Speaker Crossover VS Speaker phasing

Thu Jan 26, 2012 3:38 pm   

Hi,

I am a bit confuse, while most speaker crossover design connect all
speaker negative post togheter, one of mine connect the woofer in
reverse polarity. This result in a DC out of phase with my other
speaker in the room. A coil is in serie with the woofer, so I must
assume that this cause a 90 phase shift in lower frequency, still the
woofer will still be out of phase with the other. Can someone
clarified the reason why the woofer is reverse on that particular
crossover? My problem is that those two speaker boxes are no longer
use stand alone, they are part of a 5.1 system and the bass level is
far than be satisfaying, I think the main woofer been out of phase
with the subwoofer cause that lack of bass reponse. Using the two main
speaker alone is working fine, but now that they are assited by the
subwoofer, bass level tend to be inferior than before. I check the
output of the main amplifiers with a scope in regard to a tone at the
input. While the output is not in phase with the input, the left,
right, center and sub are nearly in phase, just the sub that is
slighly out of phase, probably because of the active filter involve,
both surround speaker are 180 degree out of phase. So the only problem
can only originate in the speaker crossover, so I reverse the polarity
of the main speaker just to check, I not sure, but I think bass level
improve, so should I keep the main left & right speaker in reverse to
match the other?

Thu Jan 26, 2012 3:38 pm   

On Thu, 26 Jan 2012 05:38:24 -0800 (PST), Jack At Home
<jackathome2011_at_gmail.com> wrote:



And serious active subwoofers have a 180 degree phasing button just
for that purpose.

And true serious 5.1 systems allow you to set frequency cutoffs
between main speaker bass response and sub bass response so there is
no (large amount of) frequency overlap