|recording devices and the traveling field recordist
|a survey of contemporary portable recording options |
What follows is a long-winded brain-dump on how I suggest you evaluate portable sound recorders for field recording, particularly while traveling long-term, as of 2011.
Regardless of how certain I may sound here, please do your homework. Read beyond my own idiosyncratic perspective. If one thing is certain, it's that by the time you read this, my advice will be out of date.
Quick studies may only want to skim my bullet-list of considerations for highlighted text; the obsessive may wish to read my remarks on individual technologies after it, in which I consider various current and vanishing technologies individually.
Before I inundate you with specifics, though, please consider the following:
Budget travel brings with it its own challenges. In addition to cost, size, and weight considerations, remember that a backpack can be a brutal place, wherever it's going.
Plan with the worst-case in mind. Be suspicious of the fragile, whatever its feature set. Don't fall for hype. The latest-and-greatest is also the unproven-in-the-field.
When you find a piece of gear you like, comb its users' forums. Search for 'X problem' and 'better than X' and 'worse than X.' Troll support archives, FAQs, and mailing lists for both the skinny and the dirt. Look for downloadable firmware updates with an eye to see what was (and how much) was had been fixed, and what remains unaddressed. And so on... it's a tough world out there.
But please... go record it. Much of it is changing all too quickly.
things to consider
overview of technologies
|things to consider when choosing a recorder || || |
0. it's not really about the recorder
Your choice of subjects, and your approach to them, matters more than your equipment.
Your choice of microphones outweighs the (often subtle) differences between the recording quality of most contemporary recorders. An all-but-inviolable rule of thumb is that your microphones should cost more than your recorder.
Despite the attention I lavish on the issue here, the quality of conventional recording done with almost any dedicated digital sound recorder is 'good enough' for most people for most uses.
That said, you should still make an informed choice.
I'm just sayin'... don't lose any sleep wondering if you have the best possible gear. (I have... and it isn't worth it.)
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|1. file formats || || |
Contemporary recorders allow recording in a wide variety of digital formats, defined in terms of sample rate, bit depth, and, in some cases, compression (both lossy and lossless). As manufacturers often use these attributes as a selling point, I will address them first.
sample rate and bit depth
Defined for a layperson, sample rate determines the highest frequency that can be represented in a sound file; bit depth determines the number (and hence granularity, or fine-ness) of the steps representable between the loudest possible sound and silence.
In both cases higher numbers are nominally better. There is more variability in sample rates, ranging from CD-quality at 44.1 kHz up to 192 kHz (or beyond!), than in bit depth, which is almost always either 16 or 24. (The fundamentally different approach to digital recording underlying DSD, currently available only on two Korg recorders, is beyond the scope of this advice.)
The must-have capability du jour is record up to 24-bit and 96 kHz, or even 192 kHz — the latter being a de facto gold standard. Indeed, in ideal circumstance, 24-bit 192 kHz audio, the highest quality supported by the DVD-A standard, is heard by many people to be as lifelike as anything but the very finest analog recordings.
In practice, high sample rates provide little or no benefit in inexpensive recorders. On the contrary, they consume battery life and storage space without actually improving the quality of your recordings.
The dirty secret of contemporary digital recording is that few devices provide (or maintain) an analog signal clean enough to take advantage of high sample rates. Advantages emerge only when a recorder is fed (or maintains) a very clean analog signal. (For what that takes, see the bullet below.)
On the other hand, because quality devices do actually surpass the representational ability of 16-bit samples, I do recommend recording in 24 bit when possible.
In my experience, there is a readily discernible different between 16-bit and 24-bit recordings. (As I hear it, 24-bit recordings have a more clearly defined spatiality and more detail in very quiet sounds; this is most noticeable in 'reverb trails' or room echoes.)
For typical subjects, using my regular microphones, I record 24-bit at a mere 44.1 kHz. Recorders aside, very few microphones are capable of providing useful (or any) information above the 22 kHz supported by this sample rate. (Capturing high frequencies is not the only reason to use high sample rates, but it is probably the most cited.)
The situation with sample rate and bit depth marketing is eerily akin to the arms race of megapixel count in point-and-shoot digital cameras with mediocre optics and miniature CCDs. To wit: there is no point in using many times the media space to record high-resolution noise in either domain.
Many recorders can record directly into lossy compression formats.
The most common lossy compression schemes are minidisc's ATRAC and mp3; the odd recorder supports alternatives such as the excellent open-source Ogg Vorbis. These schemes use various tactics to discard portions of the original recorded sound; the design goal is that the information loss will not be noticeable — or at least not distracting; high quality compression results in more of a sense that something is missing, than any discernible artifact.
