Bits and bytes are mighty tasty. How does one store them for maximum freshness?

Portrait of the Artist as an IT Professional

Artists, designers, composers, mixers, and audio folks of all stripes must be conversant with the tools of their trade, and in this digital world, that means playing some role in managing hardware and software. This is where your hard-won creative output of blood, bits, and tears will be stored…and possibly lost.

This article is meant to help frame the challenge of selecting hard drives for one’s own home studio. I’m no IT professional, but I’ve been dealing with digital multimedia production for nearly 20 years, so I’ve at least got some perspective as a creative professional. I’ve seen my share of hard drives literally catch fire, glitch out, play the national anthem, and just simply stop working, sometimes one a day for three days in a row. I’ve had to manage IT issues from single machines to small clusters to an entire small studio. What follows, then, is what home-studio creatives of all stripes should consider when thinking about storing their creative output on hard drives.

This article is won’t give you a fish to eat for a day; the goal is to teach you how to fish, so you can feed yourself for a lifetime. Very few specific purchase recommendations will be made so that you can simply make a more informed decision based on your own personal needs.

There are loads of hard drive buyer’s guides online, and Wikipedia is a definitive source for things like RAID levels and hard drive terminology, for anyone who’d like to read more on this topic.

Hard Drive Types

There are two general kinds of hard drives: Mechanical and solid state.

Mechanical hard drives are what we all know, love, and often abhor. They have metal plates with data magnetically encoded on them. They are very susceptible to jostling, physical damage, and magnetic damage. However, they are also reasonably fault-tolerant. When things go awry, utilities or the drive itself can try to work around the problem. They also can give clues as to their imminent failure, such as odd noises, slow mounting or read/write times.

Solid state hard drives are essentially large flash memory devices, like Compact Flash cards. There are no moving parts. They are lightning-fast, small, light, and much less prone to physical or magnetic damage. They suffer from two things: High price and catastrophic failure. They’re extremely expensive per gigabyte, and when a solid state drive fails – not common, but they do, I’ve seen it – it fails immediately, irrevocably, and totally. To use a materials science analogy, mechanical hard drives are like aluminum, and solid state hard drives are like carbon fiber.

Of course, this refers to just the drive itself, which usually lives inside the chassis of a computer or in an external enclosure. Enclosures, in my experience, are just as likely to fail, and often more so, than the drives themselves. Fans, power supplies, and the dreaded power-brick inline transformers of these enclosures are all possible failure points. Knowing how to get a drive out of a dead enclosure is a good skill to have!

Enclosures also tend to influence how these devices are attached to our computers. This naturally takes us to our next topic.

Hard Drive Interfaces

At the time of this writing, USB 2.0, Firewire 800, and eSATA are the most common hard drive connector standards. More exist, from legacy formats to enterprise-level: Firewire 400, iSCSI, Fibre Channel, and more. A little internet research can help you learn more about those other flavors. However, for simplicity, I stick with drives with all three of those initial connector types. USB 2.0 is so universal that I can pretty much take a drive and plug it into anything, which has merits for massive file transfers and emergencies. Firewire 800 is the MacOS X standard broadband connectivity standard (the new Thunderbolt connector notwithstanding), and has decent speeds. eSATA often requires third-party cards to support, but when it’s available it’s the fastest kid on the block. Having at least two options, and perhaps all three (or more), can help leverage your hard drive investment in case you change computers, or computer platforms, in the future.

Types of Hard Drive Storage Needs

Not all hard drives are created equal. Likewise, not all storage needs are the same. It turns out that what you want for your internal system drive may not be the best kind of drive for your daily storage needs, or for your long-term backup needs.

Below, I’ll cover five types of storage needs: System and app storage, scratch disks, external working storage, and long-term project storage.

System and Application Storage

This should be all one’s internal boot drive should be responsible for. This lets the drive stay clean and defragged, since only log files, preferences, and the like will be written to it. Speed isn’t the top concern here, but it does help; a solid state hard drive might boot a machine and launch apps up to twice as fast as a standard 7200rpm hard drive. Most laptops ship with 5200rpm drives, so upgrading to a 7200rpm will make a difference.

These drives should always be backed up with bootable copies. This means using a disk cloner application (I prefer SuperDuper!) to ensure that the copy is fully bootable, so if something disastrous happens, you can just plug in your bootable system backup disk and it’s all good.

