a long time, i had some magazines called "stereo review"!
one article that i test and works very fine....
but in my words, i don't have the magazine no more!
in stereo amplifiers we have the right and left channels,
with one speaker in each. dhahh!
each speaker have the positive (+) and negative (-) bornes
plugged in the positive (+) and in the negative (-)
of each channel from the amplifier...(dhahhh again).
with 2 more speakers, (read the hints in the end of this post)
we can get a incredible surround sound!
---> jump the NEGATIVES (-) of this news speakers TOGETHER!
--->then take one POSITIVE (+) of this speakers and plug in the
POSITIVE (+) of the RIGHT channel from the amplifier.
--->take the other POSITIVE (+) of the other speaker and plug in the
POSITIVE (+) of the LEFT channel from the amplifier.
how it works....example:
if the right channel have the guitar,
the left channel have the drums and
in both have the voice.
in the new surround speaker you will get the guitat and drums
and a little reverberation (if any) from the voice!
this new surround speakers only sound the differences from the channels!
everything that is common in the 2 channels,don't will be sound in the surround, right?
little hint:
you can use only one speaker
---> only IF
the impedance of this speaker have the DOUBLE impedance
of the minimal impedance of the amplifier use!
if the amplifier support minimal 4 ohms per channel,
the speaker needs 8 ohms minimal.
sorry the "redundance" but is to be it clear!
go ahead, i use it from 30 years ago...
a long time ago when dolby surround don't exist!