Tag Archives: microphones

Why use Sony’s UWP-D Radio Microphones?

 

There are LOTS of choices now when it comes to radio microphones. Some are better than others. Some may be smaller, some may be cheaper, some may be really terrible! So, given there are so many choices and the Sony UWP-D series isn’t amongst the cheapest, why choose them over some of the cheaper options?

Sony’s URX-P41D on an FX6 using the MI Shoe


Perhaps you are looking at some of the new miniature digital microphone kits from other well known brands such as DJI or Hollyland, or perhaps even Sony’s ECM-W3, all of which to be fair, do actually work pretty well, especially when you consider their low cost. So, why use the UWP-D series?

The vast majority of these smaller digital microphones use frequencies in the same range as used by Wifi and Bluetooth. By using these shared and licence free frequencies these devices can be made cheaply. But because the frequencies are shared and licence free the power levels that can be used are very low and there is a high risk of interference from other devices that are also using the same frequencies. Generally interference isn’t normally an issue unless you are somewhere crowded but with almost everyone carrying a mobile phone with WiFi and bluetooth enabled, if you are in a crowded place such as a large event, conference, performance etc, then interference can become a big issue. Range can be seriously reduced or in the worst case you may simply find you can’t get them to work at all.

The Sony URX-P41D attached to a Sony FX3 via MIShoe

 

The other thing about the very high frequencies used by these small devices is that they are easily blocked by solid objects, including people. So, if the presenter is wearing the transmitter on their front and they turn away from the camera so that their body now comes between the transmitter and receiver, the signal can be blocked or  degraded.

A further issue with these low cost digital systems is the time it takes to encode the audio to digital, transmit it and then convert the digital data back to a useable audio signal. It takes time, and this introduces a delay into the audio. This delay can affect the lip sync of the recorded audio or make it impossible to mix the delayed wireless audio with any un-delayed audio from a wired microphone – the timing difference leading to an echo or phase issues that can make the audio sound strange.

For me, as a professional film maker these issues are significant. Not being able to mix different types of microphones without an echo or phase shift is a huge problem as often I will have a mic on the camera for atmos sound as well as the radio mic on the talent, and I need to be able to mix these different sources and I don’t want to have to spend time shifting the timing of each audio track separately in post. 


A further issue is the rechargeable nature of the cheaper radio mics. What do you do if you forget to recharge them before the job? What do you do if you’ve been shooting all day but have yet to finish and the batteries have gone flat? You can’t simply pop in a fresh set of AA batteries as you can with the UWP-D series. Additional battery cases (BATC-4AA) can also be purchased if you wish to make changing batteries in a rush even easier. 

UTX-B40 with it’s included 2x AA battery case (part number BATC-4AA)


All of the above reasons are why I still prefer to use my UWP-D microphones whenever I can.

The latest versions have a removable battery case that takes two AA batteries, so battery swaps are quick and easy. The receivers can be connected to any Sony camera with an MI Shoe using a cheap adapter that slots into the shoe and then the receiver is powered from the camera and the audio passed directly to the camera with no need to use any cables. If you are using an FX6 with the single channel URX-P40D or dual channel URX P41D you will get an indication of the signal strength of the transmitters on the LCD/Monitor, very handy indeed.

UWP-D Transmitter battery level indication on Sony FX6

 

The UWP-D series use a hybrid of analog and digital technologies. The transmitters and receivers use a digital compander system to process the audio so that any loss of quality during the analog transmission is minimised. The URX-P40D and URX-P41D can output using either analog or digital. Most of the more recent Sony A7 and FX series cameras can now accept the digital input which helps to reduce background hiss and noise.



The URX-P41D is a dual channel receiver. It has two separate receivers and these can be switched on and off independently.  There is also an additional 3.5mm socket for a wired microphone and this additional input can be mixed with the radio mic channels. It also has a headphone socket and this is very handy for troubleshooting any audio issues as it allows you to check what the radio mic receiver is receiving before the audio is passed on to the camera or recorder. There are two threaded 3.5mm sockets that can be used with the included 3.5mm to 3.5mm or XLR cables to feed the camera or recorder if you are not using the MI Shoe.

They are also very easy to use. Pairing is simple, on the URX-P41D you just press and hold the scan/sync button on the receiver to put it into the pairing mode. It will scan for clear frequencies and then when it has found them it will ask you to pair with the transmitters using NFC. Simply hold the first transmitter against the receiver and it will automatically pair, vibrating when it is done. Then you hold the second transmitter against the receiver and it will then pair with that one. The URX-P41D also has an IR port on the side for pairing with the previous generation of UWP-D wireless transmitters that pair via infra-red.

URX-P41D – you can see the IR pairing window on the side.



As well as the compact belt pack transmitter (UTX-B40), there is also a handheld microphone (UTX-M40) and a plug in transmitter (UTX-P40). Most of my own personal experience is with the belt pack transmitters, but I have used them all and they all work really well.

