FAQ on Battery Modules and Preamps
When you want to record very loud sounds
When you want to record very loud sounds with a microphone/recorder combination, several things must be considered. All condenser type microphones need a power source to operate. For the smaller condensers (more correctly called "Electret Condensers"), this power source is generally 1.5 to 12 volts direct current (VDC). The closer you get to providing about 9vdc to the mics, the better they will be able to handle loud sounds without producing distortion. Many of the recorders available today provide a small power source at the mic input, often labeled "plug in power". This power source is commonly about 3 to 4 vdc, but can be lower in some models.
This is enough voltage to power the mics, but not enough to let them realize their full dynamic range. Because of this under-powering at the mic input of the recorder, a battery module can be used to replace the "plug in power" provided by the recorder. These battery modules provide between 9 and 12vdc, which is the optimum voltage for the microphones. Additionally, there is an added benefit to using a battery module. When you use a battery module, you are not dependent on the recorders "plug in power", so in moderately loud to very loud situations, you can use the line input of your recorder and still get acceptable recording levels (in softer recording situations, you would still need to use the mic input, even with the battery module).
The line input has less noise than most microphone inputs as it bypasses
the relatively noisy mic pre amplification stage. The line input is
also capable of handling a much higher signal level than the mic input,
and will not result in a phenomena commonly know as "brick walling",
which happens when the signal fed into a mic input is so high that it
distorts the mic input, regardless of the recording level setting.
When you are using microphones that require 9vdc bias power
Some microphones (our Audio Technica Premium Slimline mics, for example), require a higher bias voltage (9vdc) for proper operation, even in low volume situations. You would need to use a battery module with these microphones.
When the sound you are recording has excessive bass content
A battery module equipped with a "bass roll off" filter (or bass reduction filter) can be used to filter, or reduce varying degrees of bass content from the sound to be recorded. This is especially important when recording sounds with excessively high levels of bass content. Our battery modules with this feature allow 7 choice of bass reduction, from no reduction at all, to a high degree of reduction.
When you want to avoid using the microphone input of your recorder
As mentioned above, most built-in mic pre amps on the small portable recorders are rather noisy and may add unwanted coloration to the sound to be recorded. Using the line input will almost always result in a less noisy, cleaner sounding recording. Using a battery module in moderately loud to very loud situations, you can use the line input of your recorder instead of the mic input. The line input has less noise than most microphone inputs as it bypasses the relatively noisy mic pre amplification stage. The line input is also capable of handling a much higher signal level than the mic input, and will not result in a phenomena commonly know as "brick walling", which happens when the signal fed into a mic input is so high that it distorts the mic input, regardless of the recording level setting.
When you want to be able to adjust the recording level while recording on a recorder that has no recording level adjustment
A few recorders have a limitation built right into them.....they don't allow the user to manually adjust recording levels while you are recording. Because of this, we have an option available on some of our battery modules. This option allows the user to adjust the output of the battery module, effectively adjusting the recording level by changing the level of the signal going into the recorder.
When you want to use our mics with a recorder or other device that does not supply "plug in power"
As mentioned in #1 above, many recorders on the market today supply "plug in power" at the mic input. However, there are some that don't....professional recorders, very inexpensive recorders, mixers, etc. Even mixers that have 48 volt phantom would need a battery module (or phantom power adapter like this or this or this) to power the small electret mics as they are not designed to work with 48VDC, and would be damaged if plugged directly into 48VDC. Using a battery module will allow you to use the mics with just about any piece of equipment that can accept a mic or line level source.
When you want to use our mics with a Camcorder in loud situations
Most camcorders on the market today, while having "plug in power",
can't handle the high signal levels produced by microphones used in
loud situations. The signal level must be "attenuated", or lowered,
before it reaches the mic input of the recorder. Our battery modules,
when fitted with the level control option, allow the user to reduce
the output level of the mics so that a camcorders mic input can handle
the signal level without distorting or "brick walling".
When you are using a recorder that has a noisy mic input while recording quiet sounds
A microphone preamp is useful when you need to record quiet sounds and the mic preamp built into your recorder is too noisy. Using a good quality external preamp will reduce the noise and allow you to plug into the line input of the recorder.
When you own a recorder that DOES NOT have a microphone input (most MP3 recorders, some MD recorders, VCR's, etc)
Some recorders available on the market today are capable of making good quality live recordings, but only with a "pre-amplified" microphone, or preamp and microphone combination. This is because these products do not have a built-in microphone preamp, as today's digital recorders usually do. So, by combining a microphone with a preamp, you will be able to feed a signal into the line input of your recorder that is strong enough for high quality recordings.
When you want to use a microphone with a home recorder
Most home recorders do not come with microphone inputs. Using a preamplifier between your microphone and your home deck will allow you to make live recordings with the home deck, plugging into the analog line inputs.
If you have any questions regarding this topic, please contact us.