyone plays nicely...

[Russell Ault]

Well, I have up to nine AVX systems in the building, and 33 Bolero packs and, so far, everyone plays nicely...

Huh. 9 AVX on its own is more than Sennheiser recommends (let alone everything else that's going on), so that's a surprise. Of course, I just ASSumed that you were in North American; are you over in Europe right now?

-Russ

[Ike Zimbel]

Huh. 9 AVX on its own is more than Sennheiser recommends (let alone everything else that's going on), so that's a surprise. Of course, I just ASSumed that you were in North American; are you over in Europe right now?

-Russ

No, this was at the Bell Center in Montreal. I'm not 100% sure how many were in use at any one time, and I know for a fact that at least a couple that were requested didn't actually show up because that crew's equipment was jacked out of a car before they flew to Montreal. This was, on the one hand, the craziest media check-in I have ever done, with 50+ crews in the building. On the other hand, I had received advance requests from about 85% of them and had returned them with coordinated frequencies. Of those, I'd say a solid 60% of the individual EFP crews, and 100% of the 10 EFP crews hired by the client showed up with their equipment already tuned and on frequency.
As for the AVX systems, in walking around the building, I saw several of them in use in various interview spaces along or adjacent to the perimeter ring. So I doubt that many of them were out on the floor were the bulk of the Bolero was deployed. I was remotely monitoring the DECT band from my cramped little corner near the entrance and I never noticed it getting particularly busy. So the answer to my question is either "it depends" or, "wear Depends (TM)", depending on how nervous you may be about this issue.

[Russell Ault]

No, this was at the Bell Center in Montreal. I'm not 100% sure how many were in use at any one time, and I know for a fact that at least a couple that were requested didn't actually show up because that crew's equipment was jacked out of a car before they flew to Montreal. This was, on the one hand, the craziest media check-in I have ever done, with 50+ crews in the building. On the other hand, I had received advance requests from about 85% of them and had returned them with coordinated frequencies. Of those, I'd say a solid 60% of the individual EFP crews, and 100% of the 10 EFP crews hired by the client showed up with their equipment already tuned and on frequency.
As for the AVX systems, in walking around the building, I saw several of them in use in various interview spaces along or adjacent to the perimeter ring. So I doubt that many of them were out on the floor were the bulk of the Bolero was deployed. I was remotely monitoring the DECT band from my cramped little corner near the entrance and I never noticed it getting particularly busy. So the answer to my question is either "it depends" or, "wear Depends (TM)", depending on how nervous you may be about this issue.

Yipes, that sounds nuts (but as you say, less nuts than it could have been). I can also absolutely see how "location-division multiple access" ("LDMA"?) might be particularly useful in DECT applications.

That said, I don't suppose any of the AVX systems were the European model, were they? (I suppose one way to keep spectrum clear for Bolero would be for international media to use illegal frequencies...  )

-Russ

[Tim Hite]

Anyone had any experience with how the Sennheiser AVX 1.9GHz wireless  system coexists with 1.9GHz comms? Does it take up a time slot? If so, if you knew you had an AVX system in play, would that limit you to, say, 49 Bolero packs instead of 50 in one space?

I use a bunch of AVX for rentals to DJs and DIYers such. In my experience with AVX, it's easily bumped off by Reidel coms or just about anything else in the DECT band. The AVX just stops working or won't link up. Generally my AVX stuff is going out to places where this isn't an issue.

Kelly Fair would be the dude I'd ask, since he's worked at both Sennheiser and Riedel (and now Lectrosonics)

That said, I don't suppose any of the AVX systems were the European model, were they? (I suppose one way to keep spectrum clear for Bolero would be for international media to use illegal frequencies...  )

-Russ

Did you mean "international frequencies"? 

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