Hi Gents,
Silly question. Would adding neodymium magnets around the outer circumference of ferrite magnet help increase ferrite's magnetic strength ?
Silly question. Would adding neodymium magnets around the outer circumference of ferrite magnet help increase ferrite's magnetic strength ?
Ferrite is chosen for its frequency response and weak magnetism, as in SMPS transformers, and the old EHT units in CRT.
Neodymium is a permanent magnet, much stronger than Ferrite..
Changing the magnet's properties will affect the speaker's performance. And possibly increase the power needed to drive the speaker.
Neodymium is a permanent magnet, much stronger than Ferrite..
Changing the magnet's properties will affect the speaker's performance. And possibly increase the power needed to drive the speaker.
Do use the stimulation, and maybe the Ferrite is shielded, then playing with additional magnets is a waste of time, like Wise said above.
I made some custom designed kit speakers a few years ago where the seller suggested adding neodymium magnets to the rear polepiece of the drivers. He stressed that they had to be put on with the correct polarity, such that they initially repelled but attracted when you got them close enough. Sounds weird but that's what it was like. I don't know how much of an effect they had but they are still there and in use as my main system.
thank you gents, I do understand that parameters would change if it does add magnetic strength just curious in learning more about such stuff.
Cheers
Cheers
Now this Im really curious. How can it repel initially n attract when you get close to the pole piece ? unless the initial repel came from the outer ring of the speaker magnet ????
🙂
Now this is going into audiofool territory, or snake oil.
Actually, strong magnets do have this behavior, and Philips did have Alnico as the material in old speaker magnets, and yes most speaker magnets tend to be strong, and permanent.
Ferrite is mildly permanent, so the question is really that which fool used it as a speaker magnet...
Now this is going into audiofool territory, or snake oil.
Actually, strong magnets do have this behavior, and Philips did have Alnico as the material in old speaker magnets, and yes most speaker magnets tend to be strong, and permanent.
Ferrite is mildly permanent, so the question is really that which fool used it as a speaker magnet...
My understanding is that without disassembling the driver, magnets added to the back or around are not really in the magnetic circuit and the effect on flux strength in the gap will be quite small. It's easy enough to measure T/S parameters before and after if one has access to extra magnets, though I'd hesitate to drop $$$ on good Nd magnets for a shot at a 1% increase in BL product.
JBL uses Ferrite magnets?
Really?
I had no idea...
Thanks for telling me.
You can get kids magnets sets to play around with.
Even the small magnets used in ladies purses tend to be strong.
How it affects the sound is for you to find out.
Really?
I had no idea...
Thanks for telling me.
You can get kids magnets sets to play around with.
Even the small magnets used in ladies purses tend to be strong.
How it affects the sound is for you to find out.
Between the worldwide trade ban on Zaire, leading to a lack of cobalt supply, and the advent of neodymium magnets most, if not any, manufacturers used ferrite magnets in their speakers. For JBL, e.g., this meant the change from the former alnico K series to their ferrite E series of musical instrument speakers.
Best regards!
Best regards!
Yes, I think it was the field from the outer ring that was repelling, then once you got past that it attracted to the pole piece. Anyway, as has been said on other threads the best this can achieve is a minor increase in effficiency, better achieved by spending the money on the right drivers in the first place.
We NEED a drawing. Words do not describe it enough.
With due respect, you have NO CLUE about Ferrites (in general), specially HARD Anisotropic Ferrites used in Loudspeaker magnet systems.
There´s some truth in that; as usual the devil is in the details.
In some positions added external magnets can help.
Think about a billion speakers, earphones, electric motors made since the 60´s using ferrites and you´ll get a pale idea about how many "fools" populate the Earth.
In typical ceramic ring magnet systems, most of the magnetic flux is outside, surrounding them.
You can push some of it towards the gap,where the voice coil is, by repelling it "forward" adding a same size reverse polarity ring magnet glued to the back plate.
You can gain up to 20% useful flux, which is a lot and very noticeable.
Easy to measure too, both with a magnetometer inserted in the gap and by changed speaker parameters.
You have to magnetize it "outside" , on its own, and then epoxy it in place.
You will need some jig to keep it there until epoxy hardens, because it will be strongly repelled.
Imagine magnetic field around magnet system as a soft rounded "cushion" around it.
Added magnet will push that "cushion" forward, deforming it, so you will have less in free space behind, and more forward.
Where´s the [rolleyes] or [slap own face] emoji when you need it? 🙂
From that same page:
Two to three times MORE than Neo, for the same budget.
Maybe that explains why Ferrite is used 10000 to one in speakers, vs Neo.
Notice no compromise in performance is involved, quite the contrary.
So far, only real advantage is weight, (and maybe size in some niche applications) that´s why such speakers are often called "XXXXX Lite"