The advantage of lossy formats is a significantly reduced file size. Even when very high quality, compressed files use only a fraction of the file space the comparable uncompressed file would. At 320 kbps an mp3 file is just over one-third the size of its uncompressed original.
When compressed formats are supported it is usually at a range of data rates; higher data rates provide higher quality recording, at the cost of incrementally larger files.
As a long-time user of (and advocate for) MD recorders, I found ATRAC almost inaudible in most circumstances. In most respects, mature formulations of ATRAC sounded significantly better than most mp3 encoders at comparable datarates. I do not hesitate to continue to record with minidisc's ATRAC compression even today when it is convenient.
For similar reasons, for casual recording, I would not hesitate to record at very high datarate mp3 (256 kbps or 320 kbps). At such high data rates, a decent mp3 encoder can offer a very high quality recording indeed (there are always exceptions; by one analysis of the Zoom H2 recorder found that even at very high data rates, it removed all frequencies above 15 kHz...)
You can judge the results for yourself: almost all of the material you can hear on this site was recorded on consumer MD using ATRAC at a datarate roughly comparable to 320 kbps mp3.
On the other hand, now that it can be readily avoided — even with HiMD, which now supports CD-quality recording via its PCM mode — there are often cases when I avoid using any compression. It is undeniable that it is a compromise.
The most relevant of these is I will believe I will be manipulating my recordings. Such manipulation, particularly in the time domain, can quickly reveal what is missing from a recording.
You should be aware that most (not all) implementations of compressed formats on portable devices assumes a 16-bit 44.1 kHz original signal. In other words, the real advantages of 24-bit recording are not available when you use a compressed format.
One instance where I actively discourage the use of compression is any recording for scientific purposes. While the impact of minimal compression is actually quite debatable, at least in the human hearing range, uncompressed recording will spare you that debate.
Historically, compression has been synonymous with loss of fidelity. A few contemporary recorders — notably the Sound Devices 7-series — can now record in FLAC, a file format that while compressed does not suffer any loss of any fidelity.
FLAC typically provides about a 50% savings in file size, effectively doubling the amount you can record on a given medium. While presumably requiring power to crunch numbers, it's certainly an excellent way to stretch your media budget.
files as files: file wrangling, timestamps, and sizes
A nice feature of some recorders it to customize file names as files are created, and to organize them into folders while in-recorder. I myself am lazy enough to rarely fully avail myself of such features, alas.
When possible, do at least set the date and time on your recorder; it makes finding a specific recording much easier — especially if, as I now do, you snap a digital photo of yourself and your subject, whenever you make a recording.
One gotcha to be aware of, but which won't often be of concern for most people: some recorders (e.g. the Olympus LS-10) can only record files up to a certain file size, namely the 2 GB limit that is the legacy of the FAT32 filesystem employed by most recorders. (Others will gracefully close one file and open a new one for you, without dropping so much as a sample...).
That limit may seem theoretical, but at 96 kHz 24 bit, that's only a bit over an hour of recording!
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|2. the analog signal path|| || |
After microphones, most of the rest of the 'quality' of a recording comes from the clarity of its transmission to and within the recorder along the pre-digitiziation 'analog signal path.'
This path, sometimes called the front end, consists of the cables connecting your microphone to your recorder (not as important as audiophiles would have you believe), the components and traces (or wires) that transmit that signal within it, and the preamplifier that magnifies the very low signal of most microphones prior to its arrival at an analog-to-digital (A/D) converter for conversion into the digital domain (at a sample rate and bit depth discussed above).
microphone powering, connectors, and cables
Not all small audio recorders have microphone inputs; some have only line-level inputs which require an external preamplifier. Make sure your recorder has a microphone input. (Microphone inputs typically include a preamplifier to amplify the very low signals provided by microphones, and some kind of powering for microphones.)
When matching microphones with recorders, a critical consideration is the type of external powering, if any, the former requires.
Different types of microphone may require no powering, plug-in powering, or phantom powering. Plug-in power is most common on consumer-grade recorders, and is required for electret elements used in many inexpensive or small microphones; phantom power is required by condenser microphones.
Not all powering is equal. Not all recorders' plug-In power is robust enough for all microphones. Phantom power is notoriously difficult to generate with conventional low-voltage batteries; small recorders which promise phantom power may provide it in substandard form. Infamously, the first generation M-Audio Microtrack 2496 provided slightly over 30V apparently, not the industry-standard 48V. Just because a microphone 'seems' to work when you plug it in does not mean you are getting the best results it is capable of. Often problems only manifest in trying field conditions.
