[Sharpty]

Well that will identify N and S, but not give a quantitative measurement of the gauss of the stock magnet, matching a set of extra magnets, and the resulting final gauss from stacking. It also won’t allow the measurement of the difference between stacking the extra magnet with the poles in attracted vs repelled mode.

What I could do is contact a few local universities and see if any have a gauss meter, and if so ask if I can use it for a few hours.

Another option is to buy one, use it, and return or resell it.

If you really want one, you can get one with a probe for $100
https://www.amazon.com/Gaussmeter-F...8&qid=1545523128&sr=8-10&keywords=gauss+meter

The problem is that you have to destroy a speaker to measure the flux across the VC gap, so you'd want to find an old junk speaker to play with. You could even get some magnetic viewing film to watch real time changes in the field when adding/removing magnets. But honestly a bit of consideration/ study of magnetic fields makes it rather apparent that adding attracted magnets to the back, is going to pull the field away from the VC gap... contrary to intuition this can actually make the headphones louder to a certain point because the movement/momentum/overtravel of the driver is not as tightly controlled, if i understand correctly. It can also lower the impedance of the speaker.

 

[mufflertape]

UPDATE: so I went back to the drawing board with the stacking magnets on a 58x and I think the improved treble was actually some glare/ringing that the air gap flux was helping with. Also I worked to correctly implement the bucking magnet by the side of repulsion etc. and it worked good at first trying with 2 different magnets but ultimately it caused some distortion so I promptly removed it, sorry for the bust yall. Still worth looking into, but u didn't want to glue the magnets down etc. so maybe someone else can crack the code on that.

 

[kkl10]

What in the name of Jesus is happening here? People trying to do this on the Sennies? Crazy bunch.

a bit of consideration/ study of magnetic fields makes it rather apparent that adding attracted magnets to the back, is going to pull the field away from the VC gap... contrary to intuition this can actually make the headphones louder to a certain point because the movement/momentum/overtravel of the driver is not as tightly controlled, if i understand correctly.

When I stack magnets in the wrong orientation, the bass becomes looser and ill-defined. The whole sound loses definition and becomes veiled. Major loss of resolution. Earlier roll off at both ends of the spectrum. If I remember correctly, I might have heard some kind of weird distortion too. But I don't remember perceiving an increase in volume in the short time I experimented with this configuration. Which makes sense, I think, because stacking the magnet in the wrong orientation weakens the grip over the voice coil and, consequently, impulse response.

On the other hand, one of the typical effects of stacking magnets to the back of my GMP 400 drivers in the correct orientation is an effective decrease in the volume. The stronger the magnet (same size and weight), the greater the effect. This is often accompanied by the perception of a slightly tighter bass response, a smoother sound, etc... Addendum: this paragraph is true only with the stock acoustic paper on the back of the drivers.

The difference between correct and incorrect magnet orientation is quite obvious with my GMP drivers. I've commented about it earlier in this thread.

 

[kkl10]

Should update my findings. I previously said that stacking magnets on my GMP drivers (specifically, GMP400/450 drivers) caused a decrease in volume. That was when the drivers had the original acoustic paper in place. This paper was covering the tiny back vents. Neglected to mention this detail. I recently decided to remove the acoustic paper and now additional magnets don't result in lower volume output. It's about the same, possibly slightly louder with the magnets. More importantly, the extent of improvement is much greater given that the drivers are freer to move, a little underdamped. However, I'm not sure this is better than with the acoustic paper in place. With the paper in place, it was too easy to turn the sound too thin and bright. Without the paper, it's difficult to get rid of the slight sluggishness in the lower frequencies even though I prefer the larger and more impactful presentation this way. These GMP4xx driver are difficult to get right. Still have to test this with mass loading and some more damping to find the right balance.

Got an MB Quart QP 90X. Drivers feature a huge back vent. A strong ring magnet on the back improves the sound tremendously and actually raises the volume output a lot. Not sure if the magnets of these driver are ferrite, they sound pretty sluggish without an additional magnet but full of life and dynamic with one. Easy to get top tier worthy sound quality with this one. Unexpected observation with these drivers: the right orientation of the magnets is that which initially appears to be the wrong one due to the repelling effect at a distance. When brought really close to the drivers, it sticks with a lot of force though. The GMP250 drivers look very similar, need to get a working unit to test.

Didn't like the results with the closed on-ear Beyerdynamic Custom Street. Don't recommend messing around with the insides of these small closed headphones with adjustable bass vents. These sound much better with some mass loading on the outside (ugly but worth) and a cable replacement. Stock cable is crap.

 

[dhruvmeena96]

@Slater...

If we put the magnet in the orientation in which they attract... Aren't you loosing on the flux which is moving outside the magnetic field..
Normally they design drivers to have most of the field in center via adding steel or magnetic deflector and flux guider...the silver part which is noticeable to eyes....

So stacking the magnet in attracting polarity, may increase the area of flux produced by magnet...which may improve the sound....but we then also loose the magnetic flux in air mostly...so overall improvement on flux density may be 30% over stock on simulation with my Peerless HPD50N headphone driver...

If you can get MU metal tape and some steel...I think we can guide most magnetic nature back to main

And have a magnet with inner edge to be magnetized...

(Image was bad...due to my hand)
The slashed line is a magnetic deflector...


Sorry for bad image...bare with it...I will upload a better diagram

This way we can take most of the flux density concentration back into coil.... Have the driver surface demagnetized and so not prone to attracting stuff on the way plus should it with magnetic interference

 

[Slater]

Try it out and let us know! I’d be very curious myself.

One of these days I’m going to invest in a lab grade gaussmeter (and reference test magnet), which will be very interesting to use for testing many of these theories.

Until then, we just have to try different things and experiment, using our ears to see what the effects are.

 

[dhruvmeena96]

Try it out and let us know! I’d be very curious myself.

One of these days I’m going to invest in a lab grade gaussmeter (and reference test magnet), which will be very interesting to use for testing many of these theories.

Until then, we just have to try different things and experiment, using our ears to see what the effects are.

I think this might be possible if we can get some steel housing for magnets

And if we can get a cylindrical thin axial magnet with two layer of concentric magnet...

Inner circle is south and outer circle is north(or vice versa according to driver magnet structure)


Took a break from building iem and trying to perfect the Peerless HPD50 driver from Parts express...

This driver is used in kennerton vali and has its whole specsheet released... Which Is helpful as thus I will be upgrading circuitry according to magnets changing the way the flux works, having way more fine control on driver


Or we can order different type of magnets and create a concentric hall back array magnet with super power at north pole and then add a steel cap over it...to redirect flux...

That would be even more crazy


That would be easier to do plus it needs the axial ring magnets and rectangular magnet...to redirect my north pole flow...

And actually I mean way easier

According to my estimation...we can reach 1.8Tesla force if we can get a Hall back array in ring shape
sissue

Like this..

But then we have to get a steel cap with cut out for magnet with equal distance...otherwise magnets are pretty easily available...

The ring figure bellow is the structure of magnets as how we will see it..


We might hit a lot of magnetic flux plus some no flux on the down part, which makes the driver magnet assembly itself shielded...

That would be more than Beyer Tesla driver....

Hahaha

Having higher field by piggybacking magnet
1. Increase sensitivity because overall field was increased

2. Lowering Qts slightly by lowering Qes

3. Dramatically increase stray magnetic field(which has to be shielded)


But in Hall back array, we can eliminate the 3rd issue.

Qts mostly apply to speaker resonant frequency or where speaker may suck up too much signal voltage..

As we can see speaker impedance..they have peak at low frequency... That's what makes speaker bassy... As more voltage sucked in, means more energy thrown out...and resonant frequency means that speaker ....if moved manually at that specific frequency manually, will produce back emf..

Piggybacking magnet technically lower Qts.

Which means that you are damping the speaker movement itself..

Some people use foam inside the headphone cups to do the same...you are just doing it with speaker... And way more effectively..

And since the damping effect comes in place...speaker technically sucks less voltage inherently on resonant frequency which gives it flatter impedance... And as the resonant frequency is lowered....less back emf is generated


So you are

1. Reducing bass resonant frequency
2. Reducing Back emf which leads to lower linear and non linear distortion
3. More magnetic flux means way more control and less oscillations of diaphragm like modal breaks(making things sound tighter)
4. Higher sensitivity





I can make simpler structure to concentrate magnetic fields...
Which can also be done by everyone...


The above one are just concept .



And yah

N55 magnets are available now..

Those MotherF***** are crazy..

I was not able to lift them off from my iron block at all...they are so strong that if other magnet is separated with just a plastic plate.. And they are attracting each other...they can break themselves and the plastic plate

 

[dhruvmeena96]

Since everyone is working with axial cylindrical magnet with punch hole.
i will try using simulations and will find the way to concentrate a lot of magnetic flux back to motor
because i have general proof of concept but lemme try

search for steel and EMF sheilding and magnetic flux guides

and my project may require usage of steel at different places but simple enough to get the cutting.... no complex magnet casing and CNC stuff.... you might be able to find these stuff and also will try to keep most of the cost down

Aim is 1.5Tesla to coil

 

[Sharpty]

All this seems rather absurd to me. The magnet of a driver in any decent headphone, is part of the tuning design. It's not like the engineers with hundreds of thousands of dollars in test equipment, are just slapping any old random magnet on there and hoping it sounds good. It seems pretty ridiculous to assume that slapping a random magnet on it yourself, is actually improving the sound at all. Changing it, yes, improving it, I highly doubt.

 

[Slater]

All this seems rather absurd to me. The magnet of a driver in any decent headphone, is part of the tuning design. It's not like the engineers with hundreds of thousands of dollars in test equipment, are just slapping any old random magnet on there and hoping it sounds good. It seems pretty ridiculous to assume that slapping a random magnet on it yourself, is actually improving the sound at all. Changing it, yes, improving it, I highly doubt.

You’re totally entitled to your opinion. And you may be right. Who knows?

However, I could make the same argument about doubting that numerous other mods don’t make any difference too, such as changing earpads on headphones, ear tips on earphones, nozzle filters, dampening earphone cups, tuning foam, tweaking driver and air vents, etc. But the reality is, that’s not the case.

There’s so many mods that can improve the sound of earphones and headphones, over and above what “the engineers with hundreds of thousands of dollars in test equipment” came up with, that it’s impossible to list them all.

The difference is that you don’t know until you experiment and try for yourself. You’ll never learn anything sitting in an armchair and doing nothing but speculating.

 

[Sharpty]

You’re totally entitled to your opinion. And you may be right. Who knows?

However, I could make the same argument about doubting that numerous other mods don’t make any difference too, such as changing earpads on headphones, ear tips on earphones, nozzle filters, dampening earphone cups, tuning foam, tweaking driver and air vents, etc. But the reality is, that’s not the case.

There’s so many mods that can improve the sound of earphones and headphones, over and above what “the engineers with hundreds of thousands of dollars in test equipment” came up with, that it’s impossible to list them all.

The difference is that you don’t know until you experiment and try for yourself. You’ll never learn anything sitting in an armchair and doing nothing but speculating.

Fair enough. Although I would say there is a difference between custom earpads to make your headphones seal better, and changing the magnetic field of a precision driver.

I'm not going to take apart my headphones and experiment tho. Especially not based on subjective claims of improved sound by people with no real background in audio or speaker design.

Anyway, greetings from Cincinnati.

 

[dhruvmeena96]

All this seems rather absurd to me. The magnet of a driver in any decent headphone, is part of the tuning design. It's not like the engineers with hundreds of thousands of dollars in test equipment, are just slapping any old random magnet on there and hoping it sounds good. It seems pretty ridiculous to assume that slapping a random magnet on it yourself, is actually improving the sound at all. Changing it, yes, improving it, I highly doubt.

