View Full Version : Subwoofer in phase with only one speakers
fid
November 12th 07, 09:56 PM
Hello everyone,
After I installed a single Rel subwoofer into my system I realized
that it would be in phase with one speaker and not with the other.
I explain: My room is just a bit more then 4000 cubic-feet, L shaped.
I set the subwoofer into the left corner behind the left speaker
(Unfortunately this is the only option I have). So, I measured the
frequency response of each front speakers with an real-time analyzer
and I found out that when the phase of the subwoofer is set to 0 the
right speaker's mid-bass frequencies decrease the output considerably.
When I switch the sub's phase to 180 the left speaker's mid bass
portion is sucked in. I checked the wiring, all matches red-to red,
black to black. I thought... maybe I should reverse the polarity of
one of the mains to even up with the sub, but that would screw up the
phase between the two mains. Is there any solution?
Is the distance between sub and mains the cause of this phase
'disparity"?
Any input would be greatly appreciated.
Thank you.
Clyde Slick
November 12th 07, 10:52 PM
On 12 Noi, 16:56, fid > wrote:
> Hello everyone,
>
> After I installed a single Rel subwoofer into my system I realized
> that it would be in phase with one speaker and not with the other.
>
> I explain: My room is just a bit more then 4000 cubic-feet, L shaped.
> I set the subwoofer into the left corner behind the left speaker
> (Unfortunately this is the only option I have). So, I measured the
> frequency response of each front speakers with an real-time analyzer
> and I found out that when the phase of the subwoofer is set to 0 the
> right speaker's mid-bass frequencies decrease the output considerably.
> When I switch the sub's phase to 180 the left speaker's mid bass
> portion is sucked in. I checked the wiring, all matches red-to red,
> black to black. I thought... maybe I should reverse the polarity of
> one of the mains to even up with the sub, but that would screw up the
> phase between the two mains. Is there any solution?
> Is the distance between sub and mains the cause of this phase
> 'disparity"?
>
> Any input would be greatly appreciated.
> Thank you.
i say one of the drivers in one of the mains may be out of phase,
internal wiring screw up.or such
fid
November 13th 07, 12:08 AM
> i sayoneof the driversinoneof the mains may be out ofphase,
> internal wiring screw up.or such
How could that be. The speakers have never been opened,
Clyde Slick
November 13th 07, 01:22 AM
On 12 Noi, 19:08, fid > wrote:
> > i sayoneof the driversinoneof the mains may be out ofphase,
> > internal wiring screw up.or such
>
> How could that be. The speakers have never been opened,
they were open when they were assembled.
Clyde Slick
November 13th 07, 02:32 AM
On 12 Noi, 21:19, "ScottW" > wrote:
> "fid" > wrote in message
>
> oups.com...
>
>
>
> > Hello everyone,
>
> > After I installed a single Rel subwoofer into my system I realized
> > that it would be in phase with one speaker and not with the other.
>
> > I explain: My room is just a bit more then 4000 cubic-feet, L shaped.
> > I set the subwoofer into the left corner behind the left speaker
> > (Unfortunately this is the only option I have). So, I measured the
> > frequency response of each front speakers with an real-time analyzer
> > and I found out that when the phase of the subwoofer is set to 0 the
> > right speaker's mid-bass frequencies decrease the output considerably.
> > When I switch the sub's phase to 180 the left speaker's mid bass
> > portion is sucked in. I checked the wiring, all matches red-to red,
> > black to black. I thought... maybe I should reverse the polarity of
> > one of the mains to even up with the sub, but that would screw up the
> > phase between the two mains. Is there any solution?
> > Is the distance between sub and mains the cause of this phase
> > 'disparity"?
>
> > Any input would be greatly appreciated.
> > Thank you.
>
> Assume the sub crossover is set to 80 hz.
> Wavelength of 80 hz is ~14 ft.
> Half a wavelength will put you out of phase
> so it sounds like the difference in distance to the
> listening position between your right speaker
> and the sub may be a problem.
>
> Are you using an RTA with short windowing?
> They don't show the real room response for bass
> but the first arrival FR.
> Bass response is more room mode than first
> wave phase cancellation.
>
> Here's a decent room acoustics page.
>
> http://www.silcom.com/~aludwig/Room_acoustics.html
>
> ScottW
i assumed he listened to some music.
stupid me!!!!
(or "at least" measured a range)
anyway, if he moves it to 7 or 9 feet away, it
just shifts the problem to another close by frequency.
fid
November 13th 07, 02:43 AM
>
> they were open when they were assembled.
I hard to believe that a 10K speakers where wrongly assembled.
The rel sub crossover is set to 22hz. When I switch it off both
speakers present a resonably close frequency response.
The rta device I am using is called phonic paa2. Ii really don't know
much about these things. That the reason why I am asking your opinion,
and I thank you for that.
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