What is Speaker Cone Breakup?

Cone breakup is what happens when the cone is moving faster than the material it's made from can keep up with. It starts to bend and ripple, causing sounds that are generally objectionable. This happens at higher frequencies and you need to design your crossover to try to cut off the drivers response before it reaches the breakup region. Using higher order filters will more aggressively roll off the signal before the breakup and drive the level down below audibility.
Where breakup will happen is determined by several factors: What the cone is made from, how stiff it is, the shape and the diameter of the cone are the primary ones.
It's no accident or arbitrary decision why the cone is a cone shape - it it's the strongest geometry for resisting that breakup.

While I say I'm not an expert, I do know quite a bit about audio and I have a lot of practical experience. I've been messing with it since my early teens, so more than 40 years.
The information presented in these videos is as accurate as I can make it, within reasonable time constraints. I don't have weeks to thoroughly research a particular topic, but I never go on my assumptions - I always check to make sure that I have the correct understanding of what I'll be talking about.
And I ask you to do the same: if you think I've made a mistake based on your understanding of the topic, please take a few minutes to check whether you are right before commenting. And please also (and this is important) don't take the word of your favourite audio guru as a reliable source for factual information on these subjects. While I put in the time to verify that what I say in these videos is accurate, not everyone does. And there's also a strong motivation to say misleading things if there's a project being sold.
I'm not selling anything here, I'm doing this for fun and because I'm very interested in audio. I also like watching videos on the topic and figure I would make some for other who have the same passion to watch.

You can help support the work I do in making these videos:
Support this channel on Patreon:

#diyspeakers
#johnheisz
#audio

My "Scrap bin" channel:

My main channel:

[IBuildIt]

Cone breakup is what happens when the cone is moving faster than the material it's made from can keep up with. It starts to bend and ripple, causing sounds that are generally objectionable. This happens at higher frequencies and you need to design your crossover to try to cut off the drivers response before it reaches the breakup region. Using higher order filters will more aggressively roll off the signal before the breakup and drive the level down below audibility.
Where breakup will happen is determined by several factors: What the cone is made from, how stiff it is, the shape and the diameter of the cone are the primary ones.
It's no accident or arbitrary decision why the cone is a cone shape - it it's the strongest geometry for resisting that breakup.

While I say I'm not an expert, I do know quite a bit about audio and I have a lot of practical experience. I've been messing with it since my early teens, so more than 40 years.
The information presented in these videos is as accurate as I can make it, within reasonable time constraints. I don't have weeks to thoroughly research a particular topic, but I never go on my assumptions - I always check to make sure that I have the correct understanding of what I'll be talking about.
And I ask you to do the same: if you think I've made a mistake based on your understanding of the topic, please take a few minutes to check whether you are right before commenting. And please also (and this is important) don't take the word of your favourite audio guru as a reliable source for factual information on these subjects. While I put in the time to verify that what I say in these videos is accurate, not everyone does. And there's also a strong motivation to say misleading things if there's a project being sold.
I'm not selling anything here, I'm doing this for fun and because I'm very interested in audio. I also like watching videos on the topic and figure I would make some for other who have the same passion to watch.

[michaeltablet]

You may not be an expert but you are way ahead of me and I am learning a lot. Thank you!

[alexz]

Great video, I will recommend it when explaining cone breakup to new builders.

A more advanced consideration is that cone breakup can manifest as high order harmonic distortion and ringing. That can break the perceptual masking threshold, reducing audio quality. When picking crossover points, it is worth looking at the spectral decay of individual drivers. I recommend using a 30 cycle window, normalized to the frequency response.

[gregmatula]

Great topic. Back in the early '80s I would spray hairspray on four and a half inch full range drivers it lowered the resonant peaks and increased the frequency response measurably and audibly a big difference. That was a paper cone Pioneer A11EC80-02F.

[martingarrish]

For paper cones I recommend soaking diaphragm in silicone fluid. I used to use Ambersil 60'000 cst silicone oil, but there are plenty of other manufacturers. It is non toxic and environmentally benign. Brush onto paper diaphragm then let it soak in over night. I used to run in drivers at same time as soak to really get oil around fibres. In fact, I coated spider and even rear of cone. Silicone oil will weep from driver for several weeks, but doesn't affect veneer or electronics and easily wipes off.
The effect is to damp out any cone breakup without adversely affecting the flexure that you need for higher frequency dispersion and horn loading. Even after years of use and abuse my own full range designs still sound as accurate as the day they were installed.

[OnePotMeals]

An honest man. My first advice to people who build speakers or design them, or even opine on them, is get a hearing test. That way when are critiquing a design you know you can actually hear what you are talking about

[thomasduby]

I’ve really been enjoying the speaker and sound series of videos. Several years ago I picked up interest in this hobby. Unfortunately for me, my hearing drops off around 7 kHz. And it’s been dropping over time. I think there will be enough stuff going on here to get me going again despite limits to my hearing.

[johndough]

Distortion is Not merely just caused by the "Frequency". Its often a factor of how much volume (power level) and the formed higher air pressures at play. This is multiplied by what Is actually trying to be played, at those higher volume levels.

