Field Report: JK Audio RemoteMix One, BluePack

November 1, 2012


Smart phones have become the de facto news gathering tool of choice. The RemoteMix One by JK Audio and its Bluetooth twin BluePack can mix and feed one microphone and one line level device to a cell phone in a compact, portable package. It creates a professional front-end to a cell phone whether it is used for phone-ins or as an IP codec.

JK Audio BluePack

JK Audio BluePack


Connecting a professional microphone or mult box feed to that tiny 3.5 mm TRRS (tip-ring-ring-sleeve) cell phone connection can be challenging without a proper interface. What if a reporter wants to feed audio cuts in real time during a report? Lugging around a portable multi-channel mixer may be impractical. Need a wireless mic at a press conference that interfaces to your cell phone? These challenges and more are met with the RemoteMix One and BluePack.

JK Audio RemoteMix One

JK Audio RemoteMix One


These rugged, belt worn devices join an elite and innovative family of remote production tools including various Bluetooth enabled devices for transmitting and receiving audio via a cell phone. "On-the-Street" reporting demands an uber-simple interface so the correspondent has their head in the story, not the technology on their hip. There are only three user volume controls: "Mic," "Aux Send" and "Head Phone" with only two switches for "Power" and "Mic Mute." The BluePack exchanges the "Mute" for a Bluetooth pairing "Multi Function Button."

The inputs and outputs

The XLR jack is a "mic" level input and works with any standard dynamic microphone. It does not provide phantom power. A playback source can be fed through the "Aux In" 3.5 mm jack and controlled with the corresponding front panel control. This mix is sent to the phone via a 1/4" "Headset Interface" jack.

Performance at a glance
■ Operates on 9V battery
■ Wired phone connection for RemoteMix One
■ BlueTooth phone connection for BluePack
■ Belt-pack mixer and monitor amp
■ Rear-panel I/O

The 1/4" headphone jack provides a very adequate 0.5W per channel mix of the microphone, auxiliary source and return audio from the remote end. For recording purposes, a stereo 3.5 mm jack outputs the local "mic" feed on left channel and return audio on the right. The reason for this arrangement, according to JK Audio's Joe Klinger: "Most recorders loop the input (record) audio directly to the output jacks for real-time monitoring. We went out of our way to ensure that [the] 3.5 mm output does not get looped back into the input, to avoid an echo or feedback loop. You can still hear the full mix on the headphone jack."

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Popular Interface

Incorporated Bluetooth technology in the BluePack allows the user freedom of movement without a cable between the interface and phone. This freedom comes at a price however, Bluetooth technology is purposely limited in audio bandwidth (300-3400 Hz) since the additional audio information would be lost on a standard phone connection. Klinger also tells me a new Bluetooth standard called HD Voice is coming soon. It will support 50-7000 Hz bandwidth with lower noise and improved dynamic range. The RemoteMix One wired connection, however, retains the full 20k audio range.

The advent of IP codecs has changed the remote production landscape. Now, full bandwidth audio can be transmitted back to the station via the cell phone network using 3G, 4G and Wi-fi-enabled phones. The RemoteMix One is a cost-effective alternative to the stand-alone IP interface.

Out of the box

Simple to set up and operate, the RemoteMix One needs very little preparation. Install a single 9V battery, hook up the headset cable to the cell phone audio jack, plug in the mic and you're ready to broadcast. Though anecdotal, the power consumption during testing was minimal. The manufacturer boasts run times in excess of 10 hours on the BluePack (20 hours on the RemoteMix One) with a single battery.

Using the BluePack requires the process of "pairing" to a Bluetooth enabled phone. Pairing begins by pressing and holding the Multi Function Button (MFB) for 5 seconds. The pairing request should appear on any Bluetooth enabled phone within range. Once bonded, future connections will take less time as the phone data is stored in memory. Up to 16 devices are held in the memory. Pressing and holding the MFB for 20 seconds clears that history.

Tests were conducted in conjunction with an iPhone, iPad and multiple phones on the Android platform. No configuration or modification to the phone is necessary using the RemoteMix One. The phones used during the test immediately recognized and configured themselves for headset operation.

JK Audio
800-552-8346
jkaudio.com
info@jkaudio.com

A popular smart phone IP codec was chosen to test the full bandwidth capability of both the RemoteMix One and the BluePack. iPhone/iPad performance was flawless with both interfaces. Tests using a Samsung/Android and HTC/Android also yielded very satisfactory results. Only in one case was there a problem with distorted audio when using the BluePack with the IP codec. It turns out the HTC Model PC36100 running Android version 2.3.5 had a difficult time translating the Bluetooth audio to the IP codec. There were other problems encountered with the same phone model such as distorted audio when placing phone calls after using the IP codec. It was isolated to this particular phone/OS/IP codec combination. No other phone tested had these issues.

Whether it was coverage of Fan Fest at the World Series, drop-ins with a morning show host or on-the-street interviews, the RemoteMix One and BluePack met or exceeded expectation.


Chestnut is assistant chief engineer, Entercom Communications, Kansas City.



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