I fully support this conclusion—and my own testing aligns perfectly. I use steep crossover filters (e.g., 42 dB/octave or higher) not just for precision, but also to minimize sound leakage and reduce neighbor disturbance. The effect is so pronounced that even monaural (single-ear) listening reveals clear differences. This further proves that raw driver measurements alone can’t explain what we actually hear. If ‘perfectly matched’ speakers still behave differently in real-world conditions, perhaps we need to rethink how we define ‘accuracy’ altogether.
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Understanding subwoofers
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Is this true? You (or some company) have made speakers that measure virtually identical in every way known in today's science, made of different materials ie 100% Titanium vs 100% Aluminum vs 100% flax, and people have observed differences in a blind study? Could you link to this study, along with the measurements of the different speakers? This would prove the case that there is something else out there.
my statements are based on my experience. I do not copy foreign claims from the internet. If the membrane manufacturer claims there is an absolute difference in the sound of membranes, I believe the rest of the tests are unnecessary. There used to be a membrane made of bextrext for the KEF110A, absolutely soft and overly damped, now we have hard membranes, cast from plastic, and others.
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I am asking, has the speaker industry ever made 100% material specific speakers (100% only made with Titanium drivers vs Aluminum etc) that measure exactly the same on the Klippel to each other, in order to see if there is in fact, a material-related influence that is observed, yet not measured in today's science.
Rigid diaphragms are highly stable, yet beyond a certain point, they resonate. Others—like Audax’s Aerogel—decay smoothly with minimal resonance, despite their exceptional stiffness and optimized profile. Even if a speaker’s acoustic roll-off and an electrical filter match perfectly in amplitude and phase, audible differences remain due to material behavior.
For bass, diaphragm stability and mass are critical. Heavy membranes demand more energy to drive, but when they unleash it, the result is a visceral, authoritative impact. This is about power, not mere volume. Two bass drivers playing at the same loudness will not sound the same—the heavier diaphragm delivers far greater dynamics and presence.
Speakers with a linearized magnetic field, a weighted diaphragm, dual suspensions, and excellent linearity will outperform lesser designs—and inevitably cost more. As a listener, you won’t see this in specifications. You must hear it for yourself, ideally in your own room.
For bass, diaphragm stability and mass are critical. Heavy membranes demand more energy to drive, but when they unleash it, the result is a visceral, authoritative impact. This is about power, not mere volume. Two bass drivers playing at the same loudness will not sound the same—the heavier diaphragm delivers far greater dynamics and presence.
Speakers with a linearized magnetic field, a weighted diaphragm, dual suspensions, and excellent linearity will outperform lesser designs—and inevitably cost more. As a listener, you won’t see this in specifications. You must hear it for yourself, ideally in your own room.
Let's see these results with woofers. Make sure you give enough detail for replication and to understand the controls used.
I’ve created measurement graphs (amplitude, phase, impedance, etc.) and I’m happy to share them. The graphs do show some differences in amplitude response, but these are mainly useful for driver mat
That’s exactly my point: the audible differences between the materials can’t be fully explained by standard measurements. This either means we’re not measuring the right parameters, or our tools don’t have the resolution to capture these subtle effects. I can post the measurements if you like — but they will mainly confirm that the differences we hear aren’t easily visible in conventional data.
One note regarding the measurements: in some cases, the distortion (THD) values appear elevated because I measured at home at relatively low volume levels. The low signal-to-noise ratio in that environment can distort the absolute distortion figures. What matters here is not the exact THD values, but the relative shape and behavior of the distortion curve across frequency.
So please keep in mind that these measurements are intended to illustrate trends, not provide laboratory-grade absolute numbers.
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Or... when it comes to woofers, you haven't run any sort of controlled experiment and you have nothing to back up your extraordinary claim.
What you have there beyond that is a mess of measurements where you have not controlled ANY of the other confounders.
As a follow-up of my above post, and just for your reference, especially the actual example of crossover between L&R subwoofers and main SP's woofers,,,
Very recently, I re-checked re-confirmed Fq-SPL of amplifier's SP high-level output into L&R subwoofers, woofers, midranges, tweeters and super tweeters. Furthermore, I also re-checked re-confirmed my preferred Fq-SLP of room air sound at my listening position in my room acoustic environments. Please visit my post #1,009 on my project thread for the details, if you would be interested.
The following diagrams are the essence of the results thereof.
Please note I do not like, I do not apply, too-much-smoothing on Fq-SPL spectrum which hides-out various room modes.
I would rather prefer common smoothing factor (FFT size, in this case) throughout 20 Hz - 20 kHz which well visualizes various room modes.
I’m not aware of any measurements—certainly none that can be done privately at home—that truly capture or represent the acoustic structure of a diaphragm material. What I’ve done with midrange drivers applies equally to tweeters and woofers. In fact, I found a suitable woofer fairly quickly.
The point of sharing my measurements wasn’t to make extraordinary claims, but to illustrate that I’ve worked with many drivers over the years and have developed a solid sense of how different diaphragm materials sound to me. There are audible differences in acoustic behavior, and that’s what my experience reflects—acoustic impressions perceived by the ear, not easily shown in standard measurements.
If you have measurements, experience, or references that demonstrate otherwise, please share them. Otherwise, let’s stop with the constant questioning that seems more aimed at showing off than having a constructive discussion. Frankly, it feels like a textbook case of Dunning-Kruger effect at play.
antcollinet
Grand Contributor
It doesn't
Keith_W
Major Contributor
From what I understood from my conversation with the driver manufacturer, more modern materials mean that drivers can be designed with wider bandwidth, lower distortion, higher sensitivity, push break-up modes higher up the frequency range where they can be crossed over, and so on. It gives the speaker designer more options. I don't think you will find anybody making two drivers that are identical except for the cone material, because the properties of the cone material have already been exploited in the driver design.
