Are we talking of a level that would have any true acoustical significance or is it more of a clinical, albeit correct, aspect?
Sometimes I think it is necessary to balanced once comments to the level of the OP knowledge - to kind of "feel the level" of whats going on and adjust to it. These kind of threads it's not the best place to show off ones supreme electrical engineering insights perhaps? I believe it doesn't help the OP - rather perhaps confuses....
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Sometimes I think it is necessary to balanced once comments to the level of the OP knowledge - to kind of "feel the level" of whats going on and adjust to it. These kind of threads it's not the best place to show off ones supreme electrical engineering insights perhaps? I believe it doesn't help the OP - rather perhaps confuses....
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@TNT
Now that's not fair! You said that the value shouldn't change, but there are legitimate reasons why it could, so it doesn't have to be a bad meter. I've long decided that with academic stuff, as long as I can remember that something 'exists', I can always find a path to rebuilding the detailed knowledge if I really need to. I'm actually one of the 'worst' guys on the forum, often suggesting to do measurements by ear, or finding filter values iteratively rather than calculating. It's not a bad approach, when there are so many different variables.
Winding my own inductors is something I haven't done before, and it would be cool to do. I'm dithering between 2 options for my active speakers: as pull-ups in a single-ended amplifier, where there's a resistor anyway so the DCR can be quite high and a fine gauge can be used.
And winding inductors for passive XO's. I've always wanted to stick with active, but since the electronics are taking so long, the speakers are running full-range and below their capability.
Now that's not fair! You said that the value shouldn't change, but there are legitimate reasons why it could, so it doesn't have to be a bad meter. I've long decided that with academic stuff, as long as I can remember that something 'exists', I can always find a path to rebuilding the detailed knowledge if I really need to. I'm actually one of the 'worst' guys on the forum, often suggesting to do measurements by ear, or finding filter values iteratively rather than calculating. It's not a bad approach, when there are so many different variables.
Winding my own inductors is something I haven't done before, and it would be cool to do. I'm dithering between 2 options for my active speakers: as pull-ups in a single-ended amplifier, where there's a resistor anyway so the DCR can be quite high and a fine gauge can be used.
And winding inductors for passive XO's. I've always wanted to stick with active, but since the electronics are taking so long, the speakers are running full-range and below their capability.
I would like if possible to continue the thread also towards what you guys are doing with the layouts of your filter : spacing, choice of coils related to the value in the midrange and treble.
I understood nothing fancy is needed and good iron core coils can be good enough, but some air coils are now cllose price and some with very low DCR enough for most needs.
I now understand because AC, also the // coils are important. Do they nedd to have as thick wire gauge than the low pass coils ? I remember the input about thin gauge to be ok in cas of LCR notch in parralel with the driver (called serie notch in english if I am not wrong - that is the LCR elements that are in serie at the opposit of the // notch where the parts are in // with each others).
I understood nothing fancy is needed and good iron core coils can be good enough, but some air coils are now cllose price and some with very low DCR enough for most needs.
I now understand because AC, also the // coils are important. Do they nedd to have as thick wire gauge than the low pass coils ? I remember the input about thin gauge to be ok in cas of LCR notch in parralel with the driver (called serie notch in english if I am not wrong - that is the LCR elements that are in serie at the opposit of the // notch where the parts are in // with each others).
One cant say that a lower R in a notch i better - I suppose how deep and wide one want it to be... its per design.
A notch usually incorporates a resistor. Here is where some gains can be made. Say that you need:
0,5mH + 3,7 ohm in series for a notch....
a) 0,5mH (0,1 ohm) 20€ + 3,6 ohm (2€)=22€
b) 0,5mH (1 ohm) 5€ + 2,7 ohm (2€)= 7€
🙂
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A notch usually incorporates a resistor. Here is where some gains can be made. Say that you need:
0,5mH + 3,7 ohm in series for a notch....
a) 0,5mH (0,1 ohm) 20€ + 3,6 ohm (2€)=22€
b) 0,5mH (1 ohm) 5€ + 2,7 ohm (2€)= 7€
🙂
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Whether that's the point may depend on the circuit in question, but at the least the impedance will fall away.
Generally speaking when the knowledgeable people simplify their knowledge there's a risk it will become open to misinterpretation, or to amplify a misconception.
I read the Intertehnik link. Two close coils polute each others.
After having positionned the coils with good orientation, wgat should be the gap with each others? 10 cm with iron core and more with air coils. Even more distance betwen the tweeters coils from the midrange coils ?
In loudspeakers brands there us often less than 3 to 5 cm between each others!
Also, please : what about tin foil or aluminium foil caps putted between two coils: that doesn't arm ? Same with wirewound resistors ?
