Help with crossover for Sub

[Amit_112dB]

hi
i need to make a passive crossover for 100rms sub, that means i will put 25volts across the sub at max
cross over freq arounf 80hz
Should i go for 1st order or 2nd order or 3rd???

which type of capicitor will have high capicitance close to 300uf and still withstand 25v and that too without any polarity issue(non-electrolytic) ????

is it easy to find a 8mHy inductor ??? or is it toooo much???

or passive cross over at such low freq is very difficult????

[Dr.EM]

Difficult and expensive. Not really ideal, active would be far superior, 4th order is easily attainable this way. Even with a seperate amp (plate amp would do, many have filters built in) active will likely be cheaper.

[Amit_112dB]

Originally posted by Dr.EM
Difficult and expensive. Not really ideal,

i went for passive coz i wont be able to find much time for soldering making PCB, i am elecronics engg. but i work in IT sector and dont have much spare brain cells to kill for non working circuits, sir do u have any simple easy idea or ckt or any small IC for makin a filter
can u gimme any directions for a simple least soldering active filter that can be assembled with use of any PC oscilloscope n signal gen. s/w

thanks a lot for ur previous responce

[richie00boy]

I have a sub controller on my website www.readresearch.co.uk, I'll be updating the project soon to show the component values on the PCB. You don't need a PC or oscilloscope to do it

[OzMikeH]

If you REALLY want to go passive. I expect it will cost you about $1 per uF for bulk good quality caps if you don't get lucky. Then you have to solder them all together into a bigger capacitor or just buy a pre-made plate amp.