If your recorder does not provide power as your microphone requires, you'll need to lug around an extra box to do that job. I haven't tried one yet, but adapters that derive plug-in power from a phantom source are available however.
Correlated with (but not definitively implying) a powering convention is the type of analog connector found on a microphone, cable, or recorder. Phantom power is almost always carried over three-pin XLR connectors (or variants thereof such as mini-XLR); plug-in power is almost always carried over 1/8" (3.5mm) miniplug connectors (used with portable headphones) — but not all XLR-terminated microphones require phantom power, not all XLR-socketed recorders provide it, and so on.
Connector types also strongly imply whether the signal transmission on a given cable is balanced (as on XLR-terminated cables) or unbalanced (as on miniplug-terminated cables).
Generally speaking, balanced connections are preferable as they are much more immune to certain kinds of noise, and hence can be used for longer cable runs. In practice, you can get away with unbalanced cables for most of the recording scenarios that come up when traveling; this is just as well, as regardless of what is preferable, you will not have a say in the matter!
If you will be using intermediate cables between a microphone and your recorder — you may not be; my binaural microphones include a permanently attached cable — do invest in decent-quality robust, flexible, and shielded ones. Excellent cable is available at much less than audiophile-fleecing prices; dig around online for recommendations. (For my non-stealthy kit, I use custom-made Canare Star Quad.)
Unlike marketroids, what recording geeks talk about, after microphones, is the preamplification stage. High-quality preamplification means the introduction of as little noise and distortion into a microphone signal as possible.
The quality of the preamps in a recorder is important enough a consideration that for many, it outweighs most other factors (including size, weight, battery consumption, and ease of use), even in combination.
Preamplification is often defined in terms of usable gain: the amount a signal can by amplified. This can range from less than 50 to more than 70 decibels. 'Usable' means, before the inherent noise of the preamplifier itself becomes problematically audible.
How quiet a preamplifier you need is a function of both your intended subject matter, and how quiet your microphones themselves are. My beloved Sonic Studios DSM microphones have so much microphone self-noise in their own right that I do need a particularly quiet preamp with them. For those interested in capturing demanding subjects, such as very quiet natural ambiances, quiet high-gain preamplification is a must.
Harder to quantify in a preamp is its accuracy or transparency; one factor often correlated with that perception is how quickly (and precisely) very high frequency events such as transient peaks are reproduced (or 'tracked').
Certain types of signal distortion are considered euphonic (e.g. 'warm') and hence desirable in some studio recording situations, but for field recording I believe it is usually best to seek out preamplification that is as accurate or 'clinical' as possible.
If your recorder does not have good preamps, you may wish to carry an external ('outboard') preamplifier — though the additional hassle this creates must be carefully weighed against the potential benefits.
When using outboard preamps with miniature microphones of the type I recommend on this site, remember that microphones requiring plug-in power will not work directly with preamps designed for self- or phantom-powered microphones. In this scenario, plug-in-powered microphones will need to be powered with a small power supply... and you thought you liked spaghetti! (As I mentioned above, this adapter might help.)
One reason I lamented the end of minidisc is that In rigorous testing Sony HiMD recorders proved to have very quiet, clean, high-gain preamps.
Fortunately, Sony PCM-M10 has preamps that are very nearly as quiet as the HiMD recorders. The Olympus LS-11 (and older LS-10) are almost as good, but are known to roll off low frequencies.
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3. size and weight
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Historically, there was a well-maintained division between very small consumer- or prosumer-grade recorders capable of decent results, and heavy and bulky professional recorders capable of excellent ones.
That division is now largely blurred. Today it is quite possible to get truly excellent recordings with very small recorders indeed — as long as you are willing to pay for privilege; and it is possible to get very good recordings, even if you are not.
There's no point in having an exquisite recorder if it's so big or so heavy you never take it with you.
Contemporary portable recorders targeted at consumers are mostly about the volume and weight of a pack of cards or large cellphone. More feature-rich prosumer recorders are usually the size of a plump portable tape players. True professional-quality recorders (e.g. the Sound Devices 7-series) still do tend to be the size and weight of removable car stereos, not least because build quality is often correlated with weight, but there are exceptions in both directions, such as the jaw-droppingly-priced Sonosax Mini-R82 and Aaton Cantar (either of which, by the way, you should please feel free to donate if the mood strikes...)
What size and weight recorder you are willing to carry should be weighed against the features you need. High-quality phantom powering and preamplification in particular are very difficult to find in a small-form factor recorder. If stealth and battery efficiency are a requirement, something else will have to give, and it may well be having the best possible quality and richest feature set.
Regardless of the size of your recorder, you will need some way to carry it. It is much easier to discipline yourself to keep a pocket recorder with you (and always at the ready!), than something that requires an expensive shoulder bag.
