Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems What does the phase setting really do?

When I think of phase issues, I think speaker wiring gone bad on one of the speakers.
This is not hard to notice as the soundstage has no focus.

Playing with the phase setting in direct mode on my G68 I can hear an initial .5 second change in the soundstage, then back to the same. I hear no difference between the +/- setting.

So.. my question .. what does "phase" do?

/SA

When I adjust the phase, one setting is fractionally louder than the other - it can be registered in the SPL meter as a db or so difference - if the meter is say swaying between 74 and 75, out of phase may keep the reading more in the 74db, in phase it would read consistently more time in the 75db. This could be BS, but the louder phase also appears to me as being more focused. I have digital speakers front and analogue rear.

I think changing the phase +/- will actually change the absolute direction of speaker movement - I think the most widely used convention is that on a + setting both speakers drivers are in phase and move towards the audience when applied a positive signal while on the - setting they will still be in phase but move inwards when applied a positive signal.
Neither setting will place the speakers out of phase, as you wouldn't want this.
There is still a debate going on as to whether absolute phase change produces audible results. On some Chesky test&sampler CD's you do get recordings made with both phase settings to see if you can distinguish between them, and you also get some out-of-phase samples which are immediately and clearly noticeable.
If you can notice difference in spl at your listening position when switching absolute phase, then you probably listen very close to a "node" in a relatively low frequency in your room. Theory recommends you should use the absolute setting which sounds louder.
In my specific setup I can not decide between a + or - setting, although, looking for differences I sometimes feel there is a subtle advantage in bass attack for the + (which is what I use). It might also be coz' my ears are getting older , or because we sometimes hear what we want to hear

Cheers,
Dorian