Earbud wiring

[captainvalent42]

Hello engineers!

 

So my left earbud got crushed, but everything else was ok. So I got this cazy idea to hook up the wiring to a speaker from a radio. The speaker works, I have tested it, and the wires for it are plainly labeled negative and positive. That is all fine and dandy.

 

My problem stems from two facts: can my phone use a speaker like that if I get it properly wired, and I also am having trouble with the wiring in the earbud. They are the earbuds that came with my iPhone 5 and have worked fine (until being crushed). I cut the earbud off and discovered that there is three wires, not two like I had been expecting. So I have no idea what is negative positive and what the third wire does. I did some research and think I have found some solutions but the time I have spent here assures me somebody has an answer for me. I attached a photo of the wiring in the earbud.

 

Whether I overlooked something stupid and just failed miserably, or it is an understandable problem, thank you for any help!

 

[fiveworlds]

Are they color coded? I can't really see from the picture. If they are color coded then you need to lookup the standard wiring guidelines in the country of manufacture.

 

Most Likely positive, negative and ground.

Edited October 8, 2015 by fiveworlds

[Lagoon Island Pearls]

It's not necessarily a matter of positive or negative. It's a matter of hot/ground.

 

A stereo signal requires 3 conductors. The braid is common ground and acts as a shield to prevent parasitic inter-modulation (namely the dreaded 60 Hz hum from AC lines). The center conductors are both hot.

You'll also need to consider at what "level" your signal is.

Standard radios have 8 ohm speakers, in which currents might be too high or too low for your mobile device.

 

This is why audio devices have matching transformers in the output chain.

Instead of tapping into the speaker, try at the input potentiometer (otherwise known as the volume control)

[fiveworlds]

It's not necessarily a matter of positive or negative.

 

Umm it is fairly important wiring the wrong way around could cause damage to the earbud

[Lagoon Island Pearls]

That way, you can use the radio itself as an amplifier.

It's not necessarily a matter of positive or negative.

Umm it is fairly important wiring the wrong way around could cause damage to the earbud

 

No. You are not dealing with voltage. You are dealing with a signal frequency "carried" by a mere fraction of a volt, which is analog. Incorrect connection would only cause a hum.

Edited October 9, 2015 by Lagoon Island Pearls

[captainvalent42]

Thanks to both of you. I feel like an idiot forgetting about ground wires. I've been playing with simple circuits too long. And LIP I'll probably do what you said, you probably are much more experienced with science than me.

 

Thanks again!

[Lagoon Island Pearls]

Tinkering with domestic audio is pretty safe, generally. So long as you're not adding powers supplies, jumping across terminals or touching capacitors there's very little chance of burning things or electrocuting yourself.

 

Trial and error is a good learning tool, some times.

[fiveworlds]

You are dealing with a signal frequency "carried" by a mere fraction of a volt, which is analog. Incorrect connection would only cause a hum.

 

No it is a small circuit with a ground wire. This means the circuit probably has a transistor which is on the list of things which might blow from reverse polarity wiring.

[Lagoon Island Pearls]

No it is a small circuit with a ground wire. This means the circuit probably has a transistor which is on the list of things which might blow from reverse polarity wiring.

 

That might be true in some applications, but an 8 ohm radio speaker is an AC device, after all it's driven by a matching transformer. Some speakers might use one "leg" as a ground, but if no external voltages are applied, conductor polarity is a non-issue.

The reason why speakers are marked as positive and negative, is not to match voltage. It's purpose is to match "phases". A mismatch would put the phase 180 degrees out, then things like cross-over networks malfunction.

[John Cuthber]

You are dealing with a signal frequency "carried" by a mere fraction of a volt, which is analog. Incorrect connection would only cause a hum.

 

No it is a small circuit with a ground wire. This means the circuit probably has a transistor which is on the list of things which might blow from reverse polarity wiring.

Since you clearly don't know what you are talking about, why don't you stop?

 

If you get the wires which connect to a speaker swapped the worst thing you get is a phase error which might muck up the stereo imaging a bit.