Rode PodMic USB's are FAILING!

[EEVblog]

Rode PodMic USB's are FAILING, and it happened to mine. Does your Rode PodMic USB sound like crap?

Doug Ford microphone design series: https://www.youtube.com/playlist?list=PLvOlSehNtuHv98KUcud260yJBRQngBKiw

[Bud]

I could not hear any difference between the two .

[TUMEMBER]

There's definitely a difference, a "voice through the pillow," as if tones above 3 kHz were cut off, and the low frequencies were very muffled. There's a lack of background noise (reverberations, environmental reflections), which makes it difficult to orient yourself in the "acoustic space." You hear a concert hall differently, a small room differently, or a vast park differently. These reflections are interpreted by the brain and provide an "image" of the texture of the floor and walls. But there, it's a "voice through the pipe."

[golden_labels]

Compared to the other mic, there is a dip at 2 kHz and near 7 kHz, and also everything below about 300 Hz seems to be low-pass filtered. The latter must be why voice lacks substance. Why the dips and why are they so weirdly specific — no ideas.

[EEVblog]

Teardown:

[TUMEMBER]

I ruined it for you...you blew me away with those pliers as an open-end wrench. Completely advanced "expertise in selecting the right tool for the right application."

I assume you have a frequency generator... you could have done a "frequency response characteristic of the device." Now that's "tarred ass." "Unacceptable user interference with the internal structure of the device." I wouldn't accept the complaint. Sorry, but "tinkering with the breeder reactor" is not included in the "permissible range of end-user interference."

[golden_labels]

Dave, if anything, this video will help others disassemble their mics.

My guess about the spring is that at the end of the hole there is some part that may rattle. A weight perhaps? Or maybe it’s to add tension to the entire case? So the entire cylinder, after sliding into the tube, is held firmly (but softly) also in the diagonal direction? After all the construction is to some degree flexible and will have some response in audio range.

If Rode replies that it’s your fault, because you moved “the tuning screw,” we will know!

I ruined it for you...you blew me away with those pliers as an open-end wrench. Completely advanced "expertise in selecting the right tool for the right application."

That line stopped right at the moment it was about to tell us which tool is better suited for the task.

I assume you have a frequency generator... you could have done a "frequency response characteristic of the device." Now that's "tarred ass." "Unacceptable user interference with the internal structure of the device." I wouldn't accept the complaint. Sorry, but "tinkering with the breeder reactor" is not included in the "permissible range of end-user interference."

A very rough description is already given in the preceding post.

From that alone we may make a reasonable guess it’s not just a simple low-pass or high-pass filtering. So what would feeding a chirp help with? The mic also goes to the manufacturer, without any attempts to fix it, so that knowledge would not be too useful even if we gained it somehow from the response chart.

A frequency generator isn’t needed either, if it’s going to be fed through speakers. Frequency sweep can be just played from a file. 20 – 20 kHz chirp in attachment, if you wish to characterize your microphone, Tumember. But I swear… good luck making any conclusions about how impedances in the speakers, microphone, and amplifiers create that response from the chart alone.

[EEVblog]

I could not hear any difference between the two .

Wow, what speakers are you using?

[EEVblog]

Repair request sent to Rode under warranty with a link to the test video, will see what happens.

[TUMEMBER]

Dave, if anything, this video will help others disassemble their mics.

My guess about the spring is that at the end of the hole there is some part that may rattle. A weight perhaps? Or maybe it’s to add tension to the entire case? So the entire cylinder, after sliding into the tube, is held firmly (but softly) also in the diagonal direction? After all the construction is to some degree flexible and will have some response in audio range.

If Rode replies that it’s your fault, because you moved “the tuning screw,” we will know!

I ruined it for you...you blew me away with those pliers as an open-end wrench. Completely advanced "expertise in selecting the right tool for the right application."

That line stopped right at the moment it was about to tell us which tool is better suited for the task.

I assume you have a frequency generator... you could have done a "frequency response characteristic of the device." Now that's "tarred ass." "Unacceptable user interference with the internal structure of the device." I wouldn't accept the complaint. Sorry, but "tinkering with the breeder reactor" is not included in the "permissible range of end-user interference."

But I swear… good luck making any conclusions about how impedances in the speakers, microphone, and amplifiers create that response from the chart alone.

