Zaxcom QRX "dual mode" real-world performance?

[Derek H]

What Tx power are you guys running? 50mW or 125?

[nysounds]

I've been running 1 QRX in dual mode for a while with whips receiving two transmitters and had no trouble with dropouts or range.  Going digital to Nomad.  Running both transmitters on 50mW.  I'll be receiving another QRX tomorrow and a Micplexer so will report on that experience as soon as I get all up and running.  I also run a QRX as a stereo hop with great success.

[RadoStefanov]

Does anyone else think it's a bit off that you need to purchase the micplexer in addition to the QRX receivers for their performance to be 'close' to a 411?

Are you still talking about dual mode? You must be.

[James Arnold]

I've been pondering this too.

 

Almost all the local sound guys I know who have used them have very mixed feelings on their performance in dual mode with the regular whips in an 'in bag' situation (no Mic Plexer). I also spoke to a retailer who confirmed that this seems to be his customer response as well. The better performance seems to come via a cart rig and a full size aerial system.

 

As I'm a Nomad owner it would make sense to go Zaxcom on my wireless, but I need performance at least as good as Lectro SR. It's going to get pretty expensive if I need a Plexer as well as the units themselves to get near this.

 

Be interesting to see what Palmer discovers.

 

James

[RadoStefanov]

It comes to this:

In dual mode qrx100 is similar to SRa.

In single mode is similar to 411.

With micplexer and dipole/sharkfin antenna it has an amazing range.

 

Digital wireless is different beast.

Rent some and try them out.

The only way to be really sure.

People seam to have very strong opinions about zax vs lectro.

So try them yourself before you invest a lot of money...

[glenn]

 

The performance of the QRX in dual mode is 4 dB less than it is in Mono mode. In a quite RF environment the micplexer makes up for the 4 lost dB restoring the range of the dual mode to the equivlent of the single transmitter true diversity mode.

 

Range comparisons to other receivers that work in analog mode are very difficult due
to the influence of interfering signals and many RF parameters that just are
difficult to compare between the Zaxcom 100% digital system and our competitors 100%
analog system.

Two things I can always guarantee. Zaxcom wireless will always have the better
audio quality and Zaxcom wireless will always have a backup recording in the
transmitter. The latter seems to negate any range issue when used for
production work. In a world where the use of any interference free location RF is now in question, backup

recording seems to be a more importaint consideration than which brand can win a range contest.

 

Zaxcom wireless range these days is very good. Our TRX900LA with 125mW output has narrowed

the range gap between our system and our compeditors. In fact, all of the player audio used by the NFL

originates from the TRX900LA.

 

 

I will be sure to talk about this at our seminar at Coffey Sound on Feb 16.

 

Glenn

 

 

[PTA]

This comparison to range between wireless is very interesting to me. Specifically to the type of work that I do, the final audio is captured on camera. That being the case, range is important because dropouts mean that the needed audio didn't reach its destination for post. I will definitely report back to what I find with the QRX in the bag with whips. My SRs and 411s have served me well and I have been pleased. With the tests I have done with the QRX, I'm hoping that they will prove to be similar to my Lectro's, but the real test is in the bag with the whips.

I feel there are many people out there who are curious to how the QRX will perform in dual mode with the whips. Many of the people I work with use their Lectro's in the bag with whips and they work very well. If the Zaxcom's work on par with them without the need for an antenna distribution, then those that have a Nomad or Zaxnet might have something to think about.

I also agree that there seems to be a wide opinion on how these systems differ in performance.

[daniel]

Two things I can always guarantee. Zaxcom wireless will always have the better

audio quality and Zaxcom wireless will always have a backup recording in the

transmitter. The latter seems to negate any range issue when used for

production work. In a world where the use of any interference free location RF is now in question, backup

recording seems to be a more importaint consideration than which brand can win a range contest.

 

 

I flinch a little at this premise.

If I owed a zaxcom wireless system I am sure I would be very pleased it has the recording function. The ability to NOT HAVE to 'write-off' a take because of some minor drop-outs (cause by a busy RF environment for example) would definitely be advantageous.

However if the transmitter is for all intents and purposes out of range the sound op has just become a 'passenger' imho (when we're paid to be 'driver').

eg.

Director: "I can't hear my actors - is there something wrong with my headphones?"

Sound Op: "No, nothing wrong with you headphones, I couldn't hear them either because they went out of range."

D: "Do we need to go again?" 

S O: "No, we'll have it on the TX recorder" ?

or

S O: "Bring the actors back in range and I'll check for you."

 

Such a scenario is a bit "seat of the pants"  for me and I imagine I may very well be asked why I didn't configure the wireless system to cover the parameters of the shot.

 

Back to the occasional drop-outs where I think the real advantage lies - is there a possibility that the functionality of the Zaxcom system could be developed to enable automatic recovery of lost audio instead of playing back the entire take from the TX or pulling the card? This question probably sounds like I think there should be a 'moon on a stick' somewhere in the system as well, but it occurs to me that if drop-outs are short and infrequent and all elements in the system are TC locked the amount of data needed to fill the gaps would be quite small and could be even be done discreetly, in the back ground, to a recovery file on a Zax recorder, when the TX comes back into range. Fantasy stuff I guess, but Glenn has raised the bar so high its fun to imagine what he'll come up with next.

 

Atb,

 

Dan.

[Zack]

The latter part is one that ENG type shooting really doesn't have time to deal with or want to pay for when sound is to end up on camera only.

[Cloud Wang]

it's tricky when using dual mode, i don't use micplexer in my bag,cart only.I did tried use it couple times but i didn't feel it help a lot in the bag with whips. But at least 95% when i do docs and eng stuff,the range in dual mode is enough by putting the TX in the front of the talent's body,it does help in that way if they facing to camera and your bag. 

 

if your budget allowed,i do suggest just get two qrx100 and use them in single mode on whips and it's what i am setting up the bag these days,the range is great, at least 30-50 meters(sometimes even greater) by positioning the TX the side it can points to your bag. Usually i put it on the one side of the body instead of back.

 

and To Jan: coffey sound made my AES cable from qrx to deva,you may want to call them. And when i use QRX in digital mode,i do change one setting in the qrx's extended menu, forgot which one, but there is one thing between NORMAL and SWAPPED, turn this one to SWAPPED and give it a try,and of course turn the digital output ON too.

[Jeff Wexler]

The range issue and comparison is an important one and I encourage the real world discussion here under the aptly named title "real-world performance". It is a difficult thing to determine and I believe that the true value of this discussion is to arrive a general consensus regarding range provided we have enough input from real world users representing the use of all the systems. This is not something that can be determined by speculation, extrapolation, persistent personal bias or loyalty.

 

I also feel that the unique and unprecedented recording feature of the Zaxcom Digital wireless does NOT negate this all important discussion of range. There is a whole sector of recording jobs where the wireless connection is all important and on these productions the producers are (unfortunately) unwilling to even discuss any form of double system recording. I think this is wrong for so many reasons and I know that many people who do this sort of work do run double system even if they have been told not to. In these situations, the use of a secondary recorder (not relying on the camera) can save the day, and the use of Zaxcom recording wireless, should there be a range issue, can be an even greater savior. 

 

From my perspective, the features and functions that Zaxcom wireless provides, things which no other wireless on the market offers, far outweigh any real or imagined penalty in the range area. For the record, I have never had range issues but I am always working from the cart. For those working out of a bag, with whip antennas, we will just have to wait until enough users weigh in on this range issue.

 

I do have a question for the Lectro users who seem to be complaining about the possible necessity of using the Zaxcom Micplexer (RF distribution) if they were to go over the Zaxcom: if everything is so perfect with all your Lectro wireless in the bag with their individual whips, why does anyone use the various multi-couplers for common antennas? What "problem" is this addressing? Why the resistance to considering Micplexer when using Zaxcom in the bag?

[RadoStefanov]

I run zaxcom qrx100s on whips for 2 days. Single mode. I get almost the same range as with dipoles. Also when not using micplexer I have a lot more open freqs because the noise is not amplified. 

I can totally do my job with whips only when on the field but using a micplexer organizes my bag and makes it easier to jump from my sound cart to a harness. And when connected to Blufins the range is unreal...

[studiomprd]

" why does anyone use the various multi-couplers for common antennas? What "problem" is this addressing? "

the antenna is about the most important factor in "range".

small improvements can yield disproportionate results

[jgbsound]

I've been using the QRX in dual mode in my bag for a few years now with two TRX900's.  

