The BulbMogul
Well-known member
What would be a top shelf "DREAM" Mic to couple to this F3 for bird audio sounds..?
I think that 32 bit float is really all about post production editing - it allows a signal above 0dBF to be pulled back and also allows a low signal to be normalised to -3dBF (as per Xeno Canto guidance) without adding significant noise due to the low the noise floor.
Post production and editing, you will probably not be able to tell the difference between 16 bit, 24 bit and 32 bit float outputs - after all audio CD's are only 16 bit, and we have been happy with the quality of music CD's for over two decades now.
I would therefore save as a 16 or 24 bit final version and then upload to EBird - quality will be substantially the same and it will save their server space,
Regards
Jon Bryant
I would agree that this is a real beauty of 32bit float, and have opted at times not to monitor recordings at all - just wing it and adjust in post. Are you using headphones at all to monitor the recording, or just relying on your judgement of whether the signal to noise (i.e. how loud the target is compared with the environment) will be OK? I have sometimes opted not to use headphones at all, although headphones can be useful to ensure directional mics (particularly parabolas) are aimed properly at the target.
I take the point on mic specifications and low noise, but I would caution this with the fact that very low noise mics are really for studio work (i.e. in a silent environment). Out in the field, I think that generally environmental noise is likely to drown out mic noise. 32bit float can't obviously solve the problem of a low volume recording in a noisy environment (and you may wish to monitor to avoid this), but the magic of not having to worry about gain or clipping is great.
Regards
Jon Bryant
Two different types, that each have their place.What would be a top shelf "DREAM" Mic to couple to this F3 for bird audio sounds..?
For me the great thing about the F3 is two XLRs with phantom power in a small 32 bit float recorder. I am therefore looking forward to trying to make my cumbersome parabola, slightly less cumbersome to use. Some parabolas actually have too outputs - either because they produce stereo recordings or because they have differently configured and positioned mic capsules - I have a Telinga mic, and both the available parabola capsules have two outputs, so require two XLR connections.What would be a top shelf "DREAM" Mic to couple to this F3 for bird audio sounds..?
My point is that the low-impedance driver stage also introduces noise and on a short cable run such as is used in portable recordings, it is simply not required. The capacitance and resistance is multiplied by the cable length. A 1m cable run really does not need a low-impedance driver stage and the noise floor benefits a fair few dB from not having it. So even with the same short cable run, a simple PiP low-noise capsule, such as the AOM-5024L with EIN of 14dBA, will typically outperform a really top-end pencil mic with a low-impedance XLR output. This is where the F2 has its place.Not every cable is the same. Real microphone cable is heavy and the free length from connector to the next resting point (ground) is a weight hanging on one end of the connector. With XLR this weight is distributed to the chassis of the connector (recorder) by the connector housing. Its not distributed via the contacts inside this plug. Not so with the jacks. The 6.3mm TRS (Jack) can handle this weight, but if you mix the two standards (mm/inch) it can end in poor contact. The 3.5mm TRS (mini jack) is not suited for this kind of cable, you can't even get it into the sleeve. Due to the weight and the much smaller shaft of the jack this will end in bent contacts inside the chassis and damage the jack beyond repair. You can buy the jack, but replacement of chassis part is an other problem.
"XLR mics are usually compromised by their low impedance output driver stage", I take this as not knowing what's going on. Most users forget that a cable is not only a connection between two electrical things, but is also a resistor and a capacitor. And together they can form a tuned filter. With a low output impedance the cut off frequency is shifted out of the frequency response of the microphone. With a higher output impedance you do have the risk that a part of the frequency response is compromised. Sometimes you can do this deliberately with a switch, but than you know what your doing. Trouble is finding the resistance and the capacitance of a particular brand of cable, sometimes its given and sometimes not. And the experience is more not then given. This is also the reason why some microphones and or recordings do have more noise. Its not always the microphone to blame. Not seldom there is a mismatch between output impedance microphone and input impedance microphone channel recorder.
