Tuesday, January 6, 2015

Audio-Technica System 10 - Now With Battery-powered Receiver & More

System 10 with AC-powered Receiver
I was very interested in Audio-Technica’s System 10 roll out a year ago. The first System 10 only offered an AC-powered receiver. That kept it from camera or bag use for location audio. It appeared that Audio-Technica was looking first at the Church, PA and Musician markets and coming in with some nice pricing. $300 for a handheld mic and receiver is head turning. The audio is compressed, using an APTX codec.

Now there's a new battery-powered receiver designed to fit on a camera and a stomp box for guitar players. That certainly changes the game, but let's backtrack.

System 10 is more than just a new, remarkably affordable wireless system, it's a technology shift. Not VHF. Not UHF, but up in 2.4 GHz with Wi-Fi. I need to make a point here; System 10 does not require Wi-Fi to operate. In fact, a thick Wi-Fi environment may make it operate closer to Audio-Technica published specs. In addition to passing 24-bit, 48 kHz, 3.8 mSec low latency audio, the System 10 transmitter and receiver are in constant communication with each other and they shift automatically as needed and without dropout or frequency coordination. Read on…!

5/2015 Addendum: While the System 10 works quite well with the Audio Technica 830 Lav, I found digital RF problems and noise when using Audio Technica's BP892 and BP896 mini lav and headworn mics. It's apparently a shielding problem. More on that as it develops.

11/6/15 Addendum: The BP892 heqdworn lav has now been altered to reject the 2.4 GHz noise. They are still working on the BP896.

AT8691 Double Receiver Mount
11/6/15 Here's some solid good news for existing System 10 owners. Audio-Technica has released a new bracket, the AT8691 that allows you to stack two System 10 receivers on top of each other. The AT8691 comes with a shoe terminal for camera or stand mounting. The bracket also ships with the AT8351 Y-connector that allows both receivers to be connected to one piece of gear via its 1/8" mini TRS jack for split track audio.

3/17/16 The Countryman B6 works well with the Audio-Technica System 10 transmitter. 

Maximum Performance?
OK, the manual for this receiver makes me a little concerned. "Place the receiver at least three feet above the ground and three feet from any wall or metal surface. In bold letters; Keep System 10 receiver 30 feet from any wireless access points. In multi-channel systems, keep receivers at least three feet apart." Well that means you can't mount two of them on top of a camera or in a location audio bag. But what about the AC-powered receivers? Those you can stack eight high? That doesn't make sense.

Gary Boss
called Gary Boss at Audio-Technica US for some background. "We've been working with digital wireless for more than a dozen years, if you count when we began research. Our current upscale product, SpectraPulse Ultra Wide Band, has been out for seven years. When we submitted it to the FCC for approval, we had to send one of our engineers because the FCC couldn't find the signal. The nature of the system has the signal buried in the noise floor."

Boss also explained that the specs and system use limitations of System 10 are typical of Audio-Technica's conservative approach to specs. "We are super cautious, to a fault. We don't quote the best case scenario, we quote the worst. So, for example, the specs on the product sheet are for not just one unit in operation, but eight units in simultaneous operation. I've seen System 10 in operation with a stomp box at a trade show just ten feet under a remote multi-anntenna Wi-Fi array with no problem. And we have gotten more than eight System 10 units running, but under laboratory conditions." 

The range quote on the stomp box is only a 60 foot radius. (which, when you stop and think about it is pretty remarkable.) The other System 10 data sheet talks about expecting a range of 100 feet for the body mics, but I and others have already exceeded Audio-Tecnica's range estimates, getting out to 125-150 feet or more. 

And what about the 2.4 GHz operating frequency. As transmitter/receiver wavelengths get shorter, it’s presumed that reception can become more fragile due to increased multipath. I was out last week in a busy and very full parking garage. Lots of reflective metal and rebar, both moving and stationary. Metal, as you may know bounces the signal around and can play havoc on wireless reception. We got 125 feet and more with one System 10 transmitter and one of the new battery-powered camera mountable receivers and I had the receiver in a shirt pocket. Very impressive. 

But back to diversity. Historically, VHF and UHF wireless systems have done better when the receiver has complete dual diversity. That means dual antennae and dual tuners in one receiver. Below that, the next level of diversity uses one tuner and switching antennae to prevent drop out due to multi-path reception. That's only Space Diversity, because the two antennae are in different spaces.