It is also easier to use a small recorder in an unobtrusive way — the more restrictive or unsafe your potential destinations, the more important a consideration that should be.
(Of course, if you are using microphones that require a tripod, boom, or windshield, your chances of stealth are already minimal...)
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By definition, field recording is always (well, almost always) done without access to mains power. All field recorders therefore require some type of battery.
Always, always, always, carry extra batteries with you in the field. There's no excuse for missing a great recording because you didn't have an extra battery in your pocket!
There are three types of battery configuration today: disposable drycells (typically AA or AAA, as with the Zoom H2, Sony PCM-M10, and Olympus LS-11); removable rechargeables (sometimes in standard if uncommon-in-the-consumer-world form factors, such as camcorder batteries, as with the Sound Devices 7-series); and non-removable rechargeable (as in the M-Audio MicroTrack and iPod).
I recommend that travelers seek out portable recorders capable of taking common disposable batteries.
It is a sad fact that using rechargeable batteries is not always feasible while traveling. On occasion one does not have the appropriate power supply (voltages vary around the world). Or the requisite plug adaptor. Or, most commonly, a place to plug in.
Therefore, whatever you do, don't get a recorder that does not have a field-replaceable battery!
Removable rechargeables are another matter, at least, as long as they are replaceable by disposables in a pinch for the reasons I just enumerated.
Combined with fast chargers, in fact, these make an excellent addition to the traveler's kit. I've had good luck to date using high-capacity contemporary NiMH rechargeable batteries in devices designed for use with disposables.
As a result, when i can I carry a recorder that accepts disposables, and the disposables to power it — but power it via rechargeables whenever possible. This is not only cheaper (and lighter!) than carrying a slew of disposables — obviously, it's much greener. (NB: do not try this with NiCad or Lion rechargeables.)
Note that phantom powering is quite difficult with small disposable batteries (or rechargeables in their form factors); recorders that provide good phantom power typically use camcorder batteries or proprietary rechargeables.
One reason I recommend plug-in powered electret microphones for travelers is that they are less power-hungry than phantom powered condenser microphones. Generally speaking, recorders designed for use with this kind of microphone are very battery efficient. My minidisc and HiMD portables consume AA batteries one at a time and have exceeded three hours of recording time on a single battery.
Early memory recorders averaged less than that, presumably because of the challenge of recording significantly more data when using uncompressed formats, but some contemporary recorders offer truly remarkable battery efficiency. The Sony PCM-M10 is mind-blowing in this regard; I have recorded twenty hours of 16 it 24 kHz uncompressed stereo using the device.
If you must use a recorder with a non-removable, or difficult to recharge, battery, the only option for extended recording times is to use an external battery sled to provides power.
The most useful sleds take conventional C- or D-cells themselves, but you can also find battery extenders that are themselves rechargeable (e.g. those intended to extend the lives of iPods, laptops, portable DVD players, and the like). The latter type are of questionable use for the long-term traveler if only because they suffer from the same limitations of all rechargeables; they are, however, generally lighter weight than large-cell sleds.
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|5. recording media || || |
I never erase any recordings and I recommend that you never do so either, if you can avoid it.
I am very strong believer in preserving the original, archival copy of any recording. I cannot overstate the value of having every recording I've made on minidisc safely ensconced on long-lived digital media.
Can you foresee the feeling you will have while reformatting a memory card after copying off its irreplaceable recordings...? One of the key advantages of minidisc over today's memory and harddrive recorders was its extremely robust media.
I have hundreds of minidiscs dating back to 1998, none of which has ever failed. Housed in a rigid shell like the obsolete 3.5" floppy disk, the CD-like magneto-optical disk within was well-protected from scratches and dust. It was itself a robust substrate: over the years I heard several accounts of physically-compromised housings being replaced, and the disks within performing flawlessly.
Today, there is no equivalent security unless you have very deep pockets. The closest equivalent would be to use SD or Compact Flash cards as a write-once medium. But the cost-per-hour on solid-state memory cards is still at the best twice (or more) what it was on minidisc (and more commonly almost ten times as much). Though the price of memory is slowly dropping, I'm going to keep kvetching until that ratio collapses significantly!
Memory cards do have one major advantage as a medium: they are so ubiquitous a technology that they are easy to find anywhere in the world, and should be supported long into the future.
Ubiquity is a thing to be cherished. In 1998 in the heydey of minidisc, I found my new Sharp MS721 MD recorder had a manufacturing defect when I was already abroad in Vietnam. But I was able to buy a replacement (at a good price) in Hanoi. When I wore out the external battery pack on my Sharp MT66 recorder in India in 2001, I similarly was able to find a replacement in Kathmandu. (Sadly, despite the popularity of the cards, memory card recorders are not yet themselves popular enough to necessarily be found around the world, just yet.)
