[mattmatt]

Is my understanding with 64 Audios Volur correct? One driver pushing air at the backside/vent of another driver?

 

[Xymordos]

I haven't actually worked with an SWFK, only an e-audio clone. I posted about that set a while back (page 967) but can't really say if it was easier or not as that was my first real multi driver set and I had different goals for it. This time I wanted nice extension without harshness but seems like ESTs are still the better option, I definitely need to try those.

Hmm, it seems that the two drivers' resonance peaks are very different right?

 

[Raketen]

Is my understanding with 64 Audios Volur correct? One driver pushing air at the backside/vent of another driver?

Looks like it, yeah, in a closed volume- AFAIK this is sometimes used in speaker designs (especially for subwoofers- suggest searching for isobaric subwoofer info). Also it looks like a similar concept to those old Audio Technica IEMs with 'push pull' drivers, except Volur looks to have diaphragms facing in the same direction.

From what I gather it effectively allows a given driver in a given enclosure space to behave more as if it were in free air (or rather, a larger speaker enclosure with a greater 'volume acoustic suspension'?).

 

[Smirk 24]

Hi everyone,

Newbie here. I wanted to ask the common methodologies of making custom shells and maybe some pros/cons of each.

I was told that 3D printing resin was one method, and injection mold is another and I’m curious if there are more.

 

[dhruvmeena96]

Finally had time to finish another set. 2x huayunxin CN10, 2389D and RAU.

Time to raid your home and steal those iems

 

[Smirk 24]

Finally had time to finish another set. 2x huayunxin CN10, 2389D and RAU.

These look so good! I saw your post on Reddit. Did you 3D print the shells, or what was your process? I'm trying to start creating new UIEM shells and I like how yours turned out.

 

[slakoth453]

These look so good! I saw your post on Reddit. Did you 3D print the shells, or what was your process? I'm trying to start creating new UIEM shells and I like how yours turned out.

Thanks! Yep, these are 3d printed.

 

[Smirk 24]

Thanks! Yep, these are 3d printed.

Thanks! Newbie question: how do you get the drivers/components inside to stay in place and not move around/rattle?

 

[PeaksZA]

I think Amplisound sell drivers in single units, instead of a pair like Soundlink, which would be why some things are half price. I’ve purchased stuff from them in the past and it came in a Soundlink branded box.

Another disaster prevented by the Home-Made IEMs forum, thank you! ended up ordering A set of GK's and RAB's from sound-link. Have FDM printed shells that I coated in UV nail gel that i'm going to install them in.

 

[slakoth453]

Thanks! Newbie question: how do you get the drivers/components inside to stay in place and not move around/rattle?

Just use some glue, the uv resin works well but you need to be careful with vented drivers. In this case I felt like the tubes were enough to hold the BAs in place but I glued the DD module down with resin. I use bondic glue to attach the tubes to the drivers and also to make sure the crossover components are held in place, otherwise you might hear a "springy" sound from the components moving every time something touches the IEMs when you listen to them. A custom pcb is a better way to do it but not great for prototyping.

 

[mckpaul]

So I have all the parts and pieces to build the piotrus-g scary crossover build. I'm going to use size 1206 SMDs. I found some thin pcb material, it's been years since I etched a pcb, and even thin it was a crude regular sized board, nothing as small a this is going to be. In the pic below you'll see a couple of small pcbs that look all nice and neat. In real life those nice looking copper traces will be tiny blobs of fine point sharpie, but hopefully I can get them in the right place in a manor that they at least work.

On this build, I know the TWFK and the CI's are wired in reverse polarity wiring wise, but based on the description on the Knowles cutsheets about increase or decrease in pressure at the sound outlet based on a positive going voltage, I understand they are actually in phase with each other in terms of increase in pressure based on the the voltage.

Sorry, I know this picture is going to show my nerd a little bit, but I'm an AutoCAD guy and have a tendency to draw things up prior to building to find issues ahead of time and make projects go smoother.

In the picture the dashed lines on the PCBs are the board edges, the shaded areas are unetched copper. Resistors are blue, caps are brown, wiring is red for positive, green for negative. Everything is scaled correctly in size in terms of comparison to items in the pic.

I'm also going to repost piotrus-g's schematic found earlier in this thread for comparison. If some of you get a chance to give it a quick look over, please look at he electrical path of my wiring and pcb layout to make sure it electrically matches the schematic. I think it does, but I've looked at it so much now my brain may be just seeing it as correct. A fresh set of eyes may see something I'm overlooking.

By the way, the large circuit board will be stuck to the top of the stacked CIs, the small circuit board will be stuck to the side of the TWFK. Haven't decided to attach them. I found double sided tape on some drivers from some Westone ears, I assume a small drop of glue or hot glue would probably work.

