digital wireless?

sporkme

sporkme

Member
Hi all,

I'm starting to look a bit at a wireless lav system. So far, one thing is really shocking to me, and that is that pretty much all the systems I've seen (even the more expensive ones) are all analog.

What's the deal with that? I can see old-timers poo-pooing new technology and all, but in every other new field where you have to get audio from point A to point B, digital is the way to go. Beyond the issue of having better sound quality, you've got overall a more robust signal and better range with stuff like spread-spectrum systems.

Is this just something where this entire field is behind the curve? Are the current vendors in some kind of rut? Is there a fear of new technology amongst old audio hands?

Or am I just dumb and missing something really obvious?
 
Re: digital wireless?

[quote author=oleg link=board=audio;num=1105208012;start=0#1 date=01/08/05 at 10:38:48]
just remmember that the zaxcom worth more then dvx - so there is your unswer :-)[/quote]

It's just odd. From a cost perspective a digital system should be cheaper to engineer. Take a consumer example, the cordless phone. Even my 6 year old Uniden 900MHz model is digital spread spectrum. It cost me $60 at the time. If Uniden were to try to engineer an analog phone with the same range, sound quality, and robustness in a crowded chunk of spectrum that phone would have cost me at least $500.

I guess my point is, good analog is hard to engineer. With wi-fi and all the other wireless stuff being engineered in such high volumes these days it seems quite odd that this particular market is so far behind the curve.

From the links you posted it seems like they don't really "get it". Both systems talked about simple cryptography as the main selling point when DSS brings so much more to the table than that odd little side-effect feature.

Anyone want to help me raise some capital? :)
 
Re: digital wireless?

1 when you ll have digital mikes it would be more cheap


2 good analog is alredy inside the systems

3 your cordless phone is about 500-5 khz spectrum- it sounds like you pay for - if they where selling less then 1000 units a year it was cost 1000$ for that toy , if zaxcom where selling 50000 a yar the price was less then 1000 per unit


4 the only better then my zaxcom is 50$ starquad wier

5 no you still didnt lern athing - continu :-)
 
Re: digital wireless?

1 when you ll have digital mikes it would be more cheap  
Click to expand...
DAC are very cheap, the most expensive, highly desired are analog to the max. The digital convert is cheap.

3 your cordless phone is about 500-5 khz spectrum- it sounds like you pay for  - if they where selling less then 1000 units a year it was cost 1000$ for that toy , if zaxcom where selling 50000 a yar the price was less then 1000 per unit
Click to expand...

Standard phone uses a 4Khz spec, its nothing but serves its purposes. Wifi uses a 2.4Ghz band its unregulated so its get stomped. Honestly, its should work, take a PDA with Wifi, theory wise should be able to push a 24-bit/96 kHz stream. The receiver will probably not be battery powered.
 
 
Re: digital wireless?

Why don't they make digital wireless mics...you got me...it most likely doesn't seem to be profitable at this time?...I don't know...companies do weird things. I spent years consulting organizations, execs.... & it's a mystery why they do the things they do....and they don't do the obvious!
 
Re: digital wireless?

thinking about again, using Wifi tcpip would require buffering of some type, timecode etc. You will lose packets. Also, it would no longer be rec/trans, it would be client/server and both would need to rec & transmit. So, transmitters which are currently small, lower would require more power. Current in these wireless system, the transmitter takes the audio from the mic and sends, thats it. Rec catches, in wifi, each would need to do both. There are power consideration too.
 
Re: digital wireless?

Okay...to clear this up.

Zaxcom does make a digital wireless system. Several actually...and they range in price from $3200 - $3500. These actually transmit a digital signal.

The Lectro 400 series is NOT a digital system. It is a digital hybrid system. It still transmits an analog signal.

Your "digital" phone is by no means digital. It still transmits an analog signal. Getting a fully digital system to work is extremely difficult. When Zaxcom announced a that they were going to make a fully digital system a few years ago, they were told it was impossible. They are now making and selling tons of these units worldwide.

-Dave
 
Re: digital wireless?

Your "digital" phone is by no means digital. It still transmits an analog signal. Getting a fully digital system to work is extremely difficult. When Zaxcom announced a that they were going to make a fully digital system a few years ago, they were told it was impossible. They are now making and selling tons of these units worldwide.
Click to expand...

digital phones are digital, there's even a standard. Though its probably sample at something like 11khz. The carrier is always analog, the digital signal is just modulated in countless ways. The problems with making digital transmitters probably have more to do with the FCC, than anything else. With phone freq range is 4k, for wireless audio you want to 20-20k at 48k, big difference. Digital phones and wifi use very high less trafficked bands to avoid interference. Making wireless work on squatted freqs in congested band, thats hard too.
 
Re: digital wireless?

If someting transmits an analog signal, then it's not really digital. It may have some digital dsp in it...for example, my phone has "digital voice enhancement"..whatever that means, but it still transmits an analog signal.

Besides..phones sound like crap anyway.

-Dave
 
Re: digital wireless?

[quote author=Dave_Fisk link=board=audio;num=1105208012;start=0#11 date=01/10/05 at 10:03:30]If someting transmits an analog signal, then it's not really digital.[/quote]

You're not going find a "pure" digital transmission outside of an old spark-gap transmitter sending morse code. Not in that sense, anyway. :-)

It's all going out modulated on some sort of "analog" carrier. PCM, PSK, BPSK, QPSK...I think there's even a 3PSK...but I may have made that up.

And then, if you want the signal to arrive in pristine condition, you have to do some encoding like 3/4 Viterbi.

Oh, my. I think I could even remember how to figure EbNo and C/N & C/kT and....after 11 years of that, no wonder I changed jobs. ;)

Dan
 
Re: digital wireless?

Right, but the difference between the Zaxcom digital wireless, and all the other wireless out there, whether it be Lectros, Sennheiser, or your phone, is that the Zaxcom wireless actually have a digital bitstream flying through the air. Lectro 411's transmit the same way the 211's and any other normal analog system does.

I've been down this "what is really digital wireless" argument before, and quite honestly, it's an exercise in futility. What matters is...what works best for you within your budget. Even though Lectro 411's aren't "true" digital wireless, they sound damn good, and work really well, and are probably the most recommended and used professional wireless out there.


-Dave
 
Re: digital wireless?

Right. I know the 700's are, but the reciever is a big rack mount reciever.

People were talking about phones being digital, which they aren't.
 
Re: digital wireless?

[quote author=GenJerDan link=board=audio;num=1105208012;start=0#12 date=01/10/05 at 10:43:22]

You're not going find a "pure" digital transmission outside of an old spark-gap transmitter sending morse code.  Not in that sense, anyway.  :-)

It's all going out modulated on some sort of "analog" carrier.  PCM, PSK, BPSK, QPSK...I think there's even a 3PSK...but I may have made that up.
[/quote]

Thanks for the reality injection. :) I'll also note that the "all digital" Zaxcom deal is most likely doing the same, 'cuz that's how it is. I hope their marketing strategy isn't revolving around some new way of moving rf pulses through the air that doesn't involve a carrier. :)

Yes, the phone is transmitting digitally-encoded audio to the base and vice-versa, regardless of the type of modulation. And more importantly if you took a phone that was analog and ran it on the same frequency in the same area, you'd want to throw it in the trash.

My intent was to compare a consumer market device and it's growth over the years to a professional device, just to see if anyone knew the logic behind the "pro" gear still being solidly in the "analog" camp.

I think we can agree it's not an engineering miracle - A/D and D/A conversion isn't magic these days. And it seems many of the current modulation methods used in some very cheap devices are very robust - the spread-spectrum stuff and the frequency-hopping techniques work amazingly well with crap electronics and no diversity antenna setups.
 
Re: digital wireless?

Right, but they don't work well enough, or sound good enough to work for production sound. When people get into the nitty gritty of wireless and all that jazz, it gets beyond me. If the Zaxcom digital wireless, or the Lectro 411's worked as reliably as a cell phone, every one of my customers would be out of a job.

-Dave
 
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