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First experience with Zaxcom qrx200 wide band RX


RadoStefanov
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If the QRX100 were in dual mode you would have a 4 dB difference to the QRX200 in dual mode. If you did your test in a high RF noise environment the difference would be negated by the noise.

 

The Difference in performance is up to 12 dB in the right environment.

 

Glenn

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If the QRX100 were in dual mode you would have a 4 dB difference to the QRX200 in dual mode. If you did your test in a high RF noise environment the difference would be negated by the noise.

 

The Difference in performance is up to 12 dB in the right environment.

 

Glenn

Ok,  i'll keep testing in more environments. 

 

the 100 and 200 were both in single mode.  I tried the 200 in dual and single.  Based on the scan it's not a very high traffic area.  

Are you using XR modulation? I saw a significant range increase.

Yeh XR modulation yep. 

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whip antennas ?

Yes the whips. 

 

I'm just curious as i'm sure there is an increase in DB's between 100 and 200,  but it was just odd that they would drop out within a few feet of each other...  both approx 150ft from the transmitter.  Going to do a bunch of tests. 

I was expecting an extra 100ft with the 200... hopefully my testing is just in it's infancy and i'm doing something stupid.

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Yes the whips.

I'm just curious as i'm sure there is an increase in DB's between 100 and 200, but it was just odd that they would drop out within a few feet of each other... both approx 150ft from the transmitter. Going to do a bunch of tests.

I was expecting an extra 100ft with the 200... hopefully my testing is just in it's infancy and i'm doing something stupid.

In single mode I find the real world performance of a qrx100 to be similar to a qrx200, regardless of antenna.

In dual mode I find the performance of the qrx200 to be much better than the qrx100.

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In single mode I find the real world performance of a qrx100 to be similar to a qrx200, regardless of antenna.

In dual mode I find the performance of the qrx200 to be much better than the qrx100.

Ok good to know, 

 

Their first video ads gave me the impression that the range would increase substantially.  Personally i'm seeing very similar 'range' between the two in single or dual modes.    

 

I was shooting in waikiki today,  I was able to compare same frequency between 100 and 200,  both on single and I was getting maybe 10 feet more with the 200.  I don't use the mic plexor, will have one soon.

 

But having 20-23 for the tx's is great.  

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  • 2 months later...

Hi, guys. I've just bought a QRX200 and a couple of TRXLA2.5.

There are a couple of questions I have. I searched throughout the web and different forums trying to find the answers, because they are quite basic matters, but I couldn't find any. If this questions have been covered somewhere else, please accept my apologies and I will appreciate to be directed there.

So, the questions are:

- Is there a way to check battery status of the receiver? I think this is a very basic feature, and kind of capital when you are in a bag/portable situation, but I couldn't find it.

- Also, couldn't find the output level gain setting. It says "-10 o 0dB line level" for analog output in the specifications, but so far is a fixed setting for me.

 

Apart from these questions, there are three design decisions that surprised me: Why is the mic power voltage so low compared to other manufacturers? Why there is no internal power option? since both the 235 and 200 are not marketed as specifically as "camera receivers" I find this very strange, but of course I understand there must be a reason. And finally, why 32k for the AES output? it is a very strange choice for pro audio.

 

Best regards to all!

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This will disappoint, but:

No power measurement on RX. The hardware doesn't support it.

No output level setting. Don't know why. Nomad is the same and I don't have a good reason for it.

Mic voltage: not sure why, but in terms of sound quality, I find the Zaxcom units comparable, though noise is slightly higher than I imagine it *could* be, it's beyond usable and the other sound issues that lavs face: clothing, rubbing, wind, etc dwarf the hiss that's there. You'll just have to live with it. Battery life is a possible design decision for a lower voltage. Requiring Lithiums already, I stay with 50mw when I have to with reality shows to maintain battery life. Not sure I'd give up the battery life for better sound. Maybe better range, but that's what 125mw is for.

No internal power: duno but I wouldn't want a bag RX any bigger than it already is. Would be very useful though. 2x 9Vs are not recommended due to the unit's power needs, not sure how an AA internal solution would fare. Either way it's not there. If that's a concern, there are smaller and better internal battery camera hop solutions available (and coming). The only solution available is what folks are already doing - rigging a L mount or similar battery to the outside of the unit.

32khz, not sure why but for voice it doesn't matter. If that's the sacrifice that gets made for bandwidth, data throughput, range, or any number of factors, I'm sure it's a decent place to sacrifice. Not much happening in lav land above 16khz. If someone rolled off my lav around 12 or so I doubt I'd notice or if anything it would get rid of some of that aforementioned hiss.

Remember these are wireless (mostly for) voice transmission units. They aren't a hardline solution as advertised, but in the portable wireless world, they are quality-wise some of the best. Perfect would be nice but all the designers have to make many many trades with your best interest in mind. I trust that Zaxcom is making a ton of the hard decisions with sound quality taking a VERY high place in line. It's in their makeup.

