[imsurokim]

You did a fantastic job, over the years lots and lots and lots of people have asked questions and bought material, but have given up in the process. You started and seen your creation through until complete, and learned a lot through the process I’m sure. My first set looked like that too. Keep at it they get better with each build!!

Thanks! I used your recipe to make negative impression, but eyeballed 1oz of glycerin not measuring exact amount. First negative impression was not firm enough it cut to pieces when I try to pull it out from container, so I heated left over and put more glycerin, and got that one on the picture. I think I will make another one with exact amount and see if that works better. At least I didn't have any bubbling issues with negative impression using microwave for 10s and pour out liquids. Hopefully my second set gets better than that.

 

[dhruvmeena96]

Great community!!!! So I wasn't giving enough UV to the bottom of the mold. I screwed up first mold by not covering up the top(gave me solid piece), second with whole showing in pictures and third one I cured longer time same position and got thicker outer wall, but still thin U shape but no hole.

The other problem I had was negative impression is ripping. As you can see from the picture, bottom of mold (thinnest part of face plate) has crack and UV resin leaks there and I had to sand them.

Is the UV source a bulb diy or a machine to especially cure the moulds

If it is a bulb, you can get a hollow cylinder with mirror surface inside it.

Attach bulb on one side and taped mould with bottom open for curing on other side.

We used it for SLA printing for fun and it works



And I saw your shell

Its great.

Keep the work going and don't loose hope


And for soldering
The trick is to apply solder on wire first
Heat it slightly
And quickly but carefully attaching it to BA taps.

This way, BA chances of getting damaged reduces

 

[dhruvmeena96]

Yes, as it throws everything into chaos If you introduce a driver in parallel or in series, it influences all other drivers as well. GV/GK has tiny smd components (I think two caps) as a crossover, you will need to adjust them if you add a driver.

@imsurokim @eunice

parallel wont deviate the signature that much since a GV/GK/GQ/HE were already wired in parallel with crossovers

if you put something parallel to these, there wont be that much issue, but tuning them to work with factory crossover driver can be hard, since they are made to cover full frequency.

ok lets go this way, putting another WBFK to GQ is okay but putting SWFK can put the balance to a loss since SWFK impedance is lower and is more sensitive, it can go mask over in additive fashion, increasing treble by lot.

Parallel means voltage distribuiton equal. This means that driver voltage will first divide in half and then go parallel.


series would need specific crossover as series is ampere eater plus the voltage can change due to a speaker being a bad inductor and resistor. since voltage is our signal in music, the other series speaker of different kind may see a very weird signal


series is recommended with single driver setup of same type

 

[vladstef]

I have a question about Knowles GQ-30783. Does anyone know which drivers is it using? One is a standard WBFK but the other one is ED with a vent, meaning ED-26821 or ED-20805 (I guess, might be wrong).

Is it possible to remove its crossover and add our own like we would with separated BAs? It comes down to - is the board glued on or is it just soldered to ED driver.

 

[dhruvmeena96]

I have a question about Knowles GQ-30783. Does anyone know which drivers is it using? One is a standard WBFK but the other one is ED with a vent, meaning ED-26821 or ED-20805 (I guess, might be wrong).

Is it possible to remove its crossover and add our own like we would with separated BAs? It comes down to - is the board glued on or is it just soldered to ED driver.

it is possible to seperate them, but dont do that as they were tuned by single spout or nozzle
and doing that at home would be more risky

well, the question you asked here was bugging me for a period of time

 

[Kulgrinda]

Thanks. I should try that.

Here is picture of my first shell which has huge hole in the middle. I think I wasn’t curing it long enough. Or my negative impression has uneven spacing between side wall and where resin is.

My first set of shells were almost solid, then there was the same situation with the hole at the bottom. I solved it by keeping greater distance between the lamp and the rotating table and using lower light setting. Of course it meant much longer exposure time. After several tries I managed to get perfect thickness in the shell, very easy to drill the holes and keep the inside clean. Try experimenting that way.

Mirror at the bottom of the negative mold actually made the nozzle solid which is not good. I also remove the shell from the form after initial exposure, flip it over and expose it some time, letting the remaining liquid plastic to run out.

 

[imsurokim]

Is the UV source a bulb diy or a machine to especially cure the moulds

If it is a bulb, you can get a hollow cylinder with mirror surface inside it.

