High-end audio fans attach great importance to loss-free transmission of the sound signal between the source and the ears. In the past, wireless audio transmission has come up against its limits. Now however, audio specialist Sennheiser is opening up a new class of wireless listening with the new RS 220 wireless headphones. The digital wireless headphones have a full, detailed sound while offering total freedom of movement.
Headphone development is driven by the challenge of reproducing sound that is as lifelike and direct as possible. Up until now, cabled headphones had a far better audio quality than wireless headphones. But now, the RS 220 from Sennheiser is setting new standards. “With these digital wireless headphones, we have succeeded for the first time in combining wireless music enjoyment with high-end quality,” said Maurice Quarré, Director Product Lifecycle Management at Sennheiser Consumer Electronics, describing the new RS 220.
Many years of experience in the field of wireless transmission and audio technology have gone into the development of the new digital headphones. Dynamic transducers with powerful neodymium magnets ensure clear, lifelike audio reproduction with a frequency response of 19 to 21,000 hertz. The maximum sound pressure level of the open, circumaural headphones is 106 decibels. In the RS 220, the transmitter sends the audio signals to the headphones without compression via a stable 2.4 GHz connection using the so-called Direct Sequence Spread Spectrum (DSSS) technique. “This is a frequency spreading process in which the output signal is spread to a width of 22 MHz by means of a specified bit sequence. If interference occurs at one point within this frequency range, the output signal experiences no interference as the data is transmitted with redundancy, in other words several times. As a result, only a minimal and inaudible part of the whole information is affected and the overall sound quality is not influenced,” explained Axel Grell, Senior Acoustical Engineer at Sennheiser. The headphones have a range of up to 100 metres without the need for the transmitter and receiver to be in the same room. A further advantage of the transmission process is the low latency and thus minimum delay of the audio signal.
The sound quality of a set of headphones is decisively dependent, among other things, on the connection between the audio source and the headphones. As the data between the transmitter and receiver is transmitted wirelessly in the RS 220, the feeding of the data from the audio source to the transmitter is particularly important. For this reason, the headphone system has an analogue, a coaxial digital and an optical digital input. Discerning users can decide themselves on the type and quality of the audio signal being fed in. Sensor buttons on the transmitter or directly on the headphones enable users to switch back and forth between the sources.
An important means of creating a musical effect is the transition between quiet and loud passages, as can be heard for example in Ravel’s Bolero. Conventional digital data transmission sometimes reduces this dynamic range, as an optimum signal volume for the entire data package is often assigned to the information when the analogue signal is converted into a digital data package. To preserve the original dynamics of a piece of music, the RS 220 completely dispenses with the automatic level control function. The data of the digital sources is transmitted unchanged, and the user can manually adjust the reference volume for the analogue inputs. As a result, the system comes very close to the audiophile ideal: a lifelike sound experience.
Operating the RS 220 is extremely easy. An on/off switch, controls for selecting the audio source and tracks, as well as a volume control are directly integrated into the headphones. There is also a control to individually adjust the volume balance between right and left. Setting up the wireless headphones for the first time is equally easy. Simply connect the transmitter to the audio or video device using the chosen connector, put on the headphones and switch on. The headphones come with rechargeable batteries that guarantee up to eight hours of listening enjoyment and which can be conveniently recharged while still in the headphones. As an added feature, the transmitter can also be used to supply a second optional set of headphones – for shared listening pleasure.
The RS 220 will be delivered to Sennheiser sales partners from September.