Memory cards also have one major disadvantage as an archival medium: a data retention time of perhaps only ten years! (Some manufacturers claim longer retention, at least for some models.).
I do not consider the harddrive an archival medium, for (the mostly obvious) reasons that follow.
avoid the single point of failure!
The modest capacity of a memory card (or minidisc) is a blessing, not a weakness. Limited capacity means no single point of failure.
Yes, it's inconvenient to carry dozens of cards (or disks) on a long trip. But the inconvenience is more than offset by the certainty that no matter what happens to any given bit of media, the rest are (in most scenarios) safe and sound. (On my honeymoon, I regularly sent batches of 20-30 minidiscs home via DHL to ensure against total loss.)
(If you blanche at the idea of buying dozens of memory cards, you can sympathize with why minidiscs at a dollar a pop were so great.)
Whatever the cost, at least minidiscs and memory cards are in my experience (and reading) almost 100% reliable as a recording medium — at least, at a physical level; specific recorders may make data errors that lead to data corruption during recording or editing.
The laptop-form-factor (or smaller) harddrives that have found their way into numerous contemporary recorders are another story, however.
Their appeal is obvious: a hand-held device can now record hundreds of hours at the highest of qualities.
But harddrive-based recorders' large capacity is a classic double-edged sword.
Convenience comes at the cost of the exposure of relying on a single mechanisms to safeguard hours (if not weeks or months) of one's work. Drives are delicate mechanical mechanisms most of us have had fail, and that when not subjected to the rigors of travel.
Even if a drive does not physically fail, data corruption is a constant possibility, and one I see reported as a grim reality all the time.
Until there are proven, practical, portable, and battery-efficient mechanisms for offloading or duplicating recordings made on HD recorders, I cannot overstate the risk one runs relying on them in the field.
For some trips I have done so myself, yes, but I'm taking truly foolish chances.
Mechanical failure is not the only risk. Sad to say, I have had one of my recorders stolen in the field. If I had been using a harddrive recorder instead of minidisc, I would have lost an entire trip's worth of recordings, instead of a day's worth. That's something I will not soon forget.
(As if to prove my point, even as I was writing this very update, I heard from a colleague who lost many gigabytes of recordings she'd just made at an expensive field study workshop in the Brazilian Amazon. Shortly after her return to 'civilization,' the laptop that held all her (as-yet unbacked up) recordings was stolen during an armed robbery.)
By the way, I am not aware of any HD recorder that allows a harddrive to be swapped out in the field.
While we all wait for the next affordable and reliable archival medium, it will be necessary, or at the very least prudent, to make backups of recordings while on the road.
They may not yet be entirely proven, but there are portable mechanisms for doing so.
Some HD recorders can copy data to external harddrives, or burn them to optical media via portable (potentially battery-powered) CD or DVD recorders.
Memory cards can be reused if the recordings on them are offloaded. For most travel recordists this means copying their contents to a 'memory card backup storage device,' a portable harddrive with a built in display and card reader, which will require its own batteries and enormous faith, again, in a harddrive.
I should note at this point that I have read speculation (e.g. in the Tapers' Section forums) that battery-powered media backpack harddrives may be prone to 'seizing' when continually used on irregular power.
In theory a laptop would offer a more palatable option, especially if it can be used to make redundant backups periodically (such as by burning optical backups, or when bandwidth is available, by sending recordings home via the internet).
But in practice, it is a very attractive target for thieves, quite fragile, and even harder to keep powered than a recorder, when in the bush for any length of time.
The problem of how to protect large amounts of data acquired on the road is not unique to sound recording. The photography community is a great place to look for accounts of how others are currently dealing with these issues.
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|6. cost, and what you pay for || || |
Like a wedding, depending on what you want and are willing to pay for, a portable recorder can be very affordable — or inconceivably expensive.
At the top end, recorders intended for specialized professional markets can run well upwards of ten thousand dollars. Examples include the aforementioned Aaton Cantar and Sonosax Mini-R2, and offerings from Nagra and Zaxcom.
Recorders likely to be of interest to budget travelers range from an only slightly more modest four thousand dollars at the top of the range, to a prosumer sweet spot of around $400-500. For half a grand today you can get a very good recorder with most (if not all) the desirable features.
By desirable features, I mean things such as robust phantom power, quiet high-gain preamps, a variety of input and output options, and a well-thought-out interface, ideally with physical switches (rather than well-buried menu options) for locking the interface or other less common but useful functions.
