"...standard steel pole pieces and front plates in speaker magnets suffer from nonlinear magnetic characteristics. As current fluctuates through the voice coil, the ... steel lags behind the varying [electric] magnetic field (hysteresis), creating unwanted eddy currents ... causing significant third-harmonic distortion."
"...replacing the standard steel areas that run concentric with the voice coil with..."
"...a specialized composite—typically made of powdered pure iron, resin, and PTFE."
"...prevents eddy currents from forming in the first place, while its high permeability maintains ... magnetic flux."
"...allows... :
- Lower third harmonic distortion by 10dB to 15dB in the 100Hz to 3kHz range.
- cleaner reproduction of complex sounds, [most notably and perceptibly improved are the] human voice and piano."
I reduced the amount of words by half, keeping everything pertinent to save you a minute of your life
So... This material... It's been around and its properties have been known for many decades now, so a reasonable person might think "if it's free to implement [excluding {inexpensive} materials], and it's so good... everyone is using it already, right?"
But you'd be wrong. One company has been using it for decades, and from what I've been able to gather they were very forthcoming with details around launch time as well as after. But still... they are the only company!!!
"How could this be?"
Well, I have a couple ideas why it's not used in the majority of speakers:
- most speakers' THD wouldn't be improved by 10-15dB
- exceptional fidelity is only a selling point for a minority of speakers
"But there are many high performance speakers sold. Surely they could benefit?"
Probably a good number of them, yes. There are a lot of companies that sell speakers that are supposed to be high fidelity and aren't. The companies that would benefit from this technology most are ones that
- sell most of their speakers in the $1500-$8000 range
The more expensive speaker companies could benefit too, but they're often more focused on making a bunch of money than being honest (if they were honest, they wouldn't be selling $7,000 of parts with a couple hundred man hours in R&D for $150,000).
The companies that sell high quality with fair profit margins (90% of their sales between $1,500-$8,000USD), their designs, with a bit of refinement here and there (eg. make sure passive crossovers are air core and properly aligned, upper-mid tier capacitors), could be substantially improved with this technology on their woofers and midranges.
So which company is monopolizing this technology? ATC. They're in the UK mostly.
They use it in their highest end professional series. It's in three different sized woofers (with the same motor), and one midwoofer (also the same motor).
The motor? It's maxed out with double stacked ceramic magnets totaling ~400 ounces, mounted on a THICK cast aluminum frame. More details:
- rectangular CCA wire
- underhung 8mm voice coil in 20mm gap
- active individually tuned 4th order crossovers
- CLD driver (layered driver with middle damping layer to smooth out frequency response as directionality increases
there are more things about the woofers that make them awesome like balanced suspension, an xmech of 4x the xmax, extremely linear magnetic field through the 20mm gap), but that's not important - showing the caliber of woofer this belongs in was the point.
The three woofers are 9, 12, and 15 inches, and the midwoofer is 150mm (actually the cone+1/3 surround measures 140mm or so)
For the last multiple decades, ATC has only done small refinements to their designs. And that's fine - their stuff is great. The material works best at reducing distortion between 100Hz and 3,000Hz, but because ATC's biggest sellers by far are the speakers with the 9, 12, and 15 inch woofers, and those woofers are crossed at 380Hz 4th order, that means only 280Hz are really being optimized for low distortion by this tech. Like 90% of the drivers made with this only hit 380Hz. Personally I have the 150mm which is crossed at 2.1kHz. I enjoy it a lot, but I think it's really sad that it's the only model speaker like it. ATC doesn't seem to be working with DSP, and in the last 5-7 years, DSP has come a long way, so I'm raising awareness.
Manufacturers of quality speakers/drivers should use this in their future designs! It doesn't take much to implement, and starting with good designs, maybe you only need to do a couple things to squeeze the max performance out of things!
"...replacing the standard steel areas that run concentric with the voice coil with..."
"...a specialized composite—typically made of powdered pure iron, resin, and PTFE."
"...prevents eddy currents from forming in the first place, while its high permeability maintains ... magnetic flux."
"...allows... :
- Lower third harmonic distortion by 10dB to 15dB in the 100Hz to 3kHz range.
- cleaner reproduction of complex sounds, [most notably and perceptibly improved are the] human voice and piano."
I reduced the amount of words by half, keeping everything pertinent to save you a minute of your life
So... This material... It's been around and its properties have been known for many decades now, so a reasonable person might think "if it's free to implement [excluding {inexpensive} materials], and it's so good... everyone is using it already, right?"
But you'd be wrong. One company has been using it for decades, and from what I've been able to gather they were very forthcoming with details around launch time as well as after. But still... they are the only company!!!
"How could this be?"
Well, I have a couple ideas why it's not used in the majority of speakers:
- most speakers' THD wouldn't be improved by 10-15dB
- exceptional fidelity is only a selling point for a minority of speakers
"But there are many high performance speakers sold. Surely they could benefit?"
Probably a good number of them, yes. There are a lot of companies that sell speakers that are supposed to be high fidelity and aren't. The companies that would benefit from this technology most are ones that
- sell most of their speakers in the $1500-$8000 range
The more expensive speaker companies could benefit too, but they're often more focused on making a bunch of money than being honest (if they were honest, they wouldn't be selling $7,000 of parts with a couple hundred man hours in R&D for $150,000).
The companies that sell high quality with fair profit margins (90% of their sales between $1,500-$8,000USD), their designs, with a bit of refinement here and there (eg. make sure passive crossovers are air core and properly aligned, upper-mid tier capacitors), could be substantially improved with this technology on their woofers and midranges.
So which company is monopolizing this technology? ATC. They're in the UK mostly.
They use it in their highest end professional series. It's in three different sized woofers (with the same motor), and one midwoofer (also the same motor).
The motor? It's maxed out with double stacked ceramic magnets totaling ~400 ounces, mounted on a THICK cast aluminum frame. More details:
- rectangular CCA wire
- underhung 8mm voice coil in 20mm gap
- active individually tuned 4th order crossovers
- CLD driver (layered driver with middle damping layer to smooth out frequency response as directionality increases
there are more things about the woofers that make them awesome like balanced suspension, an xmech of 4x the xmax, extremely linear magnetic field through the 20mm gap), but that's not important - showing the caliber of woofer this belongs in was the point.
The three woofers are 9, 12, and 15 inches, and the midwoofer is 150mm (actually the cone+1/3 surround measures 140mm or so)
For the last multiple decades, ATC has only done small refinements to their designs. And that's fine - their stuff is great. The material works best at reducing distortion between 100Hz and 3,000Hz, but because ATC's biggest sellers by far are the speakers with the 9, 12, and 15 inch woofers, and those woofers are crossed at 380Hz 4th order, that means only 280Hz are really being optimized for low distortion by this tech. Like 90% of the drivers made with this only hit 380Hz. Personally I have the 150mm which is crossed at 2.1kHz. I enjoy it a lot, but I think it's really sad that it's the only model speaker like it. ATC doesn't seem to be working with DSP, and in the last 5-7 years, DSP has come a long way, so I'm raising awareness.
Manufacturers of quality speakers/drivers should use this in their future designs! It doesn't take much to implement, and starting with good designs, maybe you only need to do a couple things to squeeze the max performance out of things!
