How many splits from one 3.5mm jack
How many splits from one 3.5mm jack
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Discussion

slowx

Original Poster:

325 posts

175 months

Sunday 12th January 2014
quotequote all
Is it possible to have more than two splits(female) from one 3.5mm jack(male)?

How many splits is too many before it does some kind of damage to the output device?

Is it possible to run six splits(female) from one jack? If so, what damage will it do if there is any?

Thanks in advance for any advice.


Finlandia

7,811 posts

255 months

Sunday 12th January 2014
quotequote all
Hardly likely to cause any damage, normal in-earphones range from 10 Ohm to 150 Ohm resistance, so there is bigger spread on that alone than on six splits.

Mr Pointy

12,861 posts

183 months

Sunday 12th January 2014
quotequote all
Finlandia said:
Hardly likely to cause any damage, normal in-earphones range from 10 Ohm to 150 Ohm resistance, so there is bigger spread on that alone than on six splits.
What do you think the effect of six splits rather than two is on the load presented to the output stage?

Finlandia

7,811 posts

255 months

Sunday 12th January 2014
quotequote all
Mr Pointy said:
Finlandia said:
Hardly likely to cause any damage, normal in-earphones range from 10 Ohm to 150 Ohm resistance, so there is bigger spread on that alone than on six splits.
What do you think the effect of six splits rather than two is on the load presented to the output stage?
It's late, I'm tired, that's my defence. hehe

It depends what the OP is trying to do, a six way splitter on a headphone out from a portable player will work without any problems, splitting a RCA cable six ways to have audio coverage over the house is probably not a wise decision, the higher the output the more likely to go boom.

Dave 500

7,700 posts

266 months

Monday 13th January 2014
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We have 8 way passive headphone splitters at work and never had any problems smile

Crackie

6,386 posts

266 months

Monday 13th January 2014
quotequote all
Do you have any info about the output impedance of the source device and the input impedance(s) of the devices being fed ?

slowx

Original Poster:

325 posts

175 months

Monday 13th January 2014
quotequote all
Thank you very much for the input from above posters! Greatly appreciated!

The question I asked is for a friend of mine, he's got a small PC accessory shop opening soon, and he's got a display going up which have about six set(or more depending on how many he can fit in the display rack) of small PC speakers for people to test before they buy.

The source is going to come from a PC with a sound card, so, me and him had a idea of getting a 3.5mm jack and wire six splits to it and plug six set of these small speakers cables to it.

If a customer wants to listen to the sound from one set of speakers, he can just power it on and sound will come out of it and do the same with the other five set.

The idea is so he doesn't have to unplug one set of speaker to plug another one in if a customer wants to test another set before they buy.

BUT! The thing we are worried about is what if someone walk past and switch them all on at once, will all six set of speakers switch on at once blow his sound card up? Or worse, blow his PC up?

The speakers he's going to display are the kinds that have a small Sub with two small speakers connected to the back of the small Sub, these speakers set have to be plugged in with their own power socket for them to work, similar to Logitech LS21 2.1 Stereo Speaker System.



Edit - The source is going to come from this sound card http://www.asus.com/Sound_Cards_and_DigitaltoAnalo...

Thanks

Edited by slowx on Monday 13th January 08:50

megaphone

11,486 posts

275 months

Monday 13th January 2014
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Why not use a switch box, then you could just toggle between the speakers. Something like this although it's only 4 way.

http://www.ebay.com.au/itm/4-PORT-3-5mm-STEREO-Man...

slowx

Original Poster:

325 posts

175 months

Monday 13th January 2014
quotequote all
I did say using a switch box will be good enough for what he wants, if the idea of using a six split is not going to work then a switch box it will be.

Main thing is he has already solder up the jack the six split, it looks like a alien octopus hehe

Any chance of this idea is going to work? or is it going to end up blowing up his shop?

paulrockliffe

16,394 posts

251 months

Monday 13th January 2014
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Can someone explain the issue with splitting the source to me please? (Have a similar question for something I'm doing at home)

Do the speakers you're talking about not all have their own internal amplifiers, which alters the equation?


slowx

Original Poster:

325 posts

175 months

Monday 13th January 2014
quotequote all
I'm not sure TBH, even with their own source of power I thought the speaker set will still draw some power from the sound card.

I honestly have no idea how these things work.

paulrockliffe

16,394 posts

251 months

Monday 13th January 2014
quotequote all
I just assumed that the input volume would be reduced proportionally, so the output from the amplified speakers would be quieter. But so long as you can avoid the signal degrading on the input and you have enough capacity to amplify there wouldn't be a problem.

I ask as I've got 6 sets of speakers that I'm wiring in my house and want to be able to chose whether to feed each individually, or to select a single source. I don't know whether to chose the source before amplifying, which would be the same case as the OP is asking about, or whether to plug all 12 speakers into a single amplifier, dedicated to the single source and to select which amplifier is in use.

Perhaps it's a job for a pre-amp, but this isn't something I know very much about!

Finlandia

7,811 posts

255 months

Monday 13th January 2014
quotequote all
Seeing as the 2.1 systems have their own power supply and amps, the pc sound card would in theory only be giving a low power DAC/pre amp signal, it should work with just a normal splitter.

megaphone

11,486 posts

275 months

Monday 13th January 2014
quotequote all
The problem with using multiple speakers is impedance matching. Speakers are rated in ohms, often 8 ohms but sometimes 4 or 16. Most amplifiers will not run into less than 4 ohms without overheating or failing, amplifiers are rated e.g. 100w/channel into 4 ohms.

If you wire speakers in parallel the impedance will halve, so two 8 ohm speakers will show 4 ohms to the amp, which is ok. Four x 8 ohm speakers will show 2 ohms to the amp, which is not okay.

A similar problem persists at 'line' level, multiple loads wired in parallel will show too lower impedance to the line level output, it will end up distorting and may cause damage to the source.

That said most PC outputs are designed to run headphones and line levels, and can adjust their output accordingly, so hopefully the OP's PC sound board will not fry!


FlossyThePig

4,138 posts

267 months

Monday 13th January 2014
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slowx said:
...If a customer wants to listen to the sound from one set of speakers, he can just power it on and sound will come out of it and do the same with the other five set.

The idea is so he doesn't have to unplug one set of speaker to plug another one in if a customer wants to test another set before they buy...
You really need a some form of switch to provide the best "customer experience". Unless you can restrict access, little fingers will turn them all on.

TonyRPH

13,472 posts

192 months

Tuesday 14th January 2014
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Most (if not all) add on PC speakers are active these days.

This means they have their own built in amplifier, and the input impedance is usually in the order of 10kΩ.

6 of these in parallel will be around 1.6kΩ - unlikely to upset the sound card.

Also - even when switched off, it is likely they will still be presenting this impedance.