Home-Made IEMs
Aug 4, 2009 at 6:36 AM Post #137 of 15,989
Okay, I'm off schedule. I had to make a run out of state to handle some family business. Right now, the bottleneck is still the plastic housing. I have been contacted by someone who is willing to help me get a prototype put together, which could be very exciting. In the interim, I'm going to take some plastic off a hook at Walmart and feed it as many drivers as I can manage. I'd like to put together a quint, or five-driver setup. Hacking somebody's junk will at least give me what George Carlin called "a place for my stuff." I'm curious to see what five drivers can do, especially with different filters.
 
Aug 8, 2009 at 2:51 AM Post #139 of 15,989
I'm almost there. Finding a practical housing has been a pain, but I just got an idea. The PL-50 has an architecture that is so plain as to invite scrutiny. The housing is basically just a rectangular box. What matters is the connecting tube allowing that sound to empty into the ear canal. I've never heard the PL-50, but it's single-driver configuration has not inspired top reviews. It's lack of dedicated tweeters keeps it at the shallow end of the pool. But that basic approach, of using the housing as just that - housing - opens the door to very basic designs that would allow a quicker foray into a multi-driver configuration. I'm interested in finding a pillbox small enough to do the job. I'm going to fill that pillbox with drivers.
 
Aug 12, 2009 at 7:02 AM Post #142 of 15,989
This baby genius started making epoxy shells for his crappy dynamics, then moved on to making rubber casts so he could pour acrylic plastic. What he ended up with looked pretty good. Just scroll through the pics. The kid was on to something, and that was several years ago.
 
Aug 13, 2009 at 2:17 AM Post #143 of 15,989
P1230199.JPG


The UE Super.Fi 5 Pro uses a single capacitor in series with the high freq driver for its crossover. I have several more pictures available if anyone is interested.

The housing on this one crumbled near the socket for the replaceable cable.
 
Aug 13, 2009 at 3:25 AM Post #144 of 15,989
Rayko, that's an awesome pic. Keep 'em coming. I'm thrilled with your contribution to this ever-expanding dialogue. It's happening. Can you feel it? The day is coming when earphone users are going to have the same power as owners of loudspeaker systems. We can custom design the earphones ourselves. We don't have to be dependent upon the hype and mark-up of manufacturers - though it would be nice if Hammond started making shells for us.

By the way, this pic shows what they're doing with the crossover. Crossovers have two purposes: (1) to protect components, mainly tweeters; and (2) to sculpt the frequency bandwith going through each driver. As you can see here, the real purpose of this crossover is not to tailor the sound. It's to protect the tweeter. That's it. All the real tailoring is being done with $6 worth of filters which are color-coded. If the earpiece is designed so that the filters go into the sound outlet for easy replacement, you could have the filter equivalent of opamp rolling. You could have filter rolling. I've done this with experiments on drivers and it's an interesting experience changing the sound signature of your own earpiece. People could literally customize their earpieces to suit their own tastes.
 
Aug 13, 2009 at 8:11 AM Post #145 of 15,989
Epiphany: There's nothing fancy going on here with the caps. Caps are used, in loudspeaker crossovers, as high-pass filters. That's what's happening here. The caps are only being connected to the tweeters because they're being used primarily for tweeter protection. If there's a secondary purpose, it's the high-pass filter. There's no low-pass filter for the bass. That function is being carried out mechanically, with colored filters.
 
Aug 13, 2009 at 11:48 PM Post #149 of 15,989
Quote:

Originally Posted by Bilavideo /img/forum/go_quote.gif
I expect to have the first prototypes available for testing by August 1st.


Hey Bilavideo,
I was wondering if you had an update yet.... I didnt see anything about you saying you had it working?
I am getting ready to purchase the drivers. I have a set of SHURE E500 PTH I was wondering if the set you built sound ok, good, or WOW! ?
And what did you use to get the Negative impression mold? I have all the tools and impression kit for the "Positive" Ear Mold with the Gun just like the audiologist would do with the Ear dam and gun. I just cant seem to find the Silicon that Hardens in 10Min Via UV light.
If anyone knows what I'm talking about ANY HELP would be great on finding this stuff!!! Here is the link on you tube.
YouTube - how to make a hearing aid

Any thoughts? Ive tried to use normal silicon and after days of waiting it never harden...
 
Aug 14, 2009 at 6:45 PM Post #150 of 15,989
I built a triple that fits into an eartip. It sounds great but I want to take it further. I want to build a super six. Because of size, I can't do that with just a tip.

My bottleneck is the housing. A friend is working on cadding something. In the meantime, I made impressions of my ears with a home kit from Microsonic. I'm going to make a negative impression mold out of rubber/silicon and then use it as the mold for an acrylic resin. Working with plastics is not my specialty, so this is where I'm still groping a bit, but I think time is on our side. Another friend just sent out his old shells from when he went custom with his UM3X, so until I get the housing issue resolved, these plastic shells will make a workable platform for experiments with a super six.
 

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