I was recording at Breiðamerkurjökull when the weather forecast suddenly changed. It was nothing special, except that I had to row a kayak with another one in tow with a lot of recording equipment about 8 km on Jökulsárlón glacier lagoon before the weather would hit the area.
It fit, as soon as I got to land on the other side of the lagoon at midnight the fool weather arrived, so I just managed to pack all the equipment in the car and on the trailer before everything got wet. It was around two in the morning when I was able to leave. But I didn’t go far. I decided to sleep in the car near the high voltage power line (Byggðalína) on Breiðamerkursandi, south of highway no.1.
The next day it was dry, but still very windy. In fact, I could barely see Öræfjajökull glacier through a sandstorm. I decided not to be on the road with the trailer and the kayaks, but to wait until later in the day when it would calm down.
I could not sit idly by, but recorded in several places close to me. Including the high voltage line with all available equipment I had. With Omni & Cardioid microphones as well as Geophone and hydrophone which I use as a contact mic.
The result was quite amusing. By the time this happened, the strongest wind had subsided. But that moment a moisture was in the air, which caused a sizzle noise from the power line, which added a different sound and gave the recording a clearer picture of the recording location.
The recording below starts with the audible sound (microphone). Then slowly the contact mics are added . In the end and microphones faded out and you will only hear the sound from the contact mics (geophone and the hydrophone)
Because the microphone are located close to the ground in grass under the electricity pylons you will hear lot of „gray noise“ when the wind wipe the grass.
If you keep your attention Whimbrel are also audible.
So I explain the name of this blog, „Byggðalína“ is a name of high-voltage line that connects all the main settlements around Iceland. „Breiðamerkursandur“ is a name of a broad sandy wasteland south of Jökulsárlón Glacier lagoon.
I have used hydrophones for several years, mainly Aquarian H2a XLR and JFR piezo’s. But I have never been happy with the sound quality. Comparison is hard to find on the internet and most hydrophone recordings there have been fixed in a post process so it doesn’t give me clear information how it actually sounds. Most hydrophone manufacturers don’t give a standard or important information so buying a quality hydrophone for thousands of dollars can be a risky task. Last summer (2020) I spent several hours recording on Jökulsárlón Glacier lagoon. I noticed behind the sound of H2a was something very interesting soundscape which H2a couldn’t clearly capture. So I decided to get a better hydrophone before I continue to record in this lagoon. I contacted both B&K and Teledyne Reson to check the price and options. Both his manufacturers gave me useful information but the price was higher than I was ready to pay for a good car so I continued the search. Ambient has two interesting hydrophones but they do not show important information. When I ask for Frequency and S/N graphs, Ambient just sends me the user manual which is already on their website. Same with Cetacean Research and Dolphin Ears, which either give me strange answers or no answer So I continue to search through several manufactures. Suddenly and surprisingly I found Benthowave, a company which was ready to custom made hydrophones for me, hydrophones where I got all necessary information for my needs. It was almost too good to be true, so it takes me several weeks to decide to let Benthowave build my dream hydrophone. The base was built on BII-7122 but additional with balanced output w. BII-1082 ultra low noise amp and 15meter long cable. No problem, I would get it after 6 to 8 weeks! But that was too late for me. My recording project actually started that time in late May. Before that project starts it is necessary to build a customized floating platform and power supply for the new hydrophone which can take two to three weeks. So I ask Benthowave which low noise hydrophone they have in stock. It was only a single output BII-7121 with internal BII-1081 amp. Two weeks later they were in my hands. My first impression was a huge disappointment. I was almost sure I had thrown money out of the window. But after I build my second power supply, these hydrophones start to rock. It was two key figures that were important to know to let them work without problem.
1. While this hydrophone is so sensitive at low frequency, higher voltage means better performance to avoid internal amplifier overload/dropout. 2. These hydrophones are sensitive for EMF. From the power supply box (made out of metal) must be a wired ground connection to the water which will be recorded if any EMF pollution is around
Other things must be kept in mind because these hydrophones use an external battery power supply, but NOT Phantom power. Use a recorder which has „Combo input“, (XLR and jack input) or 3,5mm jack input. Use only Jack to connect the hydrophone to the recorder so you will never mistakenly get Phantom Power into the hydrophone. It might be possible to use Triton Big Amp for recorders that don’t have Combo input. But I haven’t tested it yet. I will write an update when it has been tested. I use non-standard XLR connectors in and out of the battery box so even blind men can not connect the hydrophones without correct cables.
