Phillips Turnolock Speaker Cable Polarity

[RichardHawkins]

My radio speaker has the terminals marked positive and negative. The speaker wire coming out of the radio is a two core flat one core is black the other is black and white.

Does anyone know what the polarity is or how to work out which wire is positive or negative?

Richard Hawkins

[ericbushby]

Hi Richard,
As the speaker coil is a simple electromagnet and the current from the radio is alternating, it doesn`t matter which way it is wired for a single speaker set up.
The speakers are marked pos. and neg. for when you have multiple speakers or a stereo system where it does matter that the speakers are in phase and the diaphragms all move in the same direction at any one time.
Hope this helps.
Eric in Burnley
1967 S3SE DHC

[Spyder fan]

As Eric says, it doesn’t matter with a single mono speaker which way you wire it.

For 2 speakers running from the same mono radio I found this article useful https://geoffthegreygeek.com/how-to-con ... amplifier/

[RichardHawkins]

Eric and Alan,

Thanks for the advice, which makes sense as I only use one speaker.

Richard Hawkins

[Slowtus]

Hi Richard,
As the speaker coil is a simple electromagnet and the current from the radio is alternating, it doesn`t matter which way it is wired for a single speaker set up.
The speakers are marked pos. and neg. for when you have multiple speakers or a stereo system where it does matter that the speakers are in phase and the diaphragms all move in the same direction at any one time.
Hope this helps.
Eric in Burnley
1967 S3SE DHC

Very good point there, most people have no idea what "phasing" is.

[john.p.clegg]

Sorry Eric.

" diaphragms all move in the same direction at any one time. "

I think should read , all move in the correct direction at any one time "

Just being pedantic....

John

[ericbushby]

Good morning John,
Yes maybe that could be clearer.
I mean that all speaker diaphragms move together in the same mode relative to it`s speaker body even if they are actually facing different directions.
If the diaphragm moves forward it pushes air to produce a peak of the sound wave. when returning it makes a trough. If nearby speakers run in the opposite mode then they can cause some distortion or cancellation.
At my age I doubt if I could tell the difference though.
That is why the terminals are marked. I expect you could mark them 1 and 2 or A and B just as well.
But more importantly will you be at Tatton Park in August. I intend to be there unless it rains.
Cheers
Eric

[john.p.clegg]

I have applied...but I don't think they appreciate a lowly Morris Minor

John

[ericbushby]

They might be desperate
Eric

[john.p.clegg]

I hope so....

John

[Craven]

Speaker phasing first came important with in innovation of Stereophonic audio reproduction.
Stereo image or a 2D effect produced by separate Left and Right channels is loss if your speaker phasing is not correct, how that works I don’t know but it’s a real effect.

[Andy8421]

Speaker phasing first came important with in innovation of Stereophonic audio reproduction.
Stereo image or a 2D effect produced by separate Left and Right channels is loss if your speaker phasing is not correct, how that works I don’t know but it’s a real effect.

Should anyone care, its not just stereo where phase matters, its whenever there are multiple drivers present. It also matters how far away the drivers are away from your ears.

For the sake of argument, assume the speakers are door mounted, and the drivers side speaker is 1m closer to the driver's ear than the passenger's side speaker. If the speakers are in phase, then at about 500Hz the sound will be out of phase at the driver's ears and cancel out. It will do this for every frequency where the sound arrives at the driver from the two door speakers 180 degrees out of phase. If you graph this effect vs frequency, it looks like a comb with multiple peaks and the effect is called a comb response. This link explains the effect for microphones, but the same is true in reverse for loudspeakers.

https://www.dpamicrophones.com/mic-university/the-basics-about-comb-filtering-and-how-to-avoid-it

This is the main reason that audiophiles attempt to sit equidistant from their speakers.

As a result, depending on the type of music you listen to, it is possible that the sound you experience in a car with door speakers will be subjectively better if you connect the speakers out of phase, rather than in phase.

[Spyder fan]

Andy,
You post reminded me of Lotus attempting to develop noise cancelling speakers a few years back,

Here's the article on the Autocar website https://www.autocar.co.uk/car-news/new- ... rid%20cars.
Remember that this was 2009, well before all those Musky Teslas and Datsun Leaves

Lotus calls the systems Road Noise Cancellation, Engine Order Cancellation, and Electronic Sound Synthesis, and they will be developed in conjunction with Harman Becker Automotive Systems.

The Road Noise Cancellation and Engine Order Cancellation systems will provide vehicle manufacturers with the ability to greatly improve in-cabin refinement.

They reduce both overall noise levels and specific audible frequencies using electronic systems that determine the signal needed to provide noise cancellation. This signal is then seamlessly generated through the in-car entertainment system.

Exterior Electronic Sound Synthesis works by projecting a synthesised sound, dependant on speed, from speakers at the front and back of car in order to improve pedestrian safety.

This is especially important for electric and hybrid vehicles, which can be difficult to hear at lower speeds due to their quiet drive mechanism.

The occupants of the car can also benefit from a system called Internal Electronic Sound Synthesis. This creates engine speed and throttle dependant sounds that are audible through the in-car entertainment system.

Lotus says working prototypes of the systems already exist, and that it is working with car manufacturers to use them on production vehicles.

[Craven]

As an audiophile that takes delight in the complex sound stage present in a good auditorium by what seems a simple right left audio source appreciates just how ‘ clever ‘ the brain is in interpreting the air pressure waves on each ear but also the relationship between them.
BTW Wavelength at 500Hz = 600 metres.

[Andy8421]

As an audiophile that takes delight in the complex sound stage present in a good auditorium by what seems a simple right left audio source appreciates just how ‘ clever ‘ the brain is in interpreting the air pressure waves on each ear but also the relationship between them.
BTW Wavelength at 500Hz = 600 metres.

Its been a while, but if my memory serves me right,

wavelength = speed of sound in air / frequency

= 330m/s / 500Hz

= 0.66m

My example was wrong, but in my defence I did the maths in my head using round numbers. To cancel out at 1m differential distance, the lowest frequency would need a wavelength of 2m, and hence a frequency of 165Hz.