Yes 18AWG 50cm Silicone Test Leads w/ 28mm Copper Crocodile Clips (1 Pair Red+Black) | eBay
I got a couple of sets to try out. The quality is good, though one of my leads hadn't been soldered (qa miss I guess), I soldered it myself and all good. The other three were soldered as advertised.
Tony.
My advice is forget about alligator clip leads for testing crossovers. Period.
Crossovers are low impedance circuits where even wire resistance has a significant effect on the final response, let alone connectors, alligator clips etc...
Once you are into the optimising stage where you are trying to get the final response nailed down exactly there is too much resistance and too much variability of that resistance.
It will just drive you nuts wondering why you are getting inconsistent results from day to day, or hour to hour!
The fact that most of the cheap leads have fine wire and typically only crimp the wire is only part of the problem - I choose ones with heaver wire (or replace the wire!) and solder them, but that only solves half the problem.
The other half of the problem is the point contact resistance between the teeth and the wire/terminal you're clipping onto. The contact area is very small for the higher currents that can be present in a crossover (especially circulating currents in a high order filter as any filter 2nd order or higher is a resonant circuit) this causes localised heating at relatively low power levels and changes of resistance. This can even lead to audible distortion in extreme cases.
If the clip is left for any long period of time for listening evaluation - even a few days, oxidation will cause a change in resistance over time. If you disconnect and reconnect the clip you will almost always get a different resistance every time you connect it leading to inconsistent results. Sometimes vibration from the speaker can trigger movement of the alligator clip.
In short, been there done that over many years and after the hassles and misleading results I have abandoned alligator clips even for quick tests.
Although it might seem like a hassle, just use soldered joints when testing changes! It's really not that much hassle if you have a soldering iron at the ready...
A test crossover is as simple as a sheet of plywood with a few rows of long terminal tag strips attached with point to point soldered wiring.
In fact it works so well and is so cheap that for my latest crossovers I literally just used a large piece of 6mm thick good quality plywood, attached four long tag strips to the board, used point to point wiring and hot glued all the components to the board. (With the heavy coils also being strapped)
Absolutely nothing wrong with it as a permanent solution, and yet during the final tuning and testing stages it is still very easy to connect/disconnect/substitute components as the point to point wiring is fully accessible on the top side of the board and the interconnections are self evident, unlike a through hole PCB where it's difficult to trace the circuit or make temporary or last minute changes.
The same construction method can be both the prototyping board and the finished design meaning that you don't have to worry about issues like different interconnect resistances changing the response when you make the "proper" version of the crossover as a PCB, or if you go from terminals/clips during testing to soldered point to point.
Regarding the use of component legs inserted into speaker terminals shown in korpberget's post, I would avoid doing it that way either as the point contact resistance of a single solid wire lead in such terminals is going to be high and inconsistent just like an alligator clip.
Having a dozen of these inconsistent high resistance connections is going to cause a lot of variability and uncertainty in the results.
In passive crossovers I try to avoid any non-soldered joints in the crossover itself, or the wires from the crossovers to the speakers - I don't use spade terminals on drivers or terminals/sockets on the crossover board.
The only concession I make is the terminals at the back of the speaker at the input to the crossover which needs some kind of non-soldered connection back to the amplifier. But any resistance here will tend to affect all the drivers in the speaker by roughly the same amount (as will speaker cable resistance) so isn't really an issue, however intermittent additional resistance in the crossover itself or the wires to the drivers will tend to affect one driver differently to another and interfere with the balance between the drivers - this is audible even if the relative level shift between drivers is as low as 0.2dB or so, as it can affect the response over many octaves.
Crossovers are low impedance circuits where even wire resistance has a significant effect on the final response, let alone connectors, alligator clips etc...
Once you are into the optimising stage where you are trying to get the final response nailed down exactly there is too much resistance and too much variability of that resistance.
It will just drive you nuts wondering why you are getting inconsistent results from day to day, or hour to hour!
The fact that most of the cheap leads have fine wire and typically only crimp the wire is only part of the problem - I choose ones with heaver wire (or replace the wire!) and solder them, but that only solves half the problem.
The other half of the problem is the point contact resistance between the teeth and the wire/terminal you're clipping onto. The contact area is very small for the higher currents that can be present in a crossover (especially circulating currents in a high order filter as any filter 2nd order or higher is a resonant circuit) this causes localised heating at relatively low power levels and changes of resistance. This can even lead to audible distortion in extreme cases.
If the clip is left for any long period of time for listening evaluation - even a few days, oxidation will cause a change in resistance over time. If you disconnect and reconnect the clip you will almost always get a different resistance every time you connect it leading to inconsistent results. Sometimes vibration from the speaker can trigger movement of the alligator clip.
In short, been there done that over many years and after the hassles and misleading results I have abandoned alligator clips even for quick tests.
Although it might seem like a hassle, just use soldered joints when testing changes! It's really not that much hassle if you have a soldering iron at the ready...
A test crossover is as simple as a sheet of plywood with a few rows of long terminal tag strips attached with point to point soldered wiring.
In fact it works so well and is so cheap that for my latest crossovers I literally just used a large piece of 6mm thick good quality plywood, attached four long tag strips to the board, used point to point wiring and hot glued all the components to the board. (With the heavy coils also being strapped)
Absolutely nothing wrong with it as a permanent solution, and yet during the final tuning and testing stages it is still very easy to connect/disconnect/substitute components as the point to point wiring is fully accessible on the top side of the board and the interconnections are self evident, unlike a through hole PCB where it's difficult to trace the circuit or make temporary or last minute changes.
The same construction method can be both the prototyping board and the finished design meaning that you don't have to worry about issues like different interconnect resistances changing the response when you make the "proper" version of the crossover as a PCB, or if you go from terminals/clips during testing to soldered point to point.
Regarding the use of component legs inserted into speaker terminals shown in korpberget's post, I would avoid doing it that way either as the point contact resistance of a single solid wire lead in such terminals is going to be high and inconsistent just like an alligator clip.
Having a dozen of these inconsistent high resistance connections is going to cause a lot of variability and uncertainty in the results.
In passive crossovers I try to avoid any non-soldered joints in the crossover itself, or the wires from the crossovers to the speakers - I don't use spade terminals on drivers or terminals/sockets on the crossover board.
The only concession I make is the terminals at the back of the speaker at the input to the crossover which needs some kind of non-soldered connection back to the amplifier. But any resistance here will tend to affect all the drivers in the speaker by roughly the same amount (as will speaker cable resistance) so isn't really an issue, however intermittent additional resistance in the crossover itself or the wires to the drivers will tend to affect one driver differently to another and interfere with the balance between the drivers - this is audible even if the relative level shift between drivers is as low as 0.2dB or so, as it can affect the response over many octaves.
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Yes it is. I am truly sorry.
Big fan of Mr Fikus, his work and will to chare ideas and work with others.
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