Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- MicBuilders
- Messages
Search
|
Re: short pickup range options
Le 12/01/2025 à 09:40, Johan Vandermaelen via groups.io a écrit?:
?In live radio, they sometimes opt for a dynamic mic and going very close to the sound source.In this case, the nature of the transducer (dynamic, electret or condenser) does not make a difference. It's only the distance that matters. Putting the mic as close as possible to the source increases the level of desired sound, when parasitic sounds are identical, so it increases the Wanted-Signal-to-Unwanted-Signal ratio. You miss out some details and the frequency range is rather limited, but it's a way to lift ou your subject out of it's environmentDynamic microphones have an undeserved reputation for being less sensitive to ambiant sounds or feedback, when they only attenuate high frequencies. Actually most condenser mics have a better directivity control than dynamics. |
|
Re: Freshwater Soundscapes...
Hi Johan
Many thanks for your advice.?
I have a modest question. I own a Shadow (12mm). It sounds quite nice. Even on a classical guitars. Would it be possible to turn this pickup into a (small) hydrophone. I'm just wondering.
?
Btw: I didn't forgot that you might be interested in a HM-200 (#36096). But sadly I didn't came across another one yet.
?
On Fri, Jan 10, 2025 at 08:20 PM, Johan Vandermaelen wrote:
I have built electret hydrophones in the past. They have serious limitations. Noise/sensitivity is one. Another is the huge change in pressure on the (protected) membrane when passing from air to water. It asks for care to release this pressure. Condens is one more concern. In general, except for experimentation I wouldn't advise to use electret for hydrophones. |
|
Re: short pickup range options
sorry, I see I misunderstood your question. As Jerry Lee Marcel says it's difficult. The microphone is not intelligent to make an interpretation of the distance. In live radio, they sometimes opt for a dynamic mic and going very close to the sound source. You miss out some details and the frequency range is rather limited, but it's a way to lift ou your subject out of it's environment |
|
Re: short pickup range options
开云体育"Short pick-up range" does not exist. Le 12/01/2025 à 09:08, cx b via
groups.io a écrit?:
|
|
Re: short pickup range options
Hello,
?
Your message sounds a bit like a contradiction to me. The best lows you will get from an omnidirectional capsule are often way lower than what we hear. On the upper range, most go into ultrasonics. This topic is a recent treat.
If you want a more directional response you will have to sacrifice the lows. Pressure gradient microphones have a roll-off in their lows. Can you be more precise in your question? |
|
Re: Freshwater Soundscapes...
I have built electret hydrophones in the past. They have serious limitations. Noise/sensitivity is one. Another is the huge change in pressure on the (protected) membrane when passing from air to water. It asks for care to release this pressure. Condens is one more concern. In general, except for experimentation I wouldn't advise to use electret for hydrophones. |
|
Re: Freshwater Soundscapes...
Thanks, Jules! I'm sure Gladys will work well in ponds. Don't you have a pond nearby? Please dipp one of your Gladys in and tell us how it sounds. Maybe you'll discover something interesting. That would be fun! I'll definitely consider Gladys. But I must admit that I'm also intrigued by Zach Poff's relatively simple DIY method. And that I'm thinking about sacrificing an AOM-5024 for a test. Many thanks! Am Do., 9. Jan. 2025 um 21:20?Uhr schrieb Jules Ryckebusch via <ryckebusch=gmail.com@groups.io>:
|
|
Re: Freshwater Soundscapes...
Heinz, these will work fine in a pond. They are designed?almost identical to a NOAA paper on them and, like Naval Hydrophones. I have not measured the sensitivity but they are very low noise as well. Far better than encasing an electret microphone capsule.? Jules On Wed, Jan 8, 2025 at 11:54?PM Heinz via <heinz.hartfiel=gmail.com@groups.io> wrote:
--
Best Regards, Jules Ryckebusch 214 399 0931 |
|
Re: Freshwater Soundscapes...
