Audio-Technica SpectraPulse Review
Mar 19, 2010 12:00 PM, By John McJunkin
A high-tech wireless microphone system for the boardroom.
The drm141 integrates the system's UWB antenna and logic required to send the signal along a Cat-5 cable of up to 300ft. in length. It recesses into a wall or ceiling in the space of a 3-gang electrical box and is otherwise simple, with just its RJ-45 jack facilitating connection to the aci707 audio control interface. The aci707 demultiplexes the audio, making it available via Phoenix connectors on its rear panel. Up to seven channels of audio can be routed from each aci707, so two units are necessary to take advantage of all 14 channels made available by the system. The aci707 also features dipswitches that determine toggle mode, local control, channel assignment, active mode, and mic level output. Its front panel has per-channel LED indicators for link mode, muting, switch closure, and low battery. An RS-232 connector enables its connection to Audio-Technica's charger, the cei007, which also facilitates the programming of 128-bit encryption for up to seven transmitters simultaneously.
I unboxed the system and placed the drm141 up high and in line-of-sight with the system's transmitters, per the manual. The receiver exhibits a directional reception pattern and must be in the same room with the transmitters. I connected it to the aci707 and powered the aci707 on. As I powered on each transmitter, the green link LEDs on the front panel lit up, and very quickly at that; the system did not have to hunt for available frequencies. I monitored the output of the aci707 via loudspeakers in the same room. The mtu101 boundary mic units worked nicely, providing more than sufficient gain when I placed them on a table top. The mtu201 gooseneck units also provided an excellent signal. I experimented with moving transmitters out of line-of-site, and indeed, I discovered that the reception pattern of the drm141 is quite directional. I also experimented with connecting quite a number of musical instruments to the mtu201 transmitters via DI box, and I was pleased with the results. I chose to do this because I had been skeptical about the system's audio quality given its limited bandwidth, 100Hz to 12kHz. Of course the "air" frequencies above 12kHz were not conveyed, yet the quality was still better than just passable. Still, I'll be looking forward to future revisions that open up the bandwidth closer to 20Hz to 20kHz. There were absolutely no glitches, static bursts, or any other audible interference whatsoever. The noise floor was virtually inaudible, and the D/A conversion quality was very good.
This system is right out on the bleeding edge of wireless technology, and as a result, it is not inexpensive. If the budget allows, the system is worth the money because it's simple to use while at the same time providing a good quality (if bandwidth-limited) signal that is as close to being 100 percent interference free as possible. The inherent signal security combined with the optional 128-bit encryption will satisfy even the most strident requirements. I strongly recommend this system for high-end installs.
John McJunkin is the principal of Avalon Podcasting in Chandler, Ariz. He has consulted in the development of studios and installations and provides high-quality podcast production services.
- Company: Audio-Technica
- Product: SpectraPulse Wireless Microphone System
- Pros: Virtually 100 percent interference-free, no frequency hunting, no multipath interference.
- Cons: Limited to 100Hz-12kHz bandwidth, charger cannot be wall-mounted.
- Applications: Primarily boardroom, corporate, meeting-oriented applications.
- Price: $1,300 (mtu101 and mtu201); $1,700 (cei007); $4,600 (aci707); $8,600 (drm141)
- Frequency bandwidth: 500MHz
- Center frequency: 6.350GHz
- AD/DA: 16 bits
- Sample rate: 24kHz
- Latency: 1.1ms
- Sync/reacquisition time: 3ms
- Range: 75ft.
- Simultaneous channels: 14
- Power input: 100-240VAC, 50/60Hz
- System frequency response: 100Hz–12kHz
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