Some General Mic Information. Hope It Helps Out The Beginners.

Status
Not open for further replies.

karma101

因緣

Some General Mic Information. Hope it helps out some of the beginners.


A microphone is a transducer. It changes one kind of energy into another. As a comparison, the human body has two transducers: the ears and the voice box. What you need to know about microphones can be broken down into the following word: TRAP. Each letter of "TRAP" stands for a mic attribute or a fact that you should know about mics in general.

T — Type - Studio mics break down into two basic types: Dynamic and Condenser. Dynamic mics work on the principle of magnetic induction. They need no external power to run, are very simple to make and relatively cheap to buy. Dynamic mics come in two varieties: Moving coil and Ribbon. Moving coil mics use a magnet, a coil wrapped with wire and a diaphragm that sits over the top of both. Sound pressure hits the diaphragm and moves the coil across the magnet. This creates the voltage that travels out and along the mic cable on the way to the Mic Pre. A ribbon mic is a bit different. Instead of a coil and diaphragm, a thin metal corrugated ribbon is stretched across the magnetic field. Sound pressure hits the ribbon and moves it across the magnet. Both of these mics have their own particular characteristics dealing with Frequency and Transient Response.

Condenser mics are generally more expensive and have a flatter frequency response than dynamic mics. They also operate in an entirely different fashion. For one thing, these mics need power to run. This is called PHANTOM POWER and is +48Vdc. Phantom power comes down the mic cable from the console, a battery inside the mic or standalone power pack. The phantom power charges a capacitor, which holds a charge in the mics' fixed back plate. In front of the back plate resides a thin diaphragm. When the diaphragm moves in relation to the fixed back plate, a charge is developed in relation to how much movement the diaphragm makes. Unlike the signal created by the dynamic mic, a condenser's signal is very weak and must be amplified before it gets to the console. In order to do this, the mic contains a small amplifier that boosts the signal before it leaves the mic.

R — Recognition - To run a session successfully in a studio environment, you need to know your tools, just like a carpenter could tell you what his/her tools are. To achieve this, you must study mics in general, ask questions and do a lot of comparison.

A — Application - Which mic for what task? Do you know the best mic for recording kick drum? How about vocals or horns? Once again, study is the key. Do your comparisons, ask engineers; everyone has their favorite. Soon you will have a bag of tricks that will serve well a studio.

P — Patterns - The Directional Response of a mic has to do with how the mic picks up sound around its polar axis. The front of a mic is called on-axis; all other directions into the mic are called off-axis. When you talk about the on-axis and off-axis response, you are talking about how a mic picks up sound in reference to those directions. There are five basic polar patterns that mics offer: Omni, Cardioid, Hyper-cardioid, Super-cardioid and Figure eight.

• Phantom Power

Phantom power is a DC voltage (typically 48V) applied to pins 2 and 3 of a condenser microphone's XLR connector to power the microphone's electronics. Pin 1 (shield) is the ground for the phantom voltage.

All condenser microphones require power for their impedance-matching electronics. Externally biased condenser mics also require a polarizing voltage between the diaphragm and back plate. Electric condenser mics get their polarizing voltage from the static-electricity charge on the electric material, which is in the diaphragm or on the back plate.

In professional microphones, a provision is made to supply this voltage directly through the microphone cable. This procedure is called phantom powering, and the most common phantom supply voltage available in mixing consoles is 48 VDC, although other supplies of between 18-24 VDC are widely used.

How does it work? In a balanced microphone cable are two inner wires surrounded by a shield. It is on these two signal lines that the polarizing voltage is placed, with the same regulated positive voltage on each line. With the positive voltage on the two inner wires, the shield wire is used as the negative return to ground. The audio signal uses the same cable on its way to the mixer, and is not affected by the phantom DC voltage since the signal is AC.

Dynamic or ribbon microphones connected to a phantom-power input are protected from damage, theoretically, since the system results in a net zero DC potential across the coil or ribbon. However, if the dynamic or ribbon microphone is unbalanced internally (one side of the coil or ribbon accidentally tied to ground), damage is sure to occur.
 
Last edited:
Sorry, but this thread comes across as spam, not that that's your intent.

Newbies, read the stickies in the mic forum.

Tim
 
Timothy Lawler said:
Sorry, but this thread comes across as spam, not that that's your intent.

Newbies, read the stickies in the mic forum.

Tim

How does the post in question come across as spam? That would be like me saying your post's on the MSH-10's came across like spam. Where does it mention any manufacturer's name in the post starting this thread? It seems to me no matter what Karma post's there will be someone who will complain about the post.

So if Bruce Sweiden decided to post his take on using mics in the studio would that be considered spam too?
 
If you cannot tell the difference there, you won't get it when it is explained to you.

ljmaxx said:
How does the post in question come across as spam? That would be like me saying your post's on the MSH-10's came across like spam. Where does it mention any manufacturer's name in the post starting this thread? It seems to me no matter what Karma post's there will be someone who will complain about the post.

So if Bruce Sweiden decided to post his take on using mics in the studio would that be considered spam too?
 
verry handy, unfortunatly i knew all of this already but it's nicly summed up and eay to understand

I don't see why you think of it as spam, i think you just jelous :p
 
Karma101 re your PM, and...
ljmaxx said:
How does the post in question come across as spam?
The content gives me the impression that the poster hasn't read the type of questions that occur in the Newbie forum. It's a somewhat disjointed collection of info-bites rather haphazardly thrown together from an educational standpoint - helpful bits mixed with things that are meaningless to most newbies, such as the second to last paragraph discussing the electronics of phantom power. Since the OP's sig identifies him as a mic manufacturing executive or representative it gave me the impression that he's doing promo for his company more than helping newbies.

Just my opinion. Maybe others will disagree. No need for a war.

EDIT: Karma101 I just noticed that you've removed your signature advertizing your company.

Tim
 
Yeah, it could be spam. I pimp Carvin guitars, MSH- mics, and DavidK's CDs because I think they're great, and I receive nothing from them in return. Mr Karma, however, has an inherent conflict of interest because he's a marketing guy from a mic company. There's another guy here from Shure, but he readily recommends other mic brands.
 
I've seen Karma101 recommend other brands too, it's not that IMO. I think it was the previously prominent sig combined with the low post count combined with what my opinion was of the content. Forum members who are manufacturers come across best when they're low key about it.

Tim
 
fraserhutch said:
If you cannot tell the difference there, you won't get it when it is explained to you.

Please enlighten me with your wisdom. How was the original post spam?
 
fraserhutch said:
See the post above and think.

So then by your account and a few others in this thread if a poster has a sig line that plugs their bussiness it is considered spam? Then I guess every post by Warhead and Mshilarious should be considered spam as well? IMHO none of the above are spam. We'll just have to agree to disagree on this one. :)
 
if a poster has a sig line that plugs their bussiness it is considered spam?
It's a matter of degree. And the perception of established membership... post count, people knowing you, etc. Certainly not a black and white thing. Speaking only for myself.

A two inch tall commercial sig from a brand new member is pretty different than the situation of someone like mshil or DavidK. And then there's apl... :eek:

Tim
 
Last edited:
Status
Not open for further replies.
Back
Top