Hello all, do you know where to buy, if exists, a low DCR and high current variable inductor to help in crossover fine tuning? I hate unwind and rewind normal coils, also because they can easily be damaged from this practice, so I'm wondering if exists an inductor where I can simply move the inside core in & out to change the mH value, or at least what can be the best suitable in commerce inductor in which this tweak can be easily done.
Obviously I talk about both low DCR & high mH inductors for low-pass section both medium DCR and low mH value for the high-pass one.
Thank you very much.
Obviously I talk about both low DCR & high mH inductors for low-pass section both medium DCR and low mH value for the high-pass one.
Thank you very much.
It should be easy to do with an inductor that uses a solenoid core which can be dislodged. Often they are glued to the inner surfaces of a bobbin.
Exactly, do you know any commercial model made so? I was surprisingly not able to find any. Does somebody know, for example, if this Dayton Audio model is suitable has moveable core and is suitable for this purpose?
If yes, what's the mH value with core totally in place and without core at all for some model?
If yes, what's the mH value with core totally in place and without core at all for some model?
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Maybe you could use two inductors in series and adjust the distance and orientation to fine turn their inductance.
http://www.troelsgravesen.dk/coils.htm
http://www.troelsgravesen.dk/coils.htm
Long, long ago I made some some hand winded big inductors with multiple taps.
The taps were in a 1,2,5 ratio.
They were very useful, I did not see something alike available commercially.
The taps were in a 1,2,5 ratio.
They were very useful, I did not see something alike available commercially.
I wind my own inductors with multiple taps to use for wall proximity compensation on passive filters. A rotary switch then allows you to select how much BSC you want on the LP to avoid muddiness.
I also use multiple taps for crossover prototyping. Also very handy for testing tweeters and horn drivers.
I also use multiple taps for crossover prototyping. Also very handy for testing tweeters and horn drivers.
If you want a useable range, even for a simple 2-way crossover, you soon run into very large, heavy and expensive constructions.
If you are a professional speaker developer, it could make sense, even as I don't think a pro would invest in such gear today.
Good measuring in combination with crossover simulation works faster, better and cheaper. You only try and fine tune the most promising simulation results.
If you do some serious speaker development, you will build up a heavy stock of coils, caps and resistors anyhow. I can't carry all my boxes with coils at once... they are too heavy.
By the way, after adjusting a set of coils to a specific value and before permanently mounting them inside a speaker, pouring some fast curing epoxy over the windings is a good idea. The inside of a speaker is mechanically demanding.
If you are a professional speaker developer, it could make sense, even as I don't think a pro would invest in such gear today.
Good measuring in combination with crossover simulation works faster, better and cheaper. You only try and fine tune the most promising simulation results.
If you do some serious speaker development, you will build up a heavy stock of coils, caps and resistors anyhow. I can't carry all my boxes with coils at once... they are too heavy.
By the way, after adjusting a set of coils to a specific value and before permanently mounting them inside a speaker, pouring some fast curing epoxy over the windings is a good idea. The inside of a speaker is mechanically demanding.
Probably not what you were looking for, but as you want to do this to test/prototype it would it not be easier to use an active crossover? Once you get the exact values you want you can buy/build the inductor. If you need to simulate the DCR, variable resistors are easily available. (If you have enough DACs/amplifiers you should be able to get away without buying a DSP board if you can use your computer's output with something like CamillaDSP.)
While writing this comment I just googled variable inductor and apparently they do exist, for example mouser sells a few. However their inductances might be on the lower side, some are listed in nH.
While writing this comment I just googled variable inductor and apparently they do exist, for example mouser sells a few. However their inductances might be on the lower side, some are listed in nH.
Far from chesp but there is 2 available options, along with multi caps and resistors. Assumr Lozjek was reffering to the same ones above.
https://www.intertechnik.com/shop/developer-tools/583193,en,8072
https://www.intertechnik.com/shop/developer-tools/583193,en,8072
Don't ever use active crossover/ DSP to develop speaker you later want to realize in a passive version. Never, beware!
If you do, you will realize how much sound quality you loose with the passive crossover if you do a two way and how much more expensive a passive 3-way is compared to a 3-way active version.
We love passive speaker so much because we love our shiny amps and want to play with the components that are erased in the active version.