At the high end of that range, I love my Sound Devices 722. I don't believe there's a better all-around recorder for my kind of work, at any price; it's all but indestructible, not too big, offers impeccable sound quality, and has a very well-designed interface. Also, the feature set, already rich, keeps being expanded by firmware update. I have a few quibbles, yes, but I don't see giving it up any time soon!
When trade-offs are made as you move into the more affordable options, the first big things to go (in addition to impeccable sound quality) are usually materials and build quality. Overall, only expensive recorders are built to withstand the environments and abuse that a long trip may involve. As a result, when I use budget recorders, I try to always carry a backup of some kind.
At the blooming budget end of the market, there are usually intriguing and typically very portable (and easy-to-use) options around $200-250. At this price point, devices are not unlike point-and-shoot digital cameras: they don't deliver the best quality, usually, but they can sport innovative features (such as the surround-sound capabilities of the Zoom H2), and are generally quite easy to use.
This is probably the sweet spot of the market right now; recorders such as the Sony PCM-M10 offer remarkable quality in a highly portable and affordable package.
At the lower end of the range, in addition to my flock of minidisc and HiMD recorders (which I still use most of the time), I love my Zoom H2. In addition to the surround-sound capability I mentioned, its interface is dead simple and it gets several things right: it uses AA batteries, has decent metering, quite respectable built-in microphones, and records in a wide range of qualities. It does have flaws though, including a noisy signal path when using external microphones and a lack of a way to lock the interface when recording.
When minimizing cost is critical, used equipment puts recording in everyone's reach; if you're willing to settle for older or used equipment and less-expensive microphones, you can be up and recording with an entire kit today for less than $200, and probably less than $100. There are also some neat little mp3 digital voice recorders now that use integrated microphones and cost less than $100.
Remember to factor media and any mandatory accessories into your cost calculation.
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|7. bells, whistles, and icing || || |
In addition to the major features described above, the following minor ones merit some explicit attention.
user interface features
How well laid-out is the physical user interface? Are the buttons clearly labeled, and are they large and far enough apart that you can press them with cold (or wet, or gloved...) fingers?
Is there a physical 'hold' switch to lock the interface against inadvertent button pressing when it's off, or recording, in your pocket?
Are there controls for adjusting the recording gain? Are they freely rotating knobs, or detented ones?
Is the display illuminated? If so can the illumination be turned off? Is it readable in bright sunlight?
Are the menus logically laid out? Can you figure out how to use features without cracking a manual?
How are files named? Is there a clock providing automatic time stamps on files? Can you tag files with human readable names as you go?
How long does it take from turning on the recorder, until you are actually 'rolling'?
A key feature for field recordists is input metering: a recorder's display of the changing amplitude of the signal being recorded.
Some recorders (especially older ones) use a single meter to show both stereo channels; some have very slow-to-respond meters that do not display short (but potentially overly loud) transient peaks.
A good contemporary meter will track all channels individually and quickly with a high granularity, ad ideally with a temporary 'peak hold' that floats for a moment at the maximum level a signal attains.
Meters should be clearly labeled, with key thresholds (such as -12 db and -6 db) clearly indicated. Use of color is still uncommon but certainly a nice touch.
inputs and outputs
In addition to microphone inputs and headphone output, does a recorder offer line-level inputs and outputs?
Does it use digital inputs or outputs, and if so, in what logical and physical formats (optical TOSlink, coaxial SPDIF, or balanced AES/EBU?)
Many contemporary digital recorders (almost all harddrive recorders) offer USB or Firewire connections that allow their media to be 'mounted' as generic storage devices, allowing painless drag-and-drop copying of recordings. One of the Achilles' Heels of minidisc was its lack of such a useful connection to the outside world until its very last generation, HiMD.
Note that small portable recorders provide 1/8" (3.5 mm) miniplug headphone jacks, not the 1/4" TRS jacks found on home stereo components.
limiting and gain control
Beware of AGC, or automatic gain control! Make sure your recorder allows manual, fixed gain control. Ideally it should allow manual gain adjustment while recording is underway.
When AGC is enabled, a recorder will actively adjust its own gain up and down in response to how loud the microphone input is. Useful for recording lecturers by pacing lecturers, this feature is a disaster for field recording; it is vital that AGC be deactivated when recording in the field. One of the flaws of Sony's minidisc recorders, compared to those from competitors like Sharp, was that AGC had to be disabled at the beginning of every single recording...
