There are 3 basic types of earphones, each with their set of benefits and problems. Small transducers that are inserted into the auditory canal. This leaves only a few millimeters of a mismatched acoustic transmission line between the vibrating diaphragm of the transducer and the eardrum. This cavity should be sealed or have very slow air leakage to the outside world in order to prevent bass roll-off.
Click here to download the full size of the above Circuit.
This also provides a high degree of isolation from ambient sounds. To achieve this requires that the canal phones have been slightly wetted with water before insertion. They tend to be uncomfortable but can be accurate transducers if the transmission line resonance has been equalized. Their bass response is highly dependent upon the seal of the ear canal. The ear cushion wraps around the pinna so that the transducer and the outer ear form a sealed cavity. The internal geometry of this cavity varies between individuals, which makes measurements of headphones unreliable. The cavity has multiple resonances, which makes equalization difficult. The seal of the cavity affects the bass response and the resonances. They give isolation from ambient sounds and are much more comfortable than canal phones, but I begin to sweat wearing them and they tend to be heavy. I have no use for them. Here the ear cushion rests lightly on the pinna and any cavity formed between transducer and pinna is relatively open. Cavity resonances are attenuated, but there is also little isolation from the outside world. they are easily equalized. The problem is with the bass response. They are usually light and comfortable to wear. I place earbuds in this category. Inconsistencies of their placement in the outer ear and a lack of seal makes the bass and higher frequency response unpredictable. They are popular but not useable as reference phones. They might...
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: