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glenn

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Everything posted by glenn

  1. The Nova is in use on many Sound Carts and is a very capable 16 track recorder. With multiple choices of control panels and many unique features that are not offered by our competition. For example fully integrated wireless microphone control and internal wireless receivers. Zaxcom is committed to the location sound market and we are always working on new products. For Recording, wireless and IFB.
  2. The VRX will go 17 Hours on Lithium if needed. 13 hours on a NiMh is a conservative number. With a high capacity battery 14 hours continuous reception is easy to get. I would not think of the Analog FM mode as a “stop gap”. It is a very respectable way to work. Slowly transitioning to a fleet of VRX allows the switch to digital with a very low cost. All anyone needs to do is start by switching to the VRX rather than purchasing new Comtek to replace lost or broken receivers.
  3. There is nothing I know of to suggest SD cards adaptors to CF card are not reliable. They are so inexpensive you can get a few in case anything should happen.
  4. Thanks Tim for your post. My original post example focused on distortion mostly not specifically noise. I do think an exact gain setting for a microphone is the best way to get the best results for noise and distortion rather than a fixed transmitter gain. This thread is directed toward the idea that 32bit floating point transmission somehow improves the results of audio quality when not adjusting the gain of the transmitter at the transmitter. The thread is not directed at any one company as multiple companies seem to be going this way. It is a commentary on the method as a whole and what I see as a poorer choice than transmitter gain adjustment as used by multiple companies as well.
  5. The purpose is to ask people to think about the tools they use. It does not matter how many A-Ds are used in the example as 2 A-Ds with no gain control is effectively like having an input gain control with only 2 settings low and high. If the level coming into an A-D is very low (around 48dB above the noise floor), there could easily be around 256 levels or less. I am sure it happens all the time. What happens to low level audio when it is adjusted later in the chain rather than at the pre-amp is the point to consider. There is a lot of 32 bit floating point information and mis-information on this group. Some companies have adjustable gain and others don't. What gear to use is a personal decision and people will choose what is best for them.
  6. So I was thinking, if anyone would use a wireless microphone with no input gain adjustment, and the audio was very low, lets say for example that only 8 bits of the A-D converter were being utilized. In this case the audio would be represented by no more than 256 discrete levels. This works out to a dynamic range of 48 dB. Since we can not change the mic gain on the transmitter we can not boost the signal to the A-D in the transmitter to get the proper transmitter A-D resolution of let say 96 dB. So we have lost about 48 dB of dynamic range. If we were to boost the audio signal at the receiver, recorder or at a mixer, we can add 48 dB of gain to come up with a signal that we can mix into other signals at a proper level. When we do this we are now utilizing about 64000 discrete levels. The fact is the audio will never actually have more than 256 discrete levels no matter how much gain is added down stream. All that happens is that the 256 levels are in this case multiplied by 256 to make the signal louder not better. In this example signal and noise are boosted at the same time and the distortion of only 8 bits of data representing the original audio remains at exactly 8 bits or 256 discrete levels. It makes no difference if the recording and or transmission is 24 bit fixed or 32 bit float. This is exactly why adjusting the mic preamp level to match a microphone to the proper level for a A-D converter is essential to achieve the best audio quality. Nothing will restore the audio quality that was lost by not having a transmitter with adjustable gain. Suggesting that 32 bit digital connections to devices that can add gain later in the chain to make up for the lost A-D dynamic range of the transmitter input gain mismatch is promotional sales nonsense and is no different than selling snake oil at a side show.
  7. glenn

    Rode mics

    32 bit recording and it’s promotion as a better way to go over 24 bit recording is plain and simple horse shit. While some of the you tube videos message is confused by talking about 8 bit recording, the basic message that 24 bit recording with its 144 db dynamic range and 16.7 million levels is more than capable of capturing the output of any A-D converter without any loss of dynamic range. As others have pointed out if your mic input is clipped or not adjusted correctly to provide enough signal to the A-D, 32 bit floating recording will only do a great job of getting bad sound from point A to point B. Adjusting the mic preamp to the correct level is mandatory to get the best recording. Any mic input that can not be adjusted provides sub par audio that can never be improved further down the signal chain by changing the gain in a mixer or recorder. Not even 64 bits will fix that. Maybe that’s the next big thing in snake oil advertising and promotion.
  8. You can either convert the cards one at a time or Viviana has a multi card converter that I think can do 4 cards at a time speeding up the process. Either way the audio on the cards will need to be converted. This can be done in post as the files are loaded into the edit system. Glenn
  9. Codyman: Since the original poster specifically said he was looking for digital transmission wireless I think that makes how many people have companded fm analog wireless from Lectro a non factor. In terms of digital wireless Zaxcom had been selling it for over 20 years. So I know there is a lot of it out there all over the US. In LA Trew audio and Audio department have rental stock. I do not see who has sold the most as a deciding factor. If you have seen some of the polls on Doc’s Strictly Sound group Zaxcom is a leader in Sales of Digital wireless. We are also big in sports as we have gear in every NFL game.
