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new tiny Zoom F3 recorder (5 Viewers)

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 agree about 32-bit regarding post production editing. One thing that surprised me with the combination of the F3 pre-amps, and 32-bit's increased negative dynamic range, is how low a signal level one can record, then boost, and have good quality audio. The F3's pre-amps are quiet enough (I think they are -1 dB EIN different than the Sound Devices MixPre-3 II) that they don't introduce line noise/hiss into field recordings when working with lower recording volumes and then boosting them in post.

Today I was out capturing some recordings using my smartphone and Voice Record Pro with no external mic. It was frustrating after working with the Zoom F3. I was having to pay attention to, and adjust, the gain depending the circumstances.


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 don't monitor when recording. That's mostly because I'm carrying enough other gear that a set of headphones becomes a hassle to me. I'm not using a parabolic mic that is highly directional. I find that with a shotgun I can aim the mic well enough so that monitoring isn't needed. With shotguns, while directional, you've got a pretty good sized active cone area to work with when in the field. A 60° cone in the field is wider and more forgiving than a 60° cone in a studio when you are two feet from the end of the mic.


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

I agree with your thoughts about ambient sound levels in the field. It's definitely not like recording in a studio where the noise floor is -80 dB. However it is possible to get shotgun mics with self noise in the -14 dB to -10 dB range without breaking the bank. That will help the overall quality of the recording. The mic-preamp setup I had before the Zoom F3 had more self-noise than the Zoom F3's mic-preamps. When using the same mic (Sennheiser MKH-416 with -13 dB self noise), I do notice a difference between the two setups under certain conditions. But, no, recording near a creek or river is not one of those conditions!
 
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What would be a top shelf "DREAM" Mic to couple to this F3 for bird audio sounds..?
Two different types, that each have their place.
  • parabolic
  • shotgun

Parabolics are very directional and provide a lot of rejection from the rear and sides to isolate the bird in front. In the U.S., Wildtronics makes three different parabolic setups that range in price from about $320 - $750. Parabolic dish size ranges from 11.5" to 22". Their Pro Mono model for $750 is impressive.

Shotgun mics are less directional but are also less bulky and easier to haul around than parabolic mics. Price for shotgun mics range from $400-$1,500.
  • Rode NT5 is a very nice mic ($500 US) with good specs, and a compact size
  • Sennheiser MKH-8070 is a very expensive ($1,600) long shotgun mic with very good off axis rejection, very low self-noise, and high sensitivity
 
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.

As parabolas create gain by focussing sound onto the capsule, they invariably have very low signal to noise - gain is a added without any mechanics. For this reason I suspect most parabolas would work well with the F3. The big European makes are Dodotronics and Telinga.

If you are using a Shotgun it will almost certainly have only one output. If the mic has its own power, then you could actually opt for an even smaller and more portable 32 bit float recorder - something like the Tentacle Track E perhaps. All you would need would be an XLR to 3.5mm minijack cable, as smaller recorders tend to only have a single 3.5mm input (like the Zoom F1).

If you are doing ‘true’ stereo recordings with two omni mics , then I am not really sure that the F3 is the ideal solution. The mics will normally be on a rig on a stand, so having a tiny recorder does not help much. I would then prefer something like the Mix-Pre which just feels right for this type of recording - screw connections top and bottom and all controls easily accessible while facing the user when the recorder is fixed on a stand/tripod. Also the Mix-Pre is more versatile - it supports M/S stereo and if you get the 6 can even do ambisonics.

Regards

Jon Bryant
 
Just had my first play with the F3 with a Parabola (full comments in Small (But Good?) Part 5, which I posted today.

The F3 is impressive. My main bug bear is the battery compartment. If you use the rails (and probably the tripod mount) to fix the F3 in place, then the battery compartment is not accessible - you basically have to disassemble your rig to swap the batteries, which could be time consuming and a bit tricky in the field. This will probably be more of an issue with setups using two mics with phantom power, as this will likely eat batteries a bit quicker - I think Zoom suggest that lithium batteries may last 8.5 hours, but yet to see if this works out in practice - and lithium batteries are the most expensive disposable battery option in any case.

Bag recorders such as the Mix-Pre Series are normally in bags with easy access to the battery compartment - I actually use an adapter with the Mix-Pre, and power the device with a camcorder battery that is easily accessible and can be swapped in a pouch on the front of my bag. I suppose you could do similar with the F3, and it can be powered by a power bank, but then this seems to be partly doing away with the portability and design of the unit.
 
'32 bit float' is a bit of marketing magic that covers what is actually going on. There are two pre-amps per channel with fully automated levels set around 18dB apart, annotating every single sample with the ALC value applied. Hence no gain control is required (they are both automatic) and in post, with a compatible DAW app, you can adjust levels after the event seamlessly as if it were one 32-bit audio recording capturing the full dynamic range with levels set perfectly, regardless. With quoted -127dBU noise pre-amps, everything we knew about setting recording levels is suddenly redundant.