Attach bulb on one side and taped mould with bottom open for curing on other side.

We used it for SLA printing for fun and it works



And I saw your shell

Its great.

Keep the work going and don't loose hope


And for soldering
The trick is to apply solder on wire first
Heat it slightly
And quickly but carefully attaching it to BA taps.

This way, BA chances of getting damaged reduces

I used this product, straight out from box but upright position with no mirror on the bottom. I will try couple more times and hopefully it gets better.

@imsurokim @eunice

parallel wont deviate the signature that much since a GV/GK/GQ/HE were already wired in parallel with crossovers

if you put something parallel to these, there wont be that much issue, but tuning them to work with factory crossover driver can be hard, since they are made to cover full frequency.

ok lets go this way, putting another WBFK to GQ is okay but putting SWFK can put the balance to a loss since SWFK impedance is lower and is more sensitive, it can go mask over in additive fashion, increasing treble by lot.

Parallel means voltage distribuiton equal. This means that driver voltage will first divide in half and then go parallel.


series would need specific crossover as series is ampere eater plus the voltage can change due to a speaker being a bad inductor and resistor. since voltage is our signal in music, the other series speaker of different kind may see a very weird signal


series is recommended with single driver setup of same type

I am not expert on any of electrical engineering, so I am not getting this 100%, but I might want to try add driver to my GV later if I want more bass, I will ask more questions when the time comes.

My first set of shells were almost solid, then there was the same situation with the hole at the bottom. I solved it by keeping greater distance between the lamp and the rotating table and using lower light setting. Of course it meant much longer exposure time. After several tries I managed to get perfect thickness in the shell, very easy to drill the holes and keep the inside clean. Try experimenting that way.

Mirror at the bottom of the negative mold actually made the nozzle solid which is not good. I also remove the shell from the form after initial exposure, flip it over and expose it some time, letting the remaining liquid plastic to run out.

I actually had part of nozzle tip chipped out while drilling hole. I am guessing my diamond drill bit wasn't good enough.

 

[dhruvmeena96]

I used this product, straight out from box but upright position with no mirror on the bottom. I will try couple more times and hopefully it gets better.


I am not expert on any of electrical engineering, so I am not getting this 100%, but I might want to try add driver to my GV later if I want more bass, I will ask more questions when the time comes.



I actually had part of nozzle tip chipped out while drilling hole. I am guessing my diamond drill bit wasn't good enough.

well,

get a mirror slab and close the opening/hand inserting part of the UV machine


ok, letme explain the voltage and ampere basics
The voltage is your Singal

if you put a RAB 32257 speaker parallel to other RAB 32257, the voltage is divided 50% to each driver
the best part of voltage division is that, you can divide it in any percent, the signal waveform remain same(AC waverform)

So in parallel, drivers are okay


but in series RAB32257, the first speaker is fed with same voltage and other speaker will also be fed the same voltage, but the Ampere is dropped(Power of signal playing). The division is still 50% but the impedance rises and sensitivity reach becomes harder

but the problem arises when different driver are in series, since the 1st driver sees a the other driver as variable resistor and inductor and can get low or high pass randomly. same happens as second driver sees 1st driver as a different load

thats why impedance graph are important


that doesnt happens in parallel. in parallel, you isolate the driver from each other while dropping impedance

 

[imsurokim]

well,

get a mirror slab and close the opening/hand inserting part of the UV machine


ok, letme explain the voltage and ampere basics
The voltage is your Singal

if you put a RAB 32257 speaker parallel to other RAB 32257, the voltage is divided 50% to each driver
the best part of voltage division is that, you can divide it in any percent, the signal waveform remain same(AC waverform)

So in parallel, drivers are okay


but in series RAB32257, the first speaker is fed with same voltage and other speaker will also be fed the same voltage, but the Ampere is dropped(Power of signal playing). The division is still 50% but the impedance rises and sensitivity reach becomes harder

but the problem arises when different driver are in series, since the 1st driver sees a the other driver as variable resistor and inductor and can get low or high pass randomly. same happens as second driver sees 1st driver as a different load

thats why impedance graph are important


that doesnt happens in parallel. in parallel, you isolate the driver from each other while dropping impedance

I understand now. So if I want more bass from my w3 driver (TWFK+CI) and decided to add one more CI to my configuration, can I just connect them parallen and give proper damper?

