A material which inherently possesses significant damping will yield a *smoother* breakup.
Cone geometry is a VERY complex phenomenon with regards to modal behavior. However, a shorter cone angle should yield a *smother* breakup.
Work done at the bbc and by Raymond Cooke at k.e.f. found that a cone with a hyperbolic shape would operate as a aperiodic transmission line for a band extending a certain amount above its piston frequency.
This gave rise to the k.e.f.B200 style driver used in the various b.b.c. monitors.
The Jordan full range drivers is an extension of this work.
If you push up the piston range by using something like Aluminium, and keep the cone diameter to no more than around 100mm.then you have a driver that can theoretically cover the entire audio range, (except for low bass), with no resonances in the audible band.
rcw.
This gave rise to the k.e.f.B200 style driver used in the various b.b.c. monitors.
The Jordan full range drivers is an extension of this work.
If you push up the piston range by using something like Aluminium, and keep the cone diameter to no more than around 100mm.then you have a driver that can theoretically cover the entire audio range, (except for low bass), with no resonances in the audible band.
rcw.
What particular qualities of an AlNiCo magnet (compared with a ferrite magnet) allow the motor to "fade smoothly as the linear excursions are reached"? I can believe that the two magnet types will generally perform differently, amongst other reasons being that AlNiCo magnets can allow eddy currents to flow where ferrites won't, but I have always understood that performance at the excursion extremes is determined almost exclusively by gap and pole geometry rather than magnet material.
Hi Don,
The structures between the two tend to be quite different. Modern AlNiCo guitar speakers tend to follow traditional designs (magnet held in the middle of a U-shaped metal piece) that don't have as near tight tolerance or structure as their modern ceramic counterparts.
That's how it was explained to me on guitar forums.
Cheers!
The structures between the two tend to be quite different. Modern AlNiCo guitar speakers tend to follow traditional designs (magnet held in the middle of a U-shaped metal piece) that don't have as near tight tolerance or structure as their modern ceramic counterparts.
That's how it was explained to me on guitar forums.
Cheers!
In a traditional AlNiCo speaker, the inner pole piece is fastened to one end of the cylindrical AlNiCo magnet. The other end of the magnet is fastened to the U shaped piece, which curves around and is fastened to the outer pole piece / top plate. I disassembled many such speakers in my younger days, to acquire the magnets for experimentation.
I haven't pulled apart any modern AlNiCo speakers, so I can't speak for any changes that have happened in the last 40 years or so.
I haven't pulled apart any modern AlNiCo speakers, so I can't speak for any changes that have happened in the last 40 years or so.
Thanks Thadman and RCW! This is more like what I'm looking for. So I'm sort of looking for a flattish cone made our of a soft material in order to have an extended and smooth HF response? I don't want to see those high peaks that metal drivers often have even if their pistonic range is better. Anyone know of a 15" or 12"er that has these characteristics? What about doping a paper cone? Would a ribbed paper cone then be better than a straight paper cone?
Thanks again,
Dan
Acoustic Elegance produces several drivers which are characterized by a smooth, extended response. The AE TD12M and AE TD15M are prime examples.
If it helps, I believe Augerpro has taken measurements of the TD12M.
A soft material is going to have a much lower pistonic range, although it will break up more gradual and smooth. A rigid material will extend the pistonic range but break-up in basically undamped and unpredictable ways. Its a trade-off. Doped paper has been and IMO remains the best compromise. Done correctly it works well. The surround does tend to be the limiting factor in performance since it is virtually always the first point of non-pistonic motion, making the cone somewhat irrelavent.
Cone can be replaced with a disc of several milimeters thickness and balanced with local mass. Nicely damped midrange-bass drivers:
2" coil:
GDN-30-400-8-SE - Sklep internetowy
4" coil:
GDN-38-1000-8-SE - Sklep internetowy
2" coil:
GDN-30-400-8-SE - Sklep internetowy
4" coil:
GDN-38-1000-8-SE - Sklep internetowy
Attachments
Balanced mode radiators are interesting. However, I believe they may be far from a mature state of development.
Pretty simple. There are certainly many "paperish" and "dopey" materials, so there's a lot of variation on that theme. Then, of course, there's ribbed, pure straightwall, and curvilinear cones, each with their own issues. Some of the older JBLs were their own profile (123A), with a near-flat section near the surround, and a curve down into the dustcap. These sound superb, but don't meet the sensitivity and output criteria- they're 90dB and 50W.
But they stay very smooth.
Hi jzagaja
The drivers on that site seems extreemly good value for money
Seems like quite nice drivers as well. What is you impression compared to other brands?
Something like this seems like a nice 6,5" driver for less than 35 Euro!!!!
GDN-18-130-8-AKX - Sklep internetowy
also really cheap speaker components etc.
---- sorry for side stepping a bit -----
The drivers on that site seems extreemly good value for money
Seems like quite nice drivers as well. What is you impression compared to other brands?
Something like this seems like a nice 6,5" driver for less than 35 Euro!!!!
GDN-18-130-8-AKX - Sklep internetowy
also really cheap speaker components etc.
---- sorry for side stepping a bit -----
Attachments
STX is an interesting company. They take very best components from Asia and assemble in Poland. My friend who is talented speaker builder used their woofer with Seas Prestige tweeter:
GDN-18-140-8-AWX - Sklep internetowy
(enclosed picture, speaker painted with Nextel coating)
I can truly recommend them (look for AWX series). We wait for their new line of ceramic tweeter and carbon fiber drivers (3-way projects).
From my side I'll be testing their PA drivers and plan cooperation with them.
GDN-18-140-8-AWX - Sklep internetowy
(enclosed picture, speaker painted with Nextel coating)
I can truly recommend them (look for AWX series). We wait for their new line of ceramic tweeter and carbon fiber drivers (3-way projects).
From my side I'll be testing their PA drivers and plan cooperation with them.
Attachments
I would look for a linear material, which inherently possesses significant damping. Also of consideration is the impedance match between the cone and the surround, for this interaction determines how much energy is reflected back into the cone and how much energy is dissipated by the surround.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.