Conclusion of the comparison I am not sure if this comparison gives a correct picture of the Aquarian H2a. Mine have a LOM phantom power adapter which has a small amount of gain and probably makes tiny changes in the frequency curve. Anyway, with this adapter it sounds similar to the original. I put this adapter to avoid extra noise which I got only in the SD744 recorder and with HPF off. This adapter also avoids other strange and unusual noises which I think is caused by the 48Volt phantom power which I think is too high. But with the adapter the H2a is driven by 5Volt. This comparison was done in Sundahöfn port of Reykjavik. In a corner which is mainly used for depreciated ships so it was quiet, without loud ship engine noise. The hydrophones were placed side by side in 1,5m depth with 2,5m separation, from a floating pier with two bonded boats. The gain on the MixPre6 was at 30dB for both hydrophones and HPF was off There is pretty much difference between these two hydrophones, both in frequency range and sensitivity. Benthowave BII-7121 frequency range is from 0,5 hz to 60 Khz at +/-3dB V/μPa. On spectrograms I can see it can as well detect sound up to 80Khz or as high as I can record at 192Khz. The hydrophone sensitivity is -158,7 +/- 0,2dB plus +26dB BII-1081 amplifier gain (-185dB) and self noise is 25dB μPa/1KHz. Aquarian H2a frequency range is 20Hz-4.5KHz +/- 4dB and the self noise is „low noise“ whatever it means. Sensitivity is -180dB re: 1V/µPa. My Aquarian hydrophones are not new, so new model might have increased sensitivity. Compared to BII-7121 it seems be close to -165dB. With the LOM Phantom power adapter the sensitivity is closer to -170dB re: 1V/µPa and the frequency range seems to be on spectrogram close to 100-7Khz. It was not easy to normalize the level of these hydrophones while they have so different frequency ranges. To do that I tried to normalize the level by listening to constant pump noise in the background in the recordings and make it as equal as possible in combination with the level meters. At the moment I can’t say much about the self noise. It could be difficult to compare these two hydrophones while they are so different in frequency ranges. I somehow expected to hear lower self noise in BII-7121. But it might be as good as it gets. It is -24dB below sea state zero at 1Khz, which is very good, even for much more expensive hydrophones. But to know exactly what it means for me I need to test them in quiet lakes. I will put an update here as soon as I have done that. I must say, the BII-7121 has very nice sound quality, Just as I expected. It is almost possible to hear the depth of the field, while H2a sounds flat and all high frequency is missing. But keeping in mind these two hydrophones have very different prices so in fact it is unfair to compare these two hydrophones. One piece of BII-7121 cost about USD 1,244.- (base price), while H2a XLR cost USD 194. I should rather compare Benthowave to Teledyne Reason like TC-4032 which cost EUR 3,640.- or Bruel & Kær like 8106 which cost DKK 86,470.- I think they will all sound similar. Benthowave seems to be built on rather cheap plastic materials and glue, it looks very fragile and seems to be not as robust as Teledyne or B&K. But as long as Benthowave can offer me the same or similar sound quality at a lower price I am happy with that. BII-7121 could have been heavier. It weighs only 95gr while H2a weighs 125gr which is even too light. The BII-7121 cable is Gepco MP1201 Quad Star. In the recordings below you can hear in some headphones an unpleasant „low frequency noise“ due to the wind. This is because there was a lot of wind on the day when this was recorded. The cables to the hydrophones were mostly up on the pier where the wind got an awkward amount of play around them. This „wind sound“ will usually disappear once I have built the „floating platform“ for the hydrophone. I will post pictures when its done, plus other experiments too.
