Become a member
Become a member
Continuer avec Google

or
Log in
Log in
Se connecter avec Google

or
learning

Ribbon Speakers

The Operating Principles of Loudspeakers - Part 4

In the previous article we discussed compression drivers and acoustic horns. Today we'll focus on a technology whose patent was issued in the 1920s and widely used for microphones. However, its usability for loudspeaker design remained questionable up until the 1950s, when some improvements allowed ribbon speakers to be successfully marketed.

View other articles in this series...

Ribbon speakers

ribbon tweeter
Cross-section view of a ribbon tweeter

These speakers are based on the same principle as cone speakers, i.e. the interaction of the magnetic field of a magnet with that of a wire through which the signal coming from the amp passes. However, the wire is not coiled around a cylinder extending from the diaphragm. The diaphragm itself is the signal conductor, taking the form of a rectangle held by two of its sides. The electronic circuit is drawn on top, trying to spread it as evenly as possible so that the magnetic force is uniform. The fact that the voice coil and the diaphragm are combined in a single piece makes the moving section lighter, thus avoiding, at least in theory, the displacement of the diaphragm. The conductor is spread across the entire surface, exercising a more homogeneous motive power than a voice coil which has to drive a cone at one end.

Characteristics

apogee acoustics synergy
Full-range ribbon speaker ─ Apogee Synergy model  [Source: apogeeacoustics.
com]

The lightness of the ribbon, often made of aluminum, allows it to move very fast. Its transient response is good and its frequency range often goes well beyond 20 kHz. However, its small size and light weight don't withstand heat too well, which limits power handling. Ribbon drivers are usually used for high-mid and high frequencies, even though you can nowadays find some full-range models out there. Finally, the impedance of the ribbon is very low, which requires the use of an additional transformer ─ a potential source for signal degradation ─ for the amp to work correctly.

The width of the diaphragm must be low, otherwise the air gap will be too big for the magnetic field to be strong enough. It is already larger than that of a moving coil speaker, meaning it requires the use of larger or more powerful magnets to hold an equivalent magnetic field. And since magnets are expensive, so are ribbon speakers. On the other hand, the narrowness of the ribbon provides a much higher directivity in the horizontal plane.
Besides the size of the air gap, there's another factor that can compromise the speaker's efficiency: it's not hard for the ribbon to have acoustic leaks. Since the ribbon is only held by two of its sides (the other two must remain free in order for it to be able to move), the the back wave could eventually short-circuit the front wave if it's not appropriately absorbed.

Despite their fragility and high cost, ribbon speakers have won over a large community of hi-fi enthusiasts due to their qualities in terms of frequency response, directivity and transient response. Moving coil speakers are usually preferred when you know they will be exposed to harsh conditions or you need a higher efficiency.

Ascendacoustics Sierra 2 speaker with ribbon twitter
Speaker with ribbon tweeter and cone driver Ascendacoustics, Sierra-2 model [Source:ascendacoustics.
com]

With the next article dedicated to more uncommon models we'll close the chapter dedicated to electrodynamic speakers. And then we'll move on to other types of transducers.

← Previous article in this series:
Drive it Home
Next article in this series:
Unique Electrodynamic Speaker Designs →

Vous souhaitez réagir à cet article ?

Log in
Become a member
cookies

We are using cookies!

Yes, Audiofanzine is using cookies. Since the last thing that we want is disturbing your diet with too much fat or too much sugar, you'll be glad to learn that we made them ourselves with fresh, organic and fair ingredients, and with a perfect nutritional balance. What this means is that the data we store in them is used to enhance your use of our website as well as improve your user experience on our pages (learn more). To configure your cookie preferences, click here.

We did not wait for a law to make us respect our members and visitors' privacy. The cookies that we use are only meant to improve your experience on our website.

Our cookies

Cookies not subject to consent

These are cookies that guarantee the proper functioning of Audiofanzine and allow its optimization. The website cannot function properly without these cookies.

Website preferences

We store your preferences so that you do not have to re-enter them every time your come back (forums options, dark or light theme, classifieds filter, standard or buzz news, newsletters popups...).

Log in

This one makes sure you don't have to re-enter your credentials every time you visit Audiofanzine.

Analytics

This data allows us to understand the use that our visitors make of our website in an attempt to improve it.

Advertising

This information allows us to show you personalized advertisements thanks to which Audiofanzine is financed. By unchecking this box you will still have advertisements but they may be less interesting :)

We did not wait for a law to make us respect our members and visitors' privacy. The cookies that we use are only meant to improve your experience on our website.

Our cookies

Cookies not subject to consent

These are cookies that guarantee the proper functioning of Audiofanzine and allow its optimization. The website cannot function properly without these cookies.

Website preferences

We store your preferences so that you do not have to re-enter them every time your come back (forums options, dark or light theme, classifieds filter, standard or buzz news, newsletters popups...).

Log in

This one makes sure you don't have to re-enter your credentials every time you visit Audiofanzine.

Analytics

This data allows us to understand the use that our visitors make of our website in an attempt to improve it.

Advertising

This information allows us to show you personalized advertisements thanks to which Audiofanzine is financed. By unchecking this box you will still have advertisements but they may be less interesting :)


You can find more details on data protection in our privacy policy.