Model 2000 2.4GHz Digital Wireless Headphones
Wireless
headphones have been around for some time with results that often times
fall short of user's expectations. My last pair of wireless headphones
used 900MHz analog technology and most of the time worked fairly well
. However, the technology sometimes resulted in occasional static with
dropouts, range problems and limited dynamics. New wireless headphone
technology such as the Model 2000 offered by Amphony Corporation, uses
digital transmission along with sophisticated digital error correction
that results in superior performance. The Model 2000 is a very capable
product that transmits audio to the headphones using the 2.4 GHz band.
Digital data is sent at a rate in excess of 3 Mbps (million bits per second)
resulting in true CD sound quality with no audio compression. A noise-shaping
filter incorporated in the headphones is used to remove quantization noise
from the audible frequency band. The headphones have velour ear cushions
and are comfortable to wear.
Main Unit
The
main unit is fairly small measuring only 7" wide and 5" deep.
An AC adapter is included that provides 9VDC to the unit. The top of the
chassis has indicators on the left side that let the user know what input
is active. The corresponding digital input (optical or coaxial) is automatically
selected when a valid data stream is detected. If no digital input is
detected, the unit defaults to the analog inputs. The center knob is used
to control the analog input level to the analog-to-digital converter (ADC)
within the base unit. This is important in making sure the full range
of the ADC is utilized which will result in the maximum signal-to-noise
ratio. The top right indicators illuminate when valid data is being transmitted
to the headphones and when the corresponding battery compartment is populated
and charging. The Model 2000 includes two full pairs of AA NiMH rechargeable
batteries so that one pair can be used in the headphones while the other
pair is charging in the base unit. This ensures you'll always have a set
of batteries ready to go. Each battery is rated at 1.2 volts at 1600 mAH
and is said to last up to 100 hours per charge under normal use.
Interfaces
The Model 2000 is designed to interface to both analog and digital audio
sources. The level control allows the user to set the optimal front-end
gain to the analog-to-digital converter for analog sources. The goal is
to maximize the audio level without clipping the signal. This will give
the best signal-to-noise and dynamic range possible in the audio transfer
to the headphones. Toslink as well as coaxial digital inputs are available.
The digital inputs accept 32K, 44.1K or 48K sampling rates. The Data
Out port is to be used with the optional RangeBooster Transmitter
module which is said to improve reception. We didn't have one on hand
so we could not verify this.
Performance
We
connected the H2000 system to our Sony DVP-NS900V SACD/DVD players for
testing. We used the analog and digital outputs of the player to drive
the inputs on the base unit. We had to disconnect the digital inputs to
force the H2000 to switch to the analog inputs.
The headphones are fairly light even with the batteries installed. Each side of the headphones hold a single AA battery that locks securely into place. The level control is conveniently placed on the right side of the ear piece and adjustable with your thumb. The headphones had adequate power and played loud enough for my taste.
Sound quality was very good for a wireless system in my opinion. In fact, I haven't heard a better wireless system that I can recall. However, it still has serious competition with wired headphones such as the inexpensive Grado (SR-60 and SR-80) line. Taking the cost of the system into account, the H2000 delivers great performance for the money.
We disconnected our 2.4 GHz spread spectrum phone to prevent any interference with the performance of the H2000. Amphony recommends that you consider the environment in which you use the H2000 wireless system as it may encounter interference with such products as 2.4 GHz wireless phones and wireless Internet devices. While the system worked perfectly in our test setup, we did find limitations in the range of the H2000 headphone system. Shortly after moving from our main listening room where the transmitter was located, we did encounter some dropouts in the form of scratches. Much depended on the exact location and head orientation, but it was cartainly there. With this in mind, I would recommend keeping the distance between the transmitter and headphones to a minimum.
Conclusion
We have not listened to a wireless headphone system to date that worked
as well as the Amphony Model 2000. What we liked about this product is
the consistent sound quality and the fact that it supports both analog
and digital interfaces. The fidelity was as good as we've heard from a
wireless system. In short, if you need the convenience of a wireless system,
you can't go wrong with the Amphony H2000 system keeping the interference
issue in mind.
- Kevin Nakano