If you do, you will realize how much sound quality you loose with the passive crossover if you do a two way and how much more expensive a passive 3-way is compared to a 3-way active version.
We love passive speaker so much because we love our shiny amps and want to play with the components that are erased in the active version.
Thank you, I wasn’t aware of this. At the risk of going off topic could you perhaps explain why this happens? Is it “simply” real world issues like thermal noise (that could perhaps be reduced by having the crossover at line level) or is it something else? It would appear that ideally using software (for simulations or dsp testing) should be far more “reliable” when designing/tweaking a crossover.
Trying to simulate a passive crossover design using active electronics to obtain "target" filter behavior will result in a huge waste of time. That is unless you just want to do a quick listen using some passive cookie cutter filters. That's what a passive filter test box is excellent for. Theoritical simulation is a wonderful tool, but it doesn't give you any idea what the speaker can actually sound like.
Yeah, its easy to just gradually amass a big selection of caps, coils and resistors, then connect them all together using cheap, nasty clip leads, hoping there's minimal degradation of contact. That takes a ton of time. Its so much faster and economical to build a simple crossover sim box for a 2 or 3 way system. Its not as expensive as you may think. You'll be up and running very quickly and it let's you "live" with the speaker and tweak it bit by bit over the course of a day or two without a huge mess of unstable connections. This is what we did when I did crossover work for ACR. If.you like to back up your sims and try them out quickly, verifying their behavior, its a goof proof way to do it quickly.
I'll dig out my old set of sim.boxes and take some pictures when I come across the boxes in storage. The way they were built allowed for up to 3rd order filters on a 3 way system with padding and zobels on mids and HF. I wanted to do a version with an LCR on the mids, but that's a bit more labor intensive.
Yeah, its easy to just gradually amass a big selection of caps, coils and resistors, then connect them all together using cheap, nasty clip leads, hoping there's minimal degradation of contact. That takes a ton of time. Its so much faster and economical to build a simple crossover sim box for a 2 or 3 way system. Its not as expensive as you may think. You'll be up and running very quickly and it let's you "live" with the speaker and tweak it bit by bit over the course of a day or two without a huge mess of unstable connections. This is what we did when I did crossover work for ACR. If.you like to back up your sims and try them out quickly, verifying their behavior, its a goof proof way to do it quickly.
I'll dig out my old set of sim.boxes and take some pictures when I come across the boxes in storage. The way they were built allowed for up to 3rd order filters on a 3 way system with padding and zobels on mids and HF. I wanted to do a version with an LCR on the mids, but that's a bit more labor intensive.
When I started doing crossovers (long before simulation software was around) I was often surprised how different the speaker sounded with the soldered version, compared to clip leads. This is mainly because most of the cheap leads are actually magnetic, so not made from copper. With solid clips and decent copper wires this effect is much reduced.
A simple active crossover is no great help, you will see it as soon as you meet the baffle step. This is no problem in a PA system that allways got an equalizer to make the sound match.
Somethign else is a DSP, but even when you got it right and the speaker sounds great, this is no help, as it even complicates the passive crossover that would be needed.
Somethign else is a DSP, but even when you got it right and the speaker sounds great, this is no help, as it even complicates the passive crossover that would be needed.
Excuse me, but I'm not sure about what is a sim box, is it a complete software loudspeaker design as BOXSIM I already use, or is it a hardware instrument I never heard about?
It could be just what I'm looking for, even if I still think that it would have been much and much easier to produce a simple inductor with a screw-moveable core, like the MF in old radio, but if it's not produced there's evidently something I don't take in account because I don't know.
I can't agree more, I hate crocodiles too because they're higly unreliable, and so soldering and unsoldering is often the only way to work for me
If you refer to digital active crossover, far from wanting to light a debat here around analog and digital world, I already evaluate in other discussion digital active crossover, and I wasn't sufficiently convinced that the resolution of the high part of the spectrum at levels necessarily lower than the low part's levels and with volume controls that lower them further is sufficient to guarantee correct sampling and sound quality, and I believe someone has experienced this in high efficiency systems. If I continue to want to operate in analogue passive mode, it is also because I personally find it more fascinating, a matter of taste, and I know for a fact that a well-designed passive crossover can give exceptional results.
No, you can get it without a LCR bridge. You can compare it with a known value inductance and a bridge circuit or Wien bridge.