Adjusting the gain during recording is a nice-to-have feature, but not a must-have; as long as you leave the recommended 12 db or so of 'headroom' (i.e. record so that your meters show peaks of about -12 db), you should be OK unless the recording environment changes dramatically. It is a good idea to only adjust gain while recording if absolutely necessary, in any event; changes in level must be carefully removed in 'post' by hand. (Some recorders even drop samples when gain changes, potentially introducing a glitch into your recording!)
A nice (but not critical) feature on better recorders is the inclusion of an optional analog limiter, which prevents signal overload on transient peaks. Beware that some recorders such as my Zoom H2 include a post-A/D digital limiter, which is not nearly as useful (as the A/D has already potentially been overloaded).
In pursuit of offering all-in-one solutions on the point-and-shoot model, many recent recorders include their own built-in stereo microphones. (As far as I know, the Zoom H2 is unique in that it includes four microphone elements, making four-channel surround sound recording possible.)
These may certainly be handy, and for casual recording they may be all that is required. It is most certainly convenient to be able to fit an entire recording 'kit' in a pocket on a long trip; I now carry my Sony everywhere so that I won't be caught out without gear.
The drawbacks of built-in microphones include the difficulty of protecting them from wind, their relative inflexibility (they can't be repositioned for different stereo images), and the likelihood of 'handling noise' intruding on recordings if the recorder is carried or pointed by hand. On less-expensive recorders, the microphones are not as quiet or high-quality as even relatively inexpensive conventional alternatives.
If you are considering a recorder with built-in microphones, check to see if it can be mounted directly on a tripod or boom itself.
single- and multi-channel recording
All recorders record in stereo; as I write elsewhere on this site, I strongly advocate stereo recording for most travelers.
Well-designed recorders are capable of recording in true (single-channel) mono, but some will record mono into a stereo file, using twice as much memory as they should.
A defining feature of many high-end recorders is that they can record four or more channels simultaneously. The Zoom H2 is unique among very inexpensive recorders in offering 4-channel recording using (only) the internal microphones. In the mid-range the Edirol R-4 offers four-channel recording. In the high-end the Sound Devices 744T can record four channels, but it only has two microphone preamps.
Note that it is usually cheaper and easier for hobbyists to record in surround by using only informally synchronized stereo recorders. A sharp clap at the beginning and end of a recording session is usually sufficient to get 'good-enough' sync between two recordings. Note that it is vital to get a sync clap at both the beginning and the end of the recording, so as to track 'drift' between the two recorders used.
Not very common but in some situations exceedingly useful is the 'preroll' or 'prerecord' buffer. When it is enabled, a recorder is constantly recording into temporary memory, but this buffer is not actually written as the beginning of a file until the recording is explicitly triggered.
Such a buffer allows you to wait for and record an event you are not expecting or uncertain when will occur, without having to be continuously recording.
Buffers are usually quite short, on the order of two to ten seconds.
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|an overview of contemporary recording technologies
Frankly we are at an awkward moment in recording technology. We have been for several years. No recording technology currently on the market is ideal in all respects, or suitable for everyone's needs.
This is a bit paradoxical because Kurzweil's Law does hold for portable recording technology. Generally, quality is going up, cost and size are going down, and feature sets are expanding; there are a bewildering number of portable recorders (with a wide range of capabilities) dion the market, and more keep appearing, each designed with a specific market in mind. And digital recording, whatever the limitations of any particular device, does allow once-unimaginable benefits such as lossless copying and near-theoretical dynamic and frequency ranges.
When I first wrote advice on recording equipment for travelers more than six years ago, minidisc was a clear winner among the available technologies. At that time, I focused my advice on why independently traveling recordists should use it instead of DAT (digital audio tape), which was popularly understood as the 'best quality' portable recording technology of the day.
When I updated this page not so long ago in mid-2006, I recommended HiMD, the last (and in most regards, best) incarnation of minidisc technology. By that time DAT was vanishing, and the most relevant competing technology had shifted to solid-state memory recorders — i.e. those using SD, CF, and Memorystick media — and to hard drive (HD) recorders.
Today, I am genuinely sad to say that minidisc is itself rapidly following DAT towards extinction, and for that reason I can no longer recommend it as an unequivocal first choice. In fact, I am not sure I can recommend it at all.
While HiMD decks are still available from online vendors (such as my own local Minidisco), and rugged ten-year-old MD decks are still available used on eBay, the format no longer boasts its original advantages: ubiquity (especially in Asia) and the benefits (such as low cost) that come with consumer-sized markets.
My sadness stems partly from nostalgia, but mostly from the fact that despite its limitations minidisc, were it available, would still be the best option for many recording situations. In my opinion neither solid-state memory recorders nor HD recorders are particularly well suited for the long-term budget traveler's needs.
