Dan Lavry's point is that carefully following the manual for one's home hi-fi gear might nevertheless cause the end user to listen to something with incorrect acoustic polarity if the pressing, for example, being auditioned was cut with incorrect acoustic polarity, and there's no switch to flip. A switch on the home hi-fi gear allows the end user to confirm if the recording (and gear/cabling) is (net) correct. It really only matters that it's presented correctly when auditioned. (Perhaps the studio heard it correctly but it still got bounced, cut, or dubbed out of natural acoustic polarity.) Switching on the fly allows one's brief auditory memory to compare the switched sound to the unswitched sound. When the treble percussion sounds sharper and the bass sounds fuller, the switch is correctly set. It's not a matter of personal preference. If you prefer the treble percussion to sound flatter and the bass to sound less full, you are free to audition in the incorrect switch setting, but you will know that it's a sonic betrayal of that which is acoustically natural if you hear it both ways (and remember these words). (;A technical or industrial standard is not meant to prevent consumers from using the relevant technology in wrong ways. Nor is it meant to educate professionals on correct operating procedures.
It is simply meant to make life easier in that if universally followed, anyone following the instruction manual for their home hi-fi gear would end up listening in correct polarity. If they wire the speakers wrong, their problem.
Likewise in the professional end. It is not difficult to maintain absolute polarity throughout the recording production and manufacturing process. If people choose not to, their problem.
It's quite easy for the acoustic polarity to suffer during a recording's production since there are so many opportunities for it to become inverted. European tape machines like the Swiss-made Studer were pin 2-High. Ampex's ATR-102 meterbridge preamps were pin 3-High. The ATR-102's better-sounding, single-ended inputs (right next to the card cage) are pin 2-Hot, but you need a special connector to use the single ended inputs. Using a Studer to mix down through the balanced inputs of an Ampex introduces one common place where an inversion will happen if no one flips switches or uses special cables. If it's not corrected in the heat of the mix session, it will need to be corrected in mastering. If it's not corrected there, it can still be corrected by the end user during playback of the release if s/he has a stereo polarity switch on the preamp being used. Checking ø during production is good. But putting a ø switch on home hi-fi gear means that absolute polarity errors by major labels - which happen occasionally - can be corrected rather trivially.
A switch can introduce an element of preference. Personal preferences are entirely outside the scope of standard documents.
Personal preference is outside of the scope of correct acoustic polarity. If you can't hear an improvement by flipping the stereo polarity switch, either the loudspeaker crossovers mangle phase to the point of correctness being unattainable - or the listener's hearing is flawed. If you can hear the restoration of correct acoustic polarity with one deflection of the switch or the other, it won't be due to personal preference - it will be due to absolute correctness. This, everyone should prefer.
...I just watched a video with Sylvia Massey using a polarity inversion switch on the channel of the Neve console she was using to record the bottom skin of a snare drum. She said she did it because she was aiming another mic at the top skin of the same snare, so the mics were at least partially going to null each other if one wasn't switched to inverted (mic) polarity... She switched there not because she didn't have time to resolder the leads on the XLR connector for the mic. She switched there because it was very easy to do so and corrected the issue blamelessly. The drummer naturally hears the bottom skin moving away from her or his ears. So, in order to keep the bottom skin's recording acoustically correct, it should cause a negative voltage with the skin's positive pressure (caused by it approaching the diaphragm, initially, instead of secondarily). So, there are two reasons for switching, and she didn't have to disturb any connectors and could use the same proximity with each mic on the top and bottom, getting the sharp attacks she sought for (the) Melvins.Polarity inversion switches are also frequently encountered on multiple channel mixing desks, to help counter phase issues when using multiple microphones under time pressure.
What flaw is there with flipping such a switch?This is not necessarily the way to go for high fidelity recordings. Neither the polarity switch as a quick fix, nor the time pressure. I will openly admit I also have used it under time pressure, but it is far from the ideal way to do things. But if this is what the client wants from me, their problem. My job is to know what is ideal and advise accordingly, for those who do want to do things properly. Not everybody does and I respect their wishes and views.
There's no need for a new standard since the standard hasn't changed. Just look it up and implement accordingly - and, when that fails, flip (both of) the switch(es)! (;An up to date standardisation is always a good thing for an industry and it does make life much easier if universally implemented. Polarity is just one of the several aspects.
Those sliders are primarily for matching tempos of different dance cuts when you use more than one turn-table with your Gemini, Sir. Nothing's stopping anyone from cutting slow or playing back fast, either. There's no connection between vari-speed and absolute polarity.What if some fan of hardcore punk music start manufacturing turntables spinning at 38 rpm and 49 rpms, because his personal preference is that everything sounds better when played faster?
Then I could cut master sat 30 rpm and not tell anyone about it, just a matter of preference. After all, who can really know if absolute speed has been maintained anyway? Isn't that why Technics added these sliders on the side? Just set the speed to taste...
Boogie