0-180 Phase Control on Subs

[mulester7]

.....if your LFE is in operation, 80 down is going to the subs, and 80 up is going to the main's regiment, what needs to be blended as per cone movements?....I have found moving away from 0 simply makes the oscillations go away, good-bye bass, it's been real........you want 80 down to sound as good as possible, and that means as sterling of oscillations as possible....I posted this in the Philosophers and Wisemen section....hope a few show up....especially WmAx.......

.....comments on this, please.....

 

[MDS]

Are you implying that there is no purpose for a 0 - 180 phase control on a sub because the bass goes away in your room when you turn it away from zero?

It's purpose is to blend the sound of the sub with the mains. In your room, obvioulsy 0 is the right setting. In another room, it may not be 0 - it depends on alot of factors.

 

[mulester7]

Are you implying that there is no purpose for a 0 - 180 phase control on a sub because the bass goes away in your room when you turn it away from zero?

It's purpose is to blend the sound of the sub with the mains. In your room, obvioulsy 0 is the right setting. In another room, it may not be 0 - it depends on alot of factors.

.....aaahh....but the sound of the sub is not infringing on the main's regiment with decent crossovers....isn't the setting of 0 what could be considered normal?......

....edit....and let's look at the paths of projection with down and front firing subs.....

 

[mulester7]

Are you implying that there is no purpose for a 0 - 180 phase control on a sub?

.....possibly with a front-firing sub....I can see maybe more need with down-firing, but not sure of that either, the sub is dealing with 80 down exclusively......

 

[mulester7]

.....one last thing....aren't the sub and main's regiment getting the same alternating current when the pre-amped full-range signal is split by the LFE?....somebody please tell me where the conflicting cone movement bees......

 

[edwelly]

I have been playing around for about 6 hours over the past several days trying to figure the 0-180 phase. Personally, I like the 0 OR 180 switch - not the variable settings - too much to set for me...

 

[mulester7]

I have been playing around for about 6 hours over the past several days trying to figure the 0-180 phase. Personally, I like the 0 OR 180 switch - not the variable settings - too much to set for me...

.....all right, we've got a vote for all or nuthin'....anyone else?.....

 

[MDS]

Front, side, down, up firing is not relevant other than the fact that if placed in the same exact position in your room they could very well differ in the frequency response you get at your listening position.

Saying that the phase control affects the motion of the cone with respect to the other speakers is true, but is the simplified way of looking at it. You seem to be concentrating on the xover frequency and assuming that if the xover is 80 Hz, the sub gets everything below (another simplification) and the mains get everything above so there is no problem. That's not what the phase control is used for - it is to affect the frequency response in the room.

I'll leave all the technical details to WmAx because he can explain it far better than I, but suffice it to say that the phase control helps to integrate the sound from the sub with the sound from the other speakers. The room can affect the sound waves in many ways - two waves can be coincident and therefore reinforce the bass too much (the 'boominess' people talk about) or be completely out of phase and cancel each other (resulting in a 'null') or anywhere in between. The goal is to get as close to a flat frequency response as possible - if a 50 Hz tone is at 90 dB, it should be as near 90 dB as possible when it reaches your ears.

 

[mulester7]

I have been playing around for about 6 hours over the past several days trying to figure the 0-180 phase. Personally, I like the 0 OR 180 switch - not the variable settings - too much to set for me...

....EdWelly, which setting brought the cleanest oscillations and authority?....maybe this control is for those who don't want a little edge on their subs....oh, that I may never be such a person......

 

[mulester7]

Front, side, down, up firing is not relevant other than the fact that if placed in the same exact position in your room they could very well differ in the frequency response you get at your listening position.

Saying that the phase control affects the motion of the cone with respect to the other speakers is true, but is the simplified way of looking at it. You seem to be concentrating on the xover frequency and assuming that if the xover is 80 Hz, the sub gets everything below (another simplification) and the mains get everything above so there is no problem. That's not what the phase control is used for - it is to affect the frequency response in the room.

I'll leave all the technical details to WmAx because he can explain it far better than I, but suffice it to say that the phase control helps to integrate the sound from the sub with the sound from the other speakers. The room can affect the sound waves in many ways - two waves can be coincident and therefore reinforce the bass too much (the 'boominess' people talk about) or be completely out of phase and cancel each other (resulting in a 'null') or anywhere in between. The goal is to get as close to a flat frequency response as possible - if a 50 Hz tone is at 90 dB, it should be as near 90 dB as possible when it reaches your ears.

.....this is good, MDS....I'm ignorant as a green goose over the phase-control....I only know how it effected the subs that fire at me with no bounces....so, the control works with the after-effect of the firing, as to it's reaching the listening position....to me, that would apply much more to a down-firing showing up at the listening position on bounce 6 or 7..........

 

[markw]

Boy, you really like to complicate things, doncha?

You're arguing over how many angels can dance on the head of a pin here. The sub will never be 100% "in phase" with other speakers simply because of their positioning, distance from each other, room interaction/reflections and the frequencies they handle.

Just set it to wherever it sounds best to you and sleep well knowing you've done a good job.

 

[edwelly]

....Edwelly, which setting brought the cleanest oscillations and authority?....maybe this control is for those who don't want a little edge on their subs....oh, that I may never be such a person......

