So there you are, doing a gig, and soundcheck is about to start, and you have a line that is not working. Your assistant grabs his Qbox, runs onstage, plugs into the line, and turns on the tone. You see the tone coming up a different channel than you expected and realize there was a simple patching error — problem solved. Then, at the last minute, a press camera shows up and wants a feed. You give it to him and send him some signal. He tells you he is getting nothing. You grab your Qbox, take the line from his camera, plug it into the Qbox, and turn on the speaker. You both hear the signal, and you give the line back to him — problem solved. Your line works. Now you can relax and mix the show.
This is such a common scenario, which is why the Whirlwind Qbox has been an indispensable tool for sound people since the day it was invented. Sound has changed quite a bit since then. Now that digital sound has become so prevalent, there is a new scenario that the original Qbox can't handle. The original Qbox is an analog testing device. If you need to test a digital input or output, then the QBox is of no use. But now, Whirlwind has just released the AESQbox, so, finally, we have a tool to help troubleshoot digital and analog problems.
What It Does
AESQbox tests in the following three modes:
- Input/output or normal mode.
- Pass thru: The digital audio received on the input is passed through to the output at the same sample rate so that the audio content may be monitored. The AESQbox is acting as both a “wiretap” and a “repeater.”
- Cable test: The analog audio is delivered to the AES output where the user can then test your digital cable by connecting from the output back to the AES input, which should allow the user to hear the audio. This could also be described as a self-test mode for the unit.
The AESQbox recognizes digital sample rates from 32kHz to 192kHz. A set of input sample rate indicators shows the following sample frequencies (in kHz): 32, 44.1, 48, 88.2, 96, 176.4, and 192.
The AESQbox can output tone from a built-in generator, as well as from a built-in microphone or from the aux input, which accepts analog line-level signal. The analog signal is converted to AES/EBU digital and output via the male XLR jack and BNC. One of the requirements of this design is to produce high-quality audio. The headphone/speaker amp circuit has superb THD and noise specs, and the line output will have near pro-quality sound. The idea is that this unit can also double as a quality, portable AES-to-line or line-to-AES converter.
How It Came To Be
The original Qbox generates audio with a tone generator, a built-in mic, or a line input. It also receives audio and outputs that signal with its built-in speaker, headphone jack, or line output jack. So when you have a dead sound system, you can generate audio at various points in the system until it starts working. Then you've located the problem. You can also listen to the audio at various points in the system to verify what is working and what is not.
For example, you plug a mic into the stage snake, and you get no audio. You substitute the Qbox for the microphone and generate tone — still no audio. You use the Qbox to generate directly into the snake, then directly into the mixer, and then directly into the cross-over, etc., all the way to the power amp. When the system starts working, you've found the location of the problem.
Or there is no audio out of a mixer's aux bus. So you plug the mixer's aux output into the Qbox and hear audio. Now you know the mixer is okay, and the problem is farther down the line. You can continue to use the Qbox to listen and verify where the problem occurs.
“We do several trade shows a year, and some Qbox users mentioned that they would like to be able to do the same type of troubleshooting in an AES/EBU digital audio system. So the AESQbox was born,” says Al Keltz, general manager of Whirlwind. “People started talking to us before NAB 2006, and we did a mockup of the AESQbox and took it to NAB. It didn't work, but it lit up and had all of the features that we were planning. People gave us some suggestions about what they liked and didn't like. One thing was that they wanted it built into a more rugged box. After NAB, we started working on it.” After another year of development, it appeared as a fully functional unit at this past April's NAB show, to which the general consensus, according to Keltz, was, “I want one.”
“It was the first time we had done anything with AES/EBU, so the lead engineer who built it — Bob Schwartz, the design engineer — had to do a lot of research to figure out how to make it work,” adds Keltz. “We had certain considerations to keep in mind, as well: fit it in a portable box and keep it at a good price.”
Whirlwind is making a second model (AESQbox 44.1) that performs different sample rates. The standard sample rate for most people would be 48 and 96. According to Keltz, that box is almost ready to ship. “We also plan to broaden our development of specialized AES/EBU devices for the broadcast and live audio markets,” he says.
What End-Users Have To Say
“Overall I've been very happy. I had been waiting for a long time for the AESQbox. It is a good all in one box,” says Jim Hibbard, owner of Pacific Mobile Recorders. “I did some modifications to make it analog and digital. I made a cable to plug the digital in to digital out. Then if you plug something into the aux input, you have an analog tester,” he says, explaining the versatility of the unit. “I would like to see all sample rates 44.1 and 44.8 from the generators. In broadcast, 44.1 is the standard, but in recording, higher rates are more common. As for having it in my toolbox, it is at the top of my list. And it is 25% of the cost of the competitors. A comparable box is $1,000 and doesn't have a speaker built-in.” Hibbard adds, “In an emergency, you could even use it to convert digital to analog because the converters are quiet enough, and that can't be said for the competitors. I work on radio stations for a living. I build broadcast facilities all around, and I take this little box with me everywhere I go.”
Mitch Glider director of engineering Westwood One Radio Network explains, “The first time I used it, it worked great. I didn't even have to open the manual. I just plugged it in, turned it up, and monitored my sound. I plugged in to the SPIDF. There is also a loop-thru which is great. All in all, it did what it was supposed to and was easy to use. It is a great tool to always have around.”
For more information, visit www.whirlwindusa.com
Shannon Slaton is a sound designer and engineer living in New York and currently mixing Jersey Boys, The Drowsy Chaperone, and Spring Awakening on Broadway. Other Broadway mixes include Man of La Mancha, Sweet Charity, Dirty Rotten Scoundrels, and Bombay Dreams. He designed the current national tours of Hairspray, The Producers, The Full Monty, Contact, and Kiss Me Kate.