The active and digitally rectified Backes & Mueller line 50 (108000 EUR the pair) hides most of the listening space problems with their cylindrical waves radiation. The result is stunning.
- Active speaker Backes & Mueller line 50
- Data sheet
Beginning of December 2010 the editors got high visit: the latest version of Backes & Mueller line 50 made her waiting for a show at the newly established high end magazine audiophile. The two-metre-high speaker Tower sounded so convincing, that it was clear: that must be tested also in stereoplay. We had already heard of the ambitious construction of BM flagship. She would sound but sooo good…
But in turn. in 2004, BM mastermind Johannes Siegler devised the first line 50. It was created as a response to the problems of large, acoustically difficult because little damped listening rooms. Siegler: the idea “came to me when a documentary about Peter Gabriel. “He stood there in this Studio with large window surfaces, removed about five meters from the speakers, and it was to see him, it sounded not good: too much glass, to much reflection.” Not directly for Gabriel, but for the many other victims tried Siegler, the only his well-known ability to translate: the cylindrical wave radiation.
Most readers know the method of surface emitters such as electrostatic. In the appearance actually resembles a cylinder: the viewing angle is quite stable in width and opens downwards and above as well as not. The sound is so direct, ground – and ceiling reflections are avoided. Siegler calls the “Close box extension”: “the listener sits with the line of 50 in larger listening distances almost always in the near field. This blessing is also a curse. The line of 50 sounds very inhomogenous under three meters distance. From four meters for the better.”
The construction of the line 50 is responsible for this six midrange (run from 80 Hertz) form a line array that allows the combined response in the central area on the baffle. The four medium-sized drivers go to 800 hertz, the two outer expire before gently. The figure of the music scene is so not unrealistically large. The acoustic Centre and the real sting of the line 50 take over from 800 hertz: a professional high-frequency compression driver with 1-inch opening and extreme efficiency. An adapter making an angular dispersion of the original round was required to make him but also cylinder shaft justice Potter. There was no mathematical equation for this adapter.
The Fraunhofer Institut für techno and Industrial Mathematics (ITWM) in Kaiserslautern, designed a program that can exactly make these calculations for Siegler.
In the smaller models line 25 and line 35, the BM man used tapes in the treble. Why not also in the large 50s? Siegler: ‘six low-midrange driver, which are not required even at very high levels – there can keep up just a horn.”
The four 10-inch bass on the back that are regulated and extremely clean in BM are another special feature of the BM flagship. A DSP in the active crossover ensures not only 90 decibels (!) Slope, but delay also ensure that the high – and medium tone signals arrive at exactly the same time at the listeners ear – like the bass. The often demanded (and rarely reached) phase equality becomes a reality here. The power amplifiers deliver over 1000 (analog) watt alone in the bass and can produce any arbitrary volume basically.
Distribution is particularly at BM: he is settled in Germany only have two traders (Sprint service in Wesseling and BM Service Center South in Kornwestheim). If you are interested come the specialists, build the boxes and they measure a. Siegler: “most of our previous dealers could not afford this expense. I’m glad that we now offer our customers this service.”
In particular is also the sound of the line 50, their Potenzial but only opens up beyond the four-meter distance. We sat closer, at least the space was limited. Tonal default extremely dry, the line of 50 shot bass volleys (such as by Marcus Millers “Panther”) almost humorless when with them stunningly powerful and with incredible precision on the handset. How clean swung to the strings there, as three-dimensional and tangible Miller’s instrument in the room was traced, how much information of this speaker even at deafening levels still boom completely free transport was able to – this was absolute class.
And yet the BM could even more. After an intensive phase of filter translation, she got even the enamel in the voice in addition to its almost unique clarity. Sting’s rough Sung “Englishman in New York” ( stereoplay title CD 10/10) was a delight, listening with the BM, a journey of discovery through the deep staggered Orchestra with its various instruments. Plasticity and resolution goodness conveyed the feeling of being very close to the recording. In this intensity, I’ve experienced that only very rarely.
The line 50 is one of the most comprehensive transducer of the world thanks to their precision, the deep bass and the vast reserves of the level – safe – and should be for the fulfilment of Peter Gabriel. Our listening room, however – and therefore the line 50 is also only with reference – is ultimately a bit too small for this greater superbox.
Backes & Müller BM line 50
|Manufacturer||Backes & Müller|
Technical data and test results
|Installation tip:||Free-standing. Mindesthörabstand = 3,5 meters. For areas beyond the 40 square meters|
|Operating voltage for 90 dB SPL|
|Impedance minimum stp|
|Maximum volume upper value||107 dB|
|Maximum volume lower value (> 45 Hz)||107 dB|
|Lower cut-off frequency (-3dB)||29 Hz|
|Lower cut-off frequency (-6 dB)||26 Hz|
|Short conclusion||Active and deskewed digital speakers with cylinder wave radiation. Developed for large listening distances, the line 50 is unquestionably among the best speakers in the world. The combination of high level and utmost neutrality is unique.|
|Sound||Absolute top class|
|Sound points (70 points)||68|
|Overall rating (max. 120 points)||outstanding 92|
|Price / performance||well|
|tested in output||3 / 11|