I do not know if those questions make sense. I plan for instance in a tower where the mid tweet filter is compact to put outside the mid filter as there are three binding post pairs in order to put more apart the tweeters filter parts from each others and same for the mid's filter parts...outside needed due to lack of space
After having positionned the coils with good orientation, wgat should be the gap with each others? 10 cm with iron core and more with air coils. Even more distance betwen the tweeters coils from the midrange coils ?
In loudspeakers brands there us often less than 3 to 5 cm between each others!
Also, please : what about tin foil or aluminium foil caps putted between two coils: that doesn't arm ? Same with wirewound resistors ?
I do not know if those questions make sense. I plan for instance in a tower where the mid tweet filter is compact to put outside the mid filter as there are three binding post pairs in order to put more apart the tweeters filter parts from each others and same for the mid's filter parts...outside needed due to lack of space
Inductors do interact with each other, and it might be possible to fine-tune the sound by moving them around. For instance, if the design calls for a 2mH inductor, you could use 2 x 1mH inductors in series, and try to hear the sound changing in real time by moving them closer together or changing the angle between them. Another thing to keep in mind is vibration, including self-induced vibration, so an inductor could be stabilised with epoxy.
Coupling between inductors and capacitors will probably be minimal. I've heard of people claiming to be able to hear the effect of steel screws used in speaker box construction because of magnetic interaction with the voice coil, so anything is possible. But if you start hearing extremely subtle things, which don't seem to make any sense, it could an amplifier problem, like a tube amp picking up RFI.
Coupling between inductors and capacitors will probably be minimal. I've heard of people claiming to be able to hear the effect of steel screws used in speaker box construction because of magnetic interaction with the voice coil, so anything is possible. But if you start hearing extremely subtle things, which don't seem to make any sense, it could an amplifier problem, like a tube amp picking up RFI.
The simulation is not based on an actual part. The effect is what I wanted to show and the values are arbitrary.
German brand Intertechnik showed several distortion measurements of cored coils in their old catalogues, here you can find some:
https://www.yumpu.com/de/document/read/23459563/electronic-components-intertechnik
(see page 11-15).
https://www.yumpu.com/de/document/read/23459563/electronic-components-intertechnik
(see page 11-15).
Here’s the thing that gets me about Litz wire inductors:
With an inductor, I’m usually trying to filter out high frequencies. Skin effect helps filter out high frequencies. Why would I pay extra to counteract it?
But quite useless if shown values cant occur in reality with a real single coil - and probably confusing for OP. I assume you speak of "equivalent capacitance" of a coil...
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I wrote it on purpose to make the similarities to an unwanted aspect of a coil - the equivalent resistance 🙂
How about 'parasitic resistance' 🙂
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How about 'parasitic resistance' 🙂
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Now you're just having fun at my expense! 😉
I read that there are two parasitic resistances associated with a non-ideal inductor: Equivalent Series Resistance (ESR) and Equivalent Parallel Resistance (EPR). And let's not forget the Equivalent Parallel Capacitance (EPC)!
EDIT: I should really credit the above illustration: https://resources.system-analysis.c...t-is-the-parasitic-capacitance-of-an-inductor
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Live and learn - truly, I just winged it 🙂 One should also observe at what frequencies these parasitics have a real effect on.
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It is also a common problem at audio frequencies especially with line level passive crossovers, input and interstage transformers and phono cartridges, but also at speaker level in audio output transformers, where in each case this specification is essential to look at. In most cases it can be seen to lower in frequency as the core is reduced and the coil is made larger to obtain the needed inductance.
It is something any inductor designer needs to know and would measure.
It is something any inductor designer needs to know and would measure.
I can appreciate that reference in relation to phono cartriges, as will most contributors. I'm aware that the parasitic capacitance of a moving magnet cartridge coil, in combination with the capacitance of the pickup arm wiring, interconnect and preamp, tends to produce a high frequency resonance which, if undamped, would produce a peak in the cartridge's output.
That's a result (of another result) - so a "secondary" result and even then usually at very high freq.s (beyond audible).
I like Litz Inductors (good ones with very *tight winding or good damping) for the tweeter. It's not that I achieve more high freq. content but rather that I can often hear further into the noise-floor of the signal being reproduced at higher freq.s. than with most other Inductor designs.
*ex. https://www.intertechnik.com/shop/inductors/tritec-hq-40/583193,en,2765
-best guess is that even a minute reduction in back emf from the Litz (or Foil) wire construction somehow effects this result and is not a secondary effect of having better extreme high freq. results or even a barely imperceptible alteration in heating causing a minute amount of resistance.
I like Foil lower in freq. range - likely because the mechanical damping is often a bit better relative to Litz, though I should note that I've never compared Jatzen's Waxed Litz coils vs their Waxed Foil coils (in an variation - tweeter or midrange position).