Recording straight from the recorder, only add +12dB in post Benthowave BII-7121
Recording straight from the recorder, only add +12dB in post Aquarian H2a
Normalized recording BII-7121
Normalized Recording H2a
Recording with BII-7121 of a Tugboat propeller 250-300 meter away. This recording is straight from the recorder, no extra gain. Notice at 3:55 the amplify goes up and down. I am not sure what it is. I think it could be a strange behavior of the hydrophone when they are in „strong“ current or water flow, in this case from the tug propeller, which was though not very strong. It could be as well the ground cable which lost contact to sea while waves pass the pier. H2a normally makes a low frequency noise in water flow or current. But I am sure this current was not strong enough for H2a to make a noise. I will write an update as soon as I figure out why BII-7121 acts like this. All updates will be added here below by date.
Quality open headphones are recommended while listening at mid level. If the media player doesn’t start to play, please reload this individual blog in new tab or frame
Update 9th of May 2021 ——-
Hydrophones with frequency range down to 1Hz are very sensitive for all movement in water or water flow, which seems to cause an overload for the internal amplifier so the audio output turns on and off while it happens. At the moment I would recommended for everyone who like to order Benthowave hydrophone to ask for custom HPF at 10Hz or 20Hz, otherwise the hydrophone will be only usable during calm days If default HPF is in the hydrophone then is it necessary to make some kind of „flow noise reduction“ for the hydrophone, similar protection cages which CRT make for its own hydrophones. Rycote BBG 25mm fits perfectly for this BII-7121. But that is not the final solution. Original BBG did not work well so it needs some changes which I am working on. I will post an update later when I think I have found the final solution.
Update 30th of August 2021 ——-
The BIG-7121 tested with a 25 volt power supply (with six 18650 Li-Ion cells). It does not completely fix the overload / dropout in the amplifier. Compared to 16 volt and recording from SOT Kayak the hydrophone can now withstand much higher waves (up&down) and tide current (@8m depth)
Update 17th of October 2021 ——-
Underwater recording with 25 volt power supply @3m depth. Listen here
Shortly after I set up my gear in a safe spot near the lagoon beneath the Svínafellsjökull ice fall. I heard thunder behind the Hafrafell mountain.
Two minutes later and suddenly all icebergs in the lagoon began to move around like corks in a boiling pot. Big waves paralyzed the shores of the lagoon, in some places for many meters.
„Shit“ was my first thought. „I was not in the right place“. I should have been on the other side of the lagoon and closer to the glacier, where I have spent hours and days in recent years trying to record incidents like this without success. I ran to the lagoon to see what was going on.
…Or maybe I was lucky to be where I was. I saw big waves go far up on the shore at the place where I have been recording the past years. I probably would have damage or destroyed the Phantom power adapters inside the hydrophones XLR´s.plugs
Thanks to COVID I was now in a place which has been impossible to record because of the tourist explosion in recent years.
Two microphones were now placed under a high steep crawl on the lagoon´s west bank, 5 meters above the lagoon surface. Below the microphones, two hydrophones were put in the lagoon between big rocks to prevent them from getting crushed or touched by icebergs. It was a bad placement for a successful underwater recording. But I remember quite well what happened in this lagoon few years ago. So I was sure I would lose them both and probably something more if I threw them deeper into the lagoon.
Although the outcome is OK, even though the hydrophones did not pick up the whole soundscape underneath the lagoon’s surface.
The glacier calving starts in this recording at 3:15 min far away and behind the Hafrafell mountain, so it doesn’t sound very loud. But it makes a big wave in the lagoon which makes a chain reaction of a few other glacier calving.
Just before the first incident you can hear the hydrophone pick up a sound of crushing ice. It would have been much louder if the hydrophones have been deeper in the lagoon. But recording glacier lagoons is not an easy task when the lagoon is full of ice which can flip without warning.
This recording was made in the late afternoon so traffic noise from rode no:1 is audible in the background. But compared to recent years, it is nothing. Thanks to COVID.
Quality open headphones are recommended while listening at low to mid level, or in speakers at medium level.
(mp3 256kbps / 48Mb)
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Recorder: Sound devices MixPre6
Mics: Lewitt LCT540s (NOS) & Aquarian H2n XLR (Spaced AB)
Pix: Canon EOS R
Last month I published hydrophone recording „Crawling glacier“ from the lagoon beneath Svínafellsjökul icefall.
The original recording contains two other channels with the sound above the lagoon.
