Mmm... This is for me the contrary of rigid, with controled multiple break up modes, as most full rangers work.
Rigid like ceramic or diamond gives one strong peak at break up.
C173-6-096
Yes, but a notch or impedance flatering or even passive peak trap are a good enough solution.
I never liked the speakers made with ceramic drivers! It was not about peak and sibilance, but I found the tones not natural... well maybe it was the passive parts of the filter, hard to say ! Would like to hear a Marteen one day with their astrospheric price !
Last edited:
Hi Eldam,
I meant make a single surface cone, without a dust cap, yes like the Accuton drivers but also like others.
I mean, the idea of forming the dust cap separately and gluing it on is an artifact of paper cone construction, isn't it?
It would be a little like using billet aluminum to CNC a cone in 2 parts.
Kind of ridiculous. Of course, I'm just an armchair fanboy. I don't know anything about making nice things, I'm just surprised is all.
Best,
E
Hi Erik,
ah ok, like some Elac drivers, etc... Maybe just because it's simplier so less expensive (less complicated production Tools?) to make it with dust cap or phase plug ?? (while the phase plugs of Seas drivers should not be cheap... Focal also used zamak non resonant phase plug in an old diy (my first one at 15 !) speaker I had...)
But one piece is maybe simplier that one : ?? ??? - ???... ??? ???? 3? ??? ???? ????... (subwoof on the second photograph)
I have this mid developped by Phil Jones when he made the Lynnfield serie at Boston Acoustics. As you see the dust cap which is also in black aluminium seems soldered or maybe glued.... as the big passive peak trap device in the front of it !
It sounds very good without brightness with a tricky passive filter. Now Phil Jones seems to make an aluminium one piece cone but with the dust cap shape yet : Nearfield Studio Monitor 7000i ? The Finest Two-Way Monitor Ever Built | Phil Jones Pure Sound
ah ok, like some Elac drivers, etc... Maybe just because it's simplier so less expensive (less complicated production Tools?) to make it with dust cap or phase plug ?? (while the phase plugs of Seas drivers should not be cheap... Focal also used zamak non resonant phase plug in an old diy (my first one at 15 !) speaker I had...)
But one piece is maybe simplier that one : ?? ??? - ???... ??? ???? 3? ??? ???? ????... (subwoof on the second photograph)
I have this mid developped by Phil Jones when he made the Lynnfield serie at Boston Acoustics. As you see the dust cap which is also in black aluminium seems soldered or maybe glued.... as the big passive peak trap device in the front of it !
It sounds very good without brightness with a tricky passive filter. Now Phil Jones seems to make an aluminium one piece cone but with the dust cap shape yet : Nearfield Studio Monitor 7000i ? The Finest Two-Way Monitor Ever Built | Phil Jones Pure Sound
Last edited:
Better take the C173-6-096E, by putting two holes in the cone, the break up peak is largely reduced.
I find the little ceramic 6" from SB Acoustic promising, datashhet curve is nice !
As also the new midrange Satori 5" & 6.5"... used as quasi FR ! (I'm asking myself if these two last could be XO as high as 7000/8000 Hz despite the natural beaming of a 5" or 6" above 2000/3000 Hz...
As also the new midrange Satori 5" & 6.5"... used as quasi FR ! (I'm asking myself if these two last could be XO as high as 7000/8000 Hz despite the natural beaming of a 5" or 6" above 2000/3000 Hz...
Last edited:
Mmm... This is for me the contrary of rigid, with controled multiple break up modes, as most full rangers work.
Rigid like ceramic or diamond gives one strong peak at break up.
C173-6-096
This is inherent to the Young's modulus of the ceramic material... you can find it in the wikipedia spreadsheet at the Tooth enamel (calcium phosphate) line.
https://en.wikipedia.org/wiki/Young's_modulus
did any brand tried the wooden carbon (F1, aeronautic, etc...) glued in opposite direction to make it stiff then thermo shaped ? Is it the Magico technology ?
As Dany I'm asking myself about the goal to make so much low Fs if the sensibility can not be increased ! And if the maximum Spl is limited by the Xmax or rapid distorsion if this Xmax is great enough should ask ourselves about such toys, no ? reducing the weight of the cone to reduce the force of the motor has maybe no sense but for casula listening to reduce the distorsion ! But here we need pistonic to move air if used for the bass area ?!
If you can not play louder than an ESL speaker... take the ESl speaker !