 

I use the digital outs on the QRX to my Fusion12 and everything has worked swimmingly and consistently.  

 

One person mentioned the range issue.  I've experienced this too, but I suspect it's due more to my 50mw transmitters versus the receiver.  It's true that the antenna's are dedicated to each channel which is a bummer for redundant signal confidence.  However, if you're that concerned, I'd recommending using a shark fin (unsuited for bag use I realize).

 

Needless to say, It helps to be in close proximity to get a good dropout free signal.  I really haven't had that much trouble to be honest.  

 

As a side note: One little feature that helps with possible dropout problems is the SD card in the TRX's.  They allow you to run in record mode just in case there's ever a dropout.  It's like having a hard line to the transmitter -- no interruptions.

 

Though I tend to only utilize the SD cards when I'm getting a lot of interference from towers and such, and when a simple re-scan to an open frequency still doesn't seem to help.

[Derek H]

So in dual mode there is no diversity system in place?

That can't be right.

[Jeff Wexler]

So in dual mode there is no diversity system in place?

That can't be right.

 

I'm not absolutely sure on this, but I believe that in dual mode, the diversity system becomes antenna diversity system (rather than the receiver diversity that Zaxcom uses for all the wireless). This may or may not be the case, and it may not even be a "problem" (Lectro's diversity system is all antenna diversity). 

[PTA]

To address Jeff's question, I've used Lectro's in the bag with only whips for years, and for the type of work that I do, it has been great and I don't need any type of antenna system to address any range issues.

This is what I am most interested in with the Zaxcom system. I receive my first system this week and this is why I'm so curious to how it compares with the Lectro's I am used to.

[Emory Murchison]

I have also started using my QRX100 in dual mode with two talent mics. One TRX900AA (50mW) and one TRX900LA(125mW). 

I use them in a very busy RF environment (NHL hockey game!!) and the range in dual mode definetly is less.

I am having trouble with TRX900AA starting at about 25', but the TRX900LA works great and only gives me drop outs occasionaly when a player is skating around. I'm not sure if this is because of the extra distance, movement, or the super busy RF environment, the ice etc...

needless to say in this situation the recording feature is heavily used!

I also have a Lectro system going at the same time: SRa with two SMQV at 100mW. The range on these is slightly better, but it's a different block so hard to tell if it's because of the RF environment or the different technology. Getting close to the talent in this situation is not going to be possible so I have been considering different antenna ideas. I am bag based and need to move around quite a bit but I think I could swing a dipole antenna on the bag. I'm just not sure now if I would neet two dipoles or an RF splitter to service the two antenna of my QRX100 in dual mode. My other idea was to mount some kind of fixed antenna near the ice somewhere and plug/unplug depending on where the action is. Am i crazy?

[Jeff Wexler]

To address Jeff's question, I've used Lectro's in the bag with only whips for years, and for the type of work that I do, it has been great and I don't need any type of antenna system to address any range issues.

This is what I am most interested in with the Zaxcom system. I receive my first system this week and this is why I'm so curious to how it compares with the Lectro's I am used to.

I hope no one thought I was criticizing Lectro --- I think it is fairly obvious that Lectro's use of antenna diversity rather than receiver diversity (that Zaxcom, Audio, Ltd. and a few others use) works just fine and yields more than decent range. There are more differences between Zaxcom digital dual mode receiver/transmitter set and Lerctro beyond just the diversity system. I was only offering up partial explanations on how the system works. 

[LarryF]

[snip]

(Lectro's diversity system is all antenna diversity). 

Hi Jeff,

Venue and SR series can be operated in ratio diversity rather than antenna diversity with two receivers receiving a common frequency with the identical audio signals blended (Optiblend) according to the quality of each. But in general, the statement is correct as the receiver diversity feature is rarely used.

Best Regards,

Larry Fisher

Lectrosonics

[PTA]

So after some tests with my QRX's, LTAs, TRX900AA, and SRs with SMQVs, I have some findings to report. All this is simply testing on my end and other's results will vary. All my tests were done with the whips in the bag. The Rx's were on different blocks but the frequencies were clear and open. I was sitting at the back fence in my yard and my friend was inside the house walking around room to room, doing various things.

I've found that within the Zaxcom systems, the LTAs definitely have better range than the TRX900AA. And this still holds true when the QRX w/ the LTAs are in dual mode and the QRX w/ the TRX900AA was in single mode. A noticeable difference.