Scratch Disks

Scratch disks are where apps – and sometimes RAM-constrained systems – write temporary files to facilitate things like undo, revert, and rendering crossfades or audio effects. The funny thing about scratch disks is that you want ultimate speed and don’t need backup of its data, since ideally no user-written files will be stored there at all. This is theoretically a good use for solid state hard drives, which boast lightning-fast access but aren’t as large as standard hard drives at the same price.

In fact, the smaller the drive, the faster the access speeds will usually be. Scratch disks should be small and as fast as possible without compromising their utility.

External Working Storage

This is what most of us know, love, and hate about hard drive storage. What will you be writing to and  reading from for your actual work, like session files? There are a number of approaches to this, which will vary based on each artist’s risk tolerance and budget, but it all boils down to balancing speed, capacity, reliability, redundancy, power consumption, and cost.

• Speed. 10,000rpm drives can be fast, and solid state drives are faster still, but one pays for such speed. Striping multiple slow drives together as RAID 0 can really boost read and write speeds, at the cost of buying two or more drives and not gaining anything in the redundancy department (see below). But some applications, like video editing, demand the fastest disk access possible.
• Capacity. You need a fair amount of space for your files, especially if you’re involved in high-definition audio and video, but sometimes too much space will cause problems. Pro Tools, at the time of this writing, can only play back from, or record to, volumes of 2TB or less. Most other apps do not have this limitation.
• Reliability. All drives will fail. The more drives you have, the more frequently you will have drive failures, statistically speaking (so think about this when you consider multi-disk RAIDs, below). The cheapest drives usually aren’t the most reliable. Many consumers are unaware that there are specific enterprise-class hard drives out there that are held to higher quality standards than others, and these can be good values relative to piece of mind.
• Redundancy. How many copies of your data do you have? The answer must be “more than one” if you are to be reasonably secure in preserving your life’s creative work. Many folks simply buy one drive and back it up to a second drive of the same size. This works, but it’s not a constant process, since this is done manually or via scheduled synching. Others opt for the RAID option (level 1, 5, 6, or 10), which ensures that every write to disk is duplicated automatically. One drive goes down and, based on what RAID level you’ve chosen, you either have a backup or the remaining drives can rebuild a replacement disk automatically. RAID 1 is pretty slow, while RAID 5 (one of the more popular configurations these days) is a compromise between increased speed and distributed copies of data.
• Power Consumption. Part of the TCO – total cost of ownership – of a hard drive is how much you’ll pay on your electricity bill for using that hard drive. There are now “green” versions of hard drives that can draw less than three watts when not in use. If you’re running one or more RAIDs with lots of platters a-spinning, this can really add up!
• Cost. Greater speed, reliability, and redundancy all cost more. Your workaday storage isn’t a good place to skimp, but do remember that hard drives won’t last forever. Also remember that every external hard drive you buy, you’re buying a hard drive that you can’t remove yourself without voiding the warranty, and you’re paying for another power supply and case that isn’t working for you when it’s unplugged for long-term storage.

Long-Term Project Storage

That huge project is over; you’ve got raw recordings, tons of track bounces, massive sessions. Where do you put all that when you’re done?

The first choice is online or offline storage…this means whether it’s on a drive that’s normally spun up and plugged in, or if it’s archived on physical media that is being stored somewhere that’s not attached to your workstation or network. This “hot” or “cold” storage, as I tend to call it (as the term “online” means something different these days), depends on how often you might need it.

At the moment, there is, for better or worse, no other storage device that holds as much for as long for the price as a hard drive. Hard drives are also more shelf-stable and reliable than DVD-R’s. They may be a little heavy, but they are small, and the cost per gigabyte is low.

This has given rise to the hard drive dock, into which bare hard drives are inserted, mounted, copied to, and taken offline. This provides redundancy and backup at a very low cost per terabyte, and by spending most of their time offline, bare hard drives should last a good deal longer than a hard drive that spins all day long. Speed doesn’t matter as much in this usage, either: Sure, backing up to them may take a while, but do it when you go to bed at night and it won’t make a bit of difference, and buying slower drives can save money. Hard drive docks are also great for troubleshooting: If an enclosed hard drives goes down, you can extract it and pop it in a dock to see if the fault lies in the drive or the enclosure’s power supply.

