how to connect a non powered subwoofer to a stereo system without a subwoofer output
 

i has constructed a 6 order bandpass subwoofer and i would like to connect it to my stereo system.i have observe that in car amp you can input a stereo signal and the amp convert it to a single sub out. i would like to know more on this type of system(how they do that).can someone help me by any means(links to material,website, etc).Thanks for your help! :confused:

You could use an active lowpass crossover.

thank you for your reply. i have hear of active crossover they work on the input signal and there is rely my problem my signal come for a stereo source left and right channel. how to make the two signal that is left and right becomes one so as to get a single input for the active crossover as i have only one sub and does want to use only one. if i use only one of the input (L or R which one to use and will i not loose sound when only using one of the two):cool:

Hi,

Make sure that your stereo system has a line out. Use an adder circuit to add the left signal to the right signal. You get the centre channel. Add a 4th order band pass filter (linkwitz riley has good phase response and is easier to construct). I thing this is helpful. Currently i am in office if you want more details please do reply.

Regards,
Venki

thank you for your help it sound right but can you tell me what a adder circuit is? i do has a basic knowledge of electronics. if you give me a schematic diagram of the circuit i will be able to understand it(or may be a link where i can found one).