Its all about flux and how it react with voice coil and its former..

It affects Qts and impedance chart..

And its not about improving sound per se...its all about experiment.

Tried with some drivers and they dont read well. Proper engineered driver always have Qts of 0.7, which is critically damped....and there, adding a magnet will technically kill bass response by over damping it.

Warm headphones with slightly boosted bass reacts well or grado reacts well..

Its because there Qts is high.

I won't be stacking magnet on Focal Utopia or HD800. Even HD600.

I would rather go for electrical solution, pad swap or structural mod(HD800SDR)

But modyfing cheap low budget mass level Headphones...its s good experiment.

Or if you want to create your own headphones..

I have my own separate driver from peerless (they only make headphone drivers and not headphones). Kennerton Vali and Aurorus Borealis and Australis uses that driver.

Let's see what we can do with it.


In the end its preference, some believe pad swap is for comfort and some do it for sound change...

Many people in loudspeaker industry are doing that for having larger flux though....

 

[Slater]

I'm not going to take apart my headphones and experiment tho. Especially not based on subjective claims of improved sound by people with no real background in audio or speaker design.

That's the great thing about living in a free society. You can do what makes you happy, and I can do what makes me happy. Take care

 

[dhruvmeena96]

Fair enough. Although I would say there is a difference between custom earpads to make your headphones seal better, and changing the magnetic field of a precision driver.

I'm not going to take apart my headphones and experiment tho. Especially not based on subjective claims of improved sound by people with no real background in audio or speaker design.

Anyway, greetings from Cincinnati.

OK...I read that now....

Damm bro hard

OK, I am not from audio society whatsoever...but I am a scientists for govt. Here.

And see, what you guys call drivers are actually electrical transducer which is often denoted as electrical motor in electronic circuit..

Having more flux around magnet gives it higher control and torque and also higher regenerative braking(take it as braking).

Less magnetic force makes it more resonant at resonant frequency, and dynamic driver have this on low end.. Which leads to less control over that point, and what we hear ad bass characterstics.

Qts is suspension setting of motor or shock rating. The suspension must prevent any lateral motion that might allow the voice coil and pole (or core) to touch. The suspension acts as a shock absorber. Qms is the mechanical Q, which measures the control from the speaker’s mechanical suspension system, the surround and spider. Think of these components as springs. Qes is the electrical Q, which measures the control from the speaker’s electrical suspension, the voice coil and magnet. Opposing forces from the mechanical and electrical suspensions act to absorb shock. Qts is the total Q of the speaker and is derived from an equation where Qes is multiplied by Qms. The result is divided by the sum of the same.

Qts under 0.4 means suspension is overdamped(no feeling or dynamics but more ideal). Bass is very tight. In speaker analogy, you need either a woofer crossover or vented box. Headphone will translate to tighter and resolved bass but no feeling in it.

0.1 sounds like farty bass


More than 0.4 and less than 0.7 is critically damped. And speaker analogy, it means that speaker with specific Inductance, impedance and material selection and proper study has ended up making critically damped motor/transducer. This may sound neutral to you guys with good extended bass as we go near 0.7.

Above 0.7 is under damped motor or a motor which can distorts, modal breaks etc.

Its like a car with worst suspension and when moved on road of bad quality music...it shows...

Bleeding bass in mids..overly warm and no detail whatsover....some speaker may be exception to detail part....but mostly they are very bassy.



Adding magnet is gives you more flux, so coil becomes more sensitive around more passing line of magnetic field, thus giving it more control. This lowers Qts.

And also flattens impedance..

This theory works...its just that we all are doing DIY and can only do subjective claims..

Its just that, how we learn and optimise the magnetic field around the driver in most simplistic manner..

I will see on that as I have more resources to do that.

And I will only use single axial magnet...and some steel as magnetic flux waveguide

 

[Sharpty]

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.