I also don't speak German, but google translate works good enough 🙂
That's what i presume happens.
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I'd be interested to see your results. Just bought the last pair of those tweeters from partsexpress (sorry guys).
Zvu either you're not reading that graph correctly or I'm confused on what we're talking about. I thought Scott was talking about subharmonics being produced below the fundamental? A tone plot would be needed to show this, because an HD sweep does not show subharmonics, just ones above the fundamental. Your plot DOES NOT show a reduction in subharmonic distortion at 8.7khz, it shows a reduction in 3rd harmonic distortion at 8.7khz: precisely at 26khz. Which is a different topic.
Now why that happens seems odd, I know of no mechanism for it since the distortion is produced in the motor itself, after the filtered signal.
Or maybe Scott just blurred the lines between the two things and each of us took a different message from him.
Now why that happens seems odd, I know of no mechanism for it since the distortion is produced in the motor itself, after the filtered signal.
Or maybe Scott just blurred the lines between the two things and each of us took a different message from him.
I understood that we are talking about distortion rise that can be measured lower in the audio band when resonance at 27KHz (in case of Seas 26KHz) is excited.
If i misunderstood, i do apologize.
If i misunderstood, i do apologize.
Might be a bit before I get to these, but I'm planning to use the W8-2096S underhung woofer from TB with them. I'll see what I get when I get there...
Later,
Wolf
While it was very pleasing to read the debate about inter-modulation distortion and harmonic event due to 25-27kHz peaks. I wonder what happened with the thread. I just recently discovered this tweeter and I am very curious how it would perform in relationship to my needs and psychoacoustic profile. Also curious how it would handle a waveguide. Anyway, I'll keep my eye's out for updates and until I know first hand, I'll just have to wait for more updates 🙂
Anyone try this thing yet? Theres some nice low sensitivity woofers this would work with.
HiVi LK8A 8" Sandwich Cone Woofer
HiVi LK8A 8" Sandwich Cone Woofer
Lived with the DA25 version for quite a while, but found it either dull or too bright. I couldn't find a happy medium. Maybe a notch filter would have solved it but my microphone only measures up to 20khz.
That almost sounds like an issue with the off axis response. Any measurement? I'm weary of hard domes in general because in my limited experience everything starts to sound like what its made out of, at least everything that plays mid to high frequencies
Peerless drivers, in my experience, measure exactly like shown in their DS. I would not be afraid to make a notch filter based on factory frequency response and observing transfer function to see how wide and deep notch i created. There is also a posibility to copy the factory curve and work on that a bit.
I'll do it if you promise that you'll write about it after listening it for some time 🙂
I sold the tweeters a while back. Using Wavecore TWO30WA12 now and much prefer them.
For anyone put off trying them after reading this, please take what I say with a pinch of salt, and try them yourself. I didn't notch the high frequency breakup or the impedance peak, so there's chance it was an error on my part.
For anyone put off trying them after reading this, please take what I say with a pinch of salt, and try them yourself. I didn't notch the high frequency breakup or the impedance peak, so there's chance it was an error on my part.
I don't see what notching it would do anyways, there is no signal up there. I remember reading an old post from Mark audio about how hard cone drivers have jagged mini peaks and valleys in the response. Its not something that shows in a typical measurement but we can hear it.
To a point, but Mark was talking about a functionally different type of drive unit -in his case wideband drivers designed to generate and use cone resonance to extend the response.
Most normal metal cone midbass drive units are designed & optimised for piston operation over a narrower BW, with concentrated bell modes higher up that typically need stamping on to prevent their resonance potentially amplifying HD lower down in the operating BW. In effect, as indicated in the graphic above, the same can apply to dome tweeters. If the ultrasonic resonance is excited, this can then amplify HD lower down. Whether it's a problem depends on where the peak is and what its Q is, and the baseline distortion performance of the driver. CD is indeed BW limited, but that does not necessarily apply to other formats. A non-issue in some cases to be sure, but potentially so in others, so it's unwise to place a blanket write-off on it.
Most normal metal cone midbass drive units are designed & optimised for piston operation over a narrower BW, with concentrated bell modes higher up that typically need stamping on to prevent their resonance potentially amplifying HD lower down in the operating BW. In effect, as indicated in the graphic above, the same can apply to dome tweeters. If the ultrasonic resonance is excited, this can then amplify HD lower down. Whether it's a problem depends on where the peak is and what its Q is, and the baseline distortion performance of the driver. CD is indeed BW limited, but that does not necessarily apply to other formats. A non-issue in some cases to be sure, but potentially so in others, so it's unwise to place a blanket write-off on it.
I don't have the link handy and maybe I misunderstood what he was saying. But still its reasonable that before a dome goes into break up and sounds terrible that there are little tells, like idiosyncracies in the response that we pick up. So much like a person there are little clues before they do something crazy. Now maybe one day I will buy a beryllium dome and have to admit they have invented a tweeter that is free of personality.
Be dome tweeter devoid of colouration (aka 'personality')? They aren't. I really like SB's beryllium dome Satori tweeters for e.g., but they are not completely free of personality. There's more to a driver signature than the diaphragm material & its behaviour taken independently; this is where the motor and suspension designs come in, and especially with the current fashion for the latter being used as an active radiating element. The dome itself is non-resonant at or anywhere near audio frequencies, so in effect it has no signature, but the rest of the design still does. That's the point of metal, ceramic, diamond etc. domes -they should be in pure piston operation across the entire audio band, with the lighter, more rigid materials allowing the resonant / bell mode to be pushed much higher in frequency; all other things being equal, the higher it goes, the less likely it is to cause problems lower down.
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Since we are talking about Peerless tweeters, I have to mention the seemingly overlooked DA25BG. Super value and terrific sounding. Certainly should be on short list for resolving dome tweeters that are easy to integrate.
Peerless DA25BG08-06 1" Aluminum Dome Tweeter 6 Ohm
Peerless DA25BG08-06 1" Aluminum Dome Tweeter 6 Ohm
That's what Ive heard, but I certainly don't know the physics well enough to prove whether a 1" dome of corundum or beryllium is truly pistonic at a certain frequency. Having spent a bunch of time using a PC to make metal cones not sound like metal (couldn't do it), I've given up on the whole pistonic thing as being attainable. Aluminum just sounds like a garbage can to me. Magnesium is preferred.
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