The second decision is, if you opt for “cold” storage, whether you store the data locally or on a remote network (“in the cloud,” as they say these days). The primary challenge with cloud-based storage is transfer speeds. Every recording session I do, no matter how short or informal, will usually generate at least a gigabyte of data. Even though I have a fast internet connection, it’s asynchronous, as most of them are: The upload speeds are slower than the download speeds. For my purposes, I can’t make cloud computing work given how much data I generate. Note, however, that the new (at the time of this writing) service Gobbler is optimized specifically for Pro Tools users.

It’s great for backing up your personal and business files, though. Speaking of which…

Backups

Backups are usually considered copies of your data that aren’t in daily use. Therefore, the extra disks sitting in your RAID aren’t backups; they’re for daily redundancy in case of failure. Backups are meant to be retrieved when some seriously bad juju goes down. In my opinion, everyone needs both onsite and offsite backups. Why? Two simple reasons.

• Offsite backups, depending on how far away they physically are, won’t help you when a disk dies and you need to immediately repair or replace it when you’re in the middle of a project. I store mine more than 20 miles away from my home, and it would take 2 hours to retrieve them.
• Offsite backups, by their very nature, are kept less up-to-date than onsite backups…unless your backup drives are co-located in a data center, but that’s too complex and expensive for most home studios.
• Onsite backups won’t help you if your studio is burglarized, burns down, floods, or collapses in a tornado, tsunami, or earthquake. These are not paranoid doomsday scenarios. They can and do happen all the time, almost anywhere.

There are too many backup strategies to list, so let’s stay focused on hard drives for this purpose. I prefer to match capacities between the real, “live” drive and the backup, but to use drives from different manufacturers, or at the very least, have the live drive and the backup drive be from very different serial number ranges. This way if there’s a manufacturing defect in a drive, you can at least know that the other drive has less of a chance failing around the same time for the same reason.

Whether you use a hard drive dock with bare drives, fully duplicative external hard drives, or even cloud-based network backups, do it. One massive data loss on a project without backups can cost you money, but more importantly, it will betray a client’s trust in your professionalism.

Local vs. Network Storage

This article isn’t going to focus on network-attached storage, or NAS, devices for larger studios, so I won’t get into robust, scalable rackmount RAID units, JBOD, Fiber Channel and iSCSI devices. However, NAS can have a place in the home for a few reasons.

Many of us with home studios share a network with housemates, significant others, or families. Some of us have multiple computers within our home studios. In either case, sometimes multiple machines need to access the same files, and needing to have one computer dedicated serving files just isn’t cost-effective or sensible. That’s where NAS comes in.

NAS devices are either hard drives that plug into other devices via USB to act like NAS devices, like the Apple Airport Extreme Base Station, or are hard drives with embedded computers inside of them, and they plug into an Ethernet network just like a computer would. The only reason to consider this approach is for multiple computers to access the same files without needing an external host computer to provide the shared hard drive volume on the network. NAS devices and drives largely follow the same purchase decision points as single drives to, above, but backing up a very large NAS device can be tricky and/or expensive, so be sure to think about what your backup strategy will be before you traipse off and buy a 16TB rackmount NAS!

However, the speed of accessing that NAS is dependent on your Ethernet network. With gigabit network switches being so standard and cheap, this isn’t a big deal for small files. Factor in hefty media files, though, like audio or video and the fact that many studios rely on WiFi, which is further bandwidth-constrained compared to wired gigabit Ethernet, NAS can definitely try your patience.

So…How do I do it?

I don’t skimp on hard drives or redundancy, but I do absolutely have a budget within which I need to operate. How I have my hard drives arranged and how they’re used will be the topic of my next article. Stay tuned!

Pipes along the side of the road. This is the kind of "a-ha!" or "ooh!" moment recordists wait for!

[Just had to post something orange and slightly eerie. Happy Halloween, all!]

It was a quiet night in a San Francisco warehouse district: Calm wind, not a lot of people on the streets, the sun was going down. A bunch of pipes – probably for redoing water lines beneath the street – were stacked on the sidewalk, perpendicular to the street.

This is precisely the reason that I carry a small, handheld field recorder with me at all times. I shoved it into a few pipes to check out what I could hear. I got some really nice drones with that added pipe/tube resonance and comb filtering, which will definitely go in my growing and rather extensive “unsettling drone” library. Some of the car passbys in the street had a resonant, screaming quality, which may make good spaceship pass-bys as well, or aggressive layers for expressive car ‘bys.

