# can I use very large magnet speaker with small radio



## lenaitch (Feb 10, 2014)

Without knowing the data of both the radio output and the speaker, I would guess not likely. The internal speaker will be matched to the tiny power output of the radio (watts) and likely won't be sufficient to move the magnet of the large speaker.
I'm actually surprised that a clock radio would even have an external speaker jack.


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## u3b3rg33k (Jul 17, 2018)

I don't see why the voice coil wouldn't move. are you talking about replacing a 1" 8 ohm speaker with an 8" 8 ohm speaker?


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## John Smith_inFL (Jun 15, 2018)

LOL LOL this question brings back some very fond memories. . . . . 
when I was on a Navy destroyer back in the '60s, I wanted to
hear music in my office . . . so I ran a wire from my little battery transistor
AM radio speaker to the ship's 1MC speaker in my office . . . . it worked GREAT !!
BUT - it also bled into ALL the speakers throughout the ship,
including the Captain's speaker . . . ohhhhhh not good. the ship's
electrician traced it back to my office (and me) and I got all kinds of reprimands.

so, yes . . . it "can" be done. it just depends on your expectations of the results.
try it and see . . . nothing ventured, nothing gained.

.

.


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## SPS-1 (Oct 21, 2008)

lenaitch said:


> .... tiny power output of the radio (watts) and likely won't be sufficient to move the magnet of the large speaker.



The magnet is stationary. Its the voice coil that moves.


I would think it will work fine. But don't expect it to be any louder just because its going to a bigger speaker --- you need more _power_ to make it louder.


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## lenaitch (Feb 10, 2014)

SPS-1 said:


> The magnet is stationary. Its the voice coil that moves.
> 
> 
> I would think it will work fine. But don't expect it to be any louder just because its going to a bigger speaker --- you need more _power_ to make it louder.



Yup, of course you are correct. If the power output of the radio is very small, it might not be enough to generate strong enough fields in the large magnet unless it is a good quality, high sensitivity speaker. It's the reverse of a mis-match the other way; a low power rated speaker connected to a high power source and gets 'over stimulated'.



As mentioned, it might work, just not with the results expected. Nothing will get damaged. Nothing ventured, nothing gained. At least the OP won't get hauled before the mast like Johnny did.


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## Hossenfeffer (Apr 1, 2010)

Thanks everyone. So if I understand correctly I will not damage the little amplifier in the clock (It is actually a little Seiko mantle clock with a tiny battery powered unit that chimes....loudly..yet I want to experiment. This unit does not run on AC at all, just one AA battery)


I usually wire up little amplifiers in my HO model trains decoders to little transformers, then run them into inputs into a stereo amplifier. The result is phenomenal...but decoders actually runs on 13 v and 3 amps. This mantle clock will be nothing like that.


I would have tried it already except that I did not want to damage the clock.


I would match the impedance going from a two inch speaker up to a high end 4 inch full range speaker I have pulled from a stereo.


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## BrownEyedGuy (Oct 2, 2018)

Hossenfeffer said:


> ..... I would like to replace with a very efficient large magnet speaker of the same impedance.


As was mentioned, there is nothing wrong in trying.

Just pointing out that the larger magnet isn't necessarily more efficient. What would be more efficient would be to take a smaller speaker sized appropriate for the radio, and using a neodymium magnet. The more concentrated magnetic field will get more driver movement from a smaller power source. That's why headphones use them....it was actually the breakthrough that permitted super small but powerful headphones.


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## Hossenfeffer (Apr 1, 2010)

Thanks again. Now, to be clear.... I won't toast the little circuitry by attaching this large speaker? It really is a high end speaker, believe me. Yes, I know about neodymium. I have a box of them I used for undertrack train uncouplers on the model train layout. There is a great website that sells all kinds.


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## lenaitch (Feb 10, 2014)

delete


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## u3b3rg33k (Jul 17, 2018)

Hossenfeffer said:


> Thanks again. Now, to be clear.... I won't toast the little circuitry by attaching this large speaker? It really is a high end speaker, believe me. Yes, I know about neodymium. I have a box of them I used for undertrack train uncouplers on the model train layout. There is a great website that sells all kinds.


high end does not mean a good db/W rating. just hook it up and tell us what happens already.


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## PatentPending (Aug 7, 2018)

Hossenfeffer said:


> Thanks again. Now, to be clear.... I won't toast the little circuitry by attaching this large speaker? It really is a high end speaker, believe me. Yes, I know about neodymium. I have a box of them I used for undertrack train uncouplers on the model train layout. There is a great website that sells all kinds.


As long as the new speaker has the same impedance as the old speaker, the magic smoke should remain safely contained in the circuitry.


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## Hossenfeffer (Apr 1, 2010)

PatentPending said:


> As long as the new speaker has the same impedance as the old speaker, the magic smoke should remain safely contained in the circuitry.



Thanks. I do a lot of speaker work with the train decoders. 

Sorry to be tedious about possible damage. The clock is worth over $250 and is brand new.


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