QuestionHello,
I'm about to purchase a microphone to plug it to my multimedia player (Grundig VP6200) that I bought to record the singing lessons I attend at college.
The problem I have is that first I bought a dictation machine but the recording space was too small and had to empty it every time before a lesson, sound quality was good; then I bought the multimedia player that records up to 30Gb on mp3 format but when played back the sound is very muddy and cannot hear clearly what was recorded from the class, i.e. the piano from the teacher and the singing vocals that comes out the class speaker. I can only hear clearly what I recorded if it's just a normal speaking conversation.
So I decided to buy an electret condenser mic or a mini mic, omnidirectional with plug-in power to plug it to the player. I have seen a few (Sharp MC-PS1 Electret) but not sure what would be the best specification.
Do you know what Frequency Response/Range, Impedance, Sensitivity, Direcitvity, Noise Level, I should be looking for and any other stuff I should be aware of to buy a mic that will allow me to record clear sound using my media player.
Thank you very much.
AnswerHi Tesa,
I apologize for taking so long to respond, I suspect that there are a couple of factors at play here and I wanted to type out a thorough explanation for all of them. To not confuse you let me start of with a simple synopsis of my recomendations:
-Check the Grundig to make sure you're rcording at a high enough sound quality.
-sit at the front of the room.
-get a "cheap" Cardiod CONDENSER (I don't recommend electret) that can take battery power.
Now on with the show...
The first concern of mine is sample quality - if you are recording MP3's on your Grindig at 22kHz sample rate and 16bit word-length, for instance, and your old dictation machine was either by tape or recording at a much higher sample rate - that would certainly account for a serious change in sound quality. Similar to a digital camera, lower sample quality will certainly let you store more media on your player, but it will also not be as "rich" and true to life as if you were to take one HUGE picture at the maximum resolution.
It's a little like trying to describe a painting or important event to someone else - the more you're allowed to talk and the larger your vocabulary, the richer the detail will be.
For your reference, CD's are recorded at 16-bit, 44.1kHz sample rate. This translates to roughly 5.2MB/minute(mono) for a CD, though at 16-bit, 44.1 kHz an MP3 with mild compression will usually clock in at under 4MB/minute or less.
You should check your Grundig manual and see if you can adjust the recording quality, if it's not already set to 16-bit,44.1kHz or better. If it is, try experimenting with other, higher audio qualities - 16-bit, 48kHz is the AES "Archival Quality" standard for courtrooms and legal proceedings, 24-bit/96kHz is commensurate with SACD and "studio quality" digital recordings.
Also check your manual to see if you can adjust the "compression" settings. If they are only "static" (low, medium, high) try turning it down a notch or two. If you have the option, you may want to try "variable rate" unless you are hoping to mix these recordings to CD later.
The next thing to think about is "levels". If you can adjust the sensitivity of your mic recording (think about it as "input volume") you should.
If the mic is too low you'll have to crank up the volume to hear anything, and all of your recordings will be muddied because there is very little difference between the sounds you want to record and the background noise that's just inherent in your system (that's technically referred to as "signal to noise")
If the Mic is too sensitive then it will "overload" at the loudest parts (Piano-fortissimo would be a typical culprit) and it will sound like a Hendrix solo or fast-food drive-through speaker.
So that's "Step one": Make sure your recording is the best it can be
Step two: get close.
Now we should talk about microphones.
In the recording world, we often talk about proximity - just like real-estate it's all about location, location, location. The microphone needs to be as close to the action as possible (back to signal/noise ratio). The further away it is, the more it will be muddied by room conditions (Airconditioning, echoes off walls, papers rustling, etc).
Step three: New Mic
Are you using the little microphone that's integrated into the unit? Those things very widely in quality and probably cost the manufacturer $0.01 to put in. Buying an outboard microphone may haelp a great deal, but I'm hesitant to recommend any "Electret"
Ideally, I'd say the most important microphone spec would be DIRECTIVITY. I suggest you get a directional microphone - a "Cardioid" or "Shotgun" type pattern. These would allow you to point the mirophone at what you want to hear and reject the rest. You may find the "PZM" or "Boundary" type mics particularly interesting.
The downside is that Condenser microphones require power of some kind and often require an adapter to plug into your type of recorder. It's not hard to find condensers that take battery power, though.
An "Omnidirectional" mic will pick up and record everything around it, especially the stuff up close. It's a little like going from a bare lightbulb to a spot-light.
This most likely means you'll have to buy a battery powered "condenser" microphone, which is light-years ahead of any electret in terms of sound quality (and usually 15% more expensive, a bargaiin my opinion).
Buying an outboard Omnidirectional electret (sometimes erroneously referred to as an "Electret Condenser", be not fooled) would probably help a little, the diaphram is likely to be a little bigger and more open than what's crammed inside your Grundig. If you really must, I'd say give it a try, but don't expect studio quality.
The only advantage to an electret is that they are easy to find,easy to conect to the recorder, and cheap (but in every sense of the word).
Second important might be "frequency response" - Something like 130Hz-18kHz (+/-6dB) would be excellent fo an electret but only passable for a Condenser. The human range of hearings is 20Hz-20kHz, and "+/- 3dB" would tell you that it was a much more precise microphone, if that helps.
