Frequently Asked Questions.
Q. Why should I buy from Limpet Mics.?
A. Limpet Mics. is a small company, very small, in fact it's just me! I have been building contact microphones, hydrophones and modifying induction coils for almost ten years and have extensive experience in their manufacture and use. Limpet Mics. are built from the best materials I can find and the designs have been developed, refined and tested to a very high standard of expectation. When you buy a product from Limpet Mics. you also get a lifetime of email support. I like nothing more than talking contact mics and audio recording, so if you ever have any questions about a product or its application I am only an email away!
Q. What is a Contact Microphone for?
A. A contact microphone is used to listen to and/or record the sound wave vibrations that travel through solids and liquids. This means you can hear a whole new world of sound not audible to the human ear. They are commonly used by musicians, producers, sound artists, sound designers, foley artists, natural history film makers and audio explorers. You can listen to some audio samples here.
Q. What is a Hydrophone for?
A. A hydrophone is used to listen to and/or record sound waves that travel through water or other liquids. This means you can hear a whole new world of sound not audible to the human ear. They are commonly used by environmental scientists, biologists, natural history film makers, whale & dolphin watchers, musicians, producers, sound artists, sound designers, foley artists and audio explorers. You can listen to some audio samples here.
Q. What's the difference between a Contact Microphone and a Hydrophone?
A. The contact microphones and hydrophones available here at Limpet Mics. both work on exactly the same principle. They both utilise piezoelectric technology to transfer vibrations in solid objects or liquids in to an electrical current. They work in much the same way as a conventional microphone but rather than being activated by vibrations through air (gas), they are activated by vibrations through solids and liquids. The main difference is in the physical design and construction.
Q. Why don't Limpet Mics. Contact Microphones and Hydrophones have built in pre-amps?
A. My philosophy is to keep things as simple as possible. The microphones I have designed are highly effective and I have not found built-in pre-amps, noise limiters or equalisers to be useful or beneficial. Limpet Mics. provide a raw audio file that can be manipulated in post-production, if this is not 'your bag' they also provide a perfectly good audio signal for your listening pleasure. On very long cable runs a capsule based pre-amp can be useful to boost the signal, however Limpet Mics. are not aimed at such applications.
Q. Are Contact Microphones waterproof?
A. All of the contact microphones available here at Limpet Mics. are waterproof but have not been optimised for long exposure or constant recurring use under water. If you are planning to predominantly record underwater I would recommend one of my hydrophones.
Q. What is an Induction Pick-Up Coil?
A. An induction pick-up coil converts electromagnetic activity in to an electrical current that can be amplified and recorded/listened to. Typically they are constructed from an iron rod wrapped in a thin copper wire coil. A conventional and typical use is as pick-ups on an electric guitar or as a telephone pick-up coil, used for recording telephone conversations on old style telephones. They are a great piece of kit for musicians, experimental sound artists, producers and audio explorers opening a door on strange 'other worldly' sounds from electrical devices. You can listen to some examples on the Audio Samples page.
Q. What's the best way to attach a Contact Microphone to a surface?
A. This really depends on how you intend to use it, what you're trying to achieve, what the object is and the ambient environment... If you plan on an unusual application then feel free to get in touch through the contact page and I will advise. However, for most applications some relatively low-tac adhesive tape works very well. You can also use clips, elastic bands, blutack (be advised this may leave a residue on your new contact microphone) and for a more permanent application epoxy resin. The best thing you can do is experiment!
Q. How do Contact Microphones work?
A. The contact microphones and hydrophones here at Limpet Mics. all utilise piezoelectric elements (crystals). Typically a very thin layer of piezoelectric crystals are bonded over a thin brass disk. Contact points are soldered to the crystals and to the disk. When the crystals are agitated by movement (vibrations) they create an electrical signal that passes through the contact points and is interpreted by your amp or recording unit as audible sound. They do not react to vibrations in the air (gas). Although, if you get up really close to one and shout at it, it will hear you!
Q. What's the difference between an XLR and Jack Connection?
A. An XLR connection is a standard plug/socket for professional microphones. They have three pins which means the microphone can be 'balanced' or 'in phase'. I don't need to go in to the technical stuff here but in a 'nut shell' this means a cleaner signal with less noise. A standard Mono Jack connection only has two contact points which obviously limits your wiring options... Using a Jack connection, particularly with a contact microphone that does not have its own pre-amp circuitry, means you are likely to experience some noise (buzz, hum, hiss) on the audio track. This can be particularly problematic with contact mics where you often have to push the volume quite high.
Q. Do Contact Microphones require Phantom Power?
A. None of the contact microphones or hydrophones available here at Limpet Mics. require phantom power. There is no amplification or noise reduction circuitry within the microphone capsules so sending phantom power to them would damage the sensitive piezoelectric components. Not a good idea!
If you have a question I haven't answered get in touch using the Contact page.