KEF SP4027AA - Manuals - manualsarea.com

Page 3 - Raymond Cooke, KEF founder; Tweeter

1 Introduction “If I have seen further, it is because I stand on the shoulders of Giants.” This famous quotation, attributed to Sir Isaac Newton, illustrates how progress is made in virtually all scientific disciplines - progress is evolutionary, rather than revolutionary. So it is in the developmen...

Page 4 - Metamaterials

2 3 The most important innovation in this loudspeaker is the near-perfect absorption of the unwanted rear sound generated by the tweeter dome. One might legitimately ask, “Why is this important?” It’s true that, if the tweeter is listened to on its own without the contribution of the bass/midrange d...

Page 6 - Motor Design; This ensures as much of the sound as possible from

6 7 Motor Design In addition to the tweeter motor system being modified to accommodate the wider duct through its centre pole, other changes were made to provide a more consistent drive to the voice coil. Figure 16 illustrates the difference in tweeter motor design between the original LS50 and the ...

Page 9 - Diaphragm

12 13 Appendix 2 - Ports Ports are used to augment bass response. They have the dual advantage that they enable a lower cut-off frequency than closed-box systems for the same size of enclosure and, within the operating range of the port, the bass driver moves less, thus lowering distortion. Ports ar...

Page 10 - range. This is done by introducing a flexible,; Tangerine Waveguide

14 15 Being within the human audio range, the break-up has to be tamed, rather than putting it out of hearing range. This is done by introducing a flexible, decoupling material between the cone neck and the voice coil former. The high-Q resonances are tamed to the extent that they may be properly at...

Page 11 - LS50 Wireless II

16 17 Summary As can be deduced from reading this paper, there is a lot of technology packed into the LS50 Meta, both new and existing - a culmination of many years of KEF innovation and acoustic expertise. All this technology, although tackling legitimate sound reproduction problems in a scientific...

Page 12 - socket; Streaming support; Wireless streaming supports the following:

18 19 Overview The active LS50 Wireless II incorporates all the technology described for the passive LS50 Meta, plus a few extras that either add to the presentation of the music - making it even more accurate - or add to the functionality. The electronics, mounted on the back, includes two channels...

Page 13 - Best results are found by ear.; Phase correction

20 21 DSP Processing Figures 44 & 45 show block diagrams of the electronics in the Primary and Secondary speakers respectively. All settings are controlled from the smartphone app and applied equally to both speakers. DSP allows much finer control of the signals reaching the drivers than with a ...

Page 14 - Bass Extension

22 23 Even measuring off axis in the horizontal plane results in unequal path differences once the angle is large enough that the radiation from the bass driver does not travel directly to the microphone, but has to travel first to the front of the cone. The result is that any phase correction in th...

Page 15 - Summary

24 25 Should the subwoofer have an inverting amplifier (rare) or be sited well away from the LS50 Wireless II such that the output is not in-phase with that of the LS50 Wireless II at crossover, there is the option to invert the signal to the subwoofer. In this case the appropriate toggle should be ...

Page 16 - Specification - LS50 Wireless II

26 27 Specification - LS50 Wireless II Description Wireless HiFi Speakers Drive Units Uni-Q™ Driver Array LF/MF: Nominal dia. 130mm (5.25 in) magnesium/aluminium alloy cone HF: Nominal dia. 25mm (1 in) aluminium alloy dome vented with Metamaterial Absorption Technology (MAT) Frequency Range (-6dB) 4...