Improving the Canon 5D Mark II audio so that it can produce usable production audio. The first part of any engineering effort is data gathering, so I set about to measure the input frequency response of the 5D. My end goal was to use the Marantz PMD661 field recorderas a mic pre-amp and primary production audiorecorder, however I also wanted to take the audio line output from the field recorder and feed it into the 5D to
Click here to download the full size of the above Circuit.
capture "good enough" production audio. To start off I created a stepped audiofile in Adobe Audition (20-200Hz: 20Hz steps, 200-1KHz: 100Hz steps, 1kHz-20kHz: 1kHz steps) andupload it to the Marantz field recorder SD card. Then it was simply a matter of playing back the audio into the camera with a simple resistor dividercircuit to compensate for the level difference between a line out and a mic input. The stepped audio waveform you see below is the audio extracted from the 5D video file. The top (left channel) waveform is simple resistor divider that also represents the defaultfrequency response of the 5D audio mic input. The bottom(right channel) waveform is the effect of the resistor divider, pluscustom designedpre-emphasis circuit. I also plotted thenormalizedresults in Excel to make the data a little easier to see. The bottom line:The 5D has a highpass filter at about 120Hz. Thecompensation circuit has a high pass around60Hz. The default Canon filter makes people sound like Gilbert Gottfried with a cold. Like any design there were some trade-offs. The first, and foremost, is that I had to use whatever components I had sitting around the test bench, sort of like the cook in the kitchen with a bunch of semi-random ingredients. No, my filter components aren`t necessarily optimal but they`re good enough to get the job done with respectable engineering designmargin. Second, I had to accept some input loss for the...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: