• Wish list
  • Choose your store
    All countries
  • 0

Thomann's Cool Online Guides: Small Diaphragm Mics

5. Technical Aspects

Sound is subjective. Ultimately, your personal impression should be your guide when selecting the right microphone. Still, technical data can give you valuable information about the usability of a particular microphone.

Noise Performance (Self-Noise)

Noise is an important factor for distant miking, e.g. a choir or an orchestra and for recording quiet sources such as nylon string guitars.

For condenser mics noise performance is usually specified as “self-noise.” Alternate terms are “equivalent noise level” and “equivalent sound pressure level.” The lower the self-noise figure, the less noise the microphone produces. 16 dB-A or less is an excellent figure for a small diaphragm condenser, 20 dB-A is still pretty good. At about 23 dB-A or more you’re likely to notice some background hiss, especially when you’re miking quiet sources.

Note: The “A” means the figure is weighted according to the sensitivity curve of the human ear. A-weighted figures emphasize the mid frequencies and disregard noise at the extremes of human perception, i.e. very high and very low frequencies. Some manufacturers also give unweighted noise figures (which invariably look worse). Don’t confuse weighted and unweighted figures; they’re in no way comparable.

Sensitivity

Sensitivity means output level. Various microphones will produce different output levels when exposed to the same sound source at the same distance. The usual way to specify sensitivity is in millivolts per pascal (i.e. output voltage per sound pressure). The higher the sensitivity figure, the “louder” the microphone. A typical small diaphragm condenser mic is about 5-10 mV/Pa. The higher the figure, the less gain is required from your microphone preamp.

Unfortunately, there are several other ways to specify sensitivity, the most common being in relation to a hypothetical microphone. Which apparently has an enormously hot output level, given the fact that all known real world microphones produce negative decibel figures in comparison, usually between -55 and -35 dB. Here, too, higher figures mean higher sensitivity. But don’t let the negative numbers confuse you: -35 dB is much higher and therefore “hotter” than -55 dB!

Maximum SPL

Some people think that exceeding the maximum sound pressure level specified by the manufacturer means your microphone is in jeopardy. Don’t worry! Your microphone won’t be destroyed, it just means that sound at this level will no longer be free of noticeable distortion artefacts. Max SPL is usually specified as the sound pressure level (“volume”) at which THD (total harmonic distortion) exceeds 0.5 %. Some manufacturers use 1% THD as the threshold figure, which results in – seemingly! – more impressive max SPL figures. In home applications and even most professional studio applications, maximum SPL is nothing to worry about. Usually your neighbours will greet you with a rifle, long before your Marshall stack exceeds your mic’s maximum SPL. So you better worry about your neighbours ;-)

Some sources can produce very high SPL figures in close proximity, e.g. brass instruments and drums. A few sources are much louder than you’d think because they contain very little energy in the bass department (where you’d physically feel it). A tambourine, for instance, can easily be louder than an average microphone’s maximum SPL. 130 dB-SPL is a very good maximum SPL figure, 140 dB-SPL and more is excellent. Oftentimes you can add an additional 10 or 20 dB by applying a pad which reduces the level right behind the capsule, so the internal amplifier electronics won’t overload. However, don’t use a pad unless necessary. A pad often leads to a slight increase in noise and may also compromise the sound quality somewhat.

Your Contact Persons
PA
Phone: +49-9546-9223-35
FAX: +49-9546-9223-24
Question!
Question! Give the right answer and win 1x Stairville Outdoor Stage Par 12x3W Tri worth €122.
Where did the ukulele originate?
Conditions of participation
Terms and Conditions for participation
in online competitions

Note: Participation in an online competition runs independently from any purchase at Thomann GmbH. The following Competition Rules apply when participating in any online competition run by Musikhaus Thomann:

  1. Competition

    1. The competitions are organised by Thomann GmbH, CEO: Hans Thomann, Hans-Thomann-Straße 1, 96138 Burgebrach, Germany.
  2. Participation

    1. Competitions are only open to persons of full age.
    2. To take part in the competition you must answer all questions correctly, fill in the registration form and submit your entry to Thomann GmbH by pressing the "send" button.
      By pressing the "send" button the participant accepts the aforementioned terms and conditions.
    3. The participant is responsible for entering their email and/or postal address correctly. Entries to the competition will be logged electronically.
  3. Qualifying Entrants

    1. Staff of Thomann GmbH and any cooperation partners and their dependants are excluded from participation.
    2. Should these conditions of participation be violated, especially by using illegitimate means, Thomann GmbH reserves the right to exclude persons from the competition. In case of such violations prizes can be withdrawn and claimed back subsequently.
  4. Announcing the winner

    1. The winners will be notified by Thomann GmbH by email or in writing and their names may be published on the homepage www.thomann.de. The winner accepts this form of publication explicitly.
      Should for whatever reason the winner not claim their prize, then a new winner will be drawn.
    2. The prize presented to the winner may not be identical to the item description. There can be deviances regarding the model, colour etc.
    3. The merchandise prizes will be sent by Thomann GmbH or by one of its contracting delivery companies, per freight forwarder, courier or postal service to the postal address indicated by the winner.

      The delivery is free of charge. Only extra transport costs and customs/duties must be covered by the winner. In the case that the delivery has to be made through a freight forwarding company the freight forwarding company will contact the winner to arrange delivery timings.
    4. An exchange, cash alternative or replacement prize is not possible.
    5. The claim to the prize or replacement of the prize cannot be assigned to a third party.
  5. Data protection

    1. The participant accepts explicitly that Thomann GmbH saves all necessary data for the duration of the competition and forwards them exclusively for purposes related to the winning process to the respective cooperation partner, who is also permitted to save the personal data only for the duration of the competition. The participant is free to withdraw his entry at any time. Please direct the withdrawal to:

      Thomann GmbH
      to the data protection officer
      Hans-Thomann-Straße 1
      96138 Burgebrach, Germany
    2. Thomann GmbH is obliged to consider the regulations for data protection according to the Federal Data Protection Law (BDSG) valid at the conclusion of the competition. In this context the general data protection regulations under notes regarding data protection should be noted.
  6. Liability

    1. Thomann GmbH will be released from any obligations by handing out the prize.
    2. Thomann GmbH is not liable for the insolvency of a cooperation partner and the resulting consequences for the implementation and processing of the competition.
  7. Other

    1. Legal proceedings are barred.
    2. The law of the Federal Republic of Germany applies exclusively.
Our groupies
Top class customer service
Stephen, from Ireland, 11.08.2014

Small Diaphragm Mics overview

Feedback
How would you rate this page?