relationship between inductance and frequency

[thadman 10+ year member]

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I understand the relationship between inductance and frequency...in a very simple manner.

Only that as Inductance goes up, it limits high frequency extension. Does it vary with frequency? Is there a certain frame of time that a certain inductance exhibits? (ie 1mH takes 1 nanosecond to flip over, once again just throwing numbers out here)

Is there a certain inductance with a certain ohm load that limits a certain frequency, like a certain amount of displacement at a certain frequency determines a certain SPL?

Is there a formula I could use?

ex. 1mH rolls off at 500hz (i have no idea...just threw the number out there)

I was wondering all of this, because I was curious if I could use 2 AA Ava 15s in a dipole up to 150-250hz (power @ 4ohms for each)

(The avas have a 2.4mH inductance)

Click to read more...

 

[squeak9798 5,000+ posts]

http://forum.elitecaraudio.com/showthread.php?threadid=106037

Read that, should help you some.

 

[CBFryman2 5,000+ posts]

Excelent Link Squeak. If only CA.com had thoes kinds of threads.

 

[thadman 10+ year member]

(im not sure what the actual resistance of the voice coil is...im assuming 1.8?)

Fc = Re / (2pi x Le)

so if I wired it to 4ohms itd be at 3.6ohms / 2(3.14) times 2.4

3.6/15.072 = .2389

?what am I supposed to do with that

 

[helotaxi 5,000+ posts]

Change the Le to Henries instead of mili-Henries and the result will make more sense. 238.9 hz is the beginning of the rolloff. This of course assumes that the rst of the values are correct and that the 2.4 mH is for the coils as a pair wired in series.

 

[thadman 10+ year member]

can this be overcome with equalization?

After 240hz does it not respond fast enough, or does it just get lower in output.