What value Inductor for simple lowpass @ 100hz ?

[IllNastyImpreza]

I've got some bass shakers, 4 OHMs. frequency responce of 20-100hz

What value Inductor can I use to make a simple lowpass at 100 hz ??

should I go with 100 or maybee little lower due to the narrow slope ??

[ThomasW]

This is an situation where passive line level components are a good choice...if you don't want to build your own buy F-Mods, otherwise go here....

http://www.t-linespeakers.org/tech/filters/passiveHLxo.html

[Dennis H]

6.4 mH will give you a 6dB lowpass at 100 Hz. Or you could stick an F-mod between the preamp and amp for a 12dB lowpass. It's not like you need an exact crossover with a bass shaker.

Edit: Thomas beat me to it with the F-mod.

[ThomasW]

Edit: Thomas beat me to it with the F-mod.

Some of us old geezers are surprisingly fast.... :B

[servicetech]

I won't bother with a passive crossover for bass shakers, let the natural impedance rise of the voice coil control the cutoff.

[IllNastyImpreza]

I won't bother with a passive crossover for bass shakers, let the natural impedance rise of the voice coil control the cutoff.

are you telling me to give them full range of signal ???

6.4 mH will give you a 6dB lowpass at 100 Hz. Or you could stick an F-mod between the preamp and amp for a 12dB lowpass. It's not like you need an exact crossover with a bass shaker.

Edit: Thomas beat me to it with the F-mod.

awesome... thanks guys

does it matter much which type of coil I get? whats the cheapest ?

[servicetech]

The bass shaker is 8 ohms only at certain frequencies. As frequency rises so does driver impedance creating a natural "cut off". No passive crossover is needed. If the bass shakers are being driven by a separate amp by all means use a crossover at the line level such as an F-mod.