[piotrus-g]

When you're trying to crossover drivers, do you have to take into account the driver's own impedance?

Yes, and impedance at the specific frequency, not the DC value, unless you are dealing with Planar or DD where Z=Rdc for 99% cases.

Does every driver have to have similar impedances for them to work well together?

No

When calculating for R for high/low pass filters, what else should be taken into account besides the resistor to be added, if the resistor is necessary after all.

In most cases the R is not necessary.
You need to consider electrical phase of the driver and how it fits into the rest of the design, in most of the cases when you use cap your positive wire (with the cap) has to go to the negative soldering pad of the driver to invert the phase otherwise you'll get some phase cancellations between woofer and tweeter.

 

[tonybuild]

Lol, you think I'm doing any math haha, use online calculators, you just have to know impedance plot of the driver, which you could technically measure yourself.

Yeah of course you can do that, just again be mindful of the crossover frequency - in that configuration 6-8kHz could be a sweet-spot

what is the exact model of the driver you are using? 38AM007 or 38d1xj, there's considerable difference in response between standard version and version with Acupass

It 38d1xj . I used 20 ohm resister on it . I like the volume of it .

Also I reverse the polarity on 38 . I thought I don’t need it, but I saw something crazy happening on the graph that look like cancellation .


Also ,he is my coffee time drawing lol
I want to try and see if 1 is different from 2

Now, i have to find 40 uf cap , i only have 22 on my hand right now.
Ill be honest, this driver is very confusing .

But thanks for help!

 

[shade105]

You need to consider electrical phase of the driver and how it fits into the rest of the design, in most of the cases when you use cap your positive wire (with the cap) has to go to the negative soldering pad of the driver to invert the phase otherwise you'll get some phase cancellations between woofer and tweeter.

Explain further, inverting the phase?

 

[swtnate]

Explain further, inverting the phase?

He is referring to polarity inversion, also referred to as phase inversion. Ie. Connecting the positive wire to the negative terminal and the negative(ground) wire to the positive. This allows for the coil to respond in a way that doesnt step on the other drivers in the signal chain.

 

[JEHL]

Has anyone ever addressed the problem of leakage resistance in IEMs before?

 

[swtnate]

Has anyone ever addressed the problem of leakage resistance in IEMs before?

Leakage?

 

[swtnate]

Guess everyone left to fix the leak. Nobody likes leakage.

#wellplayedCommunity

 

[tonybuild]

Guess everyone left to fix the leak. Nobody likes leakage.

#wellplayedCommunity

Lol
I don’t know what is leakage

Whatever you say, I’m for it

 

[swtnate]

Lol
I don’t know what is leakage

Whatever you say, I’m for it

Ive never heard of her

 

[JEHL]

Leakage?

Less about the leakage itself and more about the resistance to it.

I'm making the assumption that the seal that the IEM creates is an imperfect one, therefore, its frequency response changes based on how imperfect the seal it creates is.

I wonder if the way to fight this is to create an intentional leak in the form of a front vent that is consistent enough to tune around as well as choosing a bass driver with the highest Vd.

So in this context, I want to maximize the consistency of the frequency response that isn't as affected by any potential fit issues.

Would pairing this with foam eartips be considered overkill?

 

[xrecode]

Less about the leakage itself and more about the resistance to it.

I'm making the assumption that the seal that the IEM creates is an imperfect one, therefore, its frequency response changes based on how imperfect the seal it creates is.

I wonder if the way to fight this is to create an intentional leak in the form of a front vent that is consistent enough to tune around as well as choosing a bass driver with the highest Vd.

So in this context, I want to maximize the consistency of the frequency response that isn't as affected by any potential fit issues.

Would pairing this with foam eartips be considered overkill?

what

 

[shade105]

Is the SWFK-31736 good for the high end, or should I have gone for a TWFK? My plan was to build a full BA IEM as a personal project, and I got myself the CI-22955 and ED-29689 as well as the SWFK.

Also, I found this diagram deep within this thread (I redrew it, can't find the page for the diagram), do you think this is good, and if it can be modified in some way.

 

[musmecca]

Explain further, inverting the phase?

Think of a capacitor as a small bucket that gets filled..caps store charge. It takes TIME to fill the bucket right? If you use a cap, it will delay the signal so it is now out of phase. THE SOLUTION per piotrus is to move it to the negative terminal if using a cap...by the time the bucket fills it will now be in phase with the positive side, which is where you intended to put it anyway. Hope that makes sense.

Explain further, inverting the phase?

 

[shade105]

Think of a capacitor as a small bucket that gets filled..caps store charge. It takes TIME to fill the bucket right? If you use a cap, it will delay the signal so it is now out of phase. THE SOLUTION per piotrus is to move it to the negative terminal if using a cap...by the time the bucket fills it will now be in phase with the positive side, which is where you intended to put it anyway. Hope that makes sense.

So as per this diagram, it would be better to invert the ED so that the positive line with the caps enter the negative terminal in order to maintain the phase.

 

[swtnate]

So as per this diagram, it would be better to invert the ED so that the positive line with the caps enter the negative terminal in order to maintain the phase.

This is not the only strategy. I have run caps to positive terminals in certain configurations. A single series capacitor will not induce as significant of an electrical phase shift as a cap in parallel. When you have 3 drivers or more, one of those drivers is typically wired in reverse polarity in order to achieve a cleaner signal/ EQ. Example, ive run caps to swfk, wbfk, ED, 2389, etc. and connected them positive to positive.