  10. Hi Joe: There are many customers that use Zaxcom wireless with Sound Devices and other manufacturers recorders so I would hope you would be open to consider the big picture of the sound bag and your work. A RX8 with CL5 camera link is a great way to get into the system with a non Zaxcom recorder. Transmitter size, battery life, transmission reliability when used in reflective environments (Like in cars, brick walls or around metal objects), cost, transmitter pre-amp gain control, recording transmitters, continuous tuning receiver front end agility, transmitter wireless replay and re-record to name a few things that are highlights of our system. There are a few choices out there and many factors to consider. If you were to consider Nova then you only need the Nova, MRX414 receivers and transmitters. This would still be a great value for a sound bag that would be half the size, weight, power consumption and cost of competitive products. I get the fact that the integration with Nova is a big advantage of our system. Using it with a non-Zaxcom recorder does not negate the bulk of the systems advantages. It is important to think about the flexibility of 4 channel plug in receivers that are easily used in the Nova RX8, RX4 or RX12 in terms of return on investment and not keeping all your eggs in one basket.
  11. Jointed antennas cause dropouts with digital wireless unless the joints are tight. Avoid if possible.
  12. Thank You so much DSG for a very detailed comparison. I have to comment on "Best Range in the Market" sales promotion by SD as brought up in this thread. This kind of claim is to be blunt false promotional nonsense. There are so many factors that effect range , testing can be difficult to quantify. While Zaxcom has great range it excels at maintaining signal lock with a number of interfering signals, has great reception in the presence of RF overload and is superior in its ability to receive in a reflective RF environment. Real world comparisons against our competitors with sound community participants have shown us that our signal remains locked far better in the presence of obstacles that cause RF reflections on set. The result of this is not only excellent transmission over long distances but far more consistent drop out free operation on set where reflections and non line of sight operation can cause dropouts at any distance. We will never claim we have best range as that kind of thing is impossible to prove as there are too many variables to make a credible determination. What we do claim is industry leading superior transmission reliability and great overall range. We are willing to do a shootout any time any where.
  13. The post I responded to had a specific Zaxcom reference. Transmitter run time became a topic of conversation in this thread and Zaxcom was commented on by Documentary sound guy. I wanted to clarify what was being brought up about our product. It is important for people to have an understanding of our transmitter run time in terms of full power continuous transmission of 16 Hours. We rate our transmitters in terms of minimum run time with rechargeable batteries. That is an important distinction vs 12 hours maximum with Lithium in this case. It would be nice if all manufactures could rate run time as a minimum so that comparisons could be made apples to apples.
  14. ZMT4-X is a 16 hour battery life at full RF power, internal recording and transmission at the same time, Mono or stereo transmission, Zaxnet remote control with RF time code. Plain and simple. Glenn
  15. It is good to see him. I hope he reads this and knows we miss him.
  16. A Zaxcom camera link in the car transmitting with ZHD modulation will give you the best combination of no compromise audio quality and signal integrity in a mobile car to car kind of production. With recording transmitters, any number of transmitters can be replayed in sync to monitor after the fact if needed. Use a magnet mount on the transmitter car if possible.
  17. Zaxcom wireless is always intentionally limited to 16KHz of audio frequency response. We do this for multiple reasons. Better transmission reliability, higher bit resolution and most importantly to filter out all of the junk that can exist above 16KHz that can come from ultrasonic sources. Combine that with the fact there is no usable content there and its a no brainer to eliminate the interference that post does not want there in the first place. Neverclip uses 2 A-D converters to provide 20 dB of extra headroom so you will "Never Clip". Still with the 136 dB of dynamic range, it is possible to need the use of a compressor if the preamp gain is crazy hot. As a catch all we have a compressor just in case. It is seldom if ever used. The Zaxcom transmitters have local and remote gain control. This provides a 5-6 dB noise floor advantage over wireless mics that have no control of the pre-amp gain in the transmitter. Adjusting the gain of the transmitter signal forward of the transmitter pre-amp does nothing to restore the lost dynamic range of a transmitter with no pre-amp gain control. The concept that the lost audio quality of a mismatched transmitter preamp gain setting to a microphone output can be repaired or improved once the audio has left the transmitter is bogus. A low level microphone signal needs optimum gain to properly drive the A-D converter for the best noise and distortion performance. A pre-amp with no gain control will still be sub par no matter how the good the signal path is to the receiver or where the gain is adjusted forward of the transmitter preamp. Just like in the old days, the trim control of a Cooper mixer made wireless input signals louder not better.
  18. Yes we are back up and users are posting again. Facebook is not fun to deal with in terms of communication but in this case there is a good result. Kind of ironic
  19. I would love to tell everyone what we are working on but that is not possible. Exciting products are in development and that about all I can say.
