Home-Made IEMs
- Thread starter Bilavideo
- Start date
Can someone please share where can I read about filters for knowles ba? A green one is mentioned in the post and I see a red and a white ones in my knowles now, but somehow can't find the infoknowles gv-32830 quad driver with shure se 535 diy shell, knowles green filter
Wasn't sure if I could trust the quality of drivers used with the iems from China on eBay so I decided to see if I could put together my own build with drivers sourced from Mouser.com. With the Westone star silicone tips they sound pretty good. Still burning in. So far sounding brighter and opening up. The highs sounded really muffled on initial listening session. I also removed the tape that covers the two vent holes on the drivers. Low end seems to have good extension but still doesn't have the impact/pressure that dynamic drivers have. Overall very simple build. Just wire up everything. Epoxy driver to the opening inside shell. Careful not to use too much epoxy. Excess can get into the driver opening. Making sure also to get good seal around edges where driver meets with opening to exit nozzle. Not bad for approx $150 in parts.
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Can you please share the link, I can't find it)
That’s just a pic from my phone. I don’t recall where I got it. It has as much info as you’re going to find elsewhere though
Thanks a lot!
You’re welcome. There’s more out there. Lots in here too, especially about stacking dampers
mattmatt
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Yes! Efficiency of is affected by position.
Quick zobel questions:
I see conflicting info from different sources, for the resistor should I consider 1.25x DC resistance , or 1.25x impedance at some relevant frequency? I guess its only a concern if you have a high pass filter on it, because the impedance is similar to DCR for most BAs at say 500 or 1000hz.
Better to round up than round down on the resistor if you have limited values or don't want to use multiple resistors?
The formula asks for inductance of driver,
just measure it with LCR meter, or is it some how more complicated?
Going to work on a single driver knowles SR31843 first, I'll post my results.
I see conflicting info from different sources, for the resistor should I consider 1.25x DC resistance , or 1.25x impedance at some relevant frequency? I guess its only a concern if you have a high pass filter on it, because the impedance is similar to DCR for most BAs at say 500 or 1000hz.
Better to round up than round down on the resistor if you have limited values or don't want to use multiple resistors?
The formula asks for inductance of driver,
just measure it with LCR meter, or is it some how more complicated?
Going to work on a single driver knowles SR31843 first, I'll post my results.
hey guys....
did anybody could manage to rebuild the BS6 with knowles DTEC???? which DTEC (30008, 31116,31985) would come close to the DTEC from Bellsing? since all?? Knowles DTEC´s are readily wired in series.... BS6 DTEC is wired parallel??
buy the way i friggin love my new black Dragonfly!!!!!
cheers Greg
did anybody could manage to rebuild the BS6 with knowles DTEC???? which DTEC (30008, 31116,31985) would come close to the DTEC from Bellsing? since all?? Knowles DTEC´s are readily wired in series.... BS6 DTEC is wired parallel??
buy the way i friggin love my new black Dragonfly!!!!!
cheers Greg
Went with 39ohm resistor and 4.7uf cap 10% tolerance, picked the smallest ones. My 10yr old $20 lcr meter is acting up so don't have exact value of the cap, but they are similar to each other.
Sr31843 zobel, not the best looking, but it works.
Now to mess with the acoustic tubing and dayton imm6. Will test a few things open back just to get a feel for the mid/upper frequencies, try to reduce peaks. The low end probably is what it is.
Sr31843 zobel, not the best looking, but it works.
Now to mess with the acoustic tubing and dayton imm6. Will test a few things open back just to get a feel for the mid/upper frequencies, try to reduce peaks. The low end probably is what it is.
dhruvmeena96
Headphoneus Supremus
we have to find the structure of impedance and inductance behaviour changes on BA for some reason
So I bought 4 sr31843 drivers, messing with the first pair I had a noticeable mismatch in freq response.
Wired up the other pair today with the same zobel circuit, measured all 4 and I had one oddball. Turns out, that is the one I used a lighter to heat shrink directly to it. After that, I was slipping the piece of tube on and off to measure various drivers.
Anyway, apparently you can tune these with heat (just hot enough to be a little uncomfortable to hold with your fingers.) It reduces the lows and also changed the peaks in the pinna gain area. Heres 3 graphs, ended up with two pretty well matched pairs by heating and matching the -1 and -2, the -3 and -4 are as they came (no heat) and the last graph is the same driver before and after heating it with a lighter.
I wouldn't recommend it, but I was already there with one of the drivers and wanted a matched pair so... Thought it was interesting enough to post the results.
One day I promise to learn how to use the spoiler feature.
Wired up the other pair today with the same zobel circuit, measured all 4 and I had one oddball. Turns out, that is the one I used a lighter to heat shrink directly to it. After that, I was slipping the piece of tube on and off to measure various drivers.
Anyway, apparently you can tune these with heat (just hot enough to be a little uncomfortable to hold with your fingers.) It reduces the lows and also changed the peaks in the pinna gain area. Heres 3 graphs, ended up with two pretty well matched pairs by heating and matching the -1 and -2, the -3 and -4 are as they came (no heat) and the last graph is the same driver before and after heating it with a lighter.
I wouldn't recommend it, but I was already there with one of the drivers and wanted a matched pair so... Thought it was interesting enough to post the results.
One day I promise to learn how to use the spoiler feature.
dhruvmeena96
Headphoneus Supremus
zobelSo I bought 4 sr31843 drivers, messing with the first pair I had a noticeable mismatch in freq response.
Wired up the other pair today with the same zobel circuit, measured all 4 and I had one oddball. Turns out, that is the one I used a lighter to heat shrink directly to it. After that, I was slipping the piece of tube on and off to measure various drivers.
Anyway, apparently you can tune these with heat (just hot enough to be a little uncomfortable to hold with your fingers.) It reduces the lows and also changed the peaks in the pinna gain area. Heres 3 graphs, ended up with two pretty well matched pairs by heating and matching the -1 and -2, the -3 and -4 are as they came (no heat) and the last graph is the same driver before and after heating it with a lighter.
I wouldn't recommend it, but I was already there with one of the drivers and wanted a matched pair so... Thought it was interesting enough to post the results.
One day I promise to learn how to use the spoiler feature.
6.76884606976uF
31.25 ohms
try this
plus dont heat the drivers, please dont
its not a good practice
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