 

[dhruvmeena96]

I understand now. So if I want more bass from my w3 driver (TWFK+CI) and decided to add one more CI to my configuration, can I just connect them parallen and give proper damper?

Adding CI to TWFK+CI is mentioned already on this thread

https://www.head-fi.org/threads/home-made-iems.430688/page-265


Dual CI and TWFK

The CI are parallel and are heavily damped
TWFK is wired out of phase(reverse the +ve and -ve wiring)

It sounds amazing, and bass goes deeper and deeper. Soundstage is wide and treble region follows Harman kardon curve like sound

 

[Bassiklee]

well,

get a mirror slab and close the opening/hand inserting part of the UV machine


ok, letme explain the voltage and ampere basics
The voltage is your Singal

if you put a RAB 32257 speaker parallel to other RAB 32257, the voltage is divided 50% to each driver
the best part of voltage division is that, you can divide it in any percent, the signal waveform remain same(AC waverform)

So in parallel, drivers are okay


but in series RAB32257, the first speaker is fed with same voltage and other speaker will also be fed the same voltage, but the Ampere is dropped(Power of signal playing). The division is still 50% but the impedance rises and sensitivity reach becomes harder

but the problem arises when different driver are in series, since the 1st driver sees a the other driver as variable resistor and inductor and can get low or high pass randomly. same happens as second driver sees 1st driver as a different load

thats why impedance graph are important


that doesnt happens in parallel. in parallel, you isolate the driver from each other while dropping impedance

Actually, my understanding of electronics is exactly the opposite of that. If two loads are wired in parallel, they both recieve the voltage the source is putting out. If two loads are in series, the voltage is divided across them. Assuming the loads are the same impedance, then the voltage will be split equally.

 

[dhruvmeena96]

Actually, my understanding of electronics is exactly the opposite of that. If two loads are wired in parallel, they both recieve the voltage the source is putting out. If two loads are in series, the voltage is divided across them. Assuming the loads are the same impedance, then the voltage will be split equally.

Its waveform of voltage which remains same in parallel
In series, the two drivers are seen as one so are feeded with same voltage

Yes you are right, but I mentioned other driver will see first driver as variable resistor and inductor and vice versa. That's why audio quality changes and impedance rises. And voltage splits up randomly(if drivers are different)

Anything in parallel is a voltage divider

For example L-pad circuit.

Series resistor eats up the current
Parallel divides the voltage

Waveform is retained

This is a voltage division L-pad

 

[Bassiklee]

My point is that you have said that two drivers in parallel will each see half the voltage, and that is not the case. Similarly, you've said two drivers in series will both see the total voltage of the source. That is also not correct. You've got it backwards. Simple test:

Pick a source, for the sake of argument well say a 9V battery. For simplicity, let's assume it's actually putting out 9V. Two 1K resistors. Wire them in parallel, measure the voltage across either of them. You get 9V. Wire them in series, (for the sake of argument, these are precisely matched resistors), and you'll measure 4.5V across each one.

 

[dhruvmeena96]

My point is that you have said that two drivers in parallel will each see half the voltage, and that is not the case. Similarly, you've said two drivers in series will both see the total voltage of the source. That is also not correct. You've got it backwards. Simple test:

Pick a source, for the sake of argument well say a 9V battery. For simplicity, let's assume it's actually putting out 9V. Two 1K resistors. Wire them in parallel, measure the voltage across either of them. You get 9V. Wire them in series, (for the sake of argument, these are precisely matched resistors), and you'll measure 4.5V across each one.

OK......well I m wrong then
I got it wrong
But if you add a parallel resistor to a speaker, you drop impedance and test shows that voltage drops per frequency.

Actually voltage remains same, ampere drops
I asked my Senior
He said it is called voltage divider as both share voltage
Series is voltage eater.(lol he did say that, I am in office)

He showed me that voltage division means that they share same amount if voltage, reduced power..

OK I was getting it wrong but I was doing correct calculation this far...lol

My fault

Since V=I*R

Resistance drop reduces voltage when you put a shunt resistor in parallel to speaker.

Why dont we PM on this

 

[dhruvmeena96]

For piotrus-g scary crossover

2xCI and TWFK

Now you can replace the CI-22955 with CI-28352

Its a side firing CI with same specs and same response

This makes the soldering easier and placement also easier inside shells

And the tolerance is also lower due to newer driver