Friday, 27 February 2015

Parabolic reflectors

recently there has been some 'lively' discussion on parabolics - on facebook and also the yahoo 'nature recordists' website - so perhaps now is a good time for a brief mini-guide:
firstly, those of you unfamiliar with parabolics (inc. how they work etc) should check out the wide range of articles on the web - always read impartial ones. Manufacturers sometimes have articles on their site and the good ones do not make exaggerated claims about their products. It is also true that there are some articles online which fundamentally misunderstand the basics of parabolics, good sound and listening in general. If you're unsure then ask around - you can, for example, post a comment here or ask a question on the 'a quiet position' facebook group, where over 4400 recordists with a wide range of experience will be able to offer advice. Always avoid articles on various 'paranormal' websites. 

In very basic terms, a parabolic mic / dish system is the closest thing to a zoom lens for sound - allowing distant sounds to be brought into sharper focus, while rejecting the surrounding ambience (in mono parabolic systems)

It is possible to build a parabolic yourself and there are lots of 'how to' sites on the net.

There are currently 3 companies selling complete parabolic kits (dish, mic and handle etc) that are worthy of recommendation. There is also a company based in the US and the subject of a fair amount of debate online and I can't, in all honesty, recommend their products and would advise caution when considering them. I think most people who look at their website will notice a number of problematic aspects (claiming their products are the best, most advanced in the world despite there being no independent confirmation of that, that they're fairly new to the market & built by someone without a well established track record as a mic builder and whose own recordings are very, very limited to a narrow understanding of the various aspects of field recording and the act of listening).


Telinga (long, very high reputation for supplying probably the best parabolics)


(telinga universal on stand)

Lisn (Japanese small plug-in-power parabolic system - best described as a mini-version of a Telinga but with lower cost parts - and resulting affect on sound quality - but ok for the price. Distribution outside of Japan is a bit sketchy however)


(Lisn parabolic)

Dodotronic (Italian company selling a low cost but good quality alternative - ingenious design on both their mono and stereo models)


(Dodotronics 2 models)

I rarely ever advise anyone to avoid a specific company as for the most part all manufacturers have products that are good for some applications or at certain price points and, when it comes to the smaller builders of equipment, they are usually decent folks who have a strong commitment to and interest in the field in general and don't go in for misleading information, the hard sell or, shall we say, some 'interesting' sales tactics. That said and for various reasons one manufacturer I would advise extreme caution with is Wildtronics. Apart from the other aspects of their approach to the community and other respected manufacturers and individuals I have listened to the various examples of their products online and conducted side by side tests with other systems. They do work and they're 'ok' but they are not as good as others on the market, in terms of sound, portability, durational use and use outside of standard 'bird' sound collection.

As mentioned Telinga has a very long track record and receives consistently high positive feedback from fellow field recordists. Their systems are at the top end of the price range, but as with all things there is usually a good reason and I do know lots of folks who've had their Telinga's for years and years. In my experience the best sound i've heard from a parabolic system is a Telinga universal fitted with a sennheiser capsule - not a cheap option but there's an open and natural sound to this set up. Apart from the Universal above (which can be fitted with a couple of different polar pattern mics) the most listenable and open sounding systems use omni capsules. Sticking a hyper-cardioid (shotgun mic) capsule into a parabolic isn't the best idea (unless using certain sennheiser ones) as it often peaks the key sound and in very simple terms it fights with the effect of the parabolic dish - remember a hyper-cardioid is in effect normally a long metal tube with a capsule towards the bottom and sound travels from the front towards the capsule - with a parabolic dish the focal point of the sound comes from around the dish itself and reaches the capsule on a horizontal plain (nb. there will still be some signal coming from other directions of course) - hence the reason an omni polar pattern provides the most listenable sound quality.
Key factors to look out for inc.

. good protection from handling noise
. dish size - a larger dish gives better low frequency response
. clean paths (by this I mean low self noise of the mic, well constructed electronics, phantom powering etc)
. mono vs stereo - for most folks mono is what they'll want from a parabolic but there are designs out there by all of the manufacturers that are stereo. Some have a mono capsule at the focal point of the dish & additional capsule/s in very near proximity, the result being to capture not only the prime sound but also some ambience around it. For species recording you'll probably want to stick to mono (2 of the 3 designs allow you to select mono or stereo) but for more creative applications the stereo option can be useful, particularly on architectural acoustics. 
. look for sound samples on the makers websites AND elsewhere online - avoid sound samples that have any kind of processing (normalising, eq-ing or that have been recorded using only stills cameras - all of which have elements of either processing built in or do not have quality pre-amps - the better sites will have samples recorded with various recorders and for the ones with the best track record its highly likely you'll be able to find a sample online using the same model recorder as the one you have)
. 3 companies parabolics (Telinga, Lisn and Dodotronic) are built and tested throughout development, and continually since, using professional, pro-sumer and entry level field recorders. Another range from one company was developed using video and still cameras. In my opinion it is only possible to develop a decent microphone of any type when tested with the appropriate equipment. Video and stills camera's have built in limiters that often can't be turned off or other types of processing. It is of course quite possible to develop a parabolic based only on the physics, however field recording / listening has and is continuing to move forward and it is more and more understood that the role of pre-amps, processing, playback levels, subtle details of the mic capsule sound etc etc. make a big difference. For lots of folks perhaps just interested in collecting, for example, bird species sounds, they will perhaps be happy with any parabolic that in basic terms 'does the job' - but for those who want more than this the advice of any recordist would be to approach the choice of equipment with more thought and attention to how it 'feels' on the ear, rather than the physics. With conventional microphones for example, some people like the sound of Schoeps mics and some don't - some like a Sennheiser MKH and some prefer the sound of a Sanken etc etc. Buying any mic on the spec sheet alone is not a good idea. Would you buy a car or a camera just on the spec sheet ? 
. if in doubt ask the community - the wide, varied field recording community is 99% friendly, supportive and open to the sharing of knowledge. 
. don't be swayed by the science only - as with all mics, all techniques, the spec sheet or theory is only a part of the story. A good company will obviously let you know the key features of their products but those with a proven track record will not need to be critical of other makes. Put simply, the quality and wide usage of the product will speak volumes.

. avoid reviews from people who seem to only ever say positive things about the kit they test and who have been sent it for free. 
. a good tip when purchasing any piece of kit is try to buy from those folks who have a reputation beyond their own products - so companies, staff / individuals who have a good reputation for their own work or who are active in the field in various ways. Avoid companies who say things like 'the best' or 'better than everyone elses' etc - good products speak for themselves. Its quite easy to spot the good folks....

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