Fortunately there are a ton of tools from various manufacturers with all sorts of things in mind - signal stability, range, flexibility, robust construction, price, etc. Pick the mix that suits.

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There is no voltage reading in the receiver.  Since there is no internal battery (there is not enough space), voltage should be monitored externally at the power source.

There is no output level controls.  Line level or AES. 

RScott, the Nomad output levels are set in the ENG > Output levels menu.  0db, -10db, -35 db.

The mic voltage level is sufficient for most lav's on the market, and battery life was a factor in that compromise.

The digital wireless transmission operates at a sample rate of 32khz, I believe (although I haven't verified this) is why the AES output is the same.  There is now an option for a higher AES sample rate in the extended menu.

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Yer, Wandering Ear. I noticed the 96k option. It makes it even more weird not to have an intermediate 48k option, which would be standard. I guess the guys at Zaxcom for sure have their reasons.

Thank you both for the answers. My fears were confirmed, but I'm sure when I go out on the field with the gear, the purchase will prove solid. That's all that matters after all.

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It's a shame for me with the 742 especially,  since it's dealing with boom mics / stereo setups,  that it can't record at least to the internal card at 44100 / 20khz at least as an option,  wouldn't have been hard to implement this.  every cheap recorder these days has at least that.  For ambience recording,  I planned on using the 742 / 2x8040 in a stereo blimp.  But the cutoff at 16khz is unacceptable for that kind of work.

 

Lavaliers and narrative I could care less, but ambience,  would have made a really portable rig for big hikes etc. (that coudl be monitored via erx.

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Question: why would you want to use a wireless setup, even a Zaxcom setup with amazingly good sound, to record ambience? Why not direct cabled to your recorder?

I think he wants to use the 742 as a 2 channel recorder without the wireless, and it works quite well for this. For comparable size/weight I'd rather use the 742 than a zoom or similar.

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Thanks, Wandering Ear, I never thought of that use of the 742 as a standalone recorder.

It's especially effective since the addition of a menu item that allows you to turn of the rf section (on all zax transmitters), as well as the ability to send confidence audio to an erx. I've carried a 742, erx, and a MS schoeps rig on backpack trips into the mountains to get forest recordings.

Since the wireless transmission runs at 32khz, and the processing power is limited it makes sense that the unit can only operate at one sample rate. I'm not sure if this is a hardware limitation in the ad's (and anti-aliasing filter) or just a configuration choice. However this is not the intended use of the 742, it just happens to work well for it.

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The QRX200 also has a lower line output level than the RX900 receivers. However, it's sufficient to feed any mixer worthy of being considered professional.

This is interesting because I found the line level of my QRX100 to be almost as hot as my mixer output at line whereas with the old black stereo receiver line level was often too low to feed cameras at line setting.

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Question: why would you want to use a wireless setup, even a Zaxcom setup with amazingly good sound, to record ambience? Why not direct cabled to your recorder?

 

I think he wants to use the 742 as a 2 channel recorder without the wireless, and it works quite well for this. For comparable size/weight I'd rather use the 742 than a zoom or similar.

 

Yes exactly,  

Standalone,  they ought to have (maybe they still can with Howie?)   adjusted the menu to make standalone recordings at 44100 or higher...   If Wireless is disabled.   I think it would be a raging hit...  

742 + ERX  would be a great portable ambience recorder.      If it's possible,  I think it would help sell them.  32khz puts off the purist.  Not that i'm a purist, but ambience definately is neccessary I think to reach 20khz.    Glen,  Love you guys,  if it's possible,  please, please, please.

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It's especially effective since the addition of a menu item that allows you to turn of the rf section (on all zax transmitters), as well as the ability to send confidence audio to an erx. I've carried a 742, erx, and a MS schoeps rig on backpack trips into the mountains to get forest recordings.

Since the wireless transmission runs at 32khz, and the processing power is limited it makes sense that the unit can only operate at one sample rate. I'm not sure if this is a hardware limitation in the ad's (and anti-aliasing filter) or just a configuration choice. However this is not the intended use of the 742, it just happens to work well for it.

That's awsome,  that's exactly what I would like to do,  with two 8040's in a cinela zephyx ORTF rig. 

 

My guess is that if wireless processing is turned off,  it could be possible,  i'm guessing the a/d chip is good to go.  Wireless at 44100 was obviously not really possible, and i'm totally happy with their wireless sound,  it's fantastic.  

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That's awsome, that's exactly what I would like to do, with two 8040's in a cinela zephyx ORTF rig.

My guess is that if wireless processing is turned off, it could be possible, i'm guessing the a/d chip is good to go. Wireless at 44100 was obviously not really possible, and i'm totally happy with their wireless sound, it's fantastic.

If it's possible via software, I'd recommend 48k, but I don't want to presume what is and isn't possible since I don't know. I will say that even with the current sample rate, the 742 sounds a lot better than any of the similarly sized recorders I've tested. Most of them are consumer grade, and their self noise is high enough to completely mask any ambient content at that frequency range.

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