Looking over driver specs, I see that woofers can have straight, exponential, and radial cones. What is each profile for or optimized for?
Edit: What is a radial cone?
Edit: What is a radial cone?
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https://audioxpress.com/article/speaker-cones-fabrication-materials-and-performance
"The speaker cone shape (profile) is a critical factor in the speaker’s sound quality and performance. If the cone is straight-sided (perhaps with concentric reinforcing ribs molded in the cone body), it will be the strongest and more rigid at very low frequencies.
Decoupling rings can be molded into the cone body, which look like ribs, but a cross-section of the cone shows that while ribs are composed of added material on the face of the cone, decoupling rings are concentric cone corrugations. These corrugations allow the cone’s effective radiating area to decrease with rising frequency. The off-axis response tends to look better over an extended frequency range with decoupling rings (and curvilinear profile), allowing the speaker system designer the option of using a higher crossover point between the woofer and the tweeter or the midrange."
https://darko.audio/2024/05/q-acoustics-teases-continuous-curved-cone-loaded-3000c-series/
“The profile of a bass/mid driver cone has always been a compromise. Whilst a straight conic profile has benefits at bass frequencies, it exhibits undesirable break-up modes that will restrict its higher frequency range. A flared cone is a better option to control the cone break-up towards higher frequencies, however the flare shape will not hold its rigidity at low frequencies so well as a straight conic shape, particularly at the outer diameter. The profile of the unique Continuous Curve Cone® (CCC) is the result of a Q Acoustics multi-disciplinary team research project to investigate a new, multiradius complex curve contour cone profile. The goal was to design a profile that would exhibit ‘best of both’ benefits with the bass characteristics of a straight conic profile, and with the mid frequency control of a flared profile.”
"The speaker cone shape (profile) is a critical factor in the speaker’s sound quality and performance. If the cone is straight-sided (perhaps with concentric reinforcing ribs molded in the cone body), it will be the strongest and more rigid at very low frequencies.
Decoupling rings can be molded into the cone body, which look like ribs, but a cross-section of the cone shows that while ribs are composed of added material on the face of the cone, decoupling rings are concentric cone corrugations. These corrugations allow the cone’s effective radiating area to decrease with rising frequency. The off-axis response tends to look better over an extended frequency range with decoupling rings (and curvilinear profile), allowing the speaker system designer the option of using a higher crossover point between the woofer and the tweeter or the midrange."
https://darko.audio/2024/05/q-acoustics-teases-continuous-curved-cone-loaded-3000c-series/
“The profile of a bass/mid driver cone has always been a compromise. Whilst a straight conic profile has benefits at bass frequencies, it exhibits undesirable break-up modes that will restrict its higher frequency range. A flared cone is a better option to control the cone break-up towards higher frequencies, however the flare shape will not hold its rigidity at low frequencies so well as a straight conic shape, particularly at the outer diameter. The profile of the unique Continuous Curve Cone® (CCC) is the result of a Q Acoustics multi-disciplinary team research project to investigate a new, multiradius complex curve contour cone profile. The goal was to design a profile that would exhibit ‘best of both’ benefits with the bass characteristics of a straight conic profile, and with the mid frequency control of a flared profile.”
I appreciate the link.
Are radial and exponential both considered curvilinear?
Your welcome I am not sure. Exponential horn yeah! Speaker cone? Radial ? just means round as opposed to elliptical? Don't know the context.
Rob 🙂
Hi RobDon't know the context.
It's about the profile of the cone when you look at it from the side. And I guess both, exponential and radial re sometimes calle curvilinear. I don't know whether there is a big difference regarding midrange breakup between exponential and radial. But there is for sure a differnece between those two and a straight-walled cone, For my two-way I went fo the latter because I love B A S S ! But my crossover frequency is 650m Hz which ios about the highes I would go with a driver like that.
Regards
Charles
TTBOMK, no, curvilinear is unique for wide range use.I appreciate the link.
Are radial and exponential both considered curvilinear?