As far as the comparison between the Lectro and Zaxcom, I found the range on the Lectro system to be noticeably better than the Zaxcom as well. The reception of the Zaxcom system tends to jump around a bit more than the Lectro. The SR always had a strong signal even when the Zaxcom system dropped low and took a hit. That being said, the Zaxcom was great and only had 1 or 2 dropouts during the whole test, with many walls and a good distance between me and the Tx.

Thy being said, the features that the Zaxcom system has if you are using it with a Nomad are pretty amazing. PowerRoll, remote frequency/gain adjust, TC recording and sync, are all awesome. And the LTAs are quite a bit sturdier and rugged feeling than I thought they would be. Nice, small, and compact. The only gripe I have is that the clip on the LTA is sub-par in my opinion.

The real test will be how it performs out in the field this next week.

[Derek H]

So after some tests with my QRX's, LTAs, TRX900AA, and SRs with SMQVs, I have some findings to report. this is simply testing on my end and other's results will vary. All my tests were done with the whips in the bag. The Rx's were on different blocks but the frequencies were clear and open. I was sitting at the back fence in my yard and my friend was inside the house walking around room to room, doing various things.

I've found that within the Zaxcom systems, the LTAs definitely have better range than the TRX900AA. And this still holds true when the QRX w/ the LTAs are in dual mode and the QRX w/ the TRX900AA was in single mode. A noticeable difference.

As far as the comparison between the Lectro and Zaxcom, I found the range on the Lectro system to be noticeably better than the Zaxcom as well. The reception of the Zaxcom system tends to jump around a bit more than the Lectro. The SR always had a strong signal even when the Zaxcom system dropped low and took a hit. That being said, the Zaxcom was great and only had 1 or 2 dropouts during the whole test, with many walls and a good distance between me and the Tx.

Thy being said, the features that the Zaxcom system has if you are using it with a Nomad are pretty amazing. PowerRoll, remote frequency/gain adjust, TC recording and sync, are all awesome. And the LTAs are quite a bit sturdier and rugged feeling than I thought they would be. Nice, small, and compact. The only gripe I have is that the clip on the LTA is sub-par in my opinion.

The real test will be how it performs out in the field this next week.

Thanks for sharing some test results!

A few questions:

Can you clarify what transmit power settings you were using on the TRX900LA and SMQV?

Which SRa diversity mode were you using?

Also, when you say that the Lectros had better range do you mean the RF display showed a stronger signal or do you mean actual drop outs?

If you were to tape over the receiver displays, and judge just by listening which system had the least amount of audible distortion or drop outs due to range?

It seems you did not notice a significant difference between the QRX single mode or dual mode in terms of range. Is this true?

Thanks again!

[Zack]

At the point where you said the Zax systems would take a hit, was the sound of the lectros introducing the fizz of a not so strong signal as well?

[Derek H]

PS, looking forward to your field tests! And I agree about the Zaxcom wire clip, seems like they come off too easily.

[PTA]

Thanks for sharing some test results!

A few questions:

Can you clarify what transmit power settings you were using on the TRX900LA and SMQV?

Which SRa diversity mode were you using?

Also, when you say that the Lectros had better range do you mean the RF display showed a stronger signal or do you mean actual drop outs?

If you were to tape over the receiver displays, and judge just by listening which system had the least amount of audible distortion or drop outs due to range?

It seems you did not notice a significant difference between the QRX single mode or dual mode in terms of range. Is this true?

Thanks again!

So the LTAs were at 125mW and the SMQVs were at 100mW. The SR was in Switch mode where it receives two separate signals like the QRX in Dual mode. By better range, I meant that when the Zaxcom system drops low and took a hit, the Lectro system dropped a little but was still at a very strong level, and no analog artifacts were introduced like hiss or fuzz.

The Zaxcom signal has no audible distortion regardless of the signal strength, it's either there or it's not. If I were to listen blindly, my guess it the Zaxcom system would drop before the Lectro, but the Lectro might get hissy. That being said from my tests the other day, the Zaxcom dropped out before the Lectro got any hiss, therefore I thought the range was greater on the Lectro system.

There definitely was a difference between single and dual mode. I was just saying that the LTAs in dual mode performed better that the TRX900AA in single. Of course the difference there too is 50 mW and 125mW.