Preface to the book

The subtitle of the book may at first sound too much promising or inflated, which it, however, is not at all; for as will show up especially in chapter 4, the issue is indeed about a fundamental fallacy in sound reproduction technology.

We have namely been deceived − not so much with intent but by negligence or ignorance anyway − by providing to our use solely audio power equipment that disregards the realities of physics, and by establishing, as the backing of the practice, yet odd myths that do not stand up closer examination. Most regrettable in the present practice is that the manifoldly indefinite electromotive forces of the loudspeaker are freely allowed to mingle with the reproduced signal.

The book you have opened is the result of many years of investigation and work and probably the first volume ever to delve into loudspeaker current-drive. The start has been made with a clean slate, and the reader is not required to necessarily have prior knowledge in the field. The symbology used is as simple as possible, not referring to the general, difficultly configured symbology of the art.

The book is intended as an eye opener and guide into a new kind of technology as well as a source of new innovations and inspiration and clearer of common illusions for all who have any interest in sound reproduction implements or music. The content and way of representation are suitable both for the academic community and hobbyists as well as all interested; but above all for the equipment industry, the principles and ideas outlined afford a wealth of new opportunities.

A problem in entering the market may be, however, the baggage of history, that is, the justification of former products and the fact that a current-drive speaker is not suited to be used with a conventional voltage amplifier and a conventional speaker is not well suited for current-drive. Such cross-usage should be prevented by some means, and as the wayshowers would perhaps best be suited new actors that are capable of manufacturing both amplifiers and speakers.

The presented design and construction guidelines provide all DIY-minded with the opportunity to enter into experiencing in practice the dramatic sound quality improvement brought by the current-principle, without stepping into those pitfalls in which deficient knowledge easily leads and without needing to await the awakening of industrial manufacturers. At the same time, also the general pursuing of and knowledge on analogue electronics may gain new substance.

Besides actual current-drive information, novel ideas and methods e.g. for filter design, computer modelling, and measurements are also presented. The operation equations and modelling of loudspeakers are expounded in an understandable manner, and the fundamentals of linear systems are taught to those unskilled in them.

Existing faults are brought out at times even quite vigorously. However, the issues treated are universal, and nobody has reason to react to them personally although recognizing one's own misconceptions may sometimes produce inconvenience.

When it comes to the sound quality achievable by current-drive, it is probably pointless to describe it very much by words because all adjectives have already worn out in the assessment of conventional hifi gear down the ages. From my own experience, I can state, however, that although I have been able to listen to, e.g. in exhibitions, both expensive and extremely expensive voltage drive systems, I have never been satisfied with what I have heard, especially with any electro-dynamic speakers. Instead, the current-drive equipment I have used is like from a different world, and finally I have been able to be fully satisfied. The difference is so decisive that I rather listen to a current-drive system even in mono than a voltage drive system in stereo, and there is no turning back.

If you also agree that the design of loudspeaker operations should conform to the known laws of electrodynamics and other relevant sciences rather than to some old tradition or popular imagery, don't fail to do something about it. You may also consider posting a review on the store page where you shopped or elsewhere.


  E. M.