Digging a little deeper, I found that the hydrophones that David Rothenberg uses for his pond recordings were originally invented and built by Zach Poff. When it comes to hydrophones,? on his website. It seems that he also used low-noise electret capsules in his . Which puzzled me a bit. Does this mean that an AOM-5024L might work underwater? I still have two left. :-) Is it really necessary to modify the front case of the capsule to allow more contact between the silicone and the diaphragm? I have a lot of respect for this step because I'm afraid of damaging the capsule. |
|
Re: Freshwater Soundscapes...
Hi Jules First of all, thank you for your post and the instructions you put together to build these amazing Gladys hydrophones. Your humpback whale recording on YouTube is fantastic! Did you ever checked how your hydrophone?performs in ponds? I'm asking because David Rothenburg mentioned in the ?that he heard almost nothing when he used a hydrophone that was made for whale?recordings inside ponds. It seems that he used a special and very sensitive hydrophone for his pond recordings instead. To record sounds that are only a few meters away? A hydrophone that even picks up sounds from nearby underwater creatures and plants? I'm looking forward to experimenting! Heinz Am Mi., 8. Jan. 2025 um 22:53?Uhr schrieb Jules Ryckebusch via <ryckebusch=gmail.com@groups.io>:
|
|
Re: Freshwater Soundscapes...
Yes! these:?? they work really well and I have gotten great sounds with them as have several renown field?recording people. Jules On Wed, Jan 8, 2025 at 7:48?AM Heinz via <heinz.hartfiel=gmail.com@groups.io> wrote:
--
Best Regards, Jules Ryckebusch 214 399 0931 |
|
Re: Learning more - Ultrasonic Microphone building
On Tue, Jan 7, 2025 at 08:05 PM, Ivano Pelicella wrote:
.... Unfortunately, I have personally found through experimental testing that datasheets often report completely invented data, especially in the ultrasonic range.?I did wonder about that with the curves published on the Knowles app. notes I found for the SPU1410 (see here: ) The noise response follows the signal frequency response curve farily closely , so recording the noise from the mic (in as quiet an environment as I could find!) should produce a noise file that follows the same response curve. .... which it does!
So in this case it's possible to apply corrective EQ fairly acurately -- I prepared a script to do that in my DAW (Adobe Audition) and that allows for the recordings made on my Zoom F3 to have fairly accurate frequency resposne correction made up to around 75KHz.? Above that, the F3 frequency itself response tends to be a bit erratic!
I'm hoping the next generation of field recorders - using the 32 bit float file format - will enable the higher sampling rates available from the latest A/D converters to be enabled?? |
|
Re: Learning more - Ultrasonic Microphone building
In the ultrasonic field, the biggest problem is having a reference system. For my tests, I bought a B&K 4138 with a 2669 preamplifier and a NEXUS 2690 amplifier with the 140kHz extension. This system allows me to have a reference microphone with a flat frequency response up to 140kHz.? Lately, I have been using PureData (https://puredata.info/), a software originally developed for audio that I use to create a linear emission system with a frequency response up to 140kHz. With PureData, I generate frequencies in 10Hz steps from 100Hz up to 140kHz, adjusting the amplification level and loudspeakers to achieve a flat frequency response.? After calibrating the system with PureData, I can perform frequency responses for microphones and sensors over this wide frequency range. Unfortunately, I have personally found through experimental testing that datasheets often report completely invented data, especially in the ultrasonic range.? Another big problem are the ADCs. The ones used for audio have anti-aliasing filters that generate a nonlinear response at high frequencies. For this reason, the Ultramic uses a pure ADC without filters. The Ultramic384K EVO features a dual MEMS, and the WIND and BLE versions have an FG-23629.? MEMS do not have a linear response but are very sensitive, whereas the FG has a much more linear response. Other commercial sensors, like the PRIMO EM272, can reach high frequencies, but connecting these sensors to an audio acquisition system is not a good choice. Ivano |
|
Re: Learning more - Ultrasonic Microphone building
Thanks for the detailed information, Arjay1949. You made it absolutely clear why it is not so easy if not impossible to record ultrasonic sounds above 100 kHz in good quality on a limited budget.