I played around some more last night just using 0 or 180 for some time. Once I found that I liked the 180 phase better than the 0 phase I went to 90. From there I worked with 180 to 90 and found a pretty darn happy setting at 105-110 area. Using a SPL meter, this yielded the most SPL. I also used the Avia disc (the sub phase warable thingie) to help determine the starting point. Overall, I am pleased with my sub settings. I listened to some music and found it to be rather smooth (good thing for me as I hate boomy) and then watched Stars Wars 1 and found the bass to be more than enough during the pod race.

 

[WmAx]

.....if your LFE is in operation, 80 down is going to the subs, and 80 up is going to the main's regiment, what needs to be blended as per cone movements?....I have found moving away from 0 simply makes the oscillations go away, good-bye bass, it's been real........you want 80 down to sound as good as possible, and that means as sterling of oscillations as possible....I posted this in the Philosophers and Wisemen section....hope a few show up....especially WmAx.......

.....comments on this, please.....

Mulester7, I detailed the requirements and consequences of speaker position, frequency and phase in a thread last week, and again in a thread specifically for you a few months back. But as far as this current situation, I'm going to repeat what everyone else is telling you: turn the phase dial to where the bass sounds the best to you -- done. If you want to fix boominess, etc.; these are room problems and you will have to resort to using a parametric equalizer [and preferably bass traps combined with parametric equalization]. The speaker management system[DCX2496] that you expressed interest in last week would be able to correct all of these problems[and improve the crossover integration between mains and subs dramatically]. However, realize that you will have to measure the room's low frequency response at the listening position in order to dial in the parametric settings for room corrections.

-Chris

 

[Duffinator]

Where's Craigsub?

Mule, I followed Craigsub's recommendation from a few months back of using an SPL meter to determine the phase setting with my new SVS PB12-ISD. And the winner is...0. My setup noticed a drop off almost immediately from moving off of 0 with close to a 4db drop at 180. This was the same setting that worked best with my old Mirage sub without using an SPL meter. I think room acoustics and positioning probably effect this alot and my sub is close to my mains on the side sandwiched between a fireplace and sofa. You can see the placement in the photos of my system. The good news is once it's set you will probably never have to mess with it again. Unless you are tweaking all the time like you.

 

[mulester7]

The sub will never be 100% "in phase" with other speakers simply because of their positioning, distance from each other, room interaction/reflections and the frequencies they handle

.....I still say the best chance for sub interaction, imo, is front-firing, positioned in the front soundstage....the second best chance, imo, is down-firing, positioned in the front soundstage....you'll notice the common denominator here is "positioned in the front soundstage"....test on Friday......

 

[mulester7]

The good news is once it's set you will probably never have to mess with it again. Unless you are tweaking all the time like you.

.....I'll admit to being a tweaker, Duffinator....a phase setting of 0 has always been the best for me too.....

 

[mulester7]

I played around some more last night just using 0 or 180 for some time. Once I found that I liked the 180 phase better than the 0 phase I went to 90. From there I worked with 180 to 90 and found a pretty darn happy setting at 105-110 area. Using a SPL meter, this yielded the most SPL. I also used the Avia disc (the sub phase warable thingie) to help determine the starting point. Overall, I am pleased with my sub settings. I listened to some music and found it to be rather smooth (good thing for me as I hate boomy) and then watched Stars Wars 1 and found the bass to be more than enough during the pod race.

.....I appreciate the report, EdWelly....interesting....do you have a down-firing sub?....and where is it located?......

 

[mulester7]

Mulester7, I detailed the requirements and consequences of speaker position, frequency and phase in a thread last week, and again in a thread specifically for you a few months back. But as far as this current situation, I'm going to repeat what everyone else is telling you: turn the phase dial to where the bass sounds the best to you -- done. If you want to fix boominess, etc.; these are room problems and you will have to resort to using a parametric equalizer [and preferably bass traps combined with parametric equalization]. The speaker management system[DCX2496] that you expressed interest in last week would be able to correct all of these problems[and improve the crossover integration between mains and subs dramatically]. However, realize that you will have to measure the room's low frequency response at the listening position in order to dial in the parametric settings for room corrections.

-Chris

.....thanks, WmAx.....

 

[mulester7]

Mulester7, I detailed the requirements and consequences of speaker position, frequency and phase in a thread last week, and again in a thread specifically for you a few months back. But as far as this current situation, I'm going to repeat what everyone else is telling you: turn the phase dial to where the bass sounds the best to you -- done. If you want to fix boominess, etc.; these are room problems and you will have to resort to using a parametric equalizer [and preferably bass traps combined with parametric equalization]. The speaker management system[DCX2496] that you expressed interest in last week would be able to correct all of these problems[and improve the crossover integration between mains and subs dramatically]. However, realize that you will have to measure the room's low frequency response at the listening position in order to dial in the parametric settings for room corrections.

-Chris

.....WmAx, honestly no offense, but I get the impression you couldn't set levels by ear at gunpoint.....

 

[edwelly]

.....I appreciate the report, EdWelly....interesting....do you have a down-firing sub?....and where is it located?......

SVS PB10-isd front firing 10"
I have it is the far left corner facing me.