Phase Control on my Sub

[L.J.]

I've had the same Yamaha sub for about 5 years now so this is new to me. I got a Energy S12.3 to replace my Yamaha and it has a knob on the back for phase control. The range is from -180 to +180- degrees. I have no clue what this means and I dont want to spend all night doing research(I know I'm being lazy). Basically the manual says this is to adjust the phase of the sub so it fully intergrates with my system.

Is there a certain way to set this up?

I assume I'm supposed to play by ear and start at -180, play the same piece over and over and make small adjustments until I think it sounds right. Any advice will be helpful. Thanks in advance

[PAT.P]

The phase control determines whether the subwoofer piston-like action moves in and out in phase with your main speaker or opposite the main speaker.Proper phase adjustment depends on several variables such as subwoofer placement and listening position. Ajust the phase switch to maximize bass output at the listening position.There are no right or wrong setting ,this switch offers the added flexibility to ajust your sub for optimum performance for your specific listening condition without having to move your other speakers.You should experiment with the phase switch in both position and leave it in the position that maximizes bass performance.Pat.P

[snickelfritz]

The phase control does very much the same thing as the delay adjustment in an A/V receiver.
It controls the timing between the speakers and subwoofer so that their respective outputs are synchronized at the crossover frequency, at the listening position.

The easiest way to set this up is with a SPL meter and CD with 1/3 octave low frequency tones.
First set the level of the mains to 75db at the crossover (80hz for example), with the sub turned off.
Now do the same thing with the sub. ie: turn off the mains and set the subwoofer to 75db at 80hz.
The sub and speakers are now set to the same level at 80hz.
Turn on the speakers and sub, and measure the 80hz composite level from the listening position.
Room modes and acoustic interference between the drivers will either cause the composite level at 80hz to drop or rise.
Ideally it should rise, indicating that the speakers are synchronized in time as well as amplitude.

Check the level with the phase at 180 and -180; use the setting that produces the loudest 80hz tone.
If the phase control is continuously variable, as opposed to a two position switch, you can test various settings and use the one the produces the highest readings at the crossover.
It might be easier to set the phase control to the reading that produces the highest output, then use the subwoofer setup controls in your AV receiver to tweak the subwoofer "distance". (which is exactly the same thing as the phase control)

BTW, there will be some peak/null behavior below the crossover that will also be impacted by the phase setting, so it's a good idea to measure the entire range below 120hz and try to find the best compromise between precise crossover synchronization and overall low-mid bass balance.

[L.J.]

The phase control does very much the same thing as the delay adjustment in an A/V receiver.
It controls the timing between the speakers and subwoofer so that their respective outputs are synchronized at the crossover frequency, at the listening position.

The easiest way to set this up is with a SPL meter and CD with 1/3 octave low frequency tones.
First set the level of the mains to 75db at the crossover (80hz for example), with the sub turned off.
Now do the same thing with the sub. ie: turn off the mains and set the subwoofer to 75db at 80hz.
The sub and speakers are now set to the same level at 80hz.
Turn on the speakers and sub, and measure the 80hz composite level from the listening position.
Room modes and acoustic interference between the drivers will either cause the composite level at 80hz to drop or rise.
Ideally it should rise, indicating that the speakers are synchronized in time as well as amplitude.

Check the level with the phase at 180 and -180; use the setting that produces the loudest 80hz tone.
If the phase control is continuously variable, as opposed to a two position switch, you can test various settings and use the one the produces the highest readings at the crossover.
It might be easier to set the phase control to the reading that produces the highest output, then use the subwoofer setup controls in your AV receiver to tweak the subwoofer "distance". (which is exactly the same thing as the phase control)

BTW, there will be some peak/null behavior below the crossover that will also be impacted by the phase setting, so it's a good idea to measure the entire range below 120hz and try to find the best compromise between precise crossover synchronization and overall low-mid bass balance.



Thanks for the advice but I'm truely novice at this. Sounds like a different language to me. I'm figuring I can get an spl meter at radio shack but what about the cd your talking about? My denon 2805 has auto eq set up, will this help at all? Everthing sounds o.k. to my novice ears but I know my system needs some fine tuning. I guess I cant take the easy way out on this one. I'm gonna do some research on this one so I can understand this new language.

[snickelfritz]

Stereophile.com has several CDs you can order that have these tracks, among other system tests, general audiophile commentary, and music.
I believe Test CD2 has tones that are pre-compensated for the Radioshack meter.
(This meter has well known roll-off characteristics below 50hz)

You can also download tones free from the link below, and burn them to CD.
There's also a graph, RS meter compensation curve, and clear instructions provided.
http://www.realtraps.com/test-cd.htm

Your room acoustics are going to be the biggest factor in fine-tuning the sound of your system.
+/- 10db is fairly common, even if your speakers and sub are absolutely accurate in an anechoic chamber.
The trick is finding locations for the sub and listener that have the least standing wave problems in your particular room.
It has been said that 50% of the sound quality of any system is the room.

If you're just getting started with this hobby, try to find some old issues of Stereo Review magazine, before you get pounded over the head with minutia in publications like The Absolute Sound and Stereophile.
Julian Hirsch was for many years the "voice of reason" in a community filled with myths and silly superstitions.
Whether you agree with his assertions or not, there's no denying that he was always knowledgeable, honest and forthright in his observations.
http://www.audioholics.com/news/SoundVisionMagazinesTributetoJulianHirsch.html

[L.J.]

Stereophile.com has several CDs you can order that have these tracks, among other system tests, general audiophile commentary, and music.
I believe Test CD2 has tones that are pre-compensated for the Radioshack meter.
(This meter has well known roll-off characteristics below 50hz)

You can also download tones free from the link below, and burn them to CD.
There's also a graph, RS meter compensation curve, and clear instructions provided.
http://www.realtraps.com/test-cd.htm

Your room acoustics are going to be the biggest factor in fine-tuning the sound of your system.
+/- 10db is fairly common, even if your speakers and sub are absolutely accurate in an anechoic chamber.
The trick is finding locations for the sub and listener that have the least standing wave problems in your particular room.
It has been said that 50% of the sound quality of any system is the room.

If you're just getting started with this hobby, try to find some old issues of Stereo Review magazine, before you get pounded over the head with minutia in publications like The Absolute Sound and Stereophile.
Julian Hirsch was for many years the "voice of reason" in a community filled with myths and silly superstitions.
Whether you agree with his assertions or not, there's no denying that he was always knowledgeable, honest and forthright in his observations.
http://www.audioholics.com/news/SoundVisionMagazinesTributetoJulianHirsch.html



Thanks for all the advice and links. I went and picked up a spl meter from radio shack last night. All I have to do now is a ton of reading. I'm sure I'll get there soon.