I find Dodotronic's approach interesting despite the existing device limitations (USB 2.0/UAC1.1). Shouldn't current USB interfaces (USB3.2/USB4) theoretically be able to handle 32bit/768kHz if the USB microphone supports it?
?
On Tue, Jan 7, 2025 at 09:18 PM, Arjay1949 wrote:
|
|
Re: Learning more - Ultrasonic Microphone building
Many thanks for your inputs Jerry!
?
The Ono meter measurements were taken in 1987 using one of the world's first portable FFT analyzers. I should have mentioned that. Back then, the microphone was limited to 100 kHz (more than that, but not reliable). However, it seems to have been confirmed that the sound of the lava stone instruments was measured up to about 200 kHz and even higher.
?
On Tue, Jan 7, 2025 at 08:43 PM, Jerry Lee Marcel wrote:
FFT analyzers going up to GHz are known, but the problem is with transducers. Typical microphones hardly go up to 200kHz. In order to measure "sounds" up to 500kHz, I believe the only way is to use constraint gauges or optical systems. Top lab work. ?
You are absolutely right. According to the of the ULTRAMIC there are two versions available:
- 384 kHz sampling rate and 190kHz bandwidth
- 192 kHz sampling rate and 95kHz bandwidth
Resolution: 16bit
Microphone sensor: Dual SPU0410LR5H from Knowles
No high pass filter. It can record audio and ultrasound at the same
?
On Tue, Jan 7, 2025 at 08:34 PM, Jerry Lee Marcel wrote:
Very likely, 384k is the sampling rate. Although teh Nyquist theorem induces that it can process signals up to 192kHz, most hardware cannot. ? |
|
Re: Learning more - Ultrasonic Microphone building
On Tue, Jan 7, 2025 at 10:38 AM, Heinz wrote:
AFAIK, the Dodotronics USB mics use the same caspules as most other commercial ultrasonic mics -- that is either a Knowles SPU1410 series MEMs or a FG series electret. (Details of those here: )?
Add to that the limited resolution of the the USB interfaces when sampling at 384KHz, and I think the quality of recording at the higher frequencies is pretty restrictive.
The next 'rung up the ladder'? - as it were - is probably the Avisoft condensers - (see here )? Considerably more expensive and still with a question mark over the resolution of 384KHz sample rate recorders.??
Above that, it's the kind of equipment Jerry describes..... But we're talking serious money, I fear!
?
I'm hoping the next generation of Zoom field recorders might include a 384KHz sampling for their 32 bit float recording format.? That should put the limitations back onto the transducers!.
My undertanding is that Zoom's current 'F' range of recorders use the (now obselete) AK5388 A/D converter, which has a max sample rate of 192KHz. The current range of similar Asahi Kasei converters ( listed here: ) include sampling rates up to 768KHz.
If those higher rates are enabled in future ranges of audio field recorders, the frequency response of the recordings should become limited by the transducers, not the recorder sampling rate. |
|
Re: Learning more - Ultrasonic Microphone building
开云体育
Le 07/01/2025 à 11:38, Heinz via
groups.io a écrit?:
FFT analyzers going up to GHz are known, but the problem is with transducers. Typical microphones hardly go up to 200kHz. In order to measure "sounds" up to 500kHz, I believe the only way is to use constraint gauges or optical systems. Top lab work. |
|
Re: Learning more - Ultrasonic Microphone building
Le 07/01/2025 à 11:38, Heinz via groups.io a écrit?:
Has anyone tried the Dodotronic USB Ultramics which seem to record up to 384k?Very likely, 384k is the sampling rate. Although teh Nyquist theorem induces that it can process signals up to 192kHz, most hardware cannot. |
Ivano Pelicella
to navigate to use esc to dismiss