By sim box Im referring to a box which contains switchable caps, multi tap coils and resistors that can quickly be configured together to form a wide range of HP/LP filters, zobels and BSC. The biggest expense is the caps, followed by the inductors. A multi tap series inductor in the woofer LP section is the most economical way to obtain many selectable inductance values. It may seem like a large cost to build something like this, but once you have it, you can listen to your work quickly. Its extremely handy to have. I built a pair of them to audition new drivers and assess their sonic attribute or weaknesses. A variable inductor using a moving core can create higher levels of distortion due to one area of the coil being less exposed to the core. I they will only work somewhat at much lower power levels. Only a multi tap inductor will act as well as separate inductors.
I wouldn't use an inductor with a variable positionable core for permanent crossover duty. The hysteresis is different at various points of the windings throughout the inductor. It may be ok for use with lower level current as in line level applications, but for higher power crossover filtering duties it may cause distortion related problems.
The more you move it out from the core, the less dependence on the iron.. so will it be worse than it was designed for?
The ratio of distortion to inductance gets a lot worse but the thd will not change much. I'd suggest that only to do for adjusting the inductance to get the right value and then exchange it for a different coil. To have a movable chunk of metal potentially roaming around in the speaker is not a very advantageous feature, after all.
Yes, of the core. You have never heard of the saturation of a inductance core? Or a saturated transformer core? Please check Google, I'm not explaining that here.
You get all the disadvantages of air and core coils and none of their advantages. How hard is it to understand?
Real world inductors also have series resistors built in. A variable will too, but if you finally get what you want, you need to replace it with an inductor )and likely added resistor to match your variable setting.
Why not measure your drivers in the cabinet and do you tweaking on a crossover simulator like VituixCAD or my Xsim (both free). Then you'll have all the variable everything you could want.
Why not measure your drivers in the cabinet and do you tweaking on a crossover simulator like VituixCAD or my Xsim (both free). Then you'll have all the variable everything you could want.
Hello,
For my crossover fine-tune, I use a set of known value inductors, that I associate in series, positioned and oriented so to avoid cross-coupling.
This allows simple and precise fine tuning, at the expense of having quite a bunch of inductors (that will be re-used for a further x-over).
After fine-tune, i set a single inductor to the correct value.
The same with caps (parallel assiociation) or resistors (series/parallel)
Pascal
For my crossover fine-tune, I use a set of known value inductors, that I associate in series, positioned and oriented so to avoid cross-coupling.
This allows simple and precise fine tuning, at the expense of having quite a bunch of inductors (that will be re-used for a further x-over).
After fine-tune, i set a single inductor to the correct value.
The same with caps (parallel assiociation) or resistors (series/parallel)
Pascal
That's a good way to get close to the values you need. I did that too in the past. If parallel/serial connected coils didn't get the right result and I knew the value I needed, I unwound a coil until I reached the needed value. With capacitors it's not really an issue because you can get almost all values by paralleling 2-3 Cs and they are still pretty cheap. The cost of the coils however went through the roof.
The only reason I don't do that aymore is because I do most setups active with a DSP.
The only reason I don't do that aymore is because I do most setups active with a DSP.
I can't say I've ever found any issues that I could blame magnetism on, but I do know my standard advice to anybody breadboarding a passive filter is 'don't use crocodile leads -especially cheap ones', so I'm with you on that, even if for a different reason. Far too often, I've found they have sufficient resistance to alter the transfer function, so if you use that as your basis, as soon as you build the 'proper' version (whether hard-wired or on the fell PCB so many love to dread) it no longer functions as intended. I have a suspicion this is why some get so twitchy about PCBs, in the belief that they have higher resistance. Shades of irony, since it's often the opposite. 😉
Out of perverse curiosity, a few years back I measured some of those gold-plated brass strap-bars manufacturers often add between two sets of binding posts, which are often announced by the magazines and similar as the worst thing since sliced bread appeared, and should be immediately replaced by 'proper' speaker wire loops. They in fact had about 1/8 the resistance of the 5in lengths of 12ga speaker wire I compared them to. Still, never let the truth and all that. This is audio after all. 😉
You can use these perfectly, just use them to clamp the parts together instead of connecting them with their leads. Or just solder the wires to the clamps.
E: Cheap crocodiles: R 0,8-1,2 ohm
E: Cheap crocodiles soldered: R 0,05-0,3 ohm
The Wago connectors are incredibly good but not suitable for braided wires. Aside from that, it's the best solution, no questions asked. Once you are using solid wires, I completely agree, that's the best solution in my experience.
The people here usually use the clamp type WAGO, not the stick in for solid wire.
You are right, these can take any wire and are perfect for test-setups of crossovers. Way to go! 😀