System 10 operates with Frequency, Time and Space diversity all at the same time, using 2 Mhz of bandwidth. So the playing field is very different. With System 10, Frequency Diversity sends the signal on two dynamically allocated frequencies simultaneously. Time Diversity sends the same audio bit twice within the same frame, so there's redundancy. Finally, per the above, Space Diversity uses two antennas on each transmitter and receiver to increase signal integrity. This protocol would seem to offer a much more robust operation than pretty much anything that has come before. How come they didn't win a TEC Award for this technology? I mean REALLY. How Come!

Simple Operation
All of this Diversity is happening without human intervention. The systems comes ready to go right out of the box with no setup required. The numbers 1-8 are not dedicated channels, just system IDs for identification purposes. The reality is you will never know what frequency you're operating on. However, if you want to assign different ID numbers, turn on receiver, select unique ID, pair with corresponding transmitter, done. There is no frequency selection by the operator. The system figures it out. Turn on a receiver, let it find a channel. Power up a transmitter, hit the pair button on the receiver and wait a few seconds. Done! Up to eight wireless systems can be operated simultaneously, for now. The digital audio sounds great and I think we can say goodbye to analog companding and noise reduction for wireless. 

Steve Oakley
This does beg at least one question, forwarded to me by video professional Steve Oakley. What about high density situations like the Super Bowl, in which, historically, a person called a frequency coordinator charts everyone's wireless systems and lays out a frequency plan so that no one steps on someone else; either by direct frequency conflict or by intermodulation. And near a big Wi-Fi network with hundreds if not thousands of smart phones in a stadium that size, what happens? 

According to Steve, "I talked with the officials and they thought that using wireless in the Wi-Fi band probably wouldn’t be safe or reliable, especially if anyone was making a Wi-Fi hot spot off their phone or laptop….which while forbidden to be done by the pro’s, may be done by someone in the audience because they don’t know or don’t care, and good luck finding 1 guy in 50,000!"

With so much wireless at major events, finding good frequencies can be difficult. Steve was getting ready for work on a Packers/Detroit game and just received his allocated frequencies. He offers this "from the trenches" comment, "Believe it or not the Sennheiser G3’s I’m running have, so far, been much more reliable than digital Lectro’s. Go figure! In fact the wireless mics being used at the NFL games on the parabolic mics are also Sennheiser, but the higher up models with presets and the option for higher output RF. So this choice of gear probably makes the frequency coordinators job a little easier since we are all using the same systems. In fact you’ll find most of the other ENG crews at the games are also using Sennheisers."

It may take some time before "the establishment" accepts digital audio in Wi-Fi space, but continued testing will soon provide workable answers. How hard can you push this breakthrough concept before the envelope breaks? According to Boss, "In one school setting A-T had a total of 12 channels spread out over 12 different classrooms. (one system per room)  Although the system is only speced to operate a maximum of 8 simultaneous systems. The 2.4GHz band and multiple levels of diversity allowed us to take advantage of the natural range restricting cinder block construction to achieve 12 simultaneous systems in one building. 

System 10 With Stompbox Receiver
System 10 Models
As noted above, Audio-Technica offers System 10 with body packs, lavs and headworn mics with prices varying depending on the specific configuration, and a guitar stomp box version System 10 with the receiver in the metal-cased pedal (for $349.) The pedalboard-mountable receiver is designed to stand up to the abuse of a typical pedalboard, and has dual outputs that allow you to route your signal to multiple amps, or you can set one output to mute while routing the other unmuted signal to a tuner for quiet on-stage tuning. It gets power from a universal 9-12 V DC power supply.

System 10 Transmitter, AT-MT830c Lav 
and Camera-mounted Receiver $449
DSLR Friendly
The camera-mount version offers a battery powered transmitter including AT MT830c lav, receiver with a slip-in case that mounts the receiver on a camera shoe and is powered by an internal, rechargeable battery for $449. The AT MT830c is a very nice side-address lav that's been in Audio-Technica's line for years. It's not the smallest lav on the planet, but the larger diaphragm results in lower noise

The ATW-R1700 Digital Receiver is a tidy package, weighing about four ounces with battery. On the back, are two brass screw-on fittings onto which you screw the antennae. The manual says they are most effective when positioned at the angle shown below. In between the antannae is the power switch. 
System 10 ATW-R1700 Digital Receiver

Along one side are two switches and a 1/8" jack. These are the Dual Mono/Balanced switch, the three position 0 db, -10 dB and -20 dB switch and the 1/8" output jack from which you feed the camera. The Dual Mono/Balanced switch allows you to output balanced mono or unbalanced stereo from the 1/8" output jack. On the other side of the unit are a USB port for powering and recharging, a 1/8" TRS jack for headphones and a small headphone volume control. It's really nice to have the headphone option, because many DSLRs don't have a headphone output. On the front are a System ID display and choice button, a Pair button, Pair light an audio peak indicator. A 1/8" TRS to TRS cable is supplied to connect the receiver to the DSLR

The rechargeable battery is not removable, You charge it via a USB power supply/charger. That makes a lot of location audio people a little nervous. What if you forget to charge it the night before? You can’t just swap out the battery. The receiver battery takes about 4.5 hours to fully recharge. A new or freshly charged battery lasts for 12 hours, but what happens as the battery ages and holds less charge? Audio-Technica says the battery is factory replaceable.
The Ginsberg Report
Fred Ginsberg of FilmTVSound, who's had good practical experience on the System 10, had a solution for the concerns about the non-removable 12-hour battery. The ATW-R1700 receiver uses a USB port to charge the battery. You can use the very same port to externally power the receiver. Fred found a "lipstick" power supply rated at about 3000mAh for $19. The mAh rating of the battery in the receiver isn't listed in the specs, but larger batteries are easily available. You can also run System 10 receivers off of your laptop USB port in an emergency.

Fred Ginsburg CAS PhD MBKS
Here is the link to the YouTube video that Fred posted with 3 of the walk tests that he did with the System 10 camera-mount wireless. According to Fred, "The unit achieves better than expected range; easily delivering the advertised 100 feet. On multiple occasions, I was getting 150 to over 200 feet."

Fred reminds us that these are low cost systems and not intended to compete against the (high end, and very expensive) wireless used on major shoots. I agree, but for an inexpensive unit with low latency, digital audio, I think they perform surprisingly well.

Fred brought the system with him to the Cinema TV Arts Dept at California State University Northridge for more tests. He describes the situation, "CSUN has a soundstage for the film program that is approx 50 feet by 75 feet. Camera and the System 10 stayed in the rear corner, while I moved around the entire space. Even while hovering near a laptop and the lighting dimmer board -- the System 10 performed flawlessly. And, yes, there is Wi-Fi in the stage. We went into the main corridor of the film/TV building (Manzanita Hall), which is dotted with electronic RFI emitters and WiFi routers (according to the department's Chief Video Engineer). The System 10 transmitted perfectly the entire length (approx 150 feet)."
"Heading outside onto campus, on multiple tests they achieved 150 to 250 feet. Although they did encounter the occasional minor dropout on one or two of our footpaths, the unit was always reliable up to 125 feet; and depending on the pathway, sometimes good past 200 feet. I included one of those walk tests, where they made it 220 feet before the signal began to cut out."

Fred said the aforementioned Video Engineer was curious about transmitting through walls, so Fred stayed inside the 'Corridor from Hell' while the Engineer went outside and roamed around the exterior of the building. "Signal held up nicely passing through just one exterior wall, but did drop out when he turned (still outside the building) 90 degrees from the corridor and thus placed multiple interior rooms in their signal path."

I'd like to see a full-on trial with, say, multiple, fully deployed eight channel systems in a dense Wi-Fi environment, to see if the System 10 could crack the Broadway Theater market. I don't expect Audio-Technica's System 10 to have an easy ride into the high-end professional marketplace because the established wireless user base is too well invested in Lectrosonic, Sony, Sennheiser, Zaxcom, Audio Ltd., Q5X and other more expensive gear. What I do see happening is their adoption by schools and other corporate entities first. I also see sound departments buying several sets to experiment with and using them as needed. 
System 10 needs to earn its stripes. Apple's FCP X caused much ranting and raving by 'the establishment' when it came out. "It's a toy! iMovie on steroids! Bah!" Apple listened and began adding features based on who screamed the loudest (and most intelligently.) FCP X has steadily increased in popularity ever since. I don't know why they didn't get a TEC Award for System 10. They certainly deserve it. 
Wish List For System 10 (or any location gear)
Smaller transmitters that are easier to hide (for everyone)
Plug-on Transmitter with Phantom Power (contributed by Jay Massengill, a producer in Burlington N. C.)
A two channel receiver with headphone jack for camera mounting (for DSLR users)
Transmitters that also record audio to a removable, internal card (for film production)

SpectraPulse Addendum
Audio-Technica's SpectraPulse Wide Band runs at 6.3 GHz. It's a 16-bit system with a 24kHz sample rate. The UltraWide Band data is transmitted in extremely short-duration pulses sent in a timed sequence over a wide frequency spectrum. To decode the pulses, the digital receiver module must know exactly when, where and how to listen. This makes SpectraPulse inherently secure. In addition, there is optional encryption that meets NIST-approved AES 128-bit standards. It runs 14 channels without the need for human frequency coordination.

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