Phasing

[broncoupe]

Hi all

have a set of 3 way components when i installed them the sound was ok not wow.

checked my wiring all speakers wired correctly

Still wasnt happy so i checked the speaker phasing with a test CD and test box

3 pulses green 1 red

The mids were out of phase so reversed connections( wiring is out of phase to markings on crossover) and wow thats the sound i wanted

Any thoughts

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[trumpet 5,000+ posts]

Good job

 

[Boomin_tahoe 5,000+ posts]

I'm lost....so what's this thread about?

 

[youdoofus]

I'm lost....so what's this thread about?

i think hes asking why it sounds better with the mids out of phase. Its likely due to physical spacing, as all the phase does is reverse the push/pull order of a sine wave. Its the exact same thing as reversing the phase on a sub either from the deck or switching the positive and negative leads on both (if there are 2) subs. The biggest issue is when theyre out of phase with other drivers playing the same note. I recommend Sheffield Labs IASCA discs that have phasing tests so you can make a comparative test. The IASCA discs are regarded pretty highly for those who are trying to tune in a system and overcome some hurdles. Plus, some of them have some d@mn decent songs recorded in great studios. Also, there are many other CDs that are renowned for their recording integrity that can be used to test out a setup to see how it sounds, my go to back in the day was "Collective Soul"s eponymous album, specifically "Smashing Young Man", "Gel" and "Where the River Flows". Sold TONS of higher end speakers for me, including a few sets of Boston Z series

 

[youdoofus]

also, listen to a great recording of "Comfortably Numb", and if it doesnt send chills, its one of 2 things, 1: you dont like Pink Floyd(or at least that song by them) or 2: your audio system is out of whack. And if its #1 , shame on you //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif LOL

 

[broncoupe]

What i'm saying is i have never fitted any speakers or subs with the connections deliberately reversed.

Even when playing subs i have never reversed the phase have tried and didn't like the sound.

so i'm of the school of thought all speakers need to move in a forward direction

To me this was backed up by what i found that as the mid was marked up correctly the crossover was marked up correctly but the mid was out of phase with the tweeter and mid bass driver

location of drive units does not effect physical movement

Also i installed this brand in a massive install 2 x 3way kits per door with 1 set of tweeters and mids relocated to A pillar same problem

On listening it lacked something client also noticed it

his comment shall we get some better speakers

Rephased the mids and wow stunning

just trying to understand why

 

[Louisiana_CRX 5,000+ posts]

I have a set of 3 way MB quart components someplace ..the German made ones

 

[Boomin_tahoe 5,000+ posts]

Could very well be that the mid was not marked correctly, thus out of phase. It happens from time to time here in the USA. Or wherever the products were made.

Hell I had a pair of 8's that I could not figure out for the life of me that wouldn't produce any bass, but moving like crazy. Turns out, one of them was marked wrong, emailed TC and explained my situation. Told me to reverse the polarity and volah!!

 

[broncoupe]

thanks mate thats what i think

speakers are a big brand but are manufactured in china spoke to main man hes french so not reasonable to questions

 

[Boomin_tahoe 5,000+ posts]

At least you were able to figure out the problem. Kudos to ya.

 

[Louisiana_CRX 5,000+ posts]

You can use a 9v battery to independently test the phasing of your mids ..hook neg to speaker neg and pos to speaker pos ..and the speaker should move out ..if it moves in its wired wrong ..there are special meters that can pick up phasing when everything is wired up but the battery test is simple ..as far as I know this won't work through the passive crossover which could be soldered wrong inside and I wouldn't recommend on the tweeters individually ...another issue you may have is cancellation and in that case you sometimes need to wire a speaker out of phase to fix this ..the reason you sometimes see a phase switch on decks and amps

 

[sfall]

"Rephased the mids and wow stunning

just trying to understand why"

There's no simple answer. Speakers can be out of phase in different ways, and by different amounts. You can even alter phase during the install and setup without realizing it. First, look at the 3 way component system. Looking at the specs will tell you phase information. Unless the xover points are at a slope of anything other than first order (6db), the speakers are designed to work out of phase. So, if your xover points are 2nd order (12db), 3rd order(18db), 4th order (24db), etc..., the drivers will start and stop at different times, by design. To further complicate matters, any type of equalization or xover adjustments made by any other outside components (head unit, eq, xover,,,), will also alter phase for any frequencies changed by them. So, for example, when you set the system up, you could have changed a 2nd order xover point to a 3rd or 4th order point, and not know it.

Someone above mentioned doing a pop test with a battery to check absolute phase. That's good for checking what terminals are + and -. However, when you install the speaker and the signal travels through all the different components, phase will still be effected by these outside factors, and can change it.

"so i'm of the school of thought all speakers need to move in a forward direction

To me this was backed up by what i found that as the mid was marked up correctly the crossover was marked up correctly but the mid was out of phase with the tweeter and mid bass driver"

Given the above, that really didn't happen. Unless you used absolutely no signal processing, digital or analog, and had all your xover points made first order, the drivers were not starting and stopping at the same time.

A different kind of phase problem is when you have drivers out of phase with each other. (example: the rf door speaker is connected the opposite of the left door speaker. This is very easy to check and fix. Get some music that you know well, and has a strong center vocal image. If the vocal image is not centered like normal, reverse the speaker cables for 1 speaker only. Your image will go back to center.

 

[trumpet 5,000+ posts]

It's likely a 2nd order crossover network for the mids, which results in a 180 degree phase shift at the crossing frequency.