 

[piotrus-g]

So I have all the parts and pieces to build the piotrus-g scary crossover build. I'm going to use size 1206 SMDs. I found some thin pcb material, it's been years since I etched a pcb, and even thin it was a crude regular sized board, nothing as small a this is going to be. In the pic below you'll see a couple of small pcbs that look all nice and neat. In real life those nice looking copper traces will be tiny blobs of fine point sharpie, but hopefully I can get them in the right place in a manor that they at least work.

On this build, I know the TWFK and the CI's are wired in reverse polarity wiring wise, but based on the description on the Knowles cutsheets about increase or decrease in pressure at the sound outlet based on a positive going voltage, I understand they are actually in phase with each other in terms of increase in pressure based on the the voltage.

Sorry, I know this picture is going to show my nerd a little bit, but I'm an AutoCAD guy and have a tendency to draw things up prior to building to find issues ahead of time and make projects go smoother.

In the picture the dashed lines on the PCBs are the board edges, the shaded areas are unetched copper. Resistors are blue, caps are brown, wiring is red for positive, green for negative. Everything is scaled correctly in size in terms of comparison to items in the pic.

I'm also going to repost piotrus-g's schematic found earlier in this thread for comparison. If some of you get a chance to give it a quick look over, please look at he electrical path of my wiring and pcb layout to make sure it electrically matches the schematic. I think it does, but I've looked at it so much now my brain may be just seeing it as correct. A fresh set of eyes may see something I'm overlooking.

By the way, the large circuit board will be stuck to the top of the stacked CIs, the small circuit board will be stuck to the side of the TWFK. Haven't decided to attach them. I found double sided tape on some drivers from some Westone ears, I assume a small drop of glue or hot glue would probably work.

Looks Good
One thing I might suggest look into wiring negative wires for all the speakers directly to the sockets rather than the pad you chosen on the PCB, I know in theory it looks correct but in practice I think your low pass will takeover that negative leg and suck out power from all the other drivers, effectively lowpassing the whole thing.

 

[mckpaul]

I see what you're saying. That makes sense, and easy enough to route those to the connector during the build. I appreciate the input!

 

[swtnate]

So I have all the parts and pieces to build the piotrus-g scary crossover build. I'm going to use size 1206 SMDs. I found some thin pcb material, it's been years since I etched a pcb, and even thin it was a crude regular sized board, nothing as small a this is going to be. In the pic below you'll see a couple of small pcbs that look all nice and neat. In real life those nice looking copper traces will be tiny blobs of fine point sharpie, but hopefully I can get them in the right place in a manor that they at least work.

On this build, I know the TWFK and the CI's are wired in reverse polarity wiring wise, but based on the description on the Knowles cutsheets about increase or decrease in pressure at the sound outlet based on a positive going voltage, I understand they are actually in phase with each other in terms of increase in pressure based on the the voltage.

Sorry, I know this picture is going to show my nerd a little bit, but I'm an AutoCAD guy and have a tendency to draw things up prior to building to find issues ahead of time and make projects go smoother.

In the picture the dashed lines on the PCBs are the board edges, the shaded areas are unetched copper. Resistors are blue, caps are brown, wiring is red for positive, green for negative. Everything is scaled correctly in size in terms of comparison to items in the pic.

I'm also going to repost piotrus-g's schematic found earlier in this thread for comparison. If some of you get a chance to give it a quick look over, please look at he electrical path of my wiring and pcb layout to make sure it electrically matches the schematic. I think it does, but I've looked at it so much now my brain may be just seeing it as correct. A fresh set of eyes may see something I'm overlooking.

By the way, the large circuit board will be stuck to the top of the stacked CIs, the small circuit board will be stuck to the side of the TWFK. Haven't decided to attach them. I found double sided tape on some drivers from some Westone ears, I assume a small drop of glue or hot glue would probably work.

I had a REALLY difficult time getting solid copper connections on personally etched boards. I found it best to proto then, or in this case, just order the boards already etched. Good luck though!! Let us know how it turns out.

 

[mckpaul]

Yeah I don't know what to expect. I found some copper clad board on Amazon, but even the thinnest I could find was still about 1.5mm thick, way overkill. I ran across an ebay seller that had some old stock thin PCB. It was about 8 1/2 x 11 inches and is pretty flexible. I measured the thickness but don't remember the exact measurement (at work now). I hoped to make any pads where wire landed as big as possible, but 'big' is an oxymoron word working on such a tiny board. Before getting the thin board, I did a tiny test board from the 1.5mm stuff with some random extra fine tip Sharpie marks. It etched clean and the copper looked where I cleaned off the Sharpie, but didn't try to solder to it. I'll have to go home and buff it up with a tiny piece of steel wool and see how it solders to some wire. And also experiment with some of the thinner board.

I recently transferred a set of drivers from some Westone UM Pro 30s to some custom shells. There's a small crossover board in those but I found it's very easy to pull the litz wire off the board along with the copper trace just handling the driver trying to get the audio output tube pushed through the hole in the shell.

I will definitely report back on how building the crossovers goes.