What is the Best Tweeter or Woofer Material
We get this question more often than you’d think. What is the best tweeter or woofer material? If cost was no object, which is definitively the best? It’s a fun thought experiment but often the question comes on the heels of, “I was shopping for speakers and was wondering…” That’s where we run into problems. While there are real, objective metrics that suggest that one material is better than another, speaking in absolutes is dangerous. First, let’s look at what makes a good material for a tweeter or woofer.
What Makes a “Best” Tweeter or Woofer Material
When recreating sound, you want your driver material to be two things – light and stiff. As the driver moves in and out, you want it to be easy to move (light) and you don’t want it to distort or bend while it moves (stiff). At different frequencies, these materials look different. While silk might be fine at higher frequencies, it is inappropriate for lower frequencies. Paper cones are great for bass but not so good for the high frequencies. Matching the material to the frequencies is important.
This is because no material is perfect. At some point it starts to flex or has other problems. One might be lighter but it flexes at a specific frequency. Another might be heavier but is much more rigid. A third might be light and rigid, but it is very expensive to manufacture. When a speaker designer plans out a speaker, they are not looking just at “what sounds best.” They have to deal with making sure they hit specific price points and limitations.
Even in a “cost-is-no-object” speaker, there are limitations. You can’t make a speaker so big it can’t get in a normal doorway. You can’t create a speaker with a tweeter or woofer that has a diaphragm material that is so rare that only a handful can be created before the world’s supply is exhausted. So the designer has to make compromises.
We Create What We Know
When you look at a line of speakers from a specific manufacturer, you’ll see similarities between the lines. Even if they have multiple lines of speakers at vastly different price points, the speakers will generally look similar. That’s because the speaker designer (provided it is the same person or persons) uses materials that they are familiar with. Sure, the new hotness might be beryllium or magnesium or folded ribbon tweeters, but they have always used silk domes. So that’s what they use. Every material has problems that need to be addressed, and the silk dome tweeter is known to the designer. They are comfortable using them, so they do.
Occasionally, you’ll see a speaker manufacturer step out of their comfort zone. Sometimes this goes well (the KEF MUON speaker is an example) but many times they don’t. When they work out, they change the direction of future speaker designs. When they don’t, they are a one-off that is quickly abandoned.
So What is the Best Tweeter or Woofer Material?
If there were a “best” material, it would be used in all speakers. Or at least in all the high-end speakers. But there isn’t. All driver materials have issues. As such, the “best” material for tweeters or woofer is the one that the designer can optimize most effectively. When you look at a speaker and see a material used for the woofer or tweeter, you can make some assumptions about the speaker’s cost, but not its sound. The driver material doesn’t make or break the sound of a speaker. There is the internal volume of the box, the shape and length of the port, the crossover, the bracing, the baffle shape…so many more things that contribute to what you hear.
We’d love to say that a specific material is the “best” for tweeters and woofers, but it just isn’t the case. Folded ribbons have their advantages over silk domes. But in the hands of the wrong designer, they’ll sound terrible. We’ve seen some of the most expensive speakers on the market with silk dome tweeters. Does that make them the best? No. What it means is that the designer found a tweeter that had the performance and tolerances that they thought would sound best in their speaker. Could they have used a different tweeter or woofer with different materials for their diaphragms and gotten similar or better performance? Maybe.
A Speaker is an Ecosystem
But raw performance isn’t the only consideration of a speaker designer when they choose a specific driver. As we mentioned, the price and accessibility of the material/driver are considerations. But more than that, they have to consider the performance of the midrange driver and how the tweeter will cross over into it. You may have the best tweeter in the world, but if it can’t play low enough to crossover cleanly into the midrange, it won’t work.
Again, there are midrange driver materials that might be the best for specific frequencies, but if the material starts to distort before it can be crossed over into a bass woofer or tweeter, it is useless. There are a lot of things to consider when choosing a driver, and the material used for the diaphragm is usually not the defining characteristic.
How To Shop For Speakers
When shopping for speakers, you always lead with your ears. We’d love to say that “all speakers with X material for their tweeter or woofer are better than those that have Y.” It just isn’t true. In fact, we’d argue that you shouldn’t pay attention to the type of driver materials or designs at all! Instead, listen first. If you find out that a speaker has a tweeter with an exotic material or design, you might assign more value to that speaker before hearing it. By listening first, you judge all the speakers on their sonic merits. With some speakers, that’s impossible. An electrostatic speaker is visually different from any other speaker design. But try. In the end, you’ll buy a speaker because of the way it sounds, not because it has a tweeter or woofer material that the Internet told you was the “best.”