Air Inductor

[shugg]

Hi

After some time I've decided to start from scratch re a crossover build for Lynn Olsen Ariels.
I've decided to go with solen litz inductors, however the circuit diagram indicates 0.3 mH values for two of the inductors (one per tweeter and woofer) and 1.0mH for the woofer inductor.

I can get the woofer inductor at that value but the other inductors are at 0.33 mH +/- 1%

Can anyone advise ifl using 0.33 instead of 0.3 cause any major issues that I should be aware off.

Thanks

 

[Jonathan Bright]

Some would say that 10% is not big deal for a first order network. A lot of other things will vary by a lot more. You generally want tighter tolerances for the higher orders though. You've got a couple of options. I haven't seen that particular network. If it is second order you could reduce the corresponding capacitor value by a similar ratio i.e. around 10 %. That would give a close approximation to the relevant time constant. Or, given that the inductor you're proposing to buy is bigger than required you could perhaps take a few turns from the coil to reduce the inductance. Again, I don't know the physical construction of that item. It may not be easy to do. Now it probably WON'T be 9% of the turns. Chase up a formula for air coil construction and follow that up that suggestion with more science!
Good luck. I gather that the Ariel has a truly massive thread running elsewhere on the Forum. There must be loads of bods who can be more constructive.....you could do worse than post your question there.

Jonathan

 

[picowallspeaker]

Hi Shugg , my calculator tells me that 0.03 is 10% of 0,3. Usually a tolerance of 5% is admitted ,as it would provoke a slide of few hertz in the crossover circuit - in practice you can just take off some turns of precious copper , and they could be useful for wiring something else.

 

[Mario Pankov]

And why not to remove some of the coil lenght until it measures 0.3mH?