  20. Scans will look different on different gear because there are many factors like bandwidth, scale, min and max levels displayed. Most scans are there as a reference. Our products use the scan to auto pick the best frequency when used with Nova or RX8 or RX12. I am glad you got such great range. The battery life and size of the ZMT4 combined with Nova are a great combination and is very cost effective. If I can answer any questions feel free to call me at Zaxcom. Glenn
  21. Tips to getting the best distance from your wireless transmission Never use amplified antennas. They can easily create intermodulation interference that the best receiver front ends can not filter out. Even if you use one with a RF pad set to Zero it is a problem if the amp is still in line. Always use passive directional antennas with low loss coax. Use LMR-400 coax for longer runs, it has a loss of 3dB per 100 foot. This is more than acceptable as to not affect range and to get the best performance from the receivers front end filtering. Digital wireless needs a linear transmission path. Amplified antennas are very non linear when overloaded and sometimes without overload. If running 10 FT of coax you can use high loss coax as the loss is 1/10 of the 100 foot run. 10dB loss per 100 feet is fine on a 10 FT run. Using directional antennas is the best way to get the greatest distance and to minimize interference. You can double the distance your wireless will work and minimize interference from interfering walkies, cell phones and television stations if they are coming in from different directions like from the back or the sides of the antenna. If you use 2 shark fins for receiving, separating them more than about a foot is unnecessary. Mount them both in vertical orientation and parallel to each other. If using a fin for IFB transmission, mount it below the 2 receiving antennas by a few feet (2-3) for isolation from the receiving antennas. Do not mount it at the same height as the receiving antennas as it will couple more noise into the receiver than it needs to. This trick can lower RF receiver noise by 9dB. If you have a choice, stay away from dipoles. "Shark fins" Log periodic antennas are much better for digital modulations like Zaxcom Wireless and are directional. Log periodics tend to minimize the nulls that can happen as mics move through free space as their multiple elements even out the signal. Do not use a dipole with a log periodic antenna for antenna diversity. Using a good antenna with a bad antenna is not diversity, its a problem. Get your antennas up in the air as high as possible. This will help to get obstacles like people out of the way and guarantees you that someone near the sound cart can not get closer to the antenna than the height of the antenna helping to prevent overload and intermodulation. 10 feet or higher is best. With Zaxcom wireless use ZHD96 modulation indoors and in reflective outdoor spaces. Use XR in Iowa corn fields where there are no reflections. Don't keep transmitters on at your cart that are inside your receiver's filter bandpass. This can have the effect of desensitizing the receiver and make it easier to create intermodulation if there are other high power transmitters nearby. We call this near/far effect. It is much easier to go 500 feet if you do not have an actor with a live transmitter looking over your shoulder at the cart. Avoid antenna distribution amplifiers if possible. They, like amplified antennas, can cause intermodulation that can really mess up a receiver. If you must use one make sure it has a band pass filter in front of it or built onto it. Our Micplexer II has the Zaxcom flux capacitor filter that limits the bandpass to 35MHz and also has overload lights to tell you someone is looking over your shoulder with a live transmitter. Keep transmitter antennas away from direct skin contact. The body does a great job of sucking all the RF out of the air and de-tuning the transmitter antenna. Use a 1/2" diameter or better a 1" diameter foam tube to hold the antenna away from the skin if placed under clothing like on a leg or arm. If a transmitter is being used very close to the receiver like 10 feet or less use the lowest power transmitter setting. This is just good practice and can minimize interference to receivers that might pick up signals if they do not have a transmitter to listen to on their own frequencies. Our receivers can decode a signal with only 7 dB of signal to noise at a level of -100 dB noise floor. You will never be too close to a Zaxcom receiver at any power level to cause it to not decode. I have been wanting to put this out for a while. This is by no means a complete list but I hope it might prevent some bad situations as more sound mixers move from analog to digital wireless. For bag use, Keep UHF IFB transmitters at least 50 MHz away from the frequencies used for body pack receivers. If possible use a filter on the transmitter to eliminate any wide band noise that might fall into the receivers pass band. No receiver front end can eliminate the wide band noise from a transmitter located within a foot of the wireless receivers in a sound bag. This is because the transmitter noise is in the receivers pass band and can not be filtered out by the receivers front end filter. Any claim that a receiver by it self can solve this problem is sales promotion nonsense. Glenn
  22. Just saw this topic. Here are some comments. Filters should be passive devices and will not add any noise to the RF signal. Active antennas with filters are a different story as the manufactures of such devices don't tell you enough about them in most cases to be useful. The micplexer has a great filter before its buffer amp that feeds the splitters so that the output of the micplexer has only a few dB of gain with the protection of our tunable filter before the amp. Its bandwidth is about 35 MHz +/- 17.5 MHz. Do not use active amplified antennas. Use low loss coax instead . Active antennas are the industry's version of snake oil and will often do much more harm than good by creating intermodulation interference ahead of a good receiver front end that can not be filtered out. I will look for my RF tips to post here that cover a lot of this. Glenn
  23. Zaxcom URX100 IFB receivers interface with Motorola walkies and also listen to any Zaxcom bodypack or cart transmitter at the same time. It might be the bridge you are looking for. Glenn
  24. I am certain our dealers will be happy to send out a demo unit to you to get going. If you have any difficulty please call me direct I will get you hooked up. Glenn
  25. If you are looking for a new system backfocus you might look at the Zaxcom ZMT4 transmitter. It is about 1/2 the size of the A20 and will run at full power for 7 hours with a rechargeable battery. Cost to run every day is nearly Free. There are many other advantages that you can learn about on our site Zaxcom. Com
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