# Speaker Polarity



## stevei (Apr 9, 2008)

Just bought a Samsung HT-Q20 second hand, without speakers. Can anyone tell me if the left or right connection at the back of the unit is the + or - speaker connection
Thanks


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## V0lt (Sep 14, 2002)

Aren't they labeled or colored in any way (like red=+ and black=-)?


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## stevei (Apr 9, 2008)

That would be too obvious


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## DonaldG (Aug 23, 2007)

Here you go....:smile:

*Page 12* of the manual....











After Googling: "Samsung HT-Q20 Manual" (with quotes), I got several hits.

For the full manual, try here:
http://www.retrevo.com/search/v2/jsp/downloadPage.jsp?doc=42bd1751b6d4fc4202d015800e458918&q=Samsung+HT-Q20

It is a pdf file 8Mb.

Cheers...


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## yustr (Sep 27, 2004)

It appears from Donald's diagram that it uses special plugs to access the speaker output terminals. You may be able to buy the right plug at Radio Shack or like store or from Samsung (doubtful). Then it's just a matter of connecting the speaker wire to the new plugs on one end and your speakers on the other.


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## DonaldG (Aug 23, 2007)

EDIT: Opps - I may have misinterpreted the drawing slightly. What I have said below the separator line is applicable to the speaker housing configuration. 

Yustr is absolutely correct. I have tried to 'enlarge' the pdf image to see if I can identify the speaker sockets but unable to be sure. The speaker plugs needed for the back of the main unit should be readily available Radio Shack any good audio supply shop. In the UK car audio shops stock a wide range of speaker fittings...

===================

Speaker housing:
The terminals are 'pinch' type. Special plugs are not required. Just remove about 1/4" of the insulation. Twist the strands of wire so they are in a neat condition. Pull the little plastic lever down, as shown in the diagram (1 & 2). Insert the wire into the hole above it an then let go of the lever. That will 'pinch' the conductors and make the connection.

Most speakers units will have some form of indicating the polarisation. It is important to observe the polarisation throughout all the speakers in a system or the sound quality will be severely degraded by the 'sound being out of phase' from one speaker to another.

On the back of the speaker housing the terminals may have '+' & '-'. Or the terminals may be coloured red & black. Or even, if a cable is fixed to the speaker housing, one strand of the cable will be polarised. The common methods of indicating polarisation on cables are: one conductor may have a stripe of a different colour molded into the plastic insulation, or it may have a raised ridge in the plastic sheathing.

Whatever method is used, to get best sound quality, always ensure each speaker is connected in their separate sockets the same way round.

When you only have one speaker, phase is not an issue. However with two or more phase is an issue.

Simple explanation of why this is important:

A speaker is nothing more than an air pump. The voltage generated by the sound, makes the speaker diaphragm move in & out. The speed at which in moves in & out depends on the *frequency* of the sound. The actual distance the speaker diaphragm moves depends on the *amplitude* or amount of driving voltage.

So, imagine two air pumps sitting side by side and the diaphragms are moving in an out at, say 1 complete cycle in a second. And also imaging that the diaphragms are moving 1 inch forward and backward. 

If both diaphragms in the air pumps move forward at the same time, then back wards at the same time, they are in phase with each other. It is easy to see that they are working together.

If, on the other hand, one of the air pumps has the connections reversed, one diaphragm will be moving forward but the other diaphragm will be moving back wards. They are out of phase and one is counteracting the other.

Now imaging those air pumps your speakers, connecting one the wrong way round and the sound output will be out of phase and will be trying to counteract the sound energy oh the others, thereby degrading the sound quality....


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