It is not as clear in this short mp3 file as it is with headphones in the field, but during the recording it seems to be possible to hear the flow of the icefall though the valley. Its is a slow event. It usually starts high above in the mountain with rumbling sound and then slowly moves in a shock wave as a silk smooth „white noise“ though the valley all the way to the toe of the icefall. Regularly the ice moves faster in some places when the pressure get high. Then it cracks, some parts brake off and other just crawl faster which is usually audible for everyone.
This behavior of the glaciers is not often audible during the day because of traffic, wind or the clear sun which can easily disturb the sound waves in the air. Then it is also too slow for impatient listeners. Nights are usually the best time to hear this sound of the „flowing mass“. Changeable nature or different types of glaciers will also play a big rule how it acts and sounds.
Quality open headphones are recommended while listening at low to mid level, or in speakers at medium level.
(mp3 256kbps / 44,3Mb)
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Recorder: Sound devices 788
Mics: Aquarian H2a-XLR & Sennheiser MKH20
Pix: Canon Eos M
It is a special feeling to stay close to a glacier. It’s like standing near a wast monster that is constantly moving, but very slowly. Everywhere around this flexible ice the gravity of the ice is visible. Glaciers usually have strong smell of fresh oxygen that glaciers have captured in ice and compressed in to locked bubbles for hundreds and thousands of years. This smell from the past is like from another world, probably because today has much more carbon dioxide in the atmosphere than it has been for 800 thousand years at least. Glaciers also make sounds, sometimes quite loud, from falling drops of water to earthquakes, but most of these sounds are not audible to human ears. Glaciers make constant sound in water which needs hydrophones to capture, as can be heard on the following recording. I can not say I have been lucky in recording glacier sounds in years past. I’ve always been at the wrong place at the wrong time when glaciers produce “big sounds”, but after many hours, and several days on the same spot, I got something interesting which is worth listening to.
One of those days was 5th of June 2015 when I was at the glacier lagoon neneath of Skaftafellsjökull glacier’s icefall. This lagoon is not big, probably around 500m squared, but the depth is around 80 meters so the soundscape beneath the surface can be pretty exhilarating when the glacier is crawling at the bottom of the lagoon.
I put two hydrophones in the lagoon and two microphones on a nearby hill and recorded there for almost fourteen hours. The gain on the recorder was almost equal on all channels, or around 48dB, and during these 14 hour session the soundscape was different mostly because the glacier surface melts differently during the day then during the night with different water flows into the lagoon. All the time the glacier was grinding the bottom of the lagoon so under the lagoon’s surface the soundscape was much nosier than above.
Then just before midnight the glacier did a “big move” (starts 25:00) which lasted for several minutes, crawling with cracking and scratching sound. The soundscape down in the lagoon sounds really strange and surreal, but the listener must keep in mind that sound travels much faster in water than in the air. The soundscape above the lagoon was different. It was possible to ‘feel’ or ‘see’ through the audio the movement of the whole Svínafellsjökull glacier icefall through the valley. But that recording will be for another soundblog.
Quality open headphones are recommended while listening at mid level, or in speakers at medium level.
(mp3 256kbps / 63Mb)
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Recorder Sound Devices 788
Mics: Aquarian H2a XLR
Pix: Canon EOS M
The 14th of September 2014 over 100 people met in a ceremony in Arnarholt, west of Iceland, to introduce the tree of the year. This tree is 105 years old European Larch (Larix decidua) so it is one of the oldest tree in Iceland .
The one hour ceremony included speeches, songs and valid measurements of the tree.
The tree was 15,2 meter high with 2 m circumference.
The following recording does not include the whole ceremony. The problem was that all the speeches were trough megaphone so the sound was awful. But the songs were ok and one speech about history of the tree too. The recording ends with another recording I made after the ceremony under the tree with binaural array and contact mics on the tree bole.
Tré ársins 2014
Í Arnarholti í Stafholtstungum var 105 ára Efrópulerki útnefnt tré ársins þann 14. september 2014. Hátt á annað hundarð manns mættu við hátíðlega athöfn og hlýddu þar á ræður og söng. Þá var tréð mælt með löggiltum hætti og reyndist það vera 15,2 metra hátt.
