Field Coil Speakers Everything You Need To Know

Field Coil Speakers, Everything you need to know

Although those who are committed audiophiles will be well aware that field coil speakers were, until recently, a thing of the past, they will also be delighted to discover that they are now starting to make a comeback as more people start to recognise the many benefits that they offer.

There is a pervasive idea that technology from the past should be overlooked in favour of new and innovative developments however, just occasionally, history has something special to offer, and certain old technologies are well-worth revisiting. Field coil drivers are one such old technology that may have been eschewed for years but which is only now seeing a resurgence due to its surprising advantages.

With this in mind, here, we take a closer look at field coil audio systems and why they offer such a superior music listening experience for those who are determined to enjoy audio at the highest possible level and with maximum emotion and engagement.

Field Coil Driver Super Tweeter
Field Coil Speakers Drivers Horns Super Tweeters
Field Coil Horn Driver Western Electric

What Is A Field Coil Speakers

Essentially, a field coil is an electromagnet, with a DC current creating its magnetism. Field coil drivers use DC powered electromagnets as a motor to propel the cone, whereas a standard dynamic driver will use a permanent magnet for moving the cone. This makes an enormous difference to the quality of sound that can be produced. A field coil speaker is a loudspeaker that features an electromagnet rather than a permanent magnet.

The History of Field Coil Speakers

The first field coils could be found in electrodynamic loudspeakers during the early years of the 20th century. Around 1920, permanent magnets that had the necessary strength were simply too heavy, too big and, most importantly, too costly. Meanwhile, field coils were more affordable, lighter and capable of producing sufficient energy by utilising a power supply that was big enough.

Over the years, permanent magnets reduced in weight, and became stronger and more affordable to produce. Thus, eventually, they replaced electromagnets in the field coil driver. These days, virtually all manufacturers use a form of permanent magnet in their loudspeaker drivers. Yet, field coils haven’t disappeared completely. In fact, some of the very best loudspeakers today still use field coils. These exotic drivers sound outstandingly transparent and musical, making their counterparts that don’t use field coils sound veiled in comparison. But why is this the case? After all, both use magnets…

Field Coil Horn Speakers
Field Coil Speakers From Classic Audio Loudspeakers
Field Coil Driver Speakers & Horns

The Difference Between Permanent Magnets And Electromagnets

Although both electromagnets and permanent magnets use magnetism, they are very different. The magnetism in permanent magnets is down to an aligned electron spin. Meanwhile, magnetic fields in electromagnets are generated via moving electric charges in which the electron spins aren’t all aligned. This is the primary factor when it comes to the sound produced by permanent magnet drivers and field coil drivers.

Field Coil Speakers Drivers and Horn Speakers
Tube Field Coil Power Supply
Tube Field Coil Power Supply
What Benefits Can Field Coil Drivers Offer Over Permanent Magnet Drivers?

A field coil driver’s flux field density will remain constant whenever voice coils move in the motor’s gap. Conversely, permanent magnets cannot always achieve this constancy. This means that permanent magnets may experience sags in flux density when the voice coil’s magnetic field draws from the field of the permanent magnet when the motive force of current is present. Field coils also have stronger motors that are determined by current and voltage and this makes their power delivery more constant and stable.

Why Are Field Coil Drivers Considered Exotic Today?

Although field coil drivers were once commonplace, these days they are rarely seen in the marketplace. They are, therefore, seen as exotic by manufacturers, primarily because they’re more costly to produce than permanent magnet drivers. Field coil speakers must, in general, be built by hand and are less convenient due to their reliance on an outboard supply of power. The manufacturing process is considerably slower due to the extra precision and difficult tooling required.

The majority of speaker manufacturers therefore find that the cost of production outweighs the revenue produced from sales, and therefore leave the technology consigned to history. Furthermore, there tends to be too much focus on looking for new advances rather than looking back at ways in which past technology can be integrated into the latest devices. Fortunately, high-end loudspeaker manufacturers have now started to look back at the field coil driver with interest and have begun to incorporate it into their designs once more.

With field coil drivers being more dynamical, speedier and capable of creating details with considerably more accuracy than the majority of standard magnetised speakers, they are set to make a major comeback in the near future. At the moment, though, only a few selected manufacturers are using this effective solution for superior musical presentation, and for those who value the highest quality sound, it is their speakers that should be a top purchasing choice.

Field Coil Horn Speakers
Field Coil Horn Speakers with OTL Amplifiers
Field Coil Horn Speakers Using OTL Amplifiers

Choosing Field Coil Speakers For Outstanding Quality

Here at Phantom-Audio, we’re dedicated to selling luxury, exotic systems that are designed to satisfy even the most demanding audiophile. It is our mission to focus on products that produce the best possible level of sound that allows a true emotional engagement to be created between the listener and their music. We don’t believe in selling audio for its own sake – rather, we believe that sound should always be produced to its highest standard for maximum enjoyment, and to this end, our range of field coil speakers have been especially chosen for the outstanding experience that they offer the listener.

We only sell the best brands in the audio industry for the enjoyment and pleasure of our customers. Our two top ranges of field coil loudspeakers include Classic Audio Loudspeakers and Line Magnetic Audio.

Classic Audio Loudspeakers provides cabinet designs to a craftsman standard that produce exceptionally emotive, evocative and intense audio. Meanwhile, Line Magnetic Audio’s audio equipment has been manufactured for highly discerning listeners to ensure the very best playback quality. With a variety of speakers within both manufacturer’s ranges, we’re confident that there is sure to be a perfect product to suit your needs, preferences and requirements.

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