Tag: Equipment

The H2a hydrophone from Aquarian Audio is a mid-range hydrophone, allowing high quality recordings for professionals, whilst remaining affordable for marine naturalists.

Like most hydrophones, the H2a is powered via a compatible recording device. Available with either a TRS 3.5mm jack (plug-in power required), or XLR connector (phantom power required) and a variety of cable lengths, you are sure to find an option suitable for your requirements.

How We Tested

We tested the H2a hydrophone across two days in varying weather conditions in early June 2021.

Our kit was made up of the 3.5mm jack H2a hydrophone, in conjunction with an old DR-05 Tascam recorder and a pair of earphones. The DR-05 is actually a discontinued model, however we do sell it’s successor, the updated DR-05X. The H2a will work well with any recorder with a 3.5mm port that can provide plug-in power. Many recorders offer this ability, but if you are unsure please do check your manual.

Setting up the hydrophone system was very straightforward. Once plug-in power was switched on via the recorder’s menu settings, we simply plugged in the H2a to the mic-in socket and were ready to begin.

Tests were performed in a number of environments including rockpools, off a small boat in deeper water and a controlled environment (container of water). Between these locations, we did find adjusting the gain accordingly was necessary, however this was straightforward, using the Tascam recorder’s input level controls.

In shallower, more disturbed water we tried attaching the cable to a makeshift ‘boom pole’ aiming to gain greater control over the movement of the hydrophone while reducing handling noise.

It is built to be durable, with a stainless steel core and rubber covering, but we still handled it with care and rinsed and dried it after each use. Aquarian themselves say the H2a can survive accidental drops, however we chose not to test this!

Recordings were made on the Tascam device, to a micro-SD card and then transferred to a computer. The open-source audio program Audacity was used to view the waveform, including adjusting levels, and also allowed us to plot the frequency spectrum.

What we found

Our initial impression was that the H2a was surprisingly lightweight and compact, measuring just 25mm x 46mm (without the cable) and weighing little over a hundred grams. This made for easy packing in a small rucksack.

The hydrophone comes in neat cardboard packaging which is not particularly suitable for use on location. Despite the hardiness of the hydrophone itself, it would certainly provide peace of mind to purchase or use some form of carry case. We would not, however, recommend a waterproof case as it may trap moisture and salts that could eventually lead to corrosion.

The hydrophone is highly sensitive and so was vulnerable to signal overload if knocked accidentally or handled roughly. During recording, our main obstacle was noise from cable handling, which was noticeable during playback. This is to be expected with any hydrophone and certainly was not the worst I have experienced, but was still slightly frustrating. We quickly learned to ensure the cable was lowered ‘hand over hand’ into deep water to minimise noise.

Even with only a 3 metre cable, slight tangling did occur, which over time could lead to damage. For future uses with longer cables we would consider investing in or making a cable spool/reel. A spool would likely also reduce the experienced cable handling noise.

In shallower water, especially along the tide line, the makeshift pole attachment was very successful and made a significant difference to cable noise level. It also allowed us to position the hydrophone with precision and avoid damage that could have occured from the stronger waves dragging it towards nearby rocks.

When working from the boat in deeper water, we simply released the cable by hand as the current was slow. We found the shape and weighting (high specific gravity) to be a clever design that kept the hydrophone more-or-less vertical even in currents. Although it is worth noting that we only tested this ourselves in relatively slow moving water.

Below is a sequence of recordings taken in varying locations. The first exhibits the sound produced by the paddling of the small boat. The hydrophone performed very well while being dragged behind the boat, catching the bubbling as the paddles broke the surface.

Of particular interest to us in the field was the man-made noise pollution from the nearby (0.5 miles away) docks. Despite being rather un-noticeable by air, loud hammering was clear through the hydrophone.

The final recording in the audio above was taken at a rising tide, with gentle waves shifting the sand and sediment below the hydrophone.

