# Phazed about Phase!



## sonicnirvana (Jan 6, 2008)

In preparation for checking the phase of my auto sound system, I decided to do some tests on my computer speakers. I have Bose "Mediamate" speakers hooked up to my computer. I am using WinMLS and M-Audio Mobile pre sound card.

I ran a test seperately on each speaker, and to my amazement, it appeared as though the phase was reversed between each of the Bose speakers. Here is the WinMLS plot:










Not believing it, I was sure this should sound better it they were not reversed. So I put a phase reversal switch in-line with one of the speakers. I tried playing different kinds of music, but they always sound better in the "Out of Phase" position as shown in the plot above. Bass was tight, imaging was better. In the "In phase position, the music sounded weak, little bass, and imaging was diffuse.

What the heck is going on here? Is it something in the Bose design? Am I doing something wrong?

HELP!!!!


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## t3sn4f2 (Jan 3, 2007)

Are they single driver per channel speakers? Does the phase test use a frequency that if the speakers were 2 way could come threw on phase reversed tweeters. Just a thought, dunno if it makes any sense


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## sonicnirvana (Jan 6, 2008)

Actually I think they are a single driver per speaker. Haven't figured out how to open them up without destroying them. Here is a picture of what they look like:


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## thylantyr (Jan 21, 2008)

Maybe you got accustomed to that setup and nothing else is worthy 

.. like drinking Bud Light inside a German label. Once you realize you
been had and really tried the German brew, you don't like it now... Gimme
some Bud.


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## sonicnirvana (Jan 6, 2008)

Ok, I am beginning to think its not me. I decided to take apart the right speaker. I managed to get it apart without totally destroying it. The typical press tabs that are nearly impossible to press without breakage.

Anyway, here is a pic of the dissassembled speaker. Pretty impressive little 2.5" speaker with rubber surround! Its a simple ported enclosure though...no waveguide here. Even a little fiberfill for good measure.

Well the bottom line is the tip of the external connector IS wired what I would think is backwards. The tip is (-) while the sleeve is the (+) connector labeled on the speaker. 

When I get some more time, I will crack (literally) open the other side with the amp. Maybe that will shed some light on it.











http://216.197.115.178/Bose/mediamate.jpg


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## drake78 (May 27, 2007)

I have read on sixmoons.com wich is excellent home audio reviews site. It's true, some audio manufactures run there amps out phase. They switch the internal wiring to output speaker bindings out of phase. Even on a high end BAT $5k cd player there is an invert phase button. You will have to do some further research on why.  I scan through that part of the review.


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## t3sn4f2 (Jan 3, 2007)

drake78 said:


> I have read on sixmoons.com wich is excellent home audio reviews site. It's true, some audio manufactures run there amps out phase. They switch the internal wiring to output speaker bindings out of phase. Even on a high end BAT $5k cd player there is an invert phase button. You will have to do some further research on why.  I scan through that part of the review.


Isn't that absolute polarity that is switched, meaning both at the same time? Like when you see the measurements section on a Stereophile mag review, they say the player being tested "didn't invert absolute polarity"


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## pontiacbird (Dec 29, 2006)

could it have something to do with any electronic filters, maybe a 4th order high pass??


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## speakerboy (Oct 2, 2007)

My father-in-law bought a bunch of those little 2" speakers from PE for .87 a piece. They aren't that impressive.


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## Fixtion (Aug 25, 2006)

*updates?*


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## ACRucrazy (Mar 13, 2007)

speakerboy said:


> My father-in-law bought a bunch of those little 2" speakers from PE for .87 a piece. They aren't that impressive.


LOL, yep, get your self a 50 cent plastic enclosure a 25 cent speaker and you have a bose speaker that cost $100!


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## dporter (Mar 25, 2008)

Hi. I saw your post and wondered if you ever figured out how to open the powered left speaker without breaking it?
Thanks,
-DP




sonicnirvana said:


> Ok, I am beginning to think its not me. I decided to take apart the right speaker. I managed to get it apart without totally destroying it. The typical press tabs that are nearly impossible to press without breakage.
> 
> Anyway, here is a pic of the dissassembled speaker. Pretty impressive little 2.5" speaker with rubber surround! Its a simple ported enclosure though...no waveguide here. Even a little fiberfill for good measure.
> 
> ...


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