Which is Better for Loudspeakers, Metal or Silk Soft-Dome Tweeters?



When Revel launched their Ultima2 line of speakers, they went with a beryllium-domed tweeter.

We audiophiles are oftentimes a strange bunch.  The endless — and if we’re honest, silly — debates that we engage are oftentimes based more on folklore than fact.  One such area is about tweeter materials.

In general terms, dome tweeters are either soft or metal.  We should note that there are other tweeter technologies too such as ribbon tweeters that we won’t get into here.  With dome tweeters, you’ll sometimes hear soft dome referred to as silk dome or fabric, depending on the material used.

High end speaker maker, Dynaudio, uses silk soft-dome tweeters in all its speaker models.  Dynaudio has relied on silk soft-dome tweeters for recreating high frequencies since the company was founded, continuously improving and perfecting the soft-dome principle over the years.

Metal dome tweeters tend to be either aluminum, titanium or beryllium.  As a rule of thumb, you’ll see aluminum dome tweeters in entry to midrange level models, titanium in midrange to high end speakers and beryllium used in very expensive high end models.  As with any rule, there are certainly exceptions, but this is a fair description of the current marketplace.

High-end French speaker manufacturer, Focal, uses a Beryllium tweeter in their flagship models. Beryllium is seven times more rigid than Titanium or Aluminum, the latter two well known for their rigidity. Focal says that this results in a sound wave propagation three times faster than Titanium and two and a half times faster than Aluminum. In the end, the linearity of the frequency response curve, the acoustic transparency and the impulse response of the Beryllium tweeter are maximized and offer near-perfect sound.

But the real question is, “Which is better?”  Gene DellaSala over at Audioholics.com has published an excellent article highlighting some of the differences between soft dome and metal tweeters in this article.

Those who have their opinions firmly rooted in one over the other may find themselves a bit disappointed.  As with all technologies, it sometimes boils down to how something is implemented.


  1. There is no definitive answer to your question.
    As with most technologies in audio (i.e. tube versus transistor amplifiers or vinyl versus digital), quality is largely dependent on implementation. It is perfectly possible to design high performance loudspeakers with both soft and metal dome tweeters, as long as specific characteristics of respective driver materials are optimized in the design of the driver and proper implementation into a loudspeaker system is taken care of. In particular for metal domes this means avoiding 'breakup modes' that will ruin sound quality.
    Well designed tweeters are build with from carefully selected and tested parts (dome material, surround, voice coil, motor etc.) to give a smooth response over the intended frequency range. The use of sophisticated and tailored waveguides will further improve the tweeters' performance (optimized on- and off-axis directivity, less distortion in the passband etc.).
    It is a general (mis)conception that metal dome tweeters will always sound harsh compared to their soft dome opponents. The Revel Ultima Salon 2, you mentioned is a perfect example. In comparison: Dynaudio's highly regarded Esotar softdome tweeter could sound rough and unbearably harsh if used improperly.