Stacking magnets?
Oct 9, 2019 at 9:54 PM Post #151 of 190
Very well. I understand the general concept of a "driver" and how VC control and resonance play into audio reproduction. It seems you have a good understanding of it.

You can gain efficiency and output in the higher frequencies by adding field strength, but at the cost of less resonance and therefore less output in the lows, roughly speaking.

I think i posted earlier and you brought it up as well, but it seems that putting a magnet in the attracted direction would pull the field away from the coil gap. If you put a repelling magnet on the driver, it should direct the field towards the VC gap. I've seen this done on cheap speakers, at least i'm fairly certain they were in reverse orientation.
It kinda pull magnetic effect away from driver, but driver flux guide still maintain the magnetic flux wave path and shape...the result is slightly increased magnetic field but a lot of stray field.
This increase the magnetic field lines

Doesnt helps in driver shielding... Actually worsen it up if used above N50



Putting it in repelling position increase resonance... But it has to be done in such a way that other pole(not stuck to anything) is shielded to get that effect..
It concentrates the magnetic field lines.

Also helps in driver shielding...

But can kill magnetic force over period of time and thus kill driver
 
Jan 22, 2020 at 8:31 PM Post #153 of 190
iso tried out this mod, krk woofer, Fluke 287, 3oz gel ball dropped from fixed hight. Etc etc
Pic lost when phone died.
Results nadda. 3 x the magnet size w/ proper neos, or a 3 magnet set up with idenical krk magnets.
Not a bit of peak recorded mv ac or dc noticed.
It was like .3 v no matter what. ..

I abused the driver so much I need to reform the coil form , I bent it, @amn it.
Ehhhh bro

You did the wrong test

Because that parameter only changes when you upgrade the voice coil itself

Magnets won't change the voltage parameters
Magnets are used to convert that electrical signal to mechanical signal

If you can measure

Measure THD, distortion, FR, and slow motion recording of nodal breakdown due to loose magnetism
 
Feb 28, 2020 at 12:45 PM Post #154 of 190
Feb 28, 2020 at 3:11 PM Post #155 of 190
Edifier H840 can use 20mm diameter and 5mm center hole. Thickness doesn’t matter as much.
Sorry I cannot post pictures right now, but they can be seen here:

https://willyboy.home.blog/2020/02/29/magnet-stacking-edifier-h840/

Thank you for the great idea of stacking magnets, I thoroughly enjoy it.

Glad you are enjoying it!

I got a Fidelio X2HR a few months ago, and I never cease to be amazed at the difference the magnets make. It made a great headphone sound even better, and it only cost me a few pennies.

I appreciate the Edifier H840 info. I’ve added your measurements to the 1st post :)
 
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Feb 28, 2020 at 5:40 PM Post #156 of 190
Glad you are enjoying it!

I got a Fidelio X2HR a few months ago, and I never cease to be amazed at the difference the magnets make. It made a great headphone sound even better, and it only cost me a few pennies.

I appreciate the Edifier H840 info. I’ve added your measurements to the 1st post :)
In my case, the chamfered side is ‘down’ and the flat side is ‘up’, because this is the position that gives stronger pull to the driver. Is there another way to verify I got it in the right orientation? Thank you.
 
Feb 28, 2020 at 6:07 PM Post #157 of 190
In my case, the chamfered side is ‘down’ and the flat side is ‘up’, because this is the position that gives stronger pull to the driver. Is there another way to verify I got it in the right orientation? Thank you.

That’s the way I usually do it.

You can also try it both ways and see if you hear a difference.

Personally, I have been unable to hear a difference. In other words, I can definitely hear a difference with no magnet vs with a magnet. But I can’t really tell a difference with the magnet being flat side up vs flat side down. Maybe someone else can, whose ears are better than mine.
 
Feb 28, 2020 at 7:54 PM Post #158 of 190
That’s the way I usually do it.

You can also try it both ways and see if you hear a difference.

Personally, I have been unable to hear a difference. In other words, I can definitely hear a difference with no magnet vs with a magnet. But I can’t really tell a difference with the magnet being flat side up vs flat side down. Maybe someone else can, whose ears are better than mine.

Thanks Slater, really appreciate it. I also put 0.12 grams of blu-tack to fill the chamfer so it’s ‘coupled’ to the bass port. Nothing scientific about the weight, but that’s the amount that was needed to fill the cavity.
 
Feb 28, 2020 at 7:57 PM Post #159 of 190
Thanks Slater, really appreciate it. I also put 0.12 grams of blu-tack to fill the chamfer so it’s ‘coupled’ to the bass port. Nothing scientific about the weight, but that’s the amount that was needed to fill the cavity.

Great idea - can’t go wrong with mass loading the driver even more :)
 
Mar 11, 2020 at 12:45 AM Post #160 of 190
After listening for 2 weeks, I found my H840 rather lifeless, so much that I put it in storage, in favor of my SR850. Then I tried reversing the magnets again, this time chamfered side up. I tried listening without additional magnets, chamfered side down, and chamfered side up. I conclude that chamfered side down brings out the mids but the rendition is lifeless. Putting it chamfered side up seems to bring things back to normal and then improve some.
 
Mar 11, 2020 at 5:50 AM Post #161 of 190
After listening for 2 weeks, I found my H840 rather lifeless, so much that I put it in storage, in favor of my SR850. Then I tried reversing the magnets again, this time chamfered side up. I tried listening without additional magnets, chamfered side down, and chamfered side up. I conclude that chamfered side down brings out the mids but the rendition is lifeless. Putting it chamfered side up seems to bring things back to normal and then improve some.
Less then 1$ for polarity measurement tool
https://www.ebay.com/itm/30mm-Mini-...el-Navigation-Wild-Survival-T-SE/133273684886
s-l1600.jpg
 
Mar 11, 2020 at 11:03 AM Post #162 of 190
After listening for 2 weeks, I found my H840 rather lifeless, so much that I put it in storage, in favor of my SR850. Then I tried reversing the magnets again, this time chamfered side up. I tried listening without additional magnets, chamfered side down, and chamfered side up. I conclude that chamfered side down brings out the mids but the rendition is lifeless. Putting it chamfered side up seems to bring things back to normal and then improve some.

Nice. I agree that you really need to try the magnets both ways.

There’s no way to know what pole orientation the stock magnet is using. So trying the stacked magnet both ways allows you to check for any differences that may exist.
 
Mar 11, 2020 at 3:47 PM Post #163 of 190
Nice. I agree that you really need to try the magnets both ways.

There’s no way to know what pole orientation the stock magnet is using. So trying the stacked magnet both ways allows you to check for any differences that may exist.
With compass you can check the polarity without open the headphones.
 
Jun 14, 2020 at 8:51 PM Post #165 of 190
Has anyone tried this with Koss porta pro or KSC75?

Is there enough room? I thought the back of the driver has a plastic housing with integrated clip that the ear clips attach to?
 

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