General Design Commentary on Grado Headphones
All Grado headphones 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. 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.

The Sonic Reproduction of Grado Headphones
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 in the U.S.A.

Grado Prestige Headphone Series Details
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.

The Latest Version, the SR225i
What does the i stand for in the new SR225i from Grado? Improved, that’s what! Features are the same as the SR125i, new driver, cable and housing designs, but this headphone has an increased rear air flow, utilizes Grado’s larger ear cushion and has closer matched drivers. Air flow is increased by 50% which is achieved through an improved rear metal screen. The use of closer matched drivers and the larger cushions results in an enlarged soundstage, while the improved rear screen frees the headphone from colorations.

Comments on the Grado SR225

"Music flows through this headphone organically and believably, with irrepressible dynamics and bounce." -HI-FI Choice Recommended

"Sounding very good at both low and high levels, these headphones are of reference quality both for the classical virtues of neutral frequency response and low coloration, as well as for their clarity and the high degree of listener involvement envoked." -HI-FI News & Record Review / Martin Colloms

"The SR225s sound unlike any other headphone. They have an amazingly solid presentation, packed with weight and presence. There is also a pleasant richness in the midrange that benefits all types of music." -WHAT Hi-Fi

"When it comes to classical music, the Grados reproduce instruments with both believable timbre and solidity. The treble boosts fine detail and no