I think it's better if we compare modern drivers with vintage drivers which did not have modern cone materials. They had to make much more significant trade-offs. Lack of amplifier power meant that drivers had to be high sensitivity. But heavy cones ruin sensitivity (since acceleration = Mass/Force), so cones had to be light. With the materials they had at the time, they could not make stiff and light cones, so they all had break-up modes. Particularly since they could not use high order crossovers, since high order crossovers also ruin sensitivity. This is why vintage drivers sound the way they do - incredibly coloured. Modern drivers don't sound like that.
@LSPhil I've only skimmed the thread (so my apologies for missing anything or repeating what others have said), but to my understanding you have measured different woofers with different materials, and found measurable differences. This is not surprising, every driver is of course different.
What I haven't found through my skimming of the thread, is how you know that these differences is due to the inherent qualities of the material rather than other things - so other properties of the drivers that are not directly related to the cone material.
What I haven't found through my skimming of the thread, is how you know that these differences is due to the inherent qualities of the material rather than other things - so other properties of the drivers that are not directly related to the cone material.
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All of this makes sense, and of course modern materials help with design flexibility and performance. But the OP isn’t shopping for a vintage sub. Just because one material makes things easier for manufacturers doesn’t mean a sub made from something else can’t sound just as good.
What I take issue with is how the discussion jumped from “more musical subwoofers” to “more musical materials,” and then to the idea that none of it is measurable. That’s pretty extraordinary.
Absolutely right. I have the Isophon PSM 120, built around 1975/80, and even today it can still compete with modern drivers. As far as I know, it was the first midrange driver equipped with a copper (Cu) ring, which reduced the modulation distortion factor by about -10 dB. I believe Isophon also used such a ring in their 12" woofers.
Today, Isophon is out of business, and Dr. Gauder, who took over the name, no longer uses these designs—though perhaps they’ll be revived one day.
Nowadays, we have excellent drivers with stiff diaphragms and precisely simulated motor structures. These not only generate very low distortion—something that’s especially important in the lower midrange—but can also move a lot of air to reproduce bass very accurately.
The problem for the consumer is knowing what kind of driver is actually used in a given product. Often it’s only through subjective listening impressions from users that you can get a sense of whether a system is technically well-designed. That’s exactly why subjective assessments are so valuable.
This is also why I chose, for example, a driver from the Dayton Audio RSS series—they deliver outstanding performance. Ultimately, the consumer often has to rely on subjective evaluations to make their decision, as they’re essentially choosing blind.
I believe that if you go with reputable brands like Canton, JBL, KEF, Seas, or ScanSpeak, your money is generally well spent. The real challenge lies with niche manufacturers, where you often don’t know what kind of driver is actually inside the subwoofer.
You’re absolutely right that any driver consists essentially of two main parts: the motor (drive unit) and the diaphragm (cone). The diaphragm itself has both its shape and material properties.
In my comparisons, I specifically looked at two drivers that are otherwise identical except for the cone material because I was searching for a suitable midrange for my three-way system (which I also showed in the photo, with the SB12CAC installed alongside the RSS315HF-4 and Audax TWO25A20Mg).
The two midrange drivers I compared were the SB12MNRX25-4 (with a paper cone) and the SB12CAC25-4 (with a ceramic-aluminum cone). Both were acoustically matched for my system. The listening impressions were absolutely different: the CAC sounded fast, bright, and highly detailed, whereas the paper cone was more restrained and didn’t project forward like the CAC.
With subwoofers it’s harder to isolate differences because of large enclosures and room placement effects. I compared three bass drivers: the RSS315HF-4, the RS270-4 (which is no longer made, though there’s a similar one from Scan-Speak), and the DSA315-8. All have aluminum cones, so here the differences came down to the motor design: the RSS has 3 shorting rings, the RS270 a different ring configuration, and the DSA only one ring.
As a pure subwoofer in a bass reflex setup, the DSA315 is fine as a low-end extension, but it’s a disaster if you try to use it as a woofer up to 500 Hz. The other two are outstanding, with the RSS315 being my clear number one choice.
I’ve also done comparisons with tweeters, but to be honest I’ve held back from sharing that because a colleague from New York already gave me quite a hard time in this discussion!
Geert
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Every time you are asked for evidence that supports your claim that cone materials for sub drivers matter because of resonance in the cone material, you start about midrange drivers or frequencies.
Now you did it again.
And again.
O mój Boże — powiedziałem to już co najmniej trzy razy: dotyczy to również głośników niskotonowych. W którym momencie ktoś stwierdzi, że takie rozważania nagle nie mają znaczenia dla głośników niskotonowych tylko ze względu na ich rozmiar?
Spróbuj sam się nad tym zastanowić. My, ludzie, jesteśmy najbardziej wrażliwi na średnie częstotliwości, tak, ale to nie znaczy, że wydajność głośnika niskotonowego i materiał membrany nie są również ważne. Przedstawiłem argument, że materiał membrany jest wysoce istotny dla dobrej reprodukcji akustycznej i że słyszalne różnice istnieją. Nawet producent wyraźnie to stwierdza na swojej stronie internetowej.
A tak przy okazji, jeśli chodzi o duże rozmiary membran w głośnikach niskotonowych, to i tak mamy do czynienia głównie z dwoma rodzajami materiałów: papierem i aluminium. Nie wystarczy czepiać się szczegółów i szukać sprzeczności — zamiast tego spróbuj zaangażować się i zrozumieć zachodzące relacje, nawet jeśli na początku wydają się trudne.
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