For sure, technically inferior materials can be engineered to perform at SOTA levels if you're willing to pay for it. Peerless makes some highly regarded corundum tweeters though that have been compared to beryllium tweeters. Flat response across a wide frequency range with low distortion.I think driver material choice is overrated. Audiophiles have a bit of a weakness in this regard.
It is important in terms of engineering properties, but on the other hand even a well engineered affordable modern aluminium dome like the Seas DXT (less then $100!) which is used for example on real reference loudspeakers like the Kii Three and Grimm LS1 can provide sufficiently good properties to be transparent (see also https://www.audiosciencereview.com/...rbeth-30-2-vs-kef-r3.14450/page-2#post-445233 ) so the quest for the exotic unobtainium material is more marketing and hype nowadays then anything else. In the 1970s the modelling, simulation and engineering of the drivers wasn't as far though, so the Yamaha Be drivers were truly a step forward though.Why would anyone think that the driver dome material is unimportant? That is an absurdly silly statement, imo.
I’m not sure, but it sure is very difficult to clap your hands in one location and listen to the echo in a different location without a microphone.Why would anybody be stupid enough to think the sound source should be coincident with the listener?
It isn't what is easy that counts though. Doing something completely inappropriate because it is easier than doing it right is stupid and pointless. Just IMO of course.I’m not sure, but it sure is very difficult to clap your hands in one location and listen to the echo in a different location without a microphone.
...and most other technologies and sciences.Modelling and simulation tools are probably the biggest reasons loudspeaker technology has advanced to where it is today.
Particularly in making cheap units have very good performance.Modelling and simulation tools are probably the biggest reasons loudspeaker technology has advanced to where it is today.
Even if properly designed, a metal cone/dome will behave like a piston only up to its first structural resonance frequency. There isn't much inherent material damping in metals, so any resonances are going to have a very high Q. This is clearly apparent in the audio passband when bass-midrange drivers make use of metal cones (and usually a bit above 20 kHz for tweeters). Even though the crossover may heavily attenuate those resonances, is it wise to have them present in the first place as a result of a poor choice of material, when better approaches are available?Properly designed the cone will act as a piston. If it does resonate, like paper and plastic do, damping will be applied to reduce the colouration.
What is meant by the characteristic sound of the cone material when it is breaking up? Doesn't a cone material simply possess properties of density, stiffness and loss factor (damping)? Aren't those the fundamental material characteristics that are needed to be identified when engineering a new cone design? How do any of these engineering properties translate to a "characteristic sound" if the frequency response of the driver is ostensibly flat? Isn't the audio performance simply a result of the structural resonances, damping and piston-range behaviour of the cone, and not the "material" per se?It is important to understand that, in a speaker, you are not listening to somebody using the cones as percussion instruments but, ideally, the cone does not breakup in its passband so that any characteristic sound the material would have won't be part of the sound coming from the speaker.
The following might provide some guidance. In terms of audibility of different materials, back in 2010, Rotter and Lindau published a paper titled "Audibility of tweeter performance beyond spectrum and phase" (PDF). They concluded that (emphasis added):Why would anyone think that the driver dome material is unimportant? That is an absurdly silly statement, imo.
That was a somewhat flawed study in my view. They did NOT test for actual audible differences. They offered linear (free of distortion) emulations (auralizations via headphones) of tweeters EQ'd to the same target. That last part is OK and actually required (since we don't want to judge frequency response as such), but using only a linear copy of the signal and the "indirect" comparison via head-tracking headphone playback is questionable. It just made the experiment much easier to conduct.Even if properly designed, a metal cone/dome will behave like a piston only up to its first structural resonance frequency. There isn't much inherent material damping in metals, so any resonances are going to have a very high Q. This is clearly apparent in the audio passband when bass-midrange drivers make use of metal cones (and usually a bit above 20 kHz for tweeters). Even though the crossover may heavily attenuate those resonances, is it wise to have them present in the first place as a result of a poor choice of material, when better approaches are available?
What is meant by the characteristic sound of the cone material when it is breaking up? Doesn't a cone material simply possess properties of density, stiffness and loss factor (damping)? Aren't those the fundamental material characteristics that are needed to be identified when engineering a new cone design? How do any of these engineering properties translate to a "characteristic sound" if the frequency response of the driver is ostensibly flat? Isn't the audio performance simply a result of the structural resonances, damping and piston-range behaviour of the cone, and not the "material" per se?
The following might provide some guidance. In terms of audibility of different materials, back in 2010, Rotter and Lindau published a paper titled "Audibility of tweeter performance beyond spectrum and phase" (PDF). They concluded that (emphasis added):
"When eliminating frequency and phase response irregularities, baffle and room interaction, non-linear behavior, and distance effects, a blind-comparison listening test could not reveal audible differences between different types of tweeters. Neither the material nor the actuator principle, neither the tweeters geometry nor the specific form of wave fronts in the far field could be shown to be distinctive features of different tweeter types. Divergent results of previous studies can only be explained by aforementioned shortcomings of the test designs. Furthermore, when excluding room and baffle interaction, FIR equalization seems to be capable to compensate for the behavior of different loudspeakers at the sweet spot within a typical range of horizontal head movements."
Correct, and correct in the case of all materials one may choose to use for a cone or dome.Even if properly designed, a metal cone/dome will behave like a piston only up to its first structural resonance frequency.
Correct, and how it is notched out is important for a mid or bass unit, possibly not for a tweeter.There isn't much inherent material damping in metals, so any resonances are going to have a very high Q.
The current approach is to use a material which is breaking up and damp it a bit. Is this a better approach?Even though the crossover may heavily attenuate those resonances, is it wise to have them present in the first place as a result of a poor choice of material, when better approaches are available?
I didn't explain this well.What is meant by the characteristic sound of the cone material when it is breaking up?
The silk dome one looks to have the best overall performance as a midrange. Really pretty impressive.New Bliesma mid dome specs!
Now I just need to see the distortion and decay.
The paper dome is the one I have an eye on-lowest fs and least power drop off-axis around 4khz. Whichever one has the best decay will get my bucks. I am interested in 500hz-4000hz and a 1ms to drop -30db... this is my wish list anyways.The silk dome one looks to have the best overall performance as a midrange. Really pretty impressive.
Reason I think the silk looks best is its complete lack of severe breakup. Even the paper is worse. The Beryllium is very good too.The paper dome is the one I have an eye on-lowest fs and least power drop off-axis around 4khz. Whichever one has the best decay will get my bucks. I am interested in 500hz-4000hz and a 1ms to drop -30db... this is my wish list anyways.
The Cumulative Spectral Decay (CSD) curves will no doubt be as expected for a bandpass driver with some very lightly-damped high-frequency resonances present. It's a pity that the designs still include these.Now I just need to see the distortion and decay.