Wireless Line 6

[NHStech]

I was on a website of a particular retail company (not sure if I can mention, but if I can I will), and there are some rave reviews of Line 6 XD-V70 wireless microphones. They are a digital wireless and has a "WFX 2010 New products award winner" logo on it. Can anyone inform me the primary difference between analog and digital mics, and any thoughts on this particular mic if you have any experience with it?

 

[avkid]

1 and 0 instead of + and -
(only half joking)

Line 6 has published some pretty extensive information for consumers.
Frequently Asked Questions about XD-V Wireless Microphone Systems | Line 6

 

[FMEng]

Digital RF transmission generally has a few differences with analog. An analog system's performance will slowly degrade as the signal strength is reduced. Noise is the result of not enough signal, and interference can result in nasty noises from the receiver output.

With digital, the sound quality does not change with lowering signal strength, until it hits the point at which it just goes silent, with no warning at all. It's called the "cliff effect." Perfection or nothing. Interference also results in drop outs or silence. Some would argue that some noisy or imperfect audio is better than no audio. On the other hand, digital may stay solid under conditions when analog might be working badly. They both have their time and place.

Disclaimer: I have no experience with the product. The Line 6 stuff is a somewhat novel design approach, and the system appears to be well thought out. It wouldn't be the first time a small, creative company out did the big boys with something new and different. At least one reviewer like the product after a brief test.
Church Sound: Road Test: Line 6 XD-V70 Digital Wireless Microphones - Pro Sound Web

I am always very skeptical when a product claims high end performance at a low end price. The other thing that makes me curious is why they aren't offering these systems with some industry standard mic capsules. Their own capsule with some phony electronic modeling screams "junkie toy," deserved or not. No amount of modeling can make the mic's directional pattern and proximity effect change, or eliminate handling noise or plosives. Note to Line 6 marketing department: get real mic capsules if you want to be taken seriously. You can fit Shure and Heil capsules on them after purchase, but apparently you can't order them that way. The same problem with the belt pack version. A stellar RF system isn't much good if the acoustic parts aren't good. I'm not saying the mic capsules they offer are bad, just that they are unknowns.

 

[dboomer]

Can anyone inform me the primary difference between analog and digital mics

There's a pretty good explanation here ... http://line6.com/media/pdf/Line 6 Wireless microphones Whitepaper UK.pdf

The biggest difference is that digital systems broadcast "data" and not the analog signal itself.

The biggest difference between Line 6 digital and the way everybody else does it is that we have a patent (applied for) for broadcasting on multiple frequencies. That way we do not require a "clear channel" to operate on. It allows us to run in the license free 2.4 GHz ISM band and away from all the problems in the core TV bands.

Don Boomer
Wireless Sales Engineer
Line 6, Inc.

 

[metti]

Note to Line 6 marketing department: get real mic capsules if you want to be taken seriously. You can fit Shure and Heil capsules on them after purchase, but apparently you can't order them that way. The same problem with the belt pack version. A stellar RF system isn't much good if the acoustic parts aren't good. I'm not saying the mic capsules they offer are bad, just that they are unknowns.

+1 on this. I would like to see the bodypacks available without any element at all for a cheaper price so I could add in my own element (Countryman, DPA, etc) to meet my needs since I don't expect Line 6 to offer their bodypack with an element that costs almost as much as the entire wireless system itself.

I also seem to recall a discussion of the Line 6 stuff over on Pro Sound Web and the impressions there were generally pretty positive and, IMO, pretty trustworthy and unbiased.

 

[mbenonis]

Hi Don,
Thanks for posting here and welcome to ControlBooth! I just read over your guide, and I must say it's a pretty friendly introduction to wireless systems.

I was wondering if perhaps you could get the Engineering team at Line6 to post some more detailed specifications for your RF line of products. I looked at the specs, and I don't see anything regarding the third order intercept point, minimum detectible signal, emission type (as an emission designator, e.g. F3E75K0 for typical analog wireless mics), adjacent channel rejection, -1dB compression point, noise figure (for receivers), etc. It would be good to have these types of specifications so that your products can be more easily compared with other systems.

Feel free to contact me offline if you'd like.

Mike

 

[techno89]

what he said.

Hi Don,
Thanks for posting here and welcome to ControlBooth! I just read over your guide, and I must say it's a pretty friendly introduction to wireless systems.

I was wondering if perhaps you could get the Engineering team at Line6 to post some more detailed specifications for your RF line of products. I looked at the specs, and I don't see anything regarding the third order intercept point, minimum detectible signal, emission type (as an emission designator, e.g. F3E75K0 for typical analog wireless mics), adjacent channel rejection, -1dB compression point, noise figure (for receivers), etc. It would be good to have these types of specifications so that your products can be more easily compared with other systems.

Feel free to contact me offline if you'd like.

Mike

 

[museav]

Don's probably tired of hearing this from me, but I have some concerns about the future of wireless mics in the 2.4GHz band. What seems interesting to me is how "wireless microphones" operating in other spectrum may be viewed in relation to the FCC rulings and orders regarding unlicensed wireless microphones and WSD/TVBD in the UHF spectrum. Now that a 'home' and process for operating unlicensed wireless microphones and IEMs in the UHF spectrum and a relation to other 'secondary use' wireless communication devices in that spectrum has been defined, could that affect operation of wireless microphones as secondary use in other spectrum as well, such as the 2.4GHz ISM spectrum?

My concern is whether the situation might be interpreted such that "wireless microphones" must first use the 'safe harbor' UHF spectrum and other approaches for larger wireless users that have now been defined before allowing wireless microphones to operate in other spectrum. It seems that this could conceivably prevent wireless microphones from operating in the 2.4GHz band or might simply mean having to identify them as something else, just another wireless communication device and not specifically a wireless microphone. So I am wary of people purchasing 2.4GHz wireless microphone systems only to have them subsequently be prohibited. Has there been any analysis of how the FCC's ruling regarding VHF and UHF wireless microphones might conceivably impact wireless microphone or IEM systems operating in other bands?

 

[dboomer]

Hey Brad

I'm afraid the nobody can answer all the "what if's" ... but XD-V wireless are considered "data devices" to the FCC and not "wireless microphones", so we basically fall under the same rules as wi-fi devices.

 

[Chris15]

It is critically important to remember that if you are using IEM you may be faced with a significant issue in latency. It's generally accepted that 6ms is about as much latency as you can afford. Line 6 are claiming <4ms of latency which eats up 2/3 of your latency budget. Add a digital console and you're over the limit in most cases...

A personal thing, but I DON'T GET digital systems that don't provide digital I/O. Why make me go back into the analogue domain (with the noise issues and additional latency of D/A and A/D conversions)?

 

[bishopthomas]

I'm not much of a wireless tech, so please excuse me if I'm way off here, but.... What about implementing some sort of frequency hopping system in these 2.4 GHz digital devices? Wireless DMX does it, why wouldn't the same technology be useful for wireless microphones? Is 2.4 GHz the way to go? Isn't that shared with cordless phones, wireless routers, others(?)? With only 12 frequencies to select from on the Line 6 product, what happens when you have interference and you're actually USING a dozen of their microphones?

 

[museav]

One of the problems with applying some data solutions to audio is that latency which is acceptable in data transmission may not be acceptable in audio. However, I do wonder if the technology used by Line 6 for the 2.4GHz 'data device' systems could also be applied to approaching them as a portable TVBD with the same technology. There are certainly TVBD specific issues such as the database lookup, but I thought that the general goals behind portable TVBDs were very similar to those of portable devices and Wi-Fi.