It also depends on the diameter of the cone. How is yours?But my crossover frequency is 650m Hz which ios about the highes I would go with a driver like that.
Well - the cone diameter is 32 cm and the VC diameter is 4*. I am aware that my construction is full of compromises but I wanted a two-way with horn that can reproduce decent bass. The price I have to pay is a little lack in midrange refinement.
Regards
Charles
Regards
Charles
These are the two drivers that Dr. Geddes used for the Summa (15TBX100) and the New Summa (15NBX100)
15TBX100 is a Radial cone profile and crossed at 900hz in the Summa. I will cross there too. To achieve a 930hz cross I would be using a LR4 at 790hz which achieves -6db at 930. That's about where it will narrow its pattern from a 13.7" radiating surface. The SEOS 15 with a BMS 4550 will be used with an LR4 cross at 1070 to be -6db at 930hz. Both drivers would be EQ'ed to one octave past the crossover points. My crossover also has variable phase adjustment.
He made it work passively so I doubt issues would arise actively. I'm not as skilled as the best of you, but that's the plan.
15TBX100:
15NBX100 is exponential crossed at 1000hz.
These are the best pictures I could find for the 15TBX100 showing the flared nature of the cone profile
Thank you for the time in responding. I'm learning.
15TBX100 is a Radial cone profile and crossed at 900hz in the Summa. I will cross there too. To achieve a 930hz cross I would be using a LR4 at 790hz which achieves -6db at 930. That's about where it will narrow its pattern from a 13.7" radiating surface. The SEOS 15 with a BMS 4550 will be used with an LR4 cross at 1070 to be -6db at 930hz. Both drivers would be EQ'ed to one octave past the crossover points. My crossover also has variable phase adjustment.
He made it work passively so I doubt issues would arise actively. I'm not as skilled as the best of you, but that's the plan.
15TBX100:
15NBX100 is exponential crossed at 1000hz.
These are the best pictures I could find for the 15TBX100 showing the flared nature of the cone profile
Thank you for the time in responding. I'm learning.
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It's about the profile of the cone when you look at it from the side.
Hello
Thanks I got that. Never heard of an exponential cone profile? An example would be a Tannoy coax driver. It has a short throat for the CD. So the question is was the throat extended by following the throat with a matching exponential profile in the bass cone?
Rob 🙂
I thought curvilinear just refers to any curve. Literally, a curved line. So exponential and radial would be specific types of curvilinear cone. No?TTBOMK, no, curvilinear is unique for wide range use.
So what does curvilinear mean, then? Clearly some cones, including those of the classic drivers you mention, have been described as curvilinear. But does that mean something specific, mathematically (as the term exponential does), or is it just a way of saying curved? (I'm not trying to be awkward. If I've missed something, I'd genuinely like to learn.)
In the waveguide world, radial and exponential are shapes of the horn and yield different response curves. A straight profile isn’t withought midrange ability. The AE TD10 and 12 have straight cones while the TD15 is curvilinear. All are very capable in the midrange. The question would be, how far up in the midrange is a curved cone improving midrange while giving up the advantages in bass of the straight cone.
In the response graphs posted above of the B&C 15” drivers, they only differ in response by a peak in the 1600 to 1800hz areas, with the 15tbx100 peaking higher.
In the response graphs posted above of the B&C 15” drivers, they only differ in response by a peak in the 1600 to 1800hz areas, with the 15tbx100 peaking higher.
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No; a couple of examples: Altec 416B, JBL 2220B measured, note the obvious profiles........
This makes it a easier to see the extended HF.
Rob 🙂
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What's the point of the extended high frequency performance if the driver is beaming at that point? The AE 15m is flat to 4k but beams after 950hz.
Well I recently collected two pairs of vintage Japanese widerange drivers, one of them highly curvilinear. After listening to the extended-HF beam, I had asked the very same question! The other pair (10" monster-alnico straight cone with ribs only near the dustcap) has become a real favorite.
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