This tutorial will help you modify the sound of your microphone in order to transform the sound of your microphone into the accurate copy of the sound of a better microphone. You can also transform a pair of identical (same model) microphones into a matched pair of microphones for stereo recording. The proposed digital mod is simpler than an electrical or mechanical mod, and in the same time it ensures incomparably higher accuracy.
It is known that the sound quality of a microphone mainly depends upon its frequency response. High quality microphones have better frequency responses than low quality mics. MathAudio Microphone Corrector VST plug-in for Windows is able to modify the frequency responses of microphones. In fact, you can take your medium quality microphone and transorm it into an acoustic replica of your high quality microphone. The process of replication takes a few minutes. After that the sound of your medium quality microphone will be very similar to the sound of your high quality microphone. Listen to the sound samples.
There is an important restriction: MathAudio Microphone Corrector doesn't reduce the self-noise of microphones. If you buy a microphone for using it with MathAudio Microphone Corrector, make sure that the microphone is not noisy. Usually condenser microphones have a smaller self-noise than dynamic ones.
MathAudio Microphone Corrector is also able to transform a pair of identical (same model) microphones into a matched pair of microphones for stereo recording. Such matching can increase the quality of stereo recordings. If the microphones acted differently, your left and right channels would not sound exactly the same, which could result in timbre anomalies between them and a smearing of the stereo image. MathAudio Microphone Corrector can match your microphones much better than they were matched at the factory. Use MathAudio Microphone Corrector to transform you right microphone into the replica of the left one. It is also possible to transform both left and right microphones into replicas of a third microphone.
MathAudio Microphone Corrector is a sort of a self-learning system: it first compares the signal of your target microphone with the signal of your reference microphone. Then it creates a mathematical algorithm which changes the spectrum of the signal of your target microphone to make it similar to the spectrum of the signal of your reference microphone. Please note that the microphone which will be corrected is referred to below as the target microphone.
The process of installation and adjustment of MathAudio Microphone Corrector includes the following steps:
1. Switch off your speakers
Your speakers must be switched off to avoid the acoustic feedback. Use headphones to monitor the sound of the microphones.
2. Connect your target microphone to the sound card of your PC
Listen to the original microphone signal by means of your VST host software. Make sure that the original microphone signal is not noisy.
3. Connect the reference microphone to another input of the sound card
Both target microphone and reference microphone must be connected to your sound card simultaneously. They must be connected to the different inputs of your sound card. For example, connect your target microphone to the left input of your sound card and connect the reference microphone to the right input. Make sure that your reference microphone works properly by means of your VST host software.
4. Close your VST host program
This step is important because the measurement program of MathAudio Microphone Corrector may not work if you will not close your VST host program (some hosts are able to occupy ASIO drivers).
5. Make sure that the direct monitoring is switched off
Make sure that the direct monitoring of your sound card is switched off (i.e. there is no sound in your headphones when you speak to the microphones) - otherwise change the corresponding setting of the sound card driver.
6. Install MathAudio Microphone Corrector
Double-click the installer file to install MathAudio Microphone Corrector and follow the instructions.
7. Run the MathAudio Microphone Corrector measurement program
Click the Start button at the desktop. Then go to All Programs - MathAudio Microphone Corrector - Microphone Corrector Measurement. As a result you will get the window shown in Fig.1.
Fig.1. Screenshot of the MathAudio Microphone Corrector measurement program.
8. Adjust the sound card settings
Select the correct sound card settings in the MathAudio Microphone Corrector window. The selected Mic Inputs must correspond to the inputs of your sound card that were used for connecting your microphone inputs. The "Reference Mic In" must correspond to your reference microphone and the "Target Mic In" must correspond to your target microphone. If you use ASIO4ALL driver, click the "ASIO Configuration" button and select the necessary WDM device inputs and outputs in accordance with the ASIO4ALL manual, then click the "Apply" button to see the chosen inputs and outputs in the Microphone Corrector combo boxes.
Both microphones must be placed at the same distance from the source of the sound. If you correct a vocal microphone - place both microphones at the favorite distance from your mouth. If you correct an instrumental microphone - place it at the preferable distance from your musical instrument.
10. Check the signals of both microphones
Use headphones to monitor the microphone signals. Click the "Start monitoring" button and select the "Reference Mic" radio button. If your sound card settings are correct you will hear the sound of your reference microphone. Use the "Main Volume Control" slider to adjust for comfortable sound volume. Then select the "Target Mic" radio button and listen to the sound of your target microphone. Use the "Target Mic Volume" slider to adjust for comfortable sound volume.
11. Stop monitoring
Click the "Stop" button to stop the monitoring of the input signals.
12. Start recording the sound of the microphones
Click the "Start recording" button. You have 10 seconds to speak to the microphones (if you correct a vocal microphone) or play all the notes of your musical instrument (if you correct an instrumental microphone). Don't bother about the quality of your speaking or playing. The progress bar at the bottom of the MathAudio Microphone Corrector window will show you your progress. Fill the full 10 seconds with the sound of your voice or the sound of your musical instrument. The signal correction algorithm will be generated automatically in a few seconds after the end of the measurement process.
13. Listen to the processed sound of your microphone
Click the "Start monitoring" button, then click the "Corrected Target Mic" radio button. Speak to your target microphone or play your musical instrument. You will hear the processed sound. Then click the "Reference Mic" radio button to compare the processed sound of your target microphone with the original sound of your reference microphone. The sounds must be very similar.
14. Save the correction file
Click the "Save corr. file" button and save the signal correction algorithm as an .alg file.
15. Close the MathAudio Microphone Corrector measurement program window
16. Open the MathAudio Microphone Corrector VST plug-in
Run your VST host program and insert the plug-in into the mono channel corresponding to the target microphone. Open the MathAudio Microphone Corrector VST plug-in window in accordance with the manual for the corresponding software. You will get the plug-in window shown in Fig.2.
Fig.2. MathAudio Microphone Corrector plug-in window.
17. Load the correction file
- Click the "Load corr. file" button in the MathAudio Microphone Corrector plug-in window and open the saved .alg file. The name of the loaded .alg file will be indicated in the plug-in window.
- Adjust the volume of the microphone sound, as necessary, by means of the volume control of your host software.