Hi everyone,
I have the good Dali Opticon 2 MK2 and would like to upgrade the crossover.
Dali is known for addressing the ferromagnetic hysteresis problem in its drivers through the use of the Soft Magnetic Compound (and Dynaudio and ATC also address the problem to be honest).
Now, in order to fully benefit from the driver hysteresis reduction, I would like to minimize this problem upstream as well.
At the amplifier level I use nCore, so I'm already quite calm because of the post LPF feedback.
In terms of crossover, however, I have some doubts.
Attached is an image of the Opticon 2 MK2 crossover. I don't know much about it, but the biggest inductor I think is related to the woofer, and I also think it's of the ironcore type (and given the price range I can understand).
The small inductor instead, presumably of the tweeter, seems to me to be air core.
Now I kindly ask someone if they can confirm this.
If confirmed, I'd like to know exactly what to measure of the ironcore inductor in order to identify an alternative air core, which keeps the characteristics of the crossover unchanged.
In this sense, with the same inductance, is it possible to find an air core with the same resistance?
Thanks in advance
I have the good Dali Opticon 2 MK2 and would like to upgrade the crossover.
Dali is known for addressing the ferromagnetic hysteresis problem in its drivers through the use of the Soft Magnetic Compound (and Dynaudio and ATC also address the problem to be honest).
Now, in order to fully benefit from the driver hysteresis reduction, I would like to minimize this problem upstream as well.
At the amplifier level I use nCore, so I'm already quite calm because of the post LPF feedback.
In terms of crossover, however, I have some doubts.
Attached is an image of the Opticon 2 MK2 crossover. I don't know much about it, but the biggest inductor I think is related to the woofer, and I also think it's of the ironcore type (and given the price range I can understand).
The small inductor instead, presumably of the tweeter, seems to me to be air core.
Now I kindly ask someone if they can confirm this.
If confirmed, I'd like to know exactly what to measure of the ironcore inductor in order to identify an alternative air core, which keeps the characteristics of the crossover unchanged.
In this sense, with the same inductance, is it possible to find an air core with the same resistance?
Thanks in advance
Attachments
Welcome to the forum!
Yes, the bottom left inductor is an air core and will be associated with the tweeter.
As you indicate, you would have to measure the inductance and DC resistance of the iron core inductor in order to source a suitable air core replacement.
An air core replacement with the same parameters would be much more bulky as it would have to use many more turns of thicker copper wire.
The thicker copper wire is required to keep the resistance low.
Yes, the bottom left inductor is an air core and will be associated with the tweeter.
As you indicate, you would have to measure the inductance and DC resistance of the iron core inductor in order to source a suitable air core replacement.
An air core replacement with the same parameters would be much more bulky as it would have to use many more turns of thicker copper wire.
The thicker copper wire is required to keep the resistance low.
Last edited:
I was interested in finding out more about Dali's patented low-loss SMC magnet system:
https://www.dali-speakers.com/en/products/opticon-mk2/opticon-2-mk2
https://www.dali-speakers.com/en/sound-academy/soft-magnetic-compound
https://www.dali-speakers.com/en/products/opticon-mk2/opticon-2-mk2
https://www.dali-speakers.com/en/sound-academy/soft-magnetic-compound
Last edited:
If you think that Dali speakers are well developed, do not change anything in the x-over. Nothing you can improve with limited knowledge and no measuring equipment.
Usually the core inductors are dimensioned in a way they suit the load capacity maximum. So do not expect any improvement at normal listening levels.
If you listen very loud, the distortion from the chassis will be much more audible than the ones induced from the iron core.
Usualy a waste of money you should save and spend on better speakers.
If you really want to improve the sound, better replace the cheap capacitor in line with the tweeter. It may be audible if you install a 4$ film cap. The ones I see in the x-over are 8 Cent versions.
About this pulverized magnet soup, nothing to write home about. Just some marketing BS as usual.
Usually the core inductors are dimensioned in a way they suit the load capacity maximum. So do not expect any improvement at normal listening levels.