An external amplifier and speakers are not necessary. All you need is a good laptop's internal sound card, two programs, good-quality in-ear headphones, and a "cardboard tube" to acoustically couple the microphone and one earphone. Do you know how "mechanical sound calibrators" work? Yes, sealing is necessary to generate the appropriate sound pressure level and "isolate from external interference." Speakers/loudspeakers are a mistake; they create reflections and secondary reverberations that reach the microphone and distort the results if you don't have all the equipment installed in an "appropriately rated measurement chamber."
To exele z wynikami mojej karty dźwiękowej i mojego mikrofonu UMIK2. Czy masz jakiekolwiek problemy w interpretacji wykresów odchylenia podanych w dB ?
This is an Excel spreadsheet with the results from my sound card and my UMIK2 microphone. Are you having any trouble interpreting the dB deviation graphs?
Both programs are free and probably still available.

[SeanB]

I could not hear any difference between the two .

Wow, what speakers are you using?

No highs, no lows, must be using Bose.

Or is using the headset from a very old telephone, with the blistering 300Hz to 2.4kHz frequency response, and with again flatness across the band of around 20dB.

[bitwelder]

I guess no difference in mic behaviour after the teardown?

[Agent24]

I could not hear any difference between the two .

You might need a hearing test...!

[thm_w]

Dave, if anything, this video will help others disassemble their mics.

Simpler one already existed, I don't blame dave for not looking I'd do the same.

youtube.com/watch?v=Fz9Ytkh55Hs

My guess about the spring is that at the end of the hole there is some part that may rattle. A weight perhaps? Or maybe it’s to add tension to the entire case? So the entire cylinder, after sliding into the tube, is held firmly (but softly) also in the diagonal direction? After all the construction is to some degree flexible and will have some response in audio range.

XLR to case earth connection, as the inner module is suspended via rubber you need a spring or flexible wire.

[EEVblog]

Magic!
Was it the percussive maintenance?

[floobydust]

A common dynamic mic capsule fail is a metal chip getting in the mic element air-gap.
A steel chip sticks to the magnet. Aluminum moves around and can sound distorted, gritty, scratchy.
I'm not sure about the vent on the backside of this mic element, that is where a chip could get in there. Manufacturing/assembly has to be spotless and leave no metal chips in the housing, despite all the machined parts. And no solder balls either.

This also happens with loudspeakers, only way to get the chip(s) out of the gap is using masking tape and stuffing that in there until the metal chip sticks to it. An old trick I learned.
 
A common condenser mic large capsule fail is spit shorting out the element lol. Dries out and it mysteriously works again.

Originally the mic sounded like no low frequency response, like a failed/cracked capacitor but very weak output would point to the diaphragm jamming or electronics having an issue.

I think the screw with spring is to provide an electrical ground connection for the housing, so it doesn't pick up hum etc.

[golden_labels]

More evidence of devices fearing repairs! The situation reminds me of mother’s hairdryer. It’s an old thing, Soviet era, and she sometimes asks me to fix it, because it no longer turns on. I come, flip the switch, it starts working perfectly fine.

I could not hear any difference between the two .

Wow, what speakers are you using?

No highs, no lows, must be using Bose.

Or is using the headset from a very old telephone, with the blistering 300Hz to 2.4kHz frequency response, and with again flatness across the band of around 20dB.

I could not hear any difference between the two .

You might need a hearing test...!

There is a much simpler explanation. What video and sound quality you get depends on what the algorithm selects for you. You may receive audio limited to less than 10 kHz.

That doesn’t explain the lower part missing, but also mind many people listen on laptop or smartphone speakers, sometimes in noisy environments.

[EEVblog]

Rode support contacted me and said they'll take care of it under warranty.

[Bud]

I could not hear any difference between the two .

Wow, what speakers are you using?

My Samsung tablet! 

[Bud]

I could not hear any difference between the two .

You might need a hearing test...!

On a positive side, I'd make a good Rode customer, 'cause I would not complain 

[Dr Bob]

Dave, A dynamic microphone is very similar to a common loudspeaker as it's a membrane connected to a coil of wire suspended in a magnetic gap. A condenser mic is a variable capacitor with a membrane being one plate which will need a preamp to get a signal large enough to push through some wire. The configuration (on the side(s) or front) is just to create certain pickup patterns, it's not indicative of the type of element. There are also piezo pickups, crystal pickups, ribbon mics, etc.

If there's a load of debris in the magnetic gap of your mic, that will short out the magnetic field (reduce output) and limit the freedom of movement of the membrane. The fix is to replace the element as they are very fiddly to take apart and reassembly is not likely without special alignment tools. I expect that Rode will just replace guts as that's going to be less expensive than paying a tech to do any component level troubleshooting.