While we had heard reports that some people have found sensitivity dropping off at higher frequencies with this unit and other hydrophones, our field tests produced recorded sounds up to 10kHz easily.

Our Opinion

Clear audio with limited unwanted noise was easily produced with the H2a hydrophone. It provides a fantastic way for ocean lovers and scientists alike to explore life underwater.

A few practical accessories such as a pole and spool would be worth considering as they can really improve audio quality while also making work in the field just that little bit simpler.

With further experimentation and potentially a bit of luck with interesting sound sources, I am confident that the H2a will continue to yield high quality recordings at a very fair price point.

The H2a hydrophone is available from the NHBS website on its own or as part of a kit including the Tascam DR-05X recorder.

Note: When deciding upon a model it is recommended to choose based first and foremost on compatibility with your recorder’s connector type. XLR is however, often the preferred choice for professionals due in part to reduced electromagnetic interference.

Visit nhbs.com to view our full range of hydrophones. If you have any questions about our range or would like some advice on the right product for you, then please contact us via email at customer.services@nhbs.com or phone on 01803 865913.

Winter migrant season is in full swing, and birders across the country are enjoying the spectacle of the ducks and geese that each year visit our shores. For the birder, no piece of equipment is more important than a good pair of binoculars, and this month we see two new additions to our range in Kite’s Ursus and Falco models.

Kite have been a powerful name in the crowded binocular market, producing high quality optical equipment for decades, and we were excited to see their new, beginner friendly binocular model land last month.

The Ursus is an entry level range, aimed at providing a quality experience for an affordable price. Easy to use and robustly built, boasting a waterproof coating, nitrogen filled interior to prevent condensation and rubber coating to protect the inner workings from impact, they are well-placed for the beginner or for a birder on a budget. There are four models, the 8×32, 8×42, 10×42 and 10×50. Generally speaking, birders will find binoculars with 8x magnification best for their needs, while a lens diameter of 42mm is generally the optimal trade off between being small and light enough to carry conveniently and allowing enough light through to provide a sharp, clear image. More information on choosing the right pair of binoculars for you can be found on a previous blog post, How to Choose a Pair of Binoculars.

Joining the Ursus, the mid-range Falcos are also new to NHBS, with the same selection of models. These are something of an update to the older Kite Toucans, an excellent set of optics in their own right, so we were curious to see how the new model measures up.

With all this in in mind, we were excited to take our new additions into the field and put them through their paces.

How We Tested

On a cold winter morning we headed down to the banks of the River Dart, loaded with the Kite Ursus 8×32 and more mid-range but equally new Kite Falco 10×42, to see how they measure up against each other. In addition to the irresistible delight of birding, we chose to focus the binoculars on a range of static objects at different distances and in different light conditions, including a buoy on the reflective surface of the river, a dead tree with the darker background of riverside foliage, and a flag set against the sky. The intention was to test how well the different models stand up against one and other at different distances and in different light conditions, hoping to pick up any lateral colour fringing or similar issues that might arise in specific conditions.

Back in the office we examined the pair closely, comparing them to other models across a diverse range of prices. It is important that portable binoculars balance a large enough lens to allow sufficient light for a good sharp image with a convenient weight for long periods around the neck or in a backpack. Comfort while holding is also important, as are practical concerns such as the quality of the waterproofing finish.

What We Found

First, the basics. The exterior of the Ursus and Falco models are quite similar, finished with the same textured soft-touch rubber to a conserved, simple design. The texturing makes them easy to grip, a particularly helpful feature in damp weather. The two-tone finish of the Falco is particularly comfortable and shows a marked improvement over older Kite models in my mind. While it may be a little unyielding for some tastes, I found that the finish on the binoculars was just as pleasant to hold as considerably more expensive brands and quite superior to the rubbery coating used by some. While the shallow thumb imprints on both models have a limited impact on the overall feel of the binoculars, they do provide a useful indication of where to place your thumbs to keep them well balanced.