If you listen very loud, the distortion from the chassis will be much more audible than the ones induced from the iron core.
Usualy a waste of money you should save and spend on better speakers.
If you really want to improve the sound, better replace the cheap capacitor in line with the tweeter. It may be audible if you install a 4$ film cap. The ones I see in the x-over are 8 Cent versions.
About this pulverized magnet soup, nothing to write home about. Just some marketing BS as usual.
When you say DALI make marketing ********, do you mean their SMC is ineffective or the problem of hysteresis is insignificant/non-existent?
Seeing some tests online and technical discussion I'm honestly more skeptical about the audibility of replacing a capacitor.
But surely I don't take sides without trying first...
In any case, thanks for your contribution!
Seeing some tests online and technical discussion I'm honestly more skeptical about the audibility of replacing a capacitor.
But surely I don't take sides without trying first...
In any case, thanks for your contribution!
Curiously I found this one on audio.de
I believe that without the indication of the smoothing applied, nor of the setup/measurement environment, these graphs should be taken with a grain of salt.
However, directivity information is not given, so the frequency response alone says little about what it actually sounds like.
I believe that without the indication of the smoothing applied, nor of the setup/measurement environment, these graphs should be taken with a grain of salt.
However, directivity information is not given, so the frequency response alone says little about what it actually sounds like.
Last edited:
Dali say that the entire driver pole piece is constructed from their Soft Magnetic Compound (SMC).
Here are the properties that Dali quotes for their SMC:
"SMC offers exactly the right physical properties; very high magnetic conductivity and very low electrical conductivity (approximately 1/10,000 of that of iron), yielding a dramatic reduction in distortion caused by mechanical loss in the magnet system – clearly measurable and indeed audible"
If my physics is correct, a "very high magnetic conductivity", means a material of very high magnetic reluctance ('resistance') and very low permeability that makes it difficult for a magnetic flux to flow through the pole piece.
Low carbon steel is commonly used to make loudspeaker pole pieces and it already has a low permeability compared to the "iron parts" mentioned by Dali - 100 compared to 5,000 (pure iron) or 200,000 (annealed iron).
Dali's SMC must be even lower in permeabilty than low carbon steel.
No it means the current resistans is high. Like when you make the iron core in and inductor of compressed iron powder
High current resistance is in accord with the "low electrical conductivity" property, something which should minimise eddy currents in the pole piece.
I was addressing the "high magnetic conductivity" property, something which should reduce the magnetic flux flow through the pole piece.
Thanks, I have looked that up. Super Linear Magnetic Material no less! Said to reduce magnetic hysteresis.
The link includes access to a pdf explaining the Super Linear technology: https://atc.audio/super-linear/
There may be some response shaping going on as well as level setting.
The crossover is likely similar to the Dali Zensor 1 one attached.
By comparing the resistor values on the Zensor crossover schematic with those on your Opticon crossover board, you may deduce the likely resistor positions.
The crossover is likely similar to the Dali Zensor 1 one attached.
By comparing the resistor values on the Zensor crossover schematic with those on your Opticon crossover board, you may deduce the likely resistor positions.
Attachments
I have DALI Zensor speakers and I've make a lot of improvements. The latest is perhaps the most dramatic, and might be helpful here. I've only recently experienced the Nodost QPoint benefit on equipment, so I decided to experiment with a Schumann Resonator placed directly beneath the Crossover. The result is spectacular, and I'd encourage anyone with an open mind to give a try. This one without the case fits through the opening after removing the back plate and is cheap enough to justify the experiment.
IMHO, Dali speakers are often better candidates for white-paper crossover rethinks than part upgrading. If you must upgrade a coil or cap it's important to measure the DCR or ESR (respectively) using Dayton DATS or a home built jig with Room EQ Wizard ESPECIALLY in even order crossover components. You can't just go around increasing coil wire size without compensating for reduced DCR. When those parts are in series with the driver it's OK to mess around but when going to ground a small difference can impact the impedance curve in unexpected and bad ways.