As Dany I'm asking myself about the goal to make so much low Fs if the sensibility can not be increased ! And if the maximum Spl is limited by the Xmax or rapid distorsion if this Xmax is great enough should ask ourselves about such toys, no ? reducing the weight of the cone to reduce the force of the motor has maybe no sense but for casula listening to reduce the distorsion ! But here we need pistonic to move air if used for the bass area ?!
If you can not play louder than an ESL speaker... take the ESl speaker !
Last edited:
Okeeeey, truuue, it's nice in the passdand....
Trouble is what xover do you need to get free of the garbage in the stopband?
LR24 and up? Ok, so lease let me forget about that pistonic perfection and will look for a better driver overall, and am ready to accept compromises in the pass band.
Of course, steep slopes linear phase xovers achieved by DSP might give me the best of both worlds, but... so much gear involved is no longer acceptable in my k.i.s world...
Yep me too ! Kiss and money is the reason I don't go for active filtering : it's expensive to preserve the quality of digital you can have with a very good standalone one !
Well, tweeter are sounding better with LR4, so yes steep filter, or Notch or both to kill the peak ! I will be more worried by the directivity above 2000/3000 and the difraction mode of the cone used in a so big range from 200 Hz to 6000 Hz with such a cone ! Well prove is in the pudding I assume ! One have to try...
And the sweet spot must be very tiny (half a head, lol !)
Well, tweeter are sounding better with LR4, so yes steep filter, or Notch or both to kill the peak ! I will be more worried by the directivity above 2000/3000 and the difraction mode of the cone used in a so big range from 200 Hz to 6000 Hz with such a cone ! Well prove is in the pudding I assume ! One have to try...
And the sweet spot must be very tiny (half a head, lol !)
Likely just an deeply oxidized surface of the aluminum. Al2O3 is what makes it 'ceramic'; it's the oxidation on the surface, making it a ceramic sandwich cone.
Later,
Wolf
They have pimped the datasheet by using 2.83v/m for a 4 ohm driver, in 1w/m it's about 85dB
Since all drivers should be measured with a voltage reference so that we get continuity with plots, the 2.83V spec is what should be preferred anyway.
If you are using 1w/1m curves, then you have to adjust for the differing impedances. It makes no sense to use the 1W curves unless all your drivers are 8 ohms.
Later,
Wolf
Looking at the 8 inch model, the FR and Impedenace curve don;t look too promising.
First breakup at 1.7khz, and two subsequent ones, at 4khz and at 9.5 khz... Not a driver to be used beyond its first breakup.
Plus, the driver is an 8ohm driver, and the spec sheet says sensitivity is 87.5 db/2.83V/1m
But looking at the curve, we can see it reaching 87.5db@31.6cm.... What gives?
First breakup at 1.7khz, and two subsequent ones, at 4khz and at 9.5 khz... Not a driver to be used beyond its first breakup.
Plus, the driver is an 8ohm driver, and the spec sheet says sensitivity is 87.5 db/2.83V/1m
But looking at the curve, we can see it reaching 87.5db@31.6cm.... What gives?
Eliminating the dust cap can introduce as many or more problems than it solves.
Implementing a phase plug prevents a resonant cavity due to the air trapped behind the dust cap, however the dust cap may also do positive things for the frequency response of the cone by bracing/damping it or creating breakup nodes which are complementary to the cone's nodes. Phase plugs are also susceptible to making chuffing noises on bass drivers as they create a leaky air path through the magnetic gap, through the spider and inside the speaker box. Drilling the pole piece is a better compromise IMO as chuffing noises generally occur at the back of the driver and are muffled by the cone/cap.
Placing a metal phase plug on the pole piece may also mess up the magnetic design of the motor. From SB's perspective it may have been cost prohibitive to re-engineer an existing design to use a phase plug without compromising various aspects**
Integrating the dust cap into the cone almost always means that the cone has to be flat or formed into a concave shape and both of those geometries generally have less desirable breakup node behaviour than a conical or exponential profile - resonance and/or breakup begin at a lower frequency. Flat or concave cones also present a manufacturing problem as there is no access to shim the voicecoil with the cone installed during assembly as there is with the 'conventional' soft-parts arrangement. Again it would be costly to make the tooling to create a new cone profile, and the average customer probably won't care for it.
The only definite positive effect of eliminating a dust cap is that it improves aesthetics. Even that is subjective, although personally I do think that phase plugs look better than flat/concave cones which in turn look better than dust caps.
**I have little doubt that these ceramic drivers are purely a marketing exercise - if the cone is made from an exotic material then it WILL sound better to the customer than some common material like paper or plastic or aluminium *rolls eyes*. Changing any other aspect of the design is just wasting time and R&D money from a business point of view.
Last edited:
