the corundum you mean ? Not sourcable anymore. I found my aluminum tweeter which is Boston Acoustics origin to sound softer than many fabrics I heard, the breakup above 20k hz is traped mechanically passivly by a device though (basicly helmotz little tubes traps). But my pre which is a Yamaha CX2 despite great clarity has a touch of soft sounding coloration though, amp is no slouch : a Chord that drives everything with no particular color (most neutral amp I have ever had and great resolution)
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How can you have a low end above 2KHz?
I mean 2k is the low end of a sb26 tweeter often in its usable range vs 20k hz which is its high end of its usable frequency range in my basic language. I should have said since or from 2k hz maybe?
The 27 TAC/GB would have been interresting choice if I could wave guided it with brandon WG and raise a little its low 89.5 db sensivity. Of course there is the other more basic model with no titanium former as well with more sensivity, its 91 db is exactly what I need and there is a no FF version side to side to the FF one.
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Who told you that? I've crossed the CDC at 1.2KHz before now. Limited power-handling at that frequency, but for a system intended for nearfield & moderate SPLs, nothing wrong with it.
I've crossed the CDC at 1.2KHz before now. Limited power-handling at that frequency, but for a system intended for nearfield & moderate SPLs, nothing wrong with it.
with a WG you mean ?
How much spl do you think it can reach around 1800 hz with no WG, please ? Btw, do you prefer the cdc off axis over the adc ?
Some like wolfteeth seems to prefer the aluminum Seas over the SB26 of the same dome material.
How much spl do you think it can reach around 1800 hz with no WG, please ? Btw, do you prefer the cdc off axis over the adc ?
Some like wolfteeth seems to prefer the aluminum Seas over the SB26 of the same dome material.
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No, direct radiating.
Depends on the crossover so there's no single answer to that. The two tweeters are essentially identical with the former having the surfaces converted to the material's oxide (aka ceramic), so in practice I've never found any significant difference.
Two points there. 1/ It's not actually the same dome material -the Seas Prestige units are an aluminium/magnesium alloy, rather than straight aluminium. And 2/ They're totally different designs, with no shared components or features beyond the broad basics of being moving coil dome tweeters. As I noted before, the SBs and the Seas TBC/G & TAC/GB are probably the highest performing affordable hard dome tweeters on the market now that the DA25TX is unavailable due to Peerless withdrawing from the DIY market. Preference as always will come down to usage & the detailed performance characteristics.
1/ : back to the topic.
2/ : indeed, I knew that.
Of course I assume one would not apply first or second order that low for the SB26. 90 dB peak seems the minimum in a living room to be confortable enough (in appartment so total spl limited). Many said the cdc had the white ceramic oxyde for avoiding corosion (though do aluminum corodes or it was a marketing thing to have a cheap white dome ?!) and the magnitude difference with the adc was about the lense in front of it that are sligthy different.
2/ : indeed, I knew that.
Of course I assume one would not apply first or second order that low for the SB26. 90 dB peak seems the minimum in a living room to be confortable enough (in appartment so total spl limited). Many said the cdc had the white ceramic oxyde for avoiding corosion (though do aluminum corodes or it was a marketing thing to have a cheap white dome ?!) and the magnitude difference with the adc was about the lense in front of it that are sligthy different.
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Since the aluminium dome is anodized TTBOMK, corrosion should be a non-issue -I've never heard of any having any such problems. What nominal variation in SPL is stated in the tablulated data I simply put down to normal production tolerance variation as I've not seen any significant differences; all the units I've had through here have been physically identical other than the cdc having the oxidised dome.
Hi,
you can work out the driver main resonance in simulator, play with vituixcad for example. Load the demo project that comes with it, rip out the xo and use the woofer only, play with circuit impedance. You can do it with xsim as well I think, never tried it though.
For the distortion stuff above driver main resonance, check out the purifi paper about notch filter, esa's article. It would be quite easy to test it with series resistor, see how harmonics drop with it. Or inductor or notch filter, if you have parts at hand.
ps. I wrote crazy long reply about the thought process but didn't post it as was crazy long 😀 perhaps will make a thread about thinking stuff
Well, you'd have to ask them -they are the only people who actually know, and anything else is pure surmise or conjecture. However, from an engineering perspective, converting the surfaces (and likely a good portion of the rest) of the substrate to its metallic oxide / crystalline equivalent will change the resonant / self-damping properties relative to the homogeneous metal original when you move above the piston band and TL modes come into play. That is certainly the case with the Markaudio MAOP units, and the cdc does seem to have a slightly better-damped characteristic in the ~26KHz region.
I am familiair with most literature, thanks 🙂
I was mostly just curious about actual practical measurements with distortion.
It's probably nice idea to start a new topic about it.
Aren't those questions not kinda obvious?
I don't mean that mean that on a bad way. 🙂
Why are there so many different styles of sofa's or cabinets would be a similar question?
In audio there is still quite a big group of people (incl engineers and companies) that believe in a special sound of a transducer material.