Your point, sorry, in the Dutch bio acoustical association we have different experience. Try this f= 1/2*pi*R*C. No such thing as EIN on the output of a microphone or other source for that matter. Performance of a microphone is not only its self noise, there is much more to it. I hope your source for PIP is sufficient noise free and as you have to use a resistor between the plus pole of the capsule and the connection for your PIP, you have also add the Johnson noise of the resistor to the total of noise. Because this is at the very beginning of the channel you will amplify that noise by the degree of amplification.My point is that the low-impedance driver stage also introduces noise and on a short cable run such as is used in portable recordings, it is simply not required. The capacitance and resistance is multiplied by the cable length. A 1m cable run really does not need a low-impedance driver stage and the noise floor benefits a fair few dB from not having it. So even with the same short cable run, a simple PiP low-noise capsule, such as the AOM-5024L with EIN of 14dBA, will typically outperform a really top-end pencil mic with a low-impedance XLR output. This is where the F2 has its place.
The rest is taken care of by the input of the recorder. In the case of the Zoom F2, and almost all recent recorders, this is well below the self-noise of the microphone. EIN A-weighted is the ISO standard for measuring microphone self-noise. If the recorder is reasonably impedance-matched and has lower EIN, and the cable is short, then by far the most significant noise is from the microphone. Hence my original comment about low-impedance output stages compromising the mic - they add noise for no benefit in practical, portable recording scenarios, i.e. with short cables.Your point, sorry, in the Dutch bio acoustical association we have different experience. Try this f= 1/2*pi*R*C. No such thing as EIN on the output of a microphone or other source for that matter. Performance of a microphone is not only its self noise, there is much more to it. I hope your source for PIP is sufficient noise free and as you have to use a resistor between the plus pole of the capsule and the connection for your PIP, you have also add the Johnson noise of the resistor to the total of noise. Because this is at the very beginning of the channel you will amplify that noise by the degree of amplification.
Hi steinn and everyone, I have just got the F3 and will be using it with the Røde NTG5. I will mostly be using it for recording visible migration (vismig). What sampling rate would you use and would you put the high pass filter on?Hi, used F3 for a while and it works really great. Use a powerbank 20000mah and it can run for days! No problem if signal is overloaded, pull it down to 0db and work further. I save as 24bit - 48 or 96khz wav and then go on as usual in Audacity or Audition etc. Here an overnight recording with F3 and parabola Telinga stereo at 69N here in Norway XC750549 Northern Hawk-Owl (Surnia ulula)Hawk-owl call
Thanks Jon that’s very helpful,I don't really think the sample rate is that important. 44.1KHz is the sampling rate used for music CDs, which sounds pretty good. The general rule of thumb is that the sample rate should be at least twice the frequency of the thing you are trying to record. Our hearing limit is less than 20KHz, which is why I understand 44.1KHz was selected for music. Most bird vocals are less than 10KHz, with a few sounds up to circa 14KHz. High frequency sound attenuates quicker, so you would be unlikely to get many Goldcrest calls (or similar) from a Vismig recording sessions.
One Hertz is one cycle per second, so with 44.1KHz you would be sampling 44,100 times per second, so for most bird vocals you would be sampling each wave at least 4.4 times. This sampling would give a fair indication of the true wave form.
That said, using the audio calculator on the Sound Devices website, with a stereo 32bit recording, and a 192KHz sampling rate, 1GB would provide 10 mins and 51 seconds of recording. With a 64GB card (not that expensive) you would get 11 hours 34 mins and 26 seconds - more than enough for a Vismig session I suspect. You can therefore record at 192KHz if you so wish (to play safe or perhaps just because the kit lets you!), and export later to a lower rate for a smaller file size and simpler distribution/storage.
For visimig, I don't think a high pass filter would detract from the recording and the filter would reduce some low frequency environmental noise - not many (any?) birds vocalise below the frequency of a high pass filters, so I don't think you would lose any bird vocals.
Regards
Jon Bryant
Why do you think you need 192kHz?That said, using the audio calculator on the Sound Devices website, with a stereo 32bit recording, and a 192KHz sampling rate, 1GB would provide 10 mins and 51 seconds of recording. With a 64GB card (not that expensive) you would get 11 hours 34 mins and 26 seconds - more than enough for a Vismig session I suspect. You can therefore record at 192KHz if you so wish (to play safe or perhaps just because the kit lets you!), and export later to a lower rate for a smaller file size and simpler distribution/storage.