And it is primarily for such a recordist on the move, in and out of challenging environments, keen to maximize convenience and minimize overhead, drifting on and off the grid that I write this advice.
Some of what I write below will reiterate the abstracted points above; my apologies.
To consider each medium in brief, as to their suitability for field recording on a shoestring:
solid-state memory and harddrive recorders
Memory and HD recorders are clearly the future. Yet at present they offer an often-frustrating mix of real advantages compromised by real handicaps. It's the latter that makes me say we are at an awkward moment in portable recording history.
One non-trivial problem is media, which as I detailed in my bullet list, still comes at a comparatively very high cost per hour of recording (in the case of memory cards), or are subject to the very real problem of the 'single point of failure' (in the case of harddrives).
Memory cards for their part are not yet quite cheap enough to be used as a consumable medium like DAT tapes or minidiscs. As I write, $5/GB seems to be the best one can reliably hope for; at typical recording rates, that's about $5 an hour in media. Compare this to the heyday of minidisc, when 80 minutes of recording could be had for around a dollar.
At this price, using memory cards as a permanently archived medium (that is, recording once on them, then never erasing them) is not yet an an option for most of us.
I eagerly anticipate the day that it is, however, as the cards' size and lack of fallible moving parts makes them a very appealing format. They have an additional advantage that comes from not being unique to sound recording: they are liable to be supported long into the future as well.
For harddrive recorders, the 'single point of failure' problem is the most pressing, but the battery consumption of harddrives is another issue to watch for. The Sony L- and M-series batteries for my beloved Sound Devices 722 are heavy; they were designed for use with camcorders. While field-swappable and are rechargeable, they cannot be supplemented with conventional drycell batteries in a pinch.
Minidisc was for many years the best technology for portable recording.
(For my thoughts in depth, see this page of crumbling vellum in my vault.)
Over ten years and many generations minidisc recorders evolved to have a quite optimal feature set. They offered very high quality digital recording, a clean analog signal paths, extremely efficient battery consumption, a generally good user interfaces, were extremely small and light recorders, and they used a ubiquitous, cheap, and extremely reliable media.
Unfortunately, the medium was always hampered by certain flaws rooted in its inventor Sony's (now-surrendered) concerns about digital rights management (DRM). These limitations (especially the way it presented no method of transferring recordings MD to a computer) resulted in its rapid decline when other options arrived.
Today, the technology is still available only in a final incarnation, HiMD, which finally unlocks some of the medium's potential — it supports uncompressed CD-quality recording, and allows easier digital uploading of recordings.
But these concessions are a classic case of too little, too late. The belated USB upload process requires Sony's proprietary (Windows-centric) software (but the latest models of HiMD did remove effectively all restrictions on file transfer at least).
Used MD recorders can still offer an excellent and very affordable option for recordists, but media is getting harder to find, and the best generation of recorders (in my opinion, the Sony MZ-R50 and R37) are now almost ten years old.
HiMD on the other hand, while an excellent technology, is no longer compelling at its price point, especially as media becomes hard to find.
For more information on the minidisc and HiMD formats, see minidisc.org (or as I said above, this page of mine).
digital tape (DAT)
DAT (few advocates are still to be found I suspect) is probably the worst portable recording option today. It is unwelcomely sensitive to precisely the environments the budget traveler is likely to record in: the dirty, the wet, the windy, and smoky. It often cannot be made particularly stealthy. It is very battery-hungry.
Most importantly, it is a dead medium: most manufacturers have ceased to produce DAT tape mechanisms. Deck repair is a serious problem. Media will be increasingly hard to find.
You may be able to pick up a used deck and some tapes at a fraction of the original price, but I wouldn't bother; would you buy a high-quality Betacam video camera?
Two words on professional open-reel tape recorders such as the justly-famous Nagra: don't bother.
While truly world-class results are of course still possible with this equipment, unless you use something like this professionally for some reason, it's simply not a rational investment today. In addition to the problem of upkeep, expect a constant struggle against deck size and weight, and constant chafing at media cost, rarity, and fragility.
Analog cassette tape (and it still does have users) is, it can be said, at least inexpensive and not particularly finicky.
It does have some (albeit meager) advantages no proprietary batteries, a brain-dead user interface, easy-to-find-all-over-the-world cheap media but the quality of recordings made on consumer tape cannot compare to any current digital option except the cheapest digital dictaphones.
Au contraire: consumer cassette recordings are almost defined by, and usually easy to recognize because of, their hiss, reduced frequency range, reduced dynamic range, and particularly types of audible distortion.
Microcassette recorders (i.e. dictaphones) have all the disadvantages and none of the advantages of regular tape. But sometimes I suppose you go into the field with the recorder you have... not the recorder you want.
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