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Lectrosonics Digital Hybrid VS D Squared | Walk Test
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- čas přidán 7. 07. 2020
- In the latest Raycom walk test we pitch the old against the new; the Lectrosonics Digital Hybrid has been a well respected wireless solution for almost two decades so we thought it would be fun to compare it to the new D Squared fully digital system unveiled by Lectrosonics in 2019.
In this test you will see all three diversity modes of the Lectro DSQD receiver range tested against the Digital Hybrid.
Products featured in this video:
- Transmitters -
SMWB www.raycom.co.uk/product/lect...
DBu www.raycom.co.uk/product/lect...
DPr www.raycom.co.uk/product/lect...
- Receivers -
DSQD www.raycom.co.uk/product/lect...
UCR411a www.raycom.co.uk/product/lect...
Remember only Raycom offer a free, no quibble, 5 year warranty on all Lectrosonics products www.raycom.co.uk/lectronsonic...
In this test we used licensed frequencies in EU Ch38 (606 to 614MHz). The channels chosen were completely free from noise. The antennas used were completely passive and have a nominal gain of 6dBi (3.85dB relative to a dipole), there was 2dB of feeder loss, the antennas were fed into the DSQD then looped out to the UCR411. All 3 transmitters were set to 50mW for this test.
Be sure to subscribe to the Raycom TV channel as we will be doing many more walk tests in various settings in the coming months.
Thanks for taking the time to do this demo. I've been using the M2R and M2T units with great success. I'm glad to see this is such a great product line that keeps getting better!
Thanks to Pyers, Andy, Doz, & Jilly & the Raycom team for this walk test and explanation of the differences in Switched, Ratio, and Frequency Diversity in the D Squared digital system.
Amazing !!! DCHR + DBu are on my way 🔥
Love these keep em up! Can we see an A10 walk test?
Yes! We'll add that to the list.
Thanks to Pyers and his team at Raycom! Nice test!
It underlines how a *true* diversity system is key to providing a robust operating range. It also shows how a modern digital transmission system cannot compete with the sensitivity of a well designed FM-DSP system. (See the impressive Wisycom MCR54 walk test!) Aside from limiting the transmitter power, without the the FM Capture Effect digital transmission systems are also more susceptible to multi-path interference. I wonder if that flutter and then drop-out at 425m was the result of the metal fencing at that street corner; hard to say. Thanks again guys... Cheers from Canada.
Hi Rob, thanks for your comments. As the Wisycom rep in Canada, even you would have to admit that analog and digital wireless systems have different advantages and in some cases mutually exclusive features. For instance, signal encryption is routine now in digital wireless systems, and can't be done in analog systems at all. Feature rich telemetry is also now routine in digital systems. There are some advantages in sound quality as well, as can probably be heard even in this video. Many digital systems out there have very clever codecs, and offer different sets of tradeoffs in terms of spectral density, than analog systems. Clearly, there is a lot of interest in digital wireless microphone systems, for obvious reasons.
Good morning Lectrosonics; while encryption is certainly in the realm of digital technologies, I do not agree that any of the other "digital features" you've noted, are available exclusively in the digital realm. Symphony's Bluetooth 5 back-channel offers 3D telemetry features with Angle of Arrival and Angel of Departure. As we by now have all learned, spectral efficiency is also not specifically a digital property. To begin with, digital systems can create intermodulation too; and many of them do not have filters or circulators in their design. As an analog (FM-DSP) system, Wisycom's unique intermodulation cancellation circuitry provides extremely efficient equidistant carriers, that combined with narrowband operation allows for 250kHz carrier spacing. Compared to digital transmission, Wisycom's FM-DSP also does not suffer from the side-lobes that a phase & amplitude system requires and that limits their power output to stay within the licence spectrum mask.
I agree that there are lots of interest in digital systems; but at the end of the day, one of the more critical requirements of a wireless system is to reliably maintain a link. This is where digital transmissions systems tend to fail much earlier then their analog counterparts - they cannot rely on the FM capture effect and are far more susceptible to multi-path interference - where it is much more common than at Raycom's idyllic location in Evesham.
I do agree that users look for a wide-range of features depending on their application, their needs/requirements; vive la différence! Different systems for different people...
Cheers!
Thanks Raycom. Love the walk tests. What are you all using to communicate back and forth with the audio engineer?
Great to hear you enjoy them! To keep communication between the team on these walk tests we use an IEM system - a Wisycom MTK952 TX to Wisycom MPR50 RX's on the guys :)
Love this content
Thank you!
Seems odd that her receiver never showed a full RF signal. Not even when she was standing next to the fins (I realize she's somewhat in a null there), but even as soon as they walk beneath the antennas outdoors, she's at half signal. I wonder if the Digital transmitter was choking hers, or maybe choking each other. Would've been interesting to see that Wisycom walk test with a pair of Transmitter so close.
Transmitters don't interfere with each other like that unless they are a few cm away and the antennas get detuned by each other, and we were at least 1m or more apart most of the time. I would be more worried about the TX de-sensing the IEM RX! I will check that the UCR411 is in spec for both meter calibration and absolute sensitivity. Those antennas do, as you say, have a deep null from the rear (plus the windows have metallised coating), they also are pretty deaf from below. The performance was broadly in line with expectations, though I will have a good look at the 411 on the workbench ASAP (we are authorised Lectro warranty service centre).
Also, her Tx was horizontal which would make it perpendicular to the antenna array. Correct me if I am wrong but wouldn't this affect how the antenna picks up the signal? I have always fount that signal is worse then the Tx antenna is sideways and the Rx antenna (or whip) is vertical.
@@scottmancrothers1 You lot are very observant! :) It did move more to the horizontal as we walked off, but it was more 'slant' polarised I would say. In the theoretical world with no reflections then you lose 100% signal when cross polarised, however in the real world reflections and clutter causes rotation of polarisation so it is not that simple. Even in a theoretical situation a 45 degree difference between antennas only gives 3dB loss, and in the real world probably less on average. also there is some radiation from the case of the TX and wires so it's not clear cut at all. I think if her antenna had been straight up it may have made a marginal improvement to range, though it would also have placed the antenna closer to her body (aka bag of water) so there would have been more attenuation and detuning of the antenna in that situation, so it's swings and roundabouts TBH.