Å? Det er jeg ikke helt enig i. Skal litt til å kjøre vedvarende konsertsalnivå på 108dB med 120 peaks. Og hva med +/- 0.25dB avvik mellom høyttalerne, med mulighet for rekalibrering etter service?
I tillegg kommer ALT spredningen av mellom og topp.
Og en SNR på 120dB.
(Jeg er ikke objektiv - det står et par i lytterommet.)
Power
The amplifiers are made up of 1000W each for the main and upper woofers, together with 250W each for the midrange and tweeter giving a total of 2500W output. "Such power permits B&O to address the issues of thermal power compression (by calculating it and adding back sufficient gain offset) and to run effortlessly at something approaching real concert hall levels (i.e. sustained real-world levels of 108 dB SPL with peaks of 120 dB SPL, should you care to entertain all of the folks on your block). A typical high end audiophile speaker system with two gigantic mono block amplifiers running at 500 W apiece will run out of steam at probably 10 dB below these levels, all other things being equal. Such power also means that at all sane levels, the BeoLab 5 is simply loafing along, never stressed in the slightest, and if you encounter any signs of distortion, you can know for sure it is occurring elsewhere in your signal path.
Finally, the speaker is fully digital, so you can plug in an S/PDIF feed if you wish. The A/D and D/A converters are of extremely high quality, so no problems will be encountered there either. But the real payoff is that extensive DSP is present, which permits each speaker to be quickly and precisely matched (+/- .25 dB) and documented during manufacture. This, to my mind, is a huge breakthrough. It means that for all intents and purposes, speakers will not be audibly different (a first for mass-produced speakers), and because of thedocumentation, they can be maintained to hold that tolerance! (Just so you know, there's an RS 232 port included, so the speaker can "talk" to the factory and its DSP is recalibrated to accept a replacement driver)." (Source)
Adaptive Bass Control (ABC) actually 'listens' to the bass reflection characteristics in the room in which BeoLab 5 is placed and adjusts its output to suit the listening position
ABL (Adaptive Bass Linearisation)
As well as the two brand new technologies, BeoLab 5 employs Bang & Olufsen's Adaptive Bass Linearisation which is a process patented by B&O and incorporated in newer (digital) BeoLab loudspeakers. The idea is to use the surplus capacity in amplifiers and driver units, arising by normal listening levels, for a bass extension - a sound reproduction with more bass, than the loudspeaker otherwise would be able to produce.
The function is adaptive. This means that the loudspeaker adapts to the signal it receives. Loudspeaker drivers are therefore fully exploited, without suffering mechanical or electronic abuse, and the built in amplifiers are not subjected to signals would otherwise create an overload situation.
ABL gives stunning bass reproduction considering the size of the loudspeaker in which it is incorporated, under normal listening levels.
BeoLab 5 & Acoustic Lens Technology
ALT is short for Acoustic Lens Technology and is a patented geometric shape that when properly mated to a conventional dome radiator yields an extremely wide, uniform horizontal dispersion characteristic. Acoustic Lenses redistribute the sound power of a driver (a tweeter, for instance) such that the resulting dispersion is very uniform over at least 180° horizontally. The vertical radiation pattern is asymmetrical. It is limited such that very little sound is directed towards the floor. Somewhat more energy is directed upwards than towards the floor but, in general, the radiation pattern may be described as a 'hemidisc'.
ALTs unique dispersion characteristics help in several ways. The most obvious is that listeners seated off-axis hear virtually the same timbre as those on the reference axis. An ALT loudspeaker has a flatter power response curve than a conventional loudspeaker. This means that the total sound energy radiated by the speaker is more closely related to the axial frequency response or direct sound. This type of behaviour correlates positively with listener preference in controlled listening tests. This is why some manufacturers have rear firing tweeters. ALT does this while minimising reflections from the floor and the wall behind the speaker. The Archimedes Project, a 5-year multimillion dollar research project that delved into the relationships between acoustic reflections and the perception of timbre, revealed that such behaviour is desirable. Finally, ALT loads the driver to which it is mated so that less electrical energy needs to be applied to achieve the same SPL as a baffle-mounted driver. This increases power handling and lowers distortion. ALT does all of this while maintaining excellent axial frequency response.
