"Best" subwoofer crossover frequency

[kexodusc]

Uhh, not sure I follow you here...but if your sub is STILL 6 feet away from your center channel speaker, it is STILL 1/2 wavelenght from the center at a 90 Hz frequency, regardless of what "Crossover" point you select....me thinks you've confused something here.
Don't think crossover point and phase are related in the way you are implying...

[Stu-r]

Uhh, not sure I follow you here...but if your sub is STILL 6 feet away from your center channel speaker, it is STILL 1/2 wavelenght from the center at a 90 Hz frequency, regardless of what "Crossover" point you select....me thinks you've confused something here.
Don't think crossover point and phase are related in the way you are implying...

Crossover point and phase *at the crossover frequency* are absolutely related as long as the distance between the sub and center are constant. The phase relationship between the sub and center change with frequency. Check your basic physics.

At 173hz, 6ft is not 1/2 wavelength, but a full wavelength. In this case, the objective is to reduce/cut off the center speaker *before* it gets down to a frequency that is 1/2 wavelength at the distance it is from the subwoofer (a half wavelength of 6ft = 80-90hz; a full wavelength of 6ft = 173hz). Think about it.

[kexodusc]

Yeah, yeah, love the jab about basic physics...much appreciated.

In keeping with basic physics, you do of course realize that you now have a multi-channel system emitting directional cues from a mono system (your subwoofer)...So left, right, andcenter channel signals (and rears if applicable), that are directional in nature (ie: above 80 Hz) will now be emitted from the subwoofer.

So much for soundstaging and imaging....how's that basic physics for ya!

[Stu-r]

Yeah, yeah, love the jab about basic physics...much appreciated.

In keeping with basic physics, you do of course realize that you now have a multi-channel system emitting directional cues from a mono system (your subwoofer)...So left, right, andcenter channel signals (and rears if applicable), that are directional in nature (ie: above 80 Hz) will now be emitted from the subwoofer.

So much for soundstaging and imaging....how's that basic physics for ya!

Ha! Ha! Good riposte! Some of the literature has long stated that approximately 200hz is the boundary for directionality. If you include audible time of arrival effects, it's lower. But the audible improvement across the board is undeniable without the cancellation effects of the two speakers operating out of phase. As a matter of fact, I find directional and surround effects are *much* improved with the change.

[kexodusc]

What you are implying is interesting, to the say the least...in my room, a 90Hz crossover is very directional at times...the sub gives itself away...not sure if this is a flaw of the sub or what, the speakers don't do it as much, but I suspect that's because they are working in stereo creating an image. Don't really know, don't care. It's pretty well documented directional cuess extend below 100 Hz now, some argue below 70Hz, I can't hear that, but maybe some can.

I have enough room acoustic issues crossed over at 40-60 Hz to worry about before I go doubling or tripling that. And my subwoofer doesn't do nearly as good a job above 80 Hz as my main speakers do together to justify the decrease in performance just to phase align the center channel.
Still, I'll toy with your suggestions...we'll call it the Stuey method.

Cheers!

[Stu-r]

What you are implying is interesting, to the say the least...in my room, a 90Hz crossover is very directional at times...the sub gives itself away...not sure if this is a flaw of the sub or what, the speakers don't do it as much, but I suspect that's because they are working in stereo creating an image. Don't really know, don't care. It's pretty well documented directional cuess extend below 100 Hz now, some argue below 70Hz, I can't hear that, but maybe some can.

I have enough room acoustic issues crossed over at 40-60 Hz to worry about before I go doubling or tripling that. And my subwoofer doesn't do nearly as good a job above 80 Hz as my main speakers do together to justify the decrease in performance just to phase align the center channel.
Still, I'll toy with your suggestions...we'll call it the Stuey method.

Cheers!

That's surprising. If the distance settings for the sub are not correct on the AV receiver, it can cause that kind of separation, or possibly if the sub is a considerable distance from both of the mains. I haven't noticed that spatial disconnect, even with cannon-fire, where it should be most noticeable. Every foot is equal to about a milliseceond. The ear is supposed to be able to resove to about 6 microseconds (I just read on another page). So it can resolve the difference. So any difference between the actual sub distance from the listener and the setting value will do it. A long decay time from the sub's location (reflection) will also do it (acts like another source). Cheers.