Originally Posted by
lurkin' eg
the only problem with this is that it is a stereo signal so its possible to get voices, vocals coming out of the subs. but with proper tweeking you can have just bass.
and if you dont want to have voices and other sound coming from the subs because its in a stero signal, use the low pass filter to only allow just bass to pass through.
Being mono or stereo has nothing to do with whether "voices come out". This only has to do with whether both left and right channels are separate (stereo obviously) or have been combined into a single channel (mono).
I think what you mean to say is that coming from a head unit, outputs that are stereo are usually full bandwidth, meaning they output the entire frequency range of the music, whereas mono outputs are often already low-pass filtered so they only output frequencies meant for a sub.
This just means that you have to know what type of outputs the head unit has, which determines whether or not you will need to use a low pass filter for your sub amp.