The big picture is I am redesigning a crossover to convert a four ohm woofer to 8 ohms ( dual coil) in order to use it with my Yamaha receiver. It worked great but I understand it is too low in ohms.
Anyway, I will need a smaller capacitor and a larger coil. I have a candidate of unknown Henry but it has a metal core. What does that mean in audio? I could possibly remove all that heavy wire and wind an air-core one. The crossover frequency is 1800-2000.
Anyway, I will need a smaller capacitor and a larger coil. I have a candidate of unknown Henry but it has a metal core. What does that mean in audio? I could possibly remove all that heavy wire and wind an air-core one. The crossover frequency is 1800-2000.
The core enhances the magnetic flux so it raises the inductance
I've said that from a practical point of view, since two same bobbins with and without the core exhibit different values. The counterpart is that the core saturates at high power.
So from a practical POV I can say that (ferrite)cored inductors are used in mid-low power preferably or for cost and space saving reasons...
About the remake of the crossover...it's a bit unclear. If it's an easy load, I guess most receivers should be able to put some power -say 20 W- on a 4Ω load. Since at the halving of the Z there's a doubling of SPL, the current would then ...don't try it !!!
But the 6-16 Ω Z allowance/bewareness that the amplifier claims must be there for a reason. Mostly, I fear is for the " all channels working, 02 % distortion, on 6 Ω loads" data which justifies the limits of the power transformer ( power supply in general ).
So, if you put in series two 4Ω coils you'll get 8 Ω .Bigger inductor, yes
I've said that from a practical point of view, since two same bobbins with and without the core exhibit different values. The counterpart is that the core saturates at high power.
So from a practical POV I can say that (ferrite)cored inductors are used in mid-low power preferably or for cost and space saving reasons...
About the remake of the crossover...it's a bit unclear. If it's an easy load, I guess most receivers should be able to put some power -say 20 W- on a 4Ω load. Since at the halving of the Z there's a doubling of SPL, the current would then ...don't try it !!!
But the 6-16 Ω Z allowance/bewareness that the amplifier claims must be there for a reason. Mostly, I fear is for the " all channels working, 02 % distortion, on 6 Ω loads" data which justifies the limits of the power transformer ( power supply in general ).
So, if you put in series two 4Ω coils you'll get 8 Ω .Bigger inductor, yes
As stated, the iron core can saturate and cause distortion at high powers. But they are smaller and cheaper - and have lower DC resistance - for a given value than air core.
These days you can buy some pretty hefty solid core inductors at places like Parts Express or Madisound. They aren't likely to cause problems under sane conditions That said, the inductors are probably no huge at that crossover frequency. Maybe 1-2mH? That would not kill you to get an aircore.
Jantzen 1.0mH 15 AWG Air Core Inductor | 255-422
Jantzen 1.0mH 15 AWG P-Core Inductor | 255-100
These days you can buy some pretty hefty solid core inductors at places like Parts Express or Madisound. They aren't likely to cause problems under sane conditions That said, the inductors are probably no huge at that crossover frequency. Maybe 1-2mH? That would not kill you to get an aircore.
Jantzen 1.0mH 15 AWG Air Core Inductor | 255-422
Jantzen 1.0mH 15 AWG P-Core Inductor | 255-100
How does all those evolved metal core coils, like Aronit or Feron coils from Mundorf come into play? These are by no means cheap or small.
Mundorf - Inner Excellence
-Mikko
Mundorf - Inner Excellence
-Mikko
Hang on... dual VC is going to end up being 8 ohms??
Ur putting them in series or in parallel?
The next thing is matching levels/sensitivity. New woofer, old woofer, needs to be proper WRT the HF section.
Even in the dual VC woofer, the sensitivity of the speaker with the VC in series and in parallel are different.
Next, what's the freq response of the old woofer?
The freq response of the new?
The xover has to actually xover the new woofer *where it needs to xover* based on the actual acoustic response.
What's the electrical slope of the xover, and what is the acoustic response of the xover *with* the original speaker?
Then, is this actually any *good*, is the original design any good?
And, why are you changing out the woofer - is the new woofer actually suitable as far as T/S parameters (in light of the box volume) and frequency response?
(many woofers have a peak/spike often around 2kHz)
I'd worry more about these things over the core of the inductor (assuming the inductor is sized for enough power).
The HF effects of a heavy core inductor are meaningless in a Low Pass filter, imo.
_-_-bear
Ur putting them in series or in parallel?
The next thing is matching levels/sensitivity. New woofer, old woofer, needs to be proper WRT the HF section.
Even in the dual VC woofer, the sensitivity of the speaker with the VC in series and in parallel are different.
Next, what's the freq response of the old woofer?
The freq response of the new?
The xover has to actually xover the new woofer *where it needs to xover* based on the actual acoustic response.
What's the electrical slope of the xover, and what is the acoustic response of the xover *with* the original speaker?
Then, is this actually any *good*, is the original design any good?
And, why are you changing out the woofer - is the new woofer actually suitable as far as T/S parameters (in light of the box volume) and frequency response?
(many woofers have a peak/spike often around 2kHz)
I'd worry more about these things over the core of the inductor (assuming the inductor is sized for enough power).
The HF effects of a heavy core inductor are meaningless in a Low Pass filter, imo.
_-_-bear
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Looking these Mundorf Feron coils Strassacker: Speaker Building, Components for the woofer crossover. I need 1.8 value. Do you know if these are good as air foil coils? There are not specially cheap (32€). Is it a rule that air coil (foil or round core) are better than iron, feron or bar wound coils?
Thanks.
Who knows
there is soooo much brochure babble in Audio that actual facts are rare.
On My planet ...'worth keeping' Cored Coils are those wound on laminated transformer stacks. Just like a 'quality' Output transformer, using very thin nickel /cobalt lams... for minimal saturation and resistance effects.
Not built for cost considerations, but size ones.
And imo; Yess... Air and foil coils often show audible advantage over even those quality cored inductors.
Testing for oneself... helps.
there is soooo much brochure babble in Audio that actual facts are rare.
On My planet ...'worth keeping' Cored Coils are those wound on laminated transformer stacks. Just like a 'quality' Output transformer, using very thin nickel /cobalt lams... for minimal saturation and resistance effects.
Not built for cost considerations, but size ones.
And imo; Yess... Air and foil coils often show audible advantage over even those quality cored inductors.
Testing for oneself... helps.
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