[Aldo40]

Anybody use un shrunk or partially shrunk heat shrink as sound tubes? I have a few times, but wondering if I need to stop.. If the iems get too hot in a car or something, it could shrink more.

I found 90*c /194*f as a common temperature for heat shrink, of course they shouldn't get that hot but if left in direct sun, maybe. Also worried they could slowly shrink over time, at lower temps.

I don’t think you need this kind of tube, they are finer and must reason a little more because they are finer, if you want to gain thickness at the end of the nozzle, you can use piercing needles for example like here
https://twister6com.files.wordpress.com/2020/11/oriolus-traillii-23.jpg?w=720

 

[Aldo40]

I would like to experiment with this setup, too. As I already have all the MASM 3 PRO drivers lying around, just need to put in an order for the 38D1XJ.
Have one question, you said you played around with tubing lengths. What lengths did you finally settle on?

.
To begin, you can test with a 1mm ID tube and 20mm long.

The longer you lengthen the tube length the more you will act in low pass.

A yellow or orange damper will also act as a low pass, there is no fixed value on the dimension of a tube, it depends on the individual response curve you want given to each driver

It also depends on which drivers it will be coupled with.

phase testing will be required to determine which filter and tube size configuration will be the most suitable.

It takes a lot of testing!

But 1mm IDx20mm with a yellow damper is a good start

The more you decrease the diameter of a tube, the more it will act in low pass it can make a low driver a little faster but you notice a loss of gain.

It’s like the history of the water hose that you go pinch with your fingers, you’re going to increase the pressure of the water but you’re going to lose flow, well it’s a metaphor

 

[kmmm]

If I have a moment I can measure both. For the Knowles measures I also noticed that they were often different. After there are several SWFK, I must have at my disposal 3 different reference to SWFK the classic 31736 which is not ammorti, the 32254 and the 32255 which are ammorti. Despite the very linear Knowles curve of the 32255, in reality there are still higher peaks than on the manufacturer curves. All this to tell you that nothing will replace our own curves in real situations.
measuring 28uap or series 33 sonion and the builder curves are very different also

This would be really interesting to see. I have only tried the 32625 my self..

 

[Aldo40]

Piotr left some comparative graph, the 32625 are the same but with a stronger built-in damper that lowered one may more peaks

 

[Jerry-S]

Thanks everyone for your help. Now I just need to wait for my shipment to arrive then start testing.

 

[Petrichor DE]

Hi everybody,

I'm trying to upgrade my CIEM with a Zobel.

It has 2x TWFK on each side.

Can anybody tell me how I should calculate the correct C and R?

 

[Wgibson]

Hi everybody,

I'm trying to upgrade my CIEM with a Zobel.

It has 2x TWFK on each side.

Can anybody tell me how I should calculate the correct C and R?

You need to measure (or find) the inductance. LCR meters aren't too expensive.

Then:
https://diyaudioprojects.com/Technical/Speaker-Zobel/

There are more complex calculations too, I'm sure someone will chime in.

 

[Aldo40]

Another method also consists in measuring the impedance of the driver and then simulating the RC in software like vituix, after which we can improve the adjustment by taking a new measurement because there can be an offset between the simulation and the real measurement

 

[Wgibson]

And of course, why estimate when you can calculate, why calculate when you can measure.

An impedance jig is simple to make, connectors and 100 ohm resistor. Room EQ wizard software is free. You can measure/test impedance with slightly different R and C zobel values.

 

[re23071998]

https://detail.1688.com/pic/651127125521.html?spm=a261y.7663282.1998411378.1.d2fb4dce7WWZl4
found this cool housing.
any recommended 6.5 - 7mm drivers?

 

[Jerry-S]

I have a question.
I have been using the standard hydrocolloid mixture when making a mold but its quite time consuming and tricky to get perfect consistency.
Has anyone used either clear silicone or Dreve/Nicefit acrylic to make a permanent reusable negative mold?

 

[piotrus-g]

Has anyone used either clear silicone or Dreve/Nicefit acrylic to make a permanent reusable negative mold?

Yes, it works, it's expensive (very) and shrinks over time - cannot be reused after 1year, and if used often probably only 6 months.

 

[Inspector Gadget]

lol, using 24 drivers, but no crossover, seems like an odd set of priorities. why? I can understand doing something akin to a 2 way with a full range plus sub, for simplicity's sake, but its not like these drivers have particularly linear response (nor does the ear). You are never going to do better just by throwing more drivers at the problem and it ceases to be an exercise in simplicity/elegance long before 24 ....

 

[kkugel]

Hey guys! Maybe anyone here has experience!
I'm trying to 3D print a 100mm 0.5 ID tube. I know it's possible to do this, but I can't get the resin out.
I use a 20ml Syringe with 0.45 and 0.75ID Needles to inject Isopropanol with pressure, but the resin never gets cleaned properly, even though the needle seals watertight. I use Siraya Build resin, which is fairly thin and my printer has no issues with details like this otherwise. Do I need a bigger ID needle or smaller diameter Syringe perhaps? No clue how to solve this at this point.

 

[Theodoric Paddlefoot]

Hey mate!
I'm by no means an expert, please keep that in mind.
From my experience, printed tubes tend to fail more and more the smaller your ID gets. Plus, if you're trying to do some kind of rollercoaster printings you might have to perfect every aspect of your settings.
Does it really have to be 0.5mm ID? Because if not, a little release on that pressure button will definitely get you there.