mathematicsforthesou...
Joined: 15/04/07
Posts: 80
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Deaf in One Ear / Ipod Problem
#968074 - 03/02/12 12:37 PM
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My mate is deaf in one ear and she says its really annoying to listen to music with one
headphone in (when guitars are panned hard left / hard right) she only gets to hear a bit
of the music.. I'd like to make an adaptor that will sum her stereo output to mono for one
ear plug.. Converting all files to mono isnt really a solution because its nice to have
stereo at home and ipod is of limited space.. I saw this only: http://www.gear4music.com/Recording-and-Computers/Mono-Jack-Stereo-Minijac
k-Adapter/3CRWill this do it? or will this just take the left side and not
sum it together? Thanks for your help! This seems to be a really common problem
for a lot of people,be good to get this sorted! PS-These seem like a good
alternative: http://www.scansound.com/single-stereo-earphone-with-eartips.html but
she has pretty good headphones already Thanks in Advance,
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UNMUTE
Joined: 01/02/12
Posts: 33
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Using a simple adaptor as in your first link may work but isn't necessarily the best
solution.
How you combine the stereo signal into a mono one depends a) on the
type/quality of headphones and b) the device they will be plugged into.
By
simply connecting both earpieces together alters (lowers) the impedance presented to the
playback device. Some devices can be damaged if you do this.
It seems they
have found a way around this in the product in the second link you sent.
If
it's an iPod etc. it should be fine as you see many Y-adaptors which just split the signal
into two for two listeners.
Combining a stereo signal to mono will affect the
sound stage and you may get cancellation in places. This will most probably be
unnoticeabl and it also depends on what type of music they listen to.
Do you
need to convert to a larger 6.35mm jack?
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chris...
active member
Joined: 12/03/03
Posts: 4152
Loc: Glasgow
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Re: Deaf in One Ear / Ipod Problem
[Re: UNMUTE]
#968384 - 05/02/12 05:39 AM
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Quote UNMUTE:
If it's an iPod
etc. it should be fine as you see many Y-adaptors which just split the signal into two for
two listeners.
No - splitting a
an output to drive 2 inputs is not the same as combining 2 outputs (in this case the iPod
left+right channels) to drive 1 input.
Splitting can be done with a Y
cable. Combining, as you hint, is best done with some electronics (effectively a mixer),
not just a cable or adaptor.
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Ojustaboo
Joined: 14/10/11
Posts: 102
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Don't know what the quality etc of these are like, but they ship internationally http://www.scansound.com/single-stereo-earphone-with-eartips.htmlbest Joe
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Hugh Robjohns
SOS Technical Editor
Joined: 25/07/03
Posts: 18403
Loc: Worcestershire
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Re: Deaf in One Ear / Ipod Problem
[Re: chris...]
#968570 - 06/02/12 03:50 PM
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Quote chris...:
Splitting can be
done with a Y cable. Combining, as you hint, is best done with some electronics
(effectively a mixer), not just a cable or adaptor.
Quite so. Splitters to feed two sources normally connect thenm in
parallel, which halves the load impedance seen by the output amplifier. Assuming the
earbuds are of a reasonable impedance in the first place (say 32 ohms or more), then the
reduced load shouldn't tax the output amplifiers unduly. If the combined impedance is too
low then you'd probably notice clipping on transients first...
However, trying
to create a mono signal from two outputs by using a simple adapter that would, in effect,
just short the two channels together, is likely to cause damage, potentially destroying
the output stages of the device. The reason is that one output amplifier will effectively
be trying to drive current into the output of the other... but "they don't like it up 'em"
as Corporal Jones used to say! This kind of situation is likely to result inthe device
going phut, permanently.
Instead, the two outputs need to be summed either
through independent load resistors of an appropriate value to minimimse cross-feeding, or
through an active mixer stage of some kind, again with appropriate input loading.
This
link shows this idea in a summing cable intended to feed a single powered speaker from
a stereo headphone output.
Hugh
--------------------
Technical Editor, Sound On Sound
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uphillbothways
Joined: 19/11/09
Posts: 190
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Recent iPods (4th gen Touch, 6th gen Nano) and the iPhone have a "mono audio" feature in
the accessibility menu, which will send a summed mono signal to both channels.
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chris...
active member
Joined: 12/03/03
Posts: 4152
Loc: Glasgow
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Re: Deaf in One Ear / Ipod Problem
[Re: uphillbothways]
#968730 - 07/02/12 11:35 AM
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Quote uphillbothways:
Recent
iPods (4th gen Touch, 6th gen Nano) and the iPhone have a "mono audio" feature in the
accessibility menu, which will send a summed mono signal to both channels.
Ooh - never noticed, but now you mention it, I see
my iPhone4 has that.
A quick google suggests this feature was added to iOS 5.
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