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Headphone Impedance - mismatch correction?

Community Veteran
Posts: 17,767
Thanks: 1,603
Fixes: 19
Registered: 06-11-2007

Headphone Impedance - mismatch correction?

OK.. one for the techies.... I have a short wave radio, that has a quarter inch headphone socket. . ( I have a reducer to use the 3.5mm jack `phones )...
I want to buy a pair of Headphones,  (mono or stereo) with BIG padded ear muffs, to reduce the external (annoying) noise my missus hears, because I need the volume up loud ! .
Problem is... the rated output for the `phone socket is between 4 and 16 ohms.... most of the `phones I have seen in Maplin, Currys, PC world, and Comet, are rated at 24 or 32 or higher impedance.  and these range in price from about £20 to  £100 ... To get an 8 ohm pair, (my preferred optimum) it seems I have to spend about £200  ( half the price of the radio!)
so, can anyone offer a reasonably simple(?) way of matching the higher impedence `phones down to around 8 or 16 ohms, without losing any dynamic sound or volume?
Alternatively anyone got a pair of 8 ohm speakers that look similar to this, with BIG PADDED EAR MUFFS ?
4 REPLIES
Community Veteran
Posts: 6,773
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Registered: 16-02-2009

Re: Headphone Impedance - mismatch correction?

I wouldn't bother too much with the "rated" impedance. You should be fine with any headphones in there. Try it with a "normal" ear bug type (normally about 32Ohms)
Community Veteran
Posts: 17,767
Thanks: 1,603
Fixes: 19
Registered: 06-11-2007

Re: Headphone Impedance - mismatch correction?

The radio works fine with my "skype" type headphones, but  I want to get the best out of it,  (bearing in mind that it is a "communications" receiver, not just for listening to forren radio programmes and I need to have some really well matched phones to be able to hear the faintest of signals from the other side of the world, (hence the high volume necessary, and the reason for BIG PADDED EAR MUFFS to minimise the external interference to `er indoors)..
as a point of interest. I had another pair of phones that I tried, but they reduced the volume by 50% just by plugging them into the radio...  :'
( Unfortunately there was no "rating" on them, so the mismatch would probably have caused the loss of volume).
MrT
Grafter
Posts: 379
Registered: 30-06-2010

Re: Headphone Impedance - mismatch correction?

You need headphones with impedance > 4ohms otherwise you'll overload the output circuit of your radio. I think anything above 4ohms will be fine. Look in Argos as they seem to have plenty for under £50.
Community Veteran
Posts: 17,767
Thanks: 1,603
Fixes: 19
Registered: 06-11-2007

Re: Headphone Impedance - mismatch correction?

Thanks MrT.  Wink