a video compilation of sound-playgrounds by James Brewster, using JrF contact mics & hydrophones in various ways.


nice recording of water snails eating aquatic plants by Sebastiane Hegarty (recorded with one of my JrF hydrophones)


news - june 2012

June 18th sees the launch of the new d-series hydrophone, which replaces the c-series hydrophone. This model makes a few adjustments to the c-series design & improves handling noise & freq. response in the mid & low freq. range. One of the features of the c-series was the larger element & capsule, which was designed to suspend itself in the water; now, some folks liked this & some folks, who used them in different depths, needed to add further weights to the cable. So, the new d-series is weighted to 
submerge itself as far as you want & your cable allows, just like the 'standard' hydrophone design.

the element in the d-series uses a new 'ceramic weld' process, meaning a smaller element can be
used to achieve the same or better results than the larger element used in the c-series design.

so, in basic terms whats the difference sound wise between the two models ? well, i'm in the process
of making some new test recordings of both so you can hear the difference for yourselves - just waiting
for the sun to come out & warm up the water ! but what I can say is:
standard: these are fine for folks with entry level recording devices up to, say, the £350 price range.

d-series: when using hydrophones with higher spec equipment or separate pre-amp stages, the d-series begins to show its advantages more fully. Those of you who know the ins & outs of this technology will know that there are limits & often the differences will be subtle but worthwhile. So, for example, the d-series will have a slightly higher, warmer signal & the higher spec cable improves slightly on the already low handling noise profile of the standard cable.

from now on all d-series hydrophones & c-series contact microphones will come Neutrik manufactured jacks.

i'm currently working on some new products, working with tab & cable microphones. more news to follow....


Hydrophone tests d-series vs dpa8011


                                                     Hydrophone tests d-series vs dpa8011

testing my new 'd-series' hydrophone design (available from June 2012 from against the DPA8011's.
The DPA's are no longer in production but did used to cost over £1000 each & if you want one now you'd be lucky to find them below £2000 each second hand.
So, my d-series will be priced around £60 each & though I say it myself i'm very pleased with the way they stacked up in comparison with the DPA's.
The DPA's have a stronger signal as they have a built in additional pre-amp, however the most interesting difference is the way the two hydrophone designs pick up all the same sounds but at different levels. The DPA's seem to focus on the higher end sounds & the d-series cover a wider range of sounds more equally. I know i'm biased but I much prefer the sound of the d-series, which to my ears capture a more diverse, richer & more complex sound world.
Another interesting fact is that the DPA's had hardly any low frequency response. I tried applying various low pass filters on the Sound Devices recorder to them & none made any difference to the sound. This was a surprise indeed & i'm somewhat puzzled by that.
Both recordings were made directly into the SD7 series recorder, with gain levels equal & in the same location: 2 hydrophones of each model either side of a small wooden pier on an inlet on the east coast of sweden in May 2012.
Of course, the d-series are my design so as I said earlier I am biased, but lets just say that i'm very pleased by the way they perform next to the high-end DPA's.
£2000 + for a DPA8011 (if you can find one)
£60 for a JrF d-series

as part of the new series of 'bang goes the theory', the BBC science series, you can watch Chris Waston as he listens to the sounds of snails, centipedes & maggots using one of my JrF c-series contact microphones.

here's an extract of the centipede recording (thanks to Chris Watson for permission to use this recording here)

The programme is available to view online via the BBC i-player for the next few days:

for those outside the UK the clip is also available on the BBC's youtube channel:


if you've seen the trailer for the new series of 'bang goes the theory' (BBC One) the sound of snails eating was recorded with one of my c-series contact mics by Chris Watson. The episode will be broadcast on 19th March - should be fun !