what do out-of-phase speakers sound like?

The wires that i'm dealing with are hard to read.

The negative wires go on the black posts right?

 

As to what OOP speakers sound like, if you are in the sweet spot, you'll certainly be lacking some bottom end as it cancels itself out. Other than that, the effects vary (apart from the stereo image feeling very odd), but here's my quote from this thread:

 

If you play a mono source with the speakers in phase, and if you stand in the sweet spot, you should hear the sound source as right in the middle of the 2 speakers. If you have the speakers out of phase this phantom center image will not be there, and the sound source will be vague and almost sound like it comes behind you. It is a very odd sensation and almost sounds like your ears are being pulled, though it's pretty hard for me to come up with the right words to accurately describe this. Btw, you don't really need a mono signal to test this, as long as the stereo mix has some center channel information. If the speakers are OOP you should not hear anything in the center.

If in doubt, reverse the polarity of the wiring to one speaker. You can't go 100% by simply looking at the wiring, because speakers have been known to be wired wrong internally. Whichever way provides the most bass and the center channel is right. I can usually tell instantly by listening, whether speakers are out of phase, but on rare occasion, if the room acoustics are bad I have been fooled. Keep in mind that acoustics can introduce standing waves and these can cause phase issues in the room regardless of speaker phase. If so, determining phase by ear can be more difficult.

And for those of you who don't understand, with a mono signal and in phase speakers both speakers will do the same thing. In other words, when one speaker goes in, so does the other. When out of phase, when one speaker goes in, the other goes out, so rather than working together, they are opposing each other.

I often use a battery to test phase. If you take a small 1.5v battery (any type will do), and hook it up the a speaker, the speaker will move one way and stop. This is because you have hooked dc up to it. The speaker will either go in or out depending on which way you hook up the battery, and stay that way until you remove the battery. Now if you hook up the other speaker the same way, you need to make sure the speaker moves the same way when the battery is hooked up to it in the same manner.

And one more thing to consider. Not only should both speakers be in phase with each other, but should be in phase with the recording. This might sound a bit confusing, but it is called absolute phase. Some people say this is very important, and others say it is not. What this refers to is this. If you are at a musical event, and there is a bass drum (for example) it's initial strike will create a wave. If the initial attack of this wave causes a push rather than a pull, it is desired to have the same thing happen in playback. This is fairly hard to test for. Not only that, but many recordings do not consider this and hence fail to preserve absolute phase integrity. If you want to play around, once you have verified your speakers are in phase, simply reverse the wiring on both speakers. The difference will no doubt be subtle but some people think this is pretty important. On top of that, absolute phase will likely vary from record to record.

 

Here's an easy way to check: Put the two speakers face-to-face and play a mono recording. If your speakers are out of phase, you'll hear almost nothing. If they're in phase, you'll hear normal volume.

 

like crap!

 

I've quickly made a phasing example in 16/44.1 WAV format here.

http://home.comcast.net/~sckott/phasing.wav It is 3.8 meg so even dialup users can hear it. It lasts only 23 seconds.

 

An easier way to check for in-phase is to use a test disk. I have an old Denon one I use. I used to have a Kenwood amp that had 2 phase switches on it so you could do all kinds of odd things with that. You could reverse the phase of the left speaker, the right one, or both.

 

Ouch--that hurt my ears!

Whose voice is that?

 

I have a Shure Audio Obstacle Course LP that demonstrates phase. In phase, the guys voice is dead center while out of phase it just kinda hangs in space with a diffused, lost quality.

I would assume there is something digital (probably on the web somewhere) that does the same thing.

 

LOL

What about partial OOP speakers ?

The ones with deliberately wired OOP HF or mid drivers ?

And some even sound good !

 

Like the AR-3 and 3a!!

 

The Mofi sound check discs have in phase and out of phase tracks at different frequencies so you can check each driver.
I used it after doing some crossover work to make sure I didn't mess things up.