Replacing a 16ohm micro speaker with an 8ohm micro speaker.

Forums › Gadgets, robotics, home automation, electronics (including wearables) › Replacing a 16ohm micro speaker with an 8ohm micro speaker.

s.joseph

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#95390 2-Jan-2012 11:54

Hey guys i have a radar detector on which the speaker blew. Ive tested another micro speaker which works fine but the physical size is wrong(so i can't close the unit up). The original is a 30mm micro speaker with 16ohm printed on the back.

Ive ordered the same speaker online but can only get them at 8ohm, will any damage be done to the transformer on the unit or something similar running half the ohms?

Cheers.

Skolink

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#563883 2-Jan-2012 22:43

It's possible you could damage the radar detector's internal amplifier, but not particularly likely. I would suggest connecting a small 8ohm resistor (1/2W) in series and see what the volume is like. If it's too quiet try without.
If it were mine though, I'd just plug in the 8ohm speaker and try it, but that's me.

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s.joseph

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#564083 3-Jan-2012 18:29

awesome, thanks mate. I think ill buy a resistor just incase because it was an expensive detector.

s.joseph

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#564084 3-Jan-2012 18:35

also, where would i get one of these resistors? are they metal film resistors from dick smiths?

is this correct?
http://www.dicksmith.co.nz/product/R0122/pack-5-metalfilm-4r3-0-6w-res-5-band-1-yel-org-blk-slv-br

Technofreak

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#564103 3-Jan-2012 19:41

It will possibly only be an issue if you were driving the speaker at high power (volume) most of the time which I guess is unlikely. You would be very unlikely to have an issue if you were to use the 8 ohm speaker on its' own.

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s.joseph

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#564114 3-Jan-2012 20:32

i do use it at full volume on the radar unit, crap..

Skolink

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#564196 4-Jan-2012 08:15

s.joseph: also, where would i get one of these resistors? are they metal film resistors from dick smiths?

is this correct?
http://www.dicksmith.co.nz/product/R0122/pack-5-metalfilm-4r3-0-6w-res-5-band-1-yel-org-blk-slv-br

Yes, two of those in series will do it. If you have Jaycar close to you I would try there first. The few components Dick Smith still lists are often not even in stock. If you are using a single resistor a 1Watt might be necessary, but I'm assuming the detector only makes sound intermittently (things won't get too hot).

Technofreak

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#564235 4-Jan-2012 10:32

If you are fitting a resistor don't even bother with Dick Smith, they used to be very good for this sort of thing but now are a complete waste of time. Go to Jaycars, the catalogue no. you need is RR2524 for a 8R2 ohm 1 Watt 5% Carbon Film Resistor.

P.S. while two 4.3 ohm resistors in series will do the same job it's much easier and simpler to fit one resistor plus you're probably tight on space as well.

P.P.S. A metal film resistor will do just as well just they are more expensive though probably smaller

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s.joseph

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#565286 6-Jan-2012 11:43

so i got the resistor and now the speaker is super quiet! :( what can i do?

Skolink

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#565556 6-Jan-2012 22:26

remove the resistor.

Technofreak

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#565575 6-Jan-2012 22:59

Did you get the correct value resistor? Have you got a meter to check it. It's possible that a resistor was put in the wrong bin. How familiar are you with resistor colour codes? For example the multiplier colour will be the only difference between a 8.2 a 82 or 820 ohm resistor.

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