Home-Made IEMs
Feb 11, 2022 at 9:46 AM Post #13,666 of 14,305

mckpaul

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Still leaning toward the GV-32830 quad driver, but I'm finding conflicting information. The sources that sell it (Soundlink, Aliexpress, Digikey etc) all say in the description that it is a quad driver with a 3-way crossover, but looking at the pics and the spec sheet, no crossover is mentioned, and no apparent crossover circuit is visible, at least not in the form of small miniature circuit board like you sometimes see on multi driver setups.

However, looking at the pics I found on Aliexpress...
1644605385788.jpeg
the high frequency drivers look like they may have a couple of surface mount devices attached directly to the solder pads on the drivers.

Does anyone have experience with this driver? If so, do they have any kind of built in crossover components? The way sellers (Soundlink in particular) advertise it, they imply you only need to add dampers.
 
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Feb 11, 2022 at 3:21 PM Post #13,667 of 14,305

swtnate

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Still leaning toward the GV-32830 quad driver, but I'm finding conflicting information. The sources that sell it (Soundlink, Aliexpress, Digikey etc) all say in the description that it is a quad driver with a 3-way crossover, but looking at the pics and the spec sheet, no crossover is mentioned, and no apparent crossover circuit is visible, at least not in the form of small miniature circuit board like you sometimes see on multi driver setups.

However, looking at the pics I found on Aliexpress...1644605385788.jpeg the high frequency drivers look like they may have a couple of surface mount devices attached directly to the solder pads on the drivers.

Does anyone have experience with this driver? If so, do they have any kind of built in crossover components? The way sellers (Soundlink in particular) advertise it, they imply you only need to add dampers.
Yes. The cross is built in.
 
Feb 11, 2022 at 3:54 PM Post #13,668 of 14,305

mckpaul

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Installing 2 GV’s per side would have no frequency response benefit. However, it will increase your headroom and allow for the drivers to be pushed harder without distorting. GV has a great bass response registering down to 20Hz. It leans darker in tonality. So, if high end extension is important to you, you may want to look for another configuration.
I may not do this as the realized advantage probably won't offset the expense, but earlier I asked about running two GV's per side. Since then I did some research on the minimum headphone impedance of my Shure body pack which is 16 ohms.

I have a set of Westone UM Pro30's (three drivers) that is 56 ohms 124dB SPL
I have a set of Westone UM Pro50's (five drivers) that is 45 ohms 115dB SPL (which as expected, all settings the same when listening and comparing, are not quite as loud)

The GV's impedance is 28 ohms, so if I did in fact run two in parallel, I assume the impedance would be half, so 14 ohms. They are rated at 116dB SPL

So 14 ohms would be a touch lower than the Shure body pack wants to see, and the battery would also not last as long, so, parallel is not a good option.
I could go series on a pair of GV's, I assume would put make the impedance 56 ohms.

Any thoughts on how running series would affect the overall output and sound? Seems like running in series each one wouldn't be working as hard.
 
Feb 12, 2022 at 12:03 AM Post #13,669 of 14,305

swtnate

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I may not do this as the realized advantage probably won't offset the expense, but earlier I asked about running two GV's per side. Since then I did some research on the minimum headphone impedance of my Shure body pack which is 16 ohms.

I have a set of Westone UM Pro30's (three drivers) that is 56 ohms 124dB SPL
I have a set of Westone UM Pro50's (five drivers) that is 45 ohms 115dB SPL (which as expected, all settings the same when listening and comparing, are not quite as loud)

The GV's impedance is 28 ohms, so if I did in fact run two in parallel, I assume the impedance would be half, so 14 ohms. They are rated at 116dB SPL

So 14 ohms would be a touch lower than the Shure body pack wants to see, and the battery would also not last as long, so, parallel is not a good option.
I could go series on a pair of GV's, I assume would put make the impedance 56 ohms.

Any thoughts on how running series would affect the overall output and sound? Seems like running in series each one wouldn't be working as hard.
Impedance with balanced armatures will fluctuate tremendously. So, its not as neat and tidy of a conclusion for you to draw. Its also important to note that the impedance at which the drivers is tested will undoubtedly be different than that which they are played through. Ifi makes a great product that matches insures consistent impedance across all devices and sources. So, you could look into that. Headfi rules prohibit marketing products outright on boards, for obvious reasons. Long of the short, you could run 2 in parallel per ear without much of an issue.
 
Feb 12, 2022 at 10:39 AM Post #13,670 of 14,305

mckpaul

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All good to know. My impedance thought process comes from 25+ years spent working in the commercial low voltage world, installing intercom, local sound reinforcement, fire alarm etc. Dealing with 25 & 70 volt speakers (8 ohm speakers with transformers with multi-wattage taps), reading impedance is pretty accurate, reading different tap settings on one speaker or overall load on groups of speakers. But I fully understand, large (in comparison to balanced armature drivers) wire wound transformers and large 8 ohm speakers can probably more easily be manufactured to produce consistent reading results. And IEM drivers are a completely different animal. Similar concept of measurement, but complete different theory of operation on a WAY smaller scale. So it makes sense the impedance on drivers would vary.

Learning as we go here.... thanks for the input!
 
Feb 12, 2022 at 1:36 PM Post #13,671 of 14,305

swtnate

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All good to know. My impedance thought process comes from 25+ years spent working in the commercial low voltage world, installing intercom, local sound reinforcement, fire alarm etc. Dealing with 25 & 70 volt speakers (8 ohm speakers with transformers with multi-wattage taps), reading impedance is pretty accurate, reading different tap settings on one speaker or overall load on groups of speakers. But I fully understand, large (in comparison to balanced armature drivers) wire wound transformers and large 8 ohm speakers can probably more easily be manufactured to produce consistent reading results. And IEM drivers are a completely different animal. Similar concept of measurement, but complete different theory of operation on a WAY smaller scale. So it makes sense the impedance on drivers would vary.