Meðfylgjandi upptaka er ekki lýsandi fyrir það sem gerðist við athöfnina enda upptakan talsvert styttri.
Menn töluðu þar óspart í afar slæmt hljóðkerfi sem ekki var áheyrilegt. Eftir stóð þó söngurinn og ein ræða þar sem stuttlega var sagt frá sögu trésins og þeim tveimur mönnum sem að gróðursetningu þess komu. Í enda upptökunar má heyra vindinn gæla við trjátoppana og hljóðin innan úr bol trésins tekin upp með „kontakt“ hljóðnemum.
Full lýsing á dagskránni þennan dag er annars ágætlega lýst í Laufblaðinu, Fréttablaði Skógræktarfélags Íslands.
Upptakan er birt með leyfi söngvara.
I got a grant to record nature sounds in the Vatnajökull national park from the association “Friends of Vatnajökull”. It was not a trouble free trip, but anyway it was very instructive and I recorded many hours of very interesting and lovely sounds. Most of the recordings are long and unbroken. Some of them are up to 6 to 10 hours long so they contains many things I have never heard until now when I am registering the collection and searching for material to publish.
In 22nd of May I spent most of the day near Jökulsárlón glacier lagoon. I recorded around three hours in the lagoon with hydrophones. I was located close to the ejection because there it was most likely to catch some wild life activity.
When I started following recording the current was flowing out of the lagoon. Three or five seals were diving nearby between the icebergs which slowly were moving towards the ejection.
It was stunning when I put the hydrophones in the lagoon.
What a sound! It was much louder than I thought and was both stunning and frighten.
The several thousand years old ice was melting with cracks, screeches and scratching the bottom of the lake. Sometimes I could detect a deep rumble sound in a distance, probably when icebergs were scratching the bottom of the 200 meters deep lake. Comparing to all those loud sounds, everything was peaceful above the surface.
Hljóðin í Jökulsárlóni. 1. hluti
Ég fékk styrk s.l. vetur til að hljóðrita hljóðvist Vatnajökulsþjóðgarðs frá samtökunum Vinum Vatnajökuls. Það gekk á ýmsu á meðan á því stóð en á endanum var ég komin með mikið af áhugaverðu og skemmtilegu efni. Mikið af þessum upptökum eru langar og ósltitnar eða 6-10 klst langar svo ég hef ekkert hlustað á fyrr en nú þegar ég stend í því að skrásetja upptökurnar.
Þann 22. maí var ég staddur við útfallið við Jökulsárlón og hljóðritaði undir yfirborði lónsins með vatnahljóðnemum. Bæði hljóð og hljóðstyrkur kom verulega á óvart. Þarna var aldagamall ísinn að bráðna með hvellum og ískri um leið og hann skrapaði botninn á leið sinni að útfallinu. Öðru hverju mátti heyra drunur einhvers staðar utan úr djúpi lónsins og stöku sinnum mátti heyra hljóð sem hugsanlega komu frá 3-5 selum sem syntu ekki langt frá upptökustaðnum.
Það var óneitanlega mun háværara niðri lóninu en á yfirborði þess.
In February I went to Geysir in Haukadal with my recording gear. The plan was to record the sound in Geysir and other hot springs in the area with hydrophones. But when I arrived it was both windy and freezing cold so I did not make as many recordings as I expected.
Anyway, I got some recordings that I mixed together in one 20 minutes session.
It started with eruption in hot spring named Strokkur. It usually erupts every five to ten minutes and is one of the most attractive things in the area today.
Then, we dived down to the tube of Geysir. It is now some decade since it erupted automatically so now it is just a quiet deep hole in the ground full of hot water.
Then Strokkur erupted again before we dived into the “blue side” of the hot spring Blesi.
After several minutes Strokkur erupted again and we dived into the ”deep side” of Blesi.
Then we went to the surface and listened to two eruptions on Strokkur in a fellowship with two tourists.
Geysir, Blesi og Strokkur.
Í febrúar gerði ég mér ferð í uppsveitir Árnessýslu með upptökutækin. Var komið við á stöðum eins og á Geysi þar sem hljóðnemar voru brúkaðir bæði ofan jarðar og neðan. Vegna roks, kulda og myrkurs náðist ekki að hljóðrita allt það sem til stóð, en eftir stóðu þó upptökur sem hér hafa verið dregnar saman í stutta 20 mínutna langa hljóðmynd.
