Professional, Statement, Reference and Prestige series
All Grado headphones (except the models of the In ear series) have a vented diaphragm design that incorporates a large air chamber. This design concept lowers the frequency resonance (distortion) of the diaphragm and extends bass response. The diaphragm is made of a low mass polymer, carefully formed to broaden resonant modes to reduce their amplitude.
The diaphragm mass is determined with the compliance of the suspension in mind so that the desired low frequency resonance is achieved. The diaphragm's total mass is calculated to provide a full 20 KHZ bandwidth, while avoiding break-up at lower frequencies.
The Professional, Statement, Reference Series and along with the Prestige Series SR325is, SR225i and SR125i feature voice-coils that are wound from ultra-high purity, long crystal (UHPLC) oxygen free copper.
The copper is slowly drawn through the die in extremely small increments and is annealed following each drawing operation. Ultra-high conductivity copper yields the clearest transmission and lowest coloration possible. The sound of UHPLC copper is smoother, cleaner and more dynamic. All use very high power neodymium magnets to provide maximum efficiency and better sound. Each headphone driver is made to Grado's high standards, then pair-matched for exact imaging. These headphones also utilize UHPLC copper in the connecting cable.
All metal work for the PS1000 and SR325is is machined from a special non-resonant, very hard alloy. Grado utilizes a special processing method to increase the material's porosity. This complex treatment insures that the earphone chamber has no "ringing" which might obscure detail or add coloration.
Grado's wooden Statement and Reference Series are hand-crafted at our labs from a new specially selected species of jarah. An intricate procedure of curing is done between production steps to achieve optimal sonic quality. The overall sound remains pure Grado, warm harmonic color, full bodied vocals, excellent dynamics and an ultra smooth top end.
Technical refinements for Grado drivers include improved diaphragm and voice coil design for increased bass response and a larger perceived sound stage. A unique process to "de-stress" the diaphragm results in enhanced inner detail. An increased ability to control driver resonance virtually eliminates distortion. For all models, an improved headband spring will afford greater comfort for the majority of listeners.
Earphones: In ear series
Contrary to the above series the In ear models do not have their own chambers, they will use your ears to function properly. The transducers are extremely small: so small that they can easily fit inside the ear, they also have a tremendous side benefit: they will (if properly fitted) drastically cut down ambient noise. If the earphone is not properly fitted and the ear canal 2 problems will arise:
The transducers are very efficient, they were, for many years used in hearing aids but a recent improvement of their quality makes them perfectly adequate for serious listening of music.
The operating principle is called "balanced armature".
A balanced armature is a sound transducer design primarily intended to increase the electrical efficiency of the element by eliminating the stress on the diaphragm characteristic of many other magnetic transducer systems. It consists of a moving magnetic armature that is pivoted so it can move in the field of the permanent magnet. When precisely centered in the magnetic field there is no net force on the armature, hence the term 'balanced.' As illustrated in the second diagram, when there is electric current through the coil, it magnetizes the armature one way or the other, causing it to rotate slightly one way or the other about the pivot thus moving the diaphragm to make sound.
AND THE SOUND?
GRADO headphones can reproduce as natural a soundstage from stereo recordings and provide as much listening pleasure as a good pair of speakers do. GRADO headphones are free of room effects and placement problems, and they minimize any interference from external noise. They also offer portability and the ability to listen without worrying about the neighbors. With GRADO headphones, you will hear recordings with greater clarity and with deeper bass than others! GRADO headphones are the antithesis of mass production, as each GRADO headphone is hand-assembled and closely scrutinized to meet full performance specifications.