[HenningJohansen]

This video brings back memories of building Radford-type transmission line speakers in the mid seventies, where we used the oval rigid-cone KEF B139 woofers. This driver used a solid styrofoam cone. I have often wondered why this method of achieving cone rigidity was not copied more often.

[NeilBlanchard]

Some tweeters, like dual ring tweeters, by design do not act like pistons. The Vifa midwoofer looks to be very clean.

[KravchenkoAudioPerth]

Nice presentation. I'll throw in my two cents as a driver designer. All speakers have cone breakup. Including soft dome tweeters. In fact Soft dome and most other tweeters have breakup around 10 kilohertz. A metal diaphragm driver, be it a woofer, midrange or tweeter should be used in the pass band that they are designed for. Where the breakup lies is where you don't want to be using them. Same goes for any other softer coned product. Even Kevlar and Carbon Fiber cones exhibit breakup modes. The key is simple. Steep enough crossover that the breakup is at least 24 db out of the drivers useful range. Not a fan of open baffles, they are to much of a compromise. Can't get loud enough for me and still be low in distortion.

How are you going to address the baffle diffraction losses on a baffle this narrow?

Mark

[davidbailey]

I wish I knew what you forgot… Thank You for these videos….!

[alexw]

Good stuff. I still say the usable frequency spec is misleading. It would be next to impossible to use that woofer up to 5k and get that breakup to be 20db down.

[macedindu]

I just pulled up an online tone generator, and it turns out I can hear a 20.154kHz tone. Barely. It's a weird sensation.

[sudd]

i thought cone breakup happened every time i sold my speakers and got new ones.

[fubartotale]

I seem to to remember you talking about designing an 8" TL sub a while ago, am I mistaken?

[GWAIHIRKV]

Interesting the data sheet said 80 - 5000 kHz! That’s one hell of a speaker going to 5MHz. . .

[mrupholsteryman]

So...in the conversations about the who was wrong...if the cone is honest... the cone would admit to the piston. .. its not you.. its me. Haha!

[johndough]

Im going to add something about Frequency specs... My first paid of Audiophile (just barely considered that) headphones, were the Sennheiser HD 500 's. Their range was 14 to 21, 000 Hz. They had an amazing 3d Soundstage, and the audio was FAR superior to anything Id heard before them. However... I later found a user pair of HD590 's. Specs: 12 to 38, 000 Hz. And let me tell you... that there was a night and day type of difference between them! While my human ears might not be able to hear above a certain frequency... it didnt seem to stop me from hearing vast sound quality bump... especially in the Highs. Crystal clear details.. without being harsh. Details that the 500s were incapable of, and or was kind of muddied / distorted.

Think about this like a Cargo Vans maximum load capability... compared to a standard Car. The cargo van, under the same exact daily loads... will perform and last MUCH longer, than the car. Why? Because its built far more Robustly. Stronger Frame. Stronger Engine. Stronger Brakes. Etc. Both can get you from point A to B... but One has a huge difference, beyond the surface level looks.

Basically... that if the Driver is capable of a much higher capability... than it wont easily suffer from distortions... compared to the lower spec drivers, that have a more limited frequency range. While you still might not be hearing anywhere near what the superior drivers are putting out... you STILL we benefit from the drivers SUPERIOR PRECISION.. which equates to a superior audio experience (and yes, you still will hear a vast difference in frequency output).

Ive given my HD 590's to a person whom I worked with, to have a listen. He claimed to have bad hearing, due to some hearing damages. But his eyes lit up, and he was utterly shocked at how different those sounded... compared to anything hes tried before... and DESPITE his self proclaimed hearing loss.

In fact, one thing to consider, in addition to what you may or may not be able to easily hear... is the fact that as you raise the volume levels.. certain things that you normally might not have been able to hear... suddenly becomes notable. And heres the thing... a poor quality driver isnt even going to be able to reproduce certain upper frequencies, or plays the ones it does... with some levels of distortions. The higher the volume, the more distortion possible. If you get a higher quality driver... you can push it much harder / higher... and there is FAR less distortion levels... not only with Normal volume levels... but even at the most Extreme volume levels.

That said, I listened to a headphone that claimed it had more range than my Senns. It was so mid-heavy, that it was unbearable to listen to. No amount of EQ was able to make it tolerable. The dude was literally half deaf, so it didnt phase him. However, it makes you realize, that you cant always trust the numbers... especially from corrupt companies.

And finally, its not just about the Frequency ranges either... (especially since some are tested at low levels). You also have to check the THD levels (Total Harmonic Distortion levels), to see what the spec'd levels of tested Distortion levels are. Ultimately, hearing the drivers in-person is the best way to know for sure, how well it sounds and performs. But, you shouldnt write off a superior driver.. just because you assume "I wont be able to hear that frequency range, anyway". When in fact, its far more about the quality and precision of the drivers... which result in FAR less distortions... especially at higher volume levels... which equates to Superior music at any and all levels of playback. Basically, its typically well worth the extra costs for the better drivers.