In Iceland it is possible to find many hot springs all over the country. Many of them have optimal temperature for bath and to relax. For centurys people have piled stones and turf around some of this known natural hot springs.
In the beginning of last centuries many of this natural hot springs were used to teach people to swim. Soon, many communities all over the country built real swimming pools of concrete near these springs.
One of these places can be found at Krossholt at Barðastönd, Southwest Iceland. There is Krosslaug, a 12 meters long swiming pool, built in 1948. There is also newly built natural hot tub, build on a hot spring in traditional style. It was the Youth Association of Barðaströnd County who piled this tub with stones, gravel and turf.
From the bottom through the ground of the tub comes the warm water with bobbles that gives relaxing sound while laying there with the ear below the surface. You can hear the bobbles moving upwards trough the gravel deep from the ground under the tub.
This recording was made with hydrophones at 15th of June 2012.
Another interesting recording from Krossholt, nearby place is: Opus for power line, bass, wind and birds.
Krosslaug í Mórudal við Barðastönd.
Á Birkimel við mynni Mórudals, hefur myndast þjónustukjarni Barðastrandar.
Það hefur reynst mér ótrúlega erfitt að afla sögulegra heimilda um þennan stað á vefnum. Því segi ég aðeins það litla sem ég tel mig muna.
Á sjöunda til níunda ártaugar síðustu aldar var þar skóli, félagsheimili, kaupfélagsútibúð og litilsháttar iðnaður. Þar var einnig reynt að koma upp fiskeldi. Það fór á hausinn.
Í dag er staðurinn líklega betur þekktur fyrir ferðaþjónustu. Stéttarfélög eru þar með orlofshús sem og ferðaþjóunsta sem rekin er frá nærliggjandi bæ. Víða í Mórudal er að finna volgar uppsprettur. Sundlaug var reist við eina slíka í fjörunni neðan við Krossholt 1948. Hefur hún átt það til að fara nokkuð illa í vondum veðrum. Vorið 2011 var laugin tekin í gegn og var þá hlaðinn heitur pottur að ég held yfir volgri uppsprettu fremur en borholu..
Það er ákaflega notalegt liggja í þessum potti í makindum með eyrun undir yfirborðinu og hlusta á volgt vatnið og loftbólur streyma upp úr jarðlögum pottsins. Meðfylgjandi upptaka var gerð í pottaferð 15. júní 2012.
Önnur áhugaverð upptaka sem gerð var við Krossholt er: Tónverk fyrir háspennustrengi, bassa, vind og fugla.
Í fjöruborðinu fyrir neðan Europe Villa Cortes GL hótelið á Tenerife er sjávarlaug. Sá ég fáar manneskjur synda í þessari laug. Hún leit því út fyrir að vera frekar líflaus. En þegar betur var að gáð var hún full af lífi. Í lauginni var urmull krabba, snigla og annarra kvikinda sem ég kann lítil deili á.
Síðla dags þann 22. desember 2011, rétt fyrir sólsetur, stakk ég hljóðnemum í laugina og gleymdi mér í rúman klukkutíma við að hlusta á einhver kvikindi gefa frá sér hljóð. Í bland við öldunið og fótatak fólks sem gekk um laugarbakkann mátti heyra ýmis hljóð. Öðru hvoru skvettust öldur inn í laugina en háværastir voru líklega sniglar sem nörtuðu botn og veggi laugarinnar í ætisleit.
In the beach below the Hotel “Europe Villa Cortes GL” at Tenerife is a sea pool. It was probably build some years ago for people to swim, but today it is full of all kinds of algae, snails, crabs and other creatures, so it looks not popular for humans.
In the afternoon at 22 of December 2011, I put hydrophone in the pool and recorded more than one hour of mystique sound. Most audible sound are rumbling sound from the surf. Sometimes the waves goes all the way in the pool with splashing sound and sometimes footsteps can be heard when people walk by the pool side. But there is also many other sounds from organic creatures, most likely from hungry snails scratching the pool surface.
HLJÓÐMYND - SOUNDIMAGE 