At Earthworks we are concerned that unfamiliarity with omni use is prohibiting some people from trying out our mics and is an obstacle to acceptance by the general microphone using population. Before begining my association with Earthworks I wouldn't have given an omni a second look, much less a listen, simply because of their lack of directionality. They pick up everything. How do you aim an omni? Can you get separation? I had heard that Omnis don't image well in stereo. They cause feed back, right? It turns out that omnis have some very positive strengths in terms of recording, measurement and sound reinforcement applications. They sound great! You just have to know how to use them. Don't let the discussions of technical issues throw you. Skip right to the specifics you are interested in if you like. If you have specific questions about applications please feel free to give me a call.

Why omni? Earthworks goal is to develop the most accurate microphones possible. To this end we have looked very closely at the impulse response of various microphones. This gives a good indication of their performance in the time domain. What we have found is that most mics smear time terribly. All microphones suffer from some degree of excess phase­ the ringing of a set of frequencies while the diaphragm settles. Multiple paths to the diaphragm also smear time response. Resonances and reflections in the cage around the diaphragm contribute heavily to coloration. Directional microphones sample the sound in two locations, using tuned rear access to achieve rejection. Directional microphones, therefore, can not approach good omnis in terms of accuracy in the time domain. Earthworks microphones are optimized for accurate impulse response which results in their being more accurate in the time domain than any other other mics we have measured.

Benefits of Earthworks Omnis: Whereas directional mics impose coloration, especially off-axis phase distortion, Earthworks omnis impose almost no coloration on the signal and have very precise phase response. This allows them to capture exactly what is happening at a very specific location in time and space. Earthworks omnis do not exhibit the bass proximity effect which you have probably experienced as a boominess when a directional mic is placed too close to a source, especially guitar. They can be positioned as close to a source as you dare. This opens up extraordinary possibilities. Having extremely high SPL handling capabilities (150dB) you will probably never overload them even close miking a snare or kick drum. Earthworks mics have extremely extended low frequency response (1dB down at 9Hz, 3dB down at 5Hz). "Not disproportionate or tweaked in any way, just accurate and full to an extent that would strain many people's credulity in a capsule so small. This is not at the expense of the top end which is flat and clean in the same way."

Ambient Room Mics: Earthworks mics are great ambient room mics when the SPL is from medium to extremely high. In a studio situation ambient mics can tie things together and help to avoid that dead studio sound. I recently recorded a blues band live to four tracks, taking two tracks from the PA mixer and two from a spread pair of Earthworks mics a foot or so from the front line of vocal mics. The sound from the PA was kind of dead and what was too loud on the stage was too soft in the tracks from the PA. Bringing up the ambient tracks produced a striking realism. It was like being there (better, actually). Placing Earthworks mics at a distance from a group of background singers makes them sound like they are in the background. Adding in an ambient Earthworks mic makes a dry sounding close miked guitar amp come alive.

Find Sweet Spots: It's a great trick. Simply listen around the room until you find a sweet spot ­ a location where you like the sound. Put a mic there. If you are recording in stereo keep the image you want in mind as you place the second mic. I have heard many happy users describe this as their primary way of placing Earthworks mics. The mic will capture exactly what is occurring at a very specific position­ even acoustically challenged rooms may have sweet spots. This does not mean that you must spend endless hours worrying over exact mic placement. In fact, many users have reported spending a lot less time tweaking mic position when using Earthworks mics. Generally, they are very forgiving and musician friendly.

Many people use a paint brush approach to microphone use, matching the coloration of the microphone with the color they want from a source, like using a mic's presence peak to make a voice sparkle or the bass proximity effect to make an announcer's voice sound larger than life. In this mode of thought the Earthworks mics are transparent. What you get is the sound of the source. With directional mics you must live within the limits of the microphone's proximity effect and it's coloration. With Earthworks omnis you are broadly looking for the right balance with respect to the room­ inside that you can choose from among the subtle variations in the sound of the source instrument. There exists a whole range of sounds emanating from an instrument which are unavailable to a mic which exhibits the bass proximity effect. You will be amazed at the variety of sounds which an instrument gives off when you listen up very close. Experiment with different positions. Try miking very close. If you like what you hear, use it.

The Inverse Square Law: As you move away from a source of sound in free space the amplitude from that source decreases in an inverse square relationship with respect to distance. As you move closer to a source the amplitude from that source increases exponentially. The proportion of sound from other sources decreases very rapidly as you move the microphone closer to the primary source. The inverse square law is your main tool to control the balance between the sound of the source and the sound of the room. If the room doesn't sound good or contains unwanted sounds, stay close to the source. When separation is desired an omni should be placed as close as possible to the primary source. If you like a wet sound back the mic up until the balance with respect to room is as desired. If the room sounds good use it, but getting close will give you a surprising amount of separation. If you usually place a directional mic 18" from a source, an omni placed 6" to 8" from that source will give you more separation.

Near Coincident Omni Miking: It is general belief that near co-incident omnis don't image well. That's what I thought, too. Earthworks mics don't image like other mics, even other omnis. One reviewer noted that they sounded farther apart than the B+K 4006s he was comparing ours to. Closely placed omnis are supposed to give you at best a fat omni or very narrow image. You'll have to try it for yourself. Place two Earthworks mics with the tips close together (near coincident, X/Y or crossed.) Position the pair 6 to 8 inches from the sound hole of an acoustic guitar or in fairly close proximity to any instrument or small ensemble, like drum overheads or vocals. Listen through headphones. Check for mono compatibility. If you are not thoroughly impressed feel free to let me know.

To EQ or not EQ?: The frequency response of Earthworks mics' is so smooth and accurate that we recommend you refrain from using EQ at all during tracking, unless you have a specific problem you wish to avoid, like low frequency rumble. If you need to EQ during tracking this probably indicates a problem at the source. Try to correct it there. You can always EQ the recorded track later.

Drums: Earthworks mics are great for overheads, kickdrum, snare and percussion (claves, cow bells ,triangle, tambourine and nearly everything else). For overheads try near coincident to spaced omni. For kick drum place the mic any where but in a hole in the front head. The sound of the room becomes more important as the distance from the source increases. If your space allows it, try using two Earthworks mics to record the whole kit using spot mics only as needed for specific effects. A stereo pair in front a percussion table is all you will need.

Guitar, acoustic: I have heard reports of very good results anywhere from very close to very distant. Several people have mentioned exciting results with a near coincident pair 6" to 8" from the face. Others have mentioned placing one mic close and one ambient. I like two mics one near the top of the fret board to get the pick and strings, the other below the bridge to get more bass.

Guitar, Electric: Just put the mic in front of the amp. If you want more room sound back up, if you want a more direct sound with more separation move in closer. Try one mic close and another distant if your room sounds good. Face the amp into a diffuser and mic that. The sound of a guitar speaker is very complex and requires extremely good transient response for accurate playback. With Earthworks mics you can get the sound as you heard it live.

Piano: Everyone has a preferred way of recording piano. For classical music, often the mics are placed 5 to 10 feet from the instrument because the music doesn't come together closer than that. (I disagree, but it is tradition) For most other types of music the mics are placed closer. Some prefer a pair of mics 2 to 3 feet out from the opened lid. Some swear by one mic midway down the left hand part of the harp, the other over the middle of the upper strings. I have heard of getting the players perspective by placing mics to either side of the player perhaps with the lid off. I have even heard of situations where Earthworks mics were used effectively for amplifying live piano, usually inside a closed lid. You will need to experiment with mic placement to get the image you want of this large and variable instrument.

Other Stringed Instruments: Mandolin and banjo can be treated like guitars, but experiment. For violins and viola try recording close. Violins can be screechy (too much rosin) up close, you may need to move back or try rotating the mic to 90° off axis to moderate the high frequency response. For cello try using one or two mics about 1 to 2 feet or closer. For double bass or standup try one or two mics about 18" from the center of the body. You will not believe the sound. If the player is active the Earthworks mic can be wrapped in foam and stuck under the strings below the bridge. When recording a lap dulcimer try bringing two (or one) mic in close. Hammered dulcimer­ adjust a pair of mics for balance with room and desired image. For harp try one mic on either side within 18" or a pair 1 to 2 feet in front of the instrument. Please call if you want advice when recording any instruments not mentioned here.

Vocals: For close miking vocals you will need a windscreen or pop filter. Earthworks mics will give you precisely what the voice sounds like. If you are recording an exceptional voice and/or want to capture exactly what the voice sounds like you will not find a better mic than Earthworks. To moderate the incredible detail of Earthworks mics rotate the mic 90° so that the artist is singing across the element. Several engineers have reported using both their old favorite and an Earthworks mic and choosing between them (or mixing them together) during mixdown. One engineer told of a singer who just couldn't do the performance with out an SM58 in his hands. The engineer gave the artiste the SM58 and fed it to his phones but recorded him also with an Earthworks mic which he had placed unobtrusively in the iso booth. He gave a great performance and they got an extraordinary take. Ambient miking of voice can be very effective. Miking background singers from a distance will make them sound as if they are in the background.

Location, Jazz and Pop: Place Earthworks mics as close as you like in front of the stage. Spread them as dictated by space and conditions. Try to get a wide image if you can. If you are using a PA for vocals you may need to place the mics to include that. If you can get the PA mix and add in two Earthworks mics placed right in front of the stage you will not be disappointed. The detail and imaging will amaze you.

Location, Classical: The classical tradition is to capture the sound of the best seat in the house. This usually means placing spaced omnis anywhere from 6 to 12 feet (or more) from a soloist or a small ensemble. A large choir or orchestra would probably be miked from even farther away. Please try placing Earthworks mics closer than you are used to, they image differently from other mics. I personally like to put mics very close to the soloists or small ensemble then add to it a pair of ambient mics which are tastefully far back and hopefully out of the sight lines.

Rehearsals and Gigs: Earthworks microphones are a great tool. Recording rehearsals can be very educational, especially for vocalists. For developing ensemble balance, timing and moderation If you happen to be a student of classical voice (or instrument) Earthworks mics will reveal exactly what you sound like. Gigs or recitals can be taped for review so that you can hear what you sounded like to the audience. Earthworks mics do not lie. You can learn from your mistakes and capture all your brilliance.

Sound Reinforcement: Omnis are limited by feedback in sound reinforcement applications. The very flat frequency response of Earthworks mics does not encourage feedback, however they are omnis. There are several circumstances where they can be used. Obviously, they are very useful and cost effective for measurement applications. Sources which do not go through the monitors, like drum overheads, can be amplified very effectively in the FOH mix. Some sources you can get very close to, (guitar amps, kick drum and snare) in these cases apply the inverse square law to get separation. Several live sound engineers have used our mics to amplify piano by close miking with the lid closed. In quieter genres the performance on the stage can be miked to enhance the dryer sound of the direct pick ups and close miked vocals and instruments. This live sound can be very refreshing and intimate. As ambient mics for in-ear monitoring they can provide a useful connection to what is happening on the stage and in the audience. Surprisingly, they make good mics to amplify voice as long as on stage monitor levels remain low. They have extremely low handling noise and when used very close the gain available is tremendous.

Preamps and Electronic considerations: We recommend using modern preamps with electronically balanced inputs. Be aware that Earthworks mics are perfectly capable of putting out 10 volts at 10 Hz. Transformers are not as accurate as good active electronic inputs­ they interpret very low frequencies as if they were DC. Please, pad the input if you are close miking percussion, Some older equipment may have trouble dealing with the fast impulse response and extended frequency range, for instance, many older NEVE modules are only marginally stable. The transient response of Earhworks mics is significantly faster than some peak reading circuits, i.e. they are capable of tracking transients faster than some peak indicators can respond. Therefore, when recording percussive sources digitally record lower than you might otherwise. On the other hand, if you find yourself opening the gain up to the point where noise becomes a problem, try moving the mic in closer and reducing the gain. If you run into RFI problems please use a power conditioning unit, confirm the validity of your ground and use double insulated mic cables.

We consider Earthworks microphones to be powerful tools which can be used to capture the sound and experience of live music. The superb impulse and frequency response of our mics provides an extremely detailed and accurate representation of what actually occurred in the room. Earthworks omni microphones give a true and accurate representation of the sound and experience of being there. Try them for yourself and hear Natural Uncolored Sound.