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[compasspnt]

Sin x/x wrote on Thu, 07 June 2007 08:22

My experience with absolute polarity is that when you use speakers with large amounts of distortion (PC speakers)or very high spl's, it's very eazy to hear absolute polarity. But when you use speakers that have very low amounts of distortion (e.g. Quad els)and low levels of spl's, it is very difficult to hear this phenomenon.

What would be the reason for this empirically observed phenomenon?

[Tomas Danko]

compasspnt wrote on Wed, 18 July 2007 05:46

Sin x/x wrote on Thu, 07 June 2007 08:22 My experience with absolute polarity is that when you use speakers with large amounts of distortion (PC speakers)or very high spl's, it's very eazy to hear absolute polarity. But when you use speakers that have very low amounts of distortion (e.g. Quad els)and low levels of spl's, it is very difficult to hear this phenomenon. What would be the reason for this empirically observed phenomenon?

I always felt that the only reason I could sometimes identify the polarity switch was that, for instance when listening to a soloed vocal track, some plosives would send air AT me whereas the inverted polarity would not.

Hence, some places in the vocals would feel/sound/act in a subtly different way.

Not that I could ever tell which one was better. They both sounded like the recorded vocal take to me.

I don't know where distortion would come to play in this matter, but I'm keen to find out.

[compasspnt]

This might all be chasing a wild beaten horse with a dead goose, or it might really be something, one of those tiny incremental things that adds up at the end of the day.

[Klaus Heyne]

Just stumbled upon this fine thread (almost too much to absorb in one sitting.)

bobkatz wrote on Thu, 18 November 2004 17:39

ted nightshade wrote on Thu, 18 November 2004 11:42 Any recommendations or leads on specific models of polarity tester? I got to get with! ...The one I used to have was made by a French company, I think it was SCV.... BK

I have used the SCV polarity tester for over a decade now, and find its sophistication yet simplicity of use still unsurpassed:

LA Audio (an SCV International Group Company),
40 Chigwell Lane, Lughton, Essex, IG10 3NY, UK
Tel:  +44 (0)208 418 0778  Fax:  +44 (0)208 418 0624.
email:  sales@laaudio.co.uk  

I use the SCV not so much for microphone testing (I use my voice, ears, headphones and a polarity reversal switch on my mic pre-amp to tell me what I need to know) but find it most useful for testing the whole recording/playback chain.

I have been in countless studios with severe polarity inconsistencies, all the way up to drivers of main monitors being out of sync with each other and the world at large.

For the last five years I have also used polarity checkers to remove polarity reversals in amplified electric instrument chains (f. ex. bass or guitar and amp): It is astounding how much better I play when the attack of my pick or other string trigger is translated into a wavefront, rather than the loudspeaker being triggered by the first impulse of the note to move backwards/inward, which would suck out the air, rather than pushing it towards my ears.
The SCV works simply and reliably for this purpose.

As there has never been an industry standard for wiring pickup, cable, amp or speaker cabinet polarities, chances are an even 50% that the first trigger of the instrument arrives at my ears polarity reversed.

Even if you don't have a polarity tester, try sometimes wiring up a second speaker cord with its polarity reversed on one end, and switch between that and a polarity-correct cord: One choice will be clearly more focussed and inspiring to play with than the other!

If the reversed cord sounds better (and is later tested as having corrected overall polarity of the chain), simply rewire the speaker's terminal.

Best regards,

[compasspnt]

Excellent post Klaus!

I am now becoming inspired to check my...everything...

[maarvold]

Did I hear about this here?

http://www.galaxyaudio.com/CRICKET.html

Around $100--it helped me make a better-sounding record the very first day I used it (I found a couple of phase flops on a rhythm tracking day).  It seems like when you get everything technically sorted out making good recordings just becomes easier.  When a few little things are wrong, I find it disorienting and it's a lot harder to work with the conviction that things will sound good when I'm done.  Sometimes, weeks after the recording date, I'll find that a mono source (like an electric bass recorded direct) was recorded with absolute polarity reversed.  I flip it around, listen, then I think, "Ah, that's better".  On some level I could tell that something was wrong, I just hadn't identified it.  

[Sin x/x]

compasspnt wrote on Tue, 17 July 2007 23:46

Sin x/x wrote on Thu, 07 June 2007 08:22 My experience with absolute polarity is that when you use speakers with large amounts of distortion (PC speakers)or very high spl's, it's very eazy to hear absolute polarity. But when you use speakers that have very low amounts of distortion (e.g. Quad els)and low levels of spl's, it is very difficult to hear this phenomenon. What would be the reason for this empirically observed phenomenon?

Your guess is as good as mine.

[Earth Terminal Studios]

In terms of the reproduction of a whole band the argument that the polarity of the playback system can be correct or incorrect is senseless. I can see that a plosive on a single vocal (for instance) should probably push the reproducing cone toward the listener but with any distance the concept rapidly breaks down.

Really people!

You'd have to have an ear in the same place as all the microphones used to experience the same absolute polarity in reality, as in a band recording!

However, I can see that being confident that a positive voltage swing comming out of ones microphones produces the same all the way father down the line to would be of some comfort.

Presumably upstrokes are negative?

Lewis
Earth Terminal Studios
UK

[Andy Simpson]

bobkatz wrote on Tue, 23 November 2004 17:00

I produced an absolute polarity test for one of the Chesky test discs. I use the term "absolute" to distinguish from "relative channel". I recorded a solo trumpet in front of a Blumlein pair in a live room. When the polarity is correct, the trumpet seems closer to the listener. Depending on your reproduction system, the difference in apparent distance is as much as 2-3 feet! ........ BK

Whether absolute polarity is important or not, Bob's point about the trumpet is interesting.

When I last looked at the wave-form displays from an orchestral recording of mine, the loud blasts from the brass section (mostly trombone) were extremely asymmetrical (heavily weighted to one side).

Andy

[Rader Ranch]

Klaus Heyne wrote on Tue, 24 July 2007 17:21

I have used the SCV polarity tester for over a decade now, and find its sophistication yet simplicity of use still unsurpassed: LA Audio (an SCV International Group Company), 40 Chigwell Lane, Lughton, Essex, IG10 3NY, UK Tel:  +44 (0)208 418 0778  Fax:  +44 (0)208 418 0624. email:  sales@laaudio.co.uk

FWIW it's called the PC90 now, cost $425, and the US distributor is www.cwsalesandmarketing.com