But, I quite liked some of the passages where this drone mixed with the activity of the street. Today’s sound is recorded within a 12″ diameter concrete pipe about six feet long. A lone man walks down the street singing, followed by a bicycle, he continues singing then crosses the street in front of me, a breath of wind really amps up the resonance for a moment, and then a few cars pass by, kicking up loose asphalt. Although it sounds like a mix of street noise with a synth drone underneath it, this is unedited except for some compression and normalization. The imaging is incredibly tight because there was about six feet of 12″ pipe in front of the mic capsules, narrowing the stereo field.

[Sony PCM-D50 recorder, 90° capsule spread]

Lookit that man out there. He's quite a dish.

One of the best reasons to spend a weekend with other sound recordists is a chance to try out new gear. A classic nature recording technique is the use of a microphone set in a parabolic dish.

The general public knows of parabolics mostly from seeing people use them on the sidelines of sporting events. In nature recording, they’re for capturing species-specific sounds rather than ambiences. This is because the microphones in parabolic dishes are mono, and have sound pushed into them by the dish itself. This creates a very narrow “beam” of listening. Perceptually, parabolics seem like they “zoom in” on sounds, but this is simply due to such microphones just attenuating all the sounds outside that narrow cone.

Parabolics are also interesting because the frequency response is directly tied to the size of the dish. For most song birds, this is fine. Besides, making and transporting a 17-meter-wide dish just to get a 20Hz-20kHz frequency response just seems silly. At that point, you’re practically into SETI territory! :-)

I got the chance to use one at the Nature Sounds Society Field Workshop. The unit you see in the photo above was the one used by the founder of the NSS, Paul Matzner, so I was holding a bit of history: Hand-made of fiberglass and aluminum, the NSS archives have lots of photos with Matzner holding this thing. Had I looked at the archives before heading into the field, I’d have gotten a way better handling technique. Holding it by its edges introduced horrendous amounts of handling noise.

Today’s sound is from this unit, recorded at 5:01am at Yuba Pass, off California Route 49. As far as I can tell, this is a chestnut-backed chickadee. You can tell, even in this recording, he’s got a lot of pals around (woodpeckers and sparrows at least).

[DPA 4006 omni microphone in custom 1m parabolic dish into Sound Devices 702 recorder]

Neither dirt, nor fog, nor clouds of mosquitos keeps a field recordist from his crack-of-dawn tasks!

I’m finally unpacked and rested from the inspiring (and exhausting) 26th Annual Nature Sounds Society Field Workshop in California’s Sierra Nevada. Since my last post was a compilation of high-level personal experiences, I thought that I’d report back about what worked, or didn’t work, in the field on the technology side of things…as well as share a recording from our first early-morning field session.

• Outdoor Gear. My REI trail stool was instrumental in keeping my body still (I can be a fidgety so-and-so), the importance of which can’t be understated when your preamp gain is at 80% of maximum and you can hear birds’ wing flaps 20 meters away. [Hint: For nature recording, more layers of softer materials - like fleece, soft-handed polyester, and wool - are the best for staying warm and silent. Consider gaffer-taping your metal zippers, too!]
• Microphones. My primary MKH 50/30 rig performed brilliantly, with a strong signal-to-noise ratio even in the quietest moments. I also got a chance to try out a rather large parabolic microphone…more on that in a later post. [Hint: If you want a mic for nature recording, you need to be looking in the <-16dBA self-noise range, the lower the better.]
• Recorders. The ol’ 702 worked its usual wonders. I monitored as mid-side in the field, only converting to left/right once I returned. A +8dB side signal using Tom Erbe’s +Matrix plug-in made for a wide, enveloping sense of space without losing center imaging.  [Hint: Batteries drain faster when cold. Store spares inside your jacket, or in your sleeping bag with you overnight!]

The gear list across everyone was pretty insane: many Olympus LS10 recorders, several Sound Devices 744T’s, a Sony PCM-D50, and mics from DPA, Neumann, Røde, Sennheiser, and Telinga. Recording techniques varied from mono to mid-side stereo, XY stereo, ORTF, Jecklin discs, and even two binaural dummy-head rigs (see this site for a good explanation of all this alphabet soup). An outdoor mic directionality seminar helped to illustrate what each is good for, which was a rare opportunity and extremely educational.

Yeah, yeah, whatever. But what did it sound like?