Learning as we go here.... thanks for the input!
Along with the frequency response charts that knowles has available, look at the data/ sales sheet for the impedance plot chart.
 
Feb 12, 2022 at 2:27 PM Post #13,672 of 14,305

Wgibson

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@mckpaul You can calculate the smallest db reduction lpad, like 2db. It will give you a small series resistor and big parallel resistor. 2 birds one stone, can add a little resistance to make sources happier, and it limits the impedance rise. Nowhere near as flat as a zobel circuit, but it helps a lot to limit impedance spikes. An option if you go 2 GV in parallel.

You might consider a Raf or rab in parallel with the GV, something full range.
 
Feb 13, 2022 at 4:52 AM Post #13,673 of 14,305

dhruvmeena96

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@mckpaul You can calculate the smallest db reduction lpad, like 2db. It will give you a small series resistor and big parallel resistor. 2 birds one stone, can add a little resistance to make sources happier, and it limits the impedance rise. Nowhere near as flat as a zobel circuit, but it helps a lot to limit impedance spikes. An option if you go 2 GV in parallel.

You might consider a Raf or rab in parallel with the GV, something full range.
in BA, Lpad kinda affects the FR
 
Feb 14, 2022 at 4:16 AM Post #13,675 of 14,305

seckarales

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Still leaning toward the GV-32830 quad driver, but I'm finding conflicting information. The sources that sell it (Soundlink, Aliexpress, Digikey etc) all say in the description that it is a quad driver with a 3-way crossover, but looking at the pics and the spec sheet, no crossover is mentioned, and no apparent crossover circuit is visible, at least not in the form of small miniature circuit board like you sometimes see on multi driver setups.

However, looking at the pics I found on Aliexpress...1644605385788.jpeg the high frequency drivers look like they may have a couple of surface mount devices attached directly to the solder pads on the drivers.

Does anyone have experience with this driver? If so, do they have any kind of built in crossover components? The way sellers (Soundlink in particular) advertise it, they imply you only need to add dampers.
I have built 5 pairs with same driver - GV-32830, and all had after some time problem with loss of bass! Better go for other solution. Anyone else had same problems?
 
Feb 14, 2022 at 8:59 AM Post #13,676 of 14,305

mckpaul

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You'd have to do some measuring and adjusting, yeah. Dayton imm6 is cheap and can get the job done.
Wow that's kind of cool. So if I understand, once it's set up and connected and running, I'm assuming the app generates a pink noise to send out the headphone output to the monitor, then uses the mic to listen to the monitor to compare it's output to the generated signal to create the graph?

I found a video of someone that had put a piece of tubing on the mic port to allow connecting it to an earbud output. For the purpose of building in ear monitors, I suppose for an accurate graph, what you'd need to attach to the mic is a complete unit, drivers in shell and shell sealed. It seems directly coupling just a bare driver to the mic would give you a graph for the driver, but how much does it change once it's enclosed and sealed in a shell?
 
Feb 14, 2022 at 9:06 AM Post #13,677 of 14,305

mckpaul

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I have built 5 pairs with same driver - GV-32830, and all had after some time problem with loss of bass! Better go for other solution. Anyone else had same problems?
I have not heard of that problem. I did an number of searches on this thread for that driver and didn't see complaints. On your 5 pairs, did you leave the ports closed or open them? Of course I have no idea if one way of the other could remotely cause this, just curious. Hopefully others who have used this driver will chime in.
 
Feb 14, 2022 at 6:07 PM Post #13,678 of 14,305

swtnate

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I have not heard of that problem. I did an number of searches on this thread for that driver and didn't see complaints. On your 5 pairs, did you leave the ports closed or open them? Of course I have no idea if one way of the other could remotely cause this, just curious. Hopefully others who have used this driver will chime in.
It sounds like the adhesive used to attach the tubing was not 100% and had a leak somewhere. Especially if it happened overtime. Also, I had NOTHING but problems attaching the soundlink tubing to drivers. It seems to not be totally pvc.
 
Feb 14, 2022 at 6:20 PM Post #13,679 of 14,305

musmecca

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I have built 5 pairs with same driver - GV-32830, and all had after some time problem with loss of bass! Better go for other solution. Anyone else had same problems?
I think others may have alluded to this, but it is 95% of the time a adhesive problem. If it sounds great, then once you start wearing it, you loose bass over time it is down to several culprits and they are adhesive based. 1) Make sure you use good adhesive on the BA to tube connection. I test mine by putting a long piece of tubing into a foam insert then putting the foam insert into my ear...I use the end of the tube like a stethoscope and run it over my tube connections WHILE i am playing a signal through the BA. If there is a sound leak, you will hear it. Fill that leak up and check your work. If you don't have good connections and don't secure your BA's to the shell, they can vibrate loose over time. You will hear a "burp" or "fart" sound from your earpiece on occasion indicating this has happened. 2. Sometimes the faceplate will be bent when you apply pressure to stick it to the shell. Once dry, it will gap open...check the EDGE of your earpiece as these can open and reduce bass significantly. 3 Secure your components as well as your sockets...check they they don't move. Simple!
 
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Feb 15, 2022 at 10:45 AM Post #13,680 of 14,305

GeneBush

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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?
Try some of the 2 component silicones at trollfactory. This is a German Company. It did great for me, bubble free and the mold remains the same. You must try new curing times cause it isn't totally clear.
 

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