Of course, no human has a range in any of their senses equivalent to 32 bits (approx 193dB) and the CD format was wisely chosen at 16 bits (approx 96dB) which is already more than most humans can appreciate from the limit of the quietest sound to hearing damage. So a recording at 96 or 192KHz avoids an overly-steep low-pass filter (to avoid digital aliasing) and at a notional 32 bits with perfect levels, the mastering can be done with all that latitude down to 16 bits @ 44.1 KHz, or if timing information to the ears is especially critical as it can be with a pure spaced stereo mic set-up, a higher sampling rate but then we are talking about perceived placement of under 1cm in the sound field.
 
For those only using a single microphone to record, the Zoom F2 looks like far better value. It is also 32 bit float, tiny and has plug-in power for the likes of an AOM-5024L capsule (9.7mm dia, EIN 14dBA and sensitivity -24dBV or 63.1 mV @1Pa). XLR mics are usually compromised by their low impedance output driver stage, essentially to drive 100m+ long runs of cable which in most applications are simply not required.
 
I think the F2 could be good for drop rig mono recordings, perhaps using the supplied lavalier - I read somewhere that a well placed cheap lavalier will outperform a distant pro shotgun every time, so just a problem of making sure you place it well!

The F2 could also be used with PiP mics used in some parabolas, but obviously not for any stereo parabolas (as the recorder is mono).

My preference is to use XLR connections, which I think are more robust, so you avoid poor contact noise when recording on the move. I am not sure what is meant by XLR mics being ‘compromised’ after all, (without trying to be snobby) these types of cables are generally used on all pro and prosumer audio equipment - PiP is generally used on consumer audio. I know that there can be possible issues with impedance matching, which is a topic beyond my technical knowledge, but I understand that this is not really an issue with modern preamp wiring. Mixing balanced and unbalanced inputs and outputs can also apparently result in signal loss, but XLR connections are normally balanced, so it should not be an issue is you use a suitable cable.

I like using a PiP video mic for ad-hoc recordings, but as a generalisation, the only directional mics that are PiP are parabolas (as mentioned above) or consumer mini shotguns targeting the video/camera market. So if you want the flexibility to use a long shotgun, or indeed a stereo rig, the F2 is no substitute for the F3. Who knows, with the F3 you could even be tempted to go old school - find a target singing from its favourite perch, run out 30m of cable then wait in hiding for the perfect recording opportunity - with a balanced XLR cable, you should have no worries about cable length or significant RF interference. The F3 is therefore a more versatile option than the F2 and arguably more ‘future proof’ to changes in your mic choice or recording methodology.
 
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.
 
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.
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.
 
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.
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.

 
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.

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.

All the relevant equations have been second nature to me for over 40 years. There is little point in quoting them. I offered a pragmatic view for specific situations over the industry orthodoxy which is suboptimal in these cases.
 
EIN is a short for Equivalent Input Noise. This is a specification used for input stages of sound equipment. I don't have manuals, specifications, leaflets and such with EIN for microphones. They do have specifications for self noise, but this is in dB(A) according DIN-IEC or CCIR. My "top-end pencil mic" has a self noise of 10dB (DIN IEC 651), "outperform" is highly speculation. But as you seems to know it so well I rest my case.
 
The conversation was too technical for me to follow. Without trying to upset either side, the argument seems to me slightly academic. Once you have invested in a mic, the powering requirements will often govern - as I understand, XLR for phantom power and mini-jack for PiP. If you have plumbed for XLR or PiP you are stuck with making the best out of your selection - unless you want to buy a separate phantom power supply to drive a P48 mic.

Some mics have their own power supplies, so perhaps you can experiment with cable options. With my ME67 I can use an AA battery or phantom power, and have both XLR to XLR and XLR to minijack cables for use with different recorders. However, with the demise of the old Senheisser K6 power capsule and the ME66/67, I don’t think there are many (if any) full size shotguns that work without phantom power.

As I say the F2 may be ideal for certain recording scenarios. In fact as a bit of a hoarder of gear I am toying with buying one for recordings made with a closely placed mic - place the recorder in a small discrete waterproof bag and run an equally discrete mic from the recorder to where the bird is likely to vocalise. Press record and wait - perhaps even go home and come back the next day (especially if you power the unit from a power bank, also in the bag). As it is 32bit float no worries about recording levels. I think this form of recording would be best with a static subject, such as a bird singing from a song post.

My point however, is that although this type of recording can produce excellent results (assuming you want a bird’s ear recording), many recordists favour hand held directional mics. In this case your options are much more limited with the F2 compared to the F3. There are a plethora of XLR shotguns, but most PiP shotguns are the small lower quality video mics - often with much greater self noise than their bigger XLR brethren. There are of course PiP parabolas, but then you would be limited to using the mono versions.

I think the F2 could have its uses and be interesting, but I don’t think it is as versatile - there are fewer compatible mics (particularly directional), and no stereo capability, which I think in combination results in fewer techniques and options for recording.

I would therefore say think (carefully) about the F2, but only if you have a compatible mic and you think it would suit your recording methodology. I have also read that the F2 is a bit plasticky and could be a bit fragile, whereas my F3 feels like a pretty robust chunk of metal, but time will tell whether the F3 proves robust.

Regards

Jon Bryant
 
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
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?
 
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
 
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
Thanks Jon that’s very helpful,
 
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.
Why do you think you need 192kHz?
 

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