The latest Sony UWP-D transmitters


The URX-B40 transmitter is compact and sturdy. It has the same AA battery holder as the receiver and a pair of good quality alkaline AA batteries will run it for around 8 hours. It has a simple but effective removable wire belt clip. These have been dropped, sat on, pulled out of pockets by the mic cable more times than I can remember and never given any issues. The supplied microphone is pretty good. None of my clients have ever found the audio quality lacking and I feel that it is perfectly acceptable for news or documentary production. Perfectionist’s may prefer to use a different capsule, but for me it does what I need it to do.

I have been using various versions of the UWP-D radio mic systems for years and the first versions I got all those years ago still work fine today. The latest receivers with the digital MI Shoe output have a lower noise floor and having the signal strength displayed on the screen of my FX6 is very useful.  A decent radio mic system isn’t a small investment, but these should last many, many years. They won’t introduce phasing and timing issues as many of the lower cost digital systems can. The range is great and they can be used in crowded venues or at large events without being worried about interferrence from phones or other devices that use WiFi. 

Microphone Latency – Don’t mix and match!

This tripped me up recently and I really should know better.

Don’t mix wireless and cabled microphones with differing amounts of latency because if you do you may have a nasty and difficult to remove echo or phase issues in your audio. 

Digital + Analog don’t mix well.

In my particular case I was using a couple of Sony UWP-D wireless microphones to mic up two out of 3 members of a discussion panel. For the 3rd member I had planned to use another UWP-D but that microphone became unavailable at the last minute, so instead I used a lower cost digital microphone that works on the 2.5Ghz band. There is absolutely nothing fundamentally wrong with this lower cost microphone but the digital processing and transmission adds a very slight delay to the audio.

The Sony UWP-D’s are extremely low latency (delay) microphones and the audio arrives at the camera almost instantly. However most of the lower cost digital microphones have a very slight delay. That delay may be 1 frame or less, but there is still a delay. So the audio from the digital microphone arrives at the camera slightly late. If this is the only microphone you are using this isn’t an issue. But if you mix a very low latency microphone with one with a very slight delay, if both mics pick up any of the same sounds in the background there will be an echo or possibly a phase issue.

As the delay is almost never exactly 1 frame  this can be difficult to resolve in most normal video post production suites where you can only shift things in 1 frame increments.

Phase Issues:

Phase issues occur when the audio from one source arrives very slightly out of sync with the other so that the one source cancels certain frequencies of the other out when the two are mixed together. This can make the audio sound thin or have a reduced frequency response.

So… don’t mix different types of digital wireless microphones and don’t mix lower cost digital microphones with more expensive low latency microphones. And when you are checking and monitoring your audio listen to a full mix of all your audio channels. If you monitor the channels separately the echo or any phasing issues might not be heard.

Hollyland Lark 150 Dual Channel wireless Mic System

In this video – live streamed on June 24th 2021 I take a look at the new Hollyland Lark 150 dual channel wireless microphone system.

The Lark 150 is a compact digital wireless microphone system that is available as a single channel or dual channel kit. If you buy the single channel kit you can add an extra transmitter pack later if you wish and pairing the units is really simple.

Each kit is supplied in a storage box that acts as a drop-in charger. To pair the transmitters to the receiver simply place them all in the storage box together and they are paired automatically, it’s as simple as that.

The transmitter units have a built in microphone and come with a clip on fluffy wind gag. But in addition a plug in lavalier microphone of pretty good quality is also included in the kit, one for each transmitter pack. There is also a mute button on each transmitter unit.

The receiver outputs a mono output or stereo output via a 3.5mm TRS socket depending on you personal preferences (connecting cables for cameras or phones are included in the kit). There is also a handy “safety mode” that outputs at full level on channel 1 and at a reduced level on channel 2. This is great for filming in environments where the audio levels can suddenly change as the lower level recording helps avoid clipping or distortion if the levels suddenly increase. There are two large control knobs on the receiver that control the levels of the two channels and allow you to switch between the different operating modes. The LCD screen clearly shows how the microphone is configured along with the audio levels. There is an additional headphone output on the receiver for headphone monitoring in case your camera doesn’t have a headphone jack.

Battery life is excellent, I got around 8 hours of use from a single charge. To charge the transmitter and receiver units just put them in the carry case and the battery built into the case will charge them back up again. The case has a USB socket to charge it.

The sound quality is very good for a low cost system. As it is entirely digital there is virtually no hiss or noise. The only downside is that the range is more limited than most much more expensive professional radio mics. This system uses the licence free 2.4Ghz band so there are no licensing issues in most countries and the digital transmissions are very secure, so you don’t need to worry about people illicitly  listening in. 

While you can get up to 100m/300ft range from them in perfect conditions. I found that I reliably and consistently get a range of about 100ft (30m). Operate them in this distance range and they are generally rock solid. However if the presenters body or some other substantial objects gets between the transmitter and receiver there is a small decrease in range, perhaps dropping to a reliable  50ft (15m). This is still plenty for most applications.

I really like these microphones. They won’t replace my much more expensive Sony UWP-D professional microphones, but they are great when you need something compact, ultra light and really simple to use. They are perfect for a lot of blogging applications as well as for interviews etc. At a cost of around £210/$275 for the dual channel kit these are excellent value for the money.