That is even subconscious in quiet some cases.
Or at least I hope so, because otherwise it would be pretty cold conscious marketing.
On the other hand, hey if people want it, there you have it, why not? 🙂
Agreed. Although as noted, it does appear to provide slightly better damped TL / resonant modes above the audio band, which in turn should make for a slightly cleaner HD lower down the range. Possibly unit variation, but the minor differences > c. 20KHz are roughly what I'd expect to see anyway from a ceramic oxide mod. For practical purposes I've not found there to be anything significant in it, but for the relatively minimal extra cost, of the two I'd be inclined to go with the cdc, and both models that I've measured have always been extremely consistent (which I can't always say about some).
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Yeah its discussed million times as current drive so I'm not too hesitant start another. Btw sorry to this thread, quite offtopic 😀 I'll post this here for completeness if more people are interested, instead of starting another thread or PM.
You can find measurements by Esa in Finnish https://foorumi.hifiharrastajat.org/index.php?threads/särövertailua.93446/ and his paper here https://acoustics.ippt.pan.pl/index.php/aa/article/view/1780 with measurements.
He talks about V/I conversion and how driver ruins it with voltage amp and proposes current amp to rescue.
V/I is literally impedance, Z=V/I. The cause for varying impedance is of course moving parts, also hysteresis and perhaps other sources as I'm not too familiar with drivers. But I can see most if not all drivers are designed to be used with voltage amps, all impedace graphs and frequency graphs are made with constant voltage. Literally the speakers are designed so that varying impedance (per frequency) gives flat/nice frequency response, assumes low impedance between driver terminals. Side effect of driver dominating circuit impedance is that the impedance varies per excursion, which is source for distortion. We'd need elevated circuit impedance to reduce the distortion, but now frequency response gets wonky. I guess this is why current drive is seen as controversial or bad or something, bad rep. But falling into that is just missing the whole point in my opinion.
All we have to do is realize its the circuit impedance that reduces acoustic distortion. Increase circuit impedance in series with the driver, impedance that does not vary with level, to reduce distortion, to get benefits of current drive. If frequency response deviates from datasheet, so what, it does it anyway slapped into a box and brought to a room, and DSP is perfect tool to fix that.
This way the driver motor distortion mechanisms make less current into the circuit, which means less acoustic output as its the current that makes the cone move, which means reduced acoustic distortion. Especially IMD stuff gets better, where low frequency makes huge excursion, and the whole bandwidth suffers.
edit. just read the paper and its nice, explains all this very nicely with good tone and concentrates on the impedance instead of "current drive".
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Oh that one, yeah I have already seen that one.
I was already aware that current drive works great for 100-200Hz and up.
I was talking about measurements with a passive filer for these break-up mode peaks.
Ah yeah, the breakup is bit of a different thing as its mechanical or acoustic amplifier, I don't know right term. Here is proof by reasoning 😀
Again, frequency response on driver datasheet is made with constant voltage, and while there is some ripple in impedance plot on breakup the impedance is pretty much the same throughout the breakup. This means, as Z=V/I that the current is relatively constant through the breakup, so force to move the cone is relatively constant and acoustic output should be, but still there is say a 10db peak in frequency response. So, amplification of this 10db peak must happen in the acoustic domain, not electrical. So, any current that is at the breakup frequency, including distortion, will get this amplification in acoustic domain as well.
Its related to the current drive/impedance/motor distortion like so: if most of the distortion you measure acoustically is from driver motor, it must be there as current, which then gets amplified in acoustic domain and you would see the peaks in the harmonic distortion plot, and be able to eliminate them increasing circuit impedance at the breakup frequency.
Again, frequency response on driver datasheet is made with constant voltage, and while there is some ripple in impedance plot on breakup the impedance is pretty much the same throughout the breakup. This means, as Z=V/I that the current is relatively constant through the breakup, so force to move the cone is relatively constant and acoustic output should be, but still there is say a 10db peak in frequency response. So, amplification of this 10db peak must happen in the acoustic domain, not electrical. So, any current that is at the breakup frequency, including distortion, will get this amplification in acoustic domain as well.
Its related to the current drive/impedance/motor distortion like so: if most of the distortion you measure acoustically is from driver motor, it must be there as current, which then gets amplified in acoustic domain and you would see the peaks in the harmonic distortion plot, and be able to eliminate them increasing circuit impedance at the breakup frequency.
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I know, which sounds great, but to get full circle, the proof is in eating the pudding, aka measurements 😉 🙂
I wish there was a STANDARDISED waterfall measurement supplied with all drivers. (measured anechoic or outdoor)
There is just so much information gained from 'waterfall plots'!
There is just so much information gained from 'waterfall plots'!
In fact -
I believe that some tweeters are a little bit like >
https://www.waves.com/plugins/aphex-vintage-aural-exciter
I believe that some tweeters are a little bit like >
https://www.waves.com/plugins/aphex-vintage-aural-exciter