As with all Kite binoculars, the finishing is meticulous. The waterproofing – IPX7 standard, indicating that an item can be submerged up to 1m, although I wasn’t brave enough to try it – means that they can be confidently used in any conditions that naturalists or star gazers are likely to encounter.

The newer Kite models are denoted by a red ring beneath the right eye cup. This is an entirely superficial but very smart feature that lends the brand a distinct identity.

Impressions of the mechanics were equally positive. The focus wheel moves smoothly and is not too stiff on either model. The hinges are a little more stubborn, particularly on the Ursus, but this is likely to become less noticeable with a bit of use and helps keep the binoculars at a comfortable width. It is worth noting that, although the Kite blurb describes the adjustable eyecups as 4 stage, they appear only to have three positions. This has no real impact on performance.

Undoubtedly the most important factor when it comes to binocular choice, the images provided by the Ursus and Falco certainly match up to Kite’s reputation of quality. Both are bright and crisp, Kite’s own brand of ‘MHR’ coating providing exceptional clarity. The Falco in particular combines a bright image with a spectacular field of view. While the clarity of the Ursus’ image did become noticeably distorted around the edges, this did not overly impact the experience and the centre of the image, where the user is likely to be focussing, was nice and clear.

We found that the Ursus performs best at medium to long distance while the Falcos are consistently impressive even at short range, and both models provide a clear view even in lower light. The Ursus do start to drop off a little earlier as the light fades, especially in shadowy areas.

We found the Falcos’ close focus to be particularly noteworthy. The 10x magnification of the pair I tested makes them a little unwieldy for this purpose but might also be advantageous when it comes to observing insects such as dragonflies. We have noted that other Kite models, such as the Lynx, excel at short distances and were pleased that this pair continue that trend. Unfortunately, the Ursus suffer a little here, providing an image that is noticeably less clear than their sister model and not focussing so close, but still perform well for their lower price bracket.

One fairly common issue among binoculars, from the most entry level models to pairs costing thousands, is lateral colour-fringing (chromatic aberration), a phenomenon in which objects, particularly dark shapes against a light background, appear with a small corona of distorted colour. This is generally a minor annoyance at worst, but I was pleased to discover that I could not spot its occurrence in the centre of either model’s image, even in dark birds set against pale clouds in the middle of the day. While fringing will inevitably crop up sometimes, the fact that it is not obvious in these conditions really does say good things about the quality of the ‘MHR’ coating.

Conclusions

The Kite Ursus are a standout contender among entry-level binoculars. While no optics in this price range are going to be perfect, the clear image and sturdy yet lightweight design create a convenient and very enjoyable user experience. I was able to spot and identify small birds at a range that I would really have struggled with when using some competitors, and their performance in lower light levels is a welcome bonus. The included neck strap is good quality, secure and extremely comfortable, well padded, and easy to attach. I would note that people planning to take them into hot environments may wish to go for something without rubber padding, but for use in the UK I’ve seldom seen better.

The intermediate Falcos join a selection of Kite binoculars that stand out positively in a crowded market. They are a marked improvement on the already quite impressive Kite Toucan, which they replace, with an improved field of view and more comfortable grip. A combination of excellent image quality, robust, distinctive design and consistently strong performance whether used at short or long range makes for an easy recommendation.

The Kite range has been respected among birders as a reasonably priced mid-level selection of good quality, robust optics. Indeed, they are so confident in the quality of their optics that they offer a staggering 30-year guarantee. The Ursus represent the welcome addition of a beginner-friendly pair that balance the lower price bracket with the quality that has become synonymous with the brand, while the Falco continues their long tradition of exceptional, reasonably priced mid-range optics that balance a robust, modern design with a surprisingly lightweight body. Whether you’re a beginner, an improver or a veteran, Kite have a model that will suit your needs.

Kite Ursus and Falco binoculars are available from the NHBS website.

To view our full range of binoculars, visit nhbs.com. If you have any questions about our range or would like some advice on the right product for you then please contact us via email at customer.services@nhbs.com or phone on 01803 865913.