Today’s sound was recorded around 5:45am on a day with a slight breeze and scads of ground fog. The location was Sierra Valley, north of state route 49 in the Sierra Nevada. This recording includes at least swallows (cave or barn, I’m unsure), American bitterns, red-winged blackbirds, white-faced ibises, yellow-faced blackbirds, and a bullfrog, and certainly more that I can’t identify.

Get those headphones on and close your eyes…

[Sennheiser MKH 50 and MKH 30 recorded as mid-side pair into Sound Devices 702 recorder]

I’m just back from the 26th Annual Nature Sounds Society Field Workshop. I thought that I’d share some video diary entries that I shot with my new iPhone 4. As far as I know, this is the first time that video of this workshop has ever been seen online.

I’ll be sharing more of the learnings, experiences, and recordings in the coming weeks. For now, I hope you enjoy this set of dispatches from the field.

[You can read about the gear I took with me in a previous post.]

European Starling, hero mutterer and goer-on-forever.

[Photo by donjd2 (CC)]

The European Starling is a common bird that yammers like a manic street preacher. They have a really varied voice, quite expressive for standard birdsong.

I recorded one in my backyard and found that the frequency content really held up well under creative processing (unlike the raspy, high-mid-peaked calls of crows). Today’s sample is a continuous utterance from a starling that’s been pitched down 800 cents and run through the GRM Tools PitchAccum filter, which I just adore for thickening sounds in unusual ways.

For me, it’s evocative of an exotic or alien ecosystem, especially with those other weird R2-D2-like tones in the background…but, again, the vast majority of those tones are being made by a single Starling.

[Sennheiser MKH 50 into Sound Devices 702 recorder]

Recording crows...it's murder, I tell ya.

Thanks to SocialSoundDesign.com, I’ve discovered the joys of iZotope RX, an amazing noise reduction tool that has made real one of my hopes: To capture reasonably clean sounds in my own back yard. I live pretty close to a major highway, so getting usable recordings has been impossible up until recently.

A neighbor’s willow tree harbors a very chatty and schizophrenic-sounding European Starling. While recording some of its yammering, a crow flew in, circled over me three or four times not more than 20 feet overhead, and then left, as if to warn me that I was too close to the community tree in Birdsville. I tracked him with my mic as he flew. Well, after that, I packed it in. It wasn’t going to get better than that.

The sounds of the background are still there, of course, but much less prominently than they were. The crow was close enough and I tracked accurately enough that while there’s a volume dropoff, there’s not a lot of apparent Dopplering. The caws are fairly shrill, so don’t turn this up too loud. (Note: From a sound design standpoint, pitch shifting crow vocalizations down doesn’t sound that interesting. They sound like asthmatic dogs coughing up a cat’s hairball, and not in a good way.)

[Sennheiser MKH 50/30 mid-side stereo pair with into Sound Devices 702 recorder]

Magnet + Hydrophone from Noise Jockey on Vimeo. [Did you miss my first video?]

It is what is says, people! ;-) I ducked out some handling noise, but for the most part the audio is unaltered. Enjoy.

Use gear made by those who make gear they themselves use, and make gear for other users. That's prosumerism.

[Gigantic über-thanks to Tim Prebble and Richard Devine for their contributions to this article.]

The title of this article isn’t what you think it is.

You can’t shop for electronics or technology without hearing “prosumer.” People assume this portmanteau is a contraction of “professional-consumer.” Only marketing wonks have made it so.

That is neither its original meaning, nor the topic of this post.

The term was coined in Alvin Toffler’s seminal book Future Shock as a contraction of “producer” and “consumer,” predicting the merging of the roles of consumption and production into the life of one individual, primarily due to customization of mass-produced objects and the creation of highly specialized products. That is, person A makes widget X, who sells X to person B who makes widget Y, which person A, in turn, buys…it’s a massively networked set of cottage industries. This trend has exploded in the last decade. When Wired writes about micro-manufacturing and “no more factories,” we’ve probably arrived at a prosumer tipping point.

That, dear friends, is what this post is about. And yes, this is audio-related. Chances are, this article is probably about you, too.

Prosumerism: Why Now?

The growth of this trend can be largely attributed to the Internet and economic globalization for increasing individual access to tools, techniques, and materials. Things may be designed anywhere, be manufactured in the same factories that major brands use, and shipped anywhere…if it’s even a physical product at all. A prosumer can build pro-level anything in his or her own home by ordering parts from anywhere in the world.

If you doubt that we’re in the era of the Tofflerian prosumer, one need look no further than two trends: The proliferation of products that can be customized online, and the increase in cottage industries – often just one person – making technically advanced or unique products for niche markets that compete in every way with mass-produced products. Even if you’re not into Marxist theory, this shift has interesting implications for those of us who use audio hardware and software.

Prosumerism in the World of Audio

ZVex pedals and Livewire synth modules.

Let’s look at those two big themes as they pertain to the world of pro audio: Mass customization and the creation of niche/unique products.

First, “mass customization” is common in the world of audio hardware. There’s Michael Joly, who modifies cult-favorite Oktava MK-012 microphones to make them lower-noise and with better frequency characteristics. The well-known Oade Brothers who modify off-the-shelf, mid-level (the marketeer’s “prosumer” range!) audio recorders to produce lower-noise results with better dynamic range that compete with higher-end professional units.

Next, consider those who basically create gear for themselves, and then wind up turning that into a business to sell those products to others like them. You have Robb Nichols from Aquarian Audio, producing some of the best-quality, low-cost hydrophones out there. Dan Dugan of San Francisco makes automatic mixers used by huge networks in his one-room (albeit massive) workshop. Musicians make their own audio hardware, like the insane effects pedals Zachary Vex, and the analogue synth modules of Mike Brown (Livewire), Tony of MakeNoise, and Scott “Harvestman” Jaeger.

This doesn’t apply to just hardware! Shareware is made by individuals, to say nothing of audio plug-ins. Most apropos to this site, individuals like Chuck Russom and Tim Prebble, who use sound effects for a living as sound designers, create sound effects for other sound designers, bucking the aggregate-effects-house business model. I’d not be surprised if each of them will wind up purchasing each other’s effects collections…the ultimate in prosumerism.

The Benefits

What I think is most interesting and exciting, though, is it puts the users of this equipment into direct contact with the manufacturer. No marketing layers to penetrate, no call centers to deal with, no email-only front-line tech support. I don’t know how many of us take advantage of this, but it’s an amazing experience. The consumer directly can influence the producer by providing feedback, or even just doing something unique with the product that the producer never intended, and letting them know about it.

So…what’s all this got to do with you?

1. I know that some of my readers are these people I’m describing, so consider this the longest thank-you letter you’ll ever get for the killer products and amazing customer service.
2. If you use these products, close the loop. Call or email the Makers of Your Things and tell them what’s great, what sucks, how it can be improved, and what you’re using it for. Otherwise they produce things that get sent into an abyss, and I suspect that’s not what they want to do. They want to make things for people, not widgets that fly off the shelves for the absolute lowest cost. It’s about relationships.(Their attention to detail also can make for better products.)
3. If you’ve been wary about small-batch, hand-made products, that’s OK…and smart. But do some research and ask around, and you’ll find that there are a lot of very experienced and smart people out there making solid products. BUY FROM THEM. It stokes the independent spirit and gets money into the hands of the makers, not the sales department or marketing team.
4. If you’re interested in electronics or make things for yourself, get online and talk about it. The law of averages would suggest that you’re probably solving someone else’s problem, too.

Be a part of the greater ecosystem and community of products, or make some of your own. You’ll be all the richer for it.

Horse hair, water, mic, and wok lid. Now we're cookin'!

My last post featured teensy finger cymbals being dipped in water while resonating, recorded with a submerged hydrophone. This time we go a bit bigger.

Bowed cymbals are one of the classic clichéd horror movie sounds…clichéd because they’re awesome! (coincidentally, just yesterday, Chuck Russom posted some great examples on his blog.) I recorded some a while back, borrowing some cymbals from a friend at work who keeps his drum kit at work. During that session I also realized that the wok lid from my kitchen made similar sounds, but with a different timbre: More groany, throaty, less musical, but with a quality I liked.

So, I played the wok lid with a violin bow as I moved it into and out of a tub of water, again with the trusty Aquarian H2a-XLR hydrophone tracking to a Sound Devices 702.  The H2a can be overly bright on some material, but for this stuff it was pretty good! (Next time I should record the above-water sound to a second channel with a small condenser mic for more mixing flexibility.)

The recording below is 100% unedited except for some slight compression and normalization.

[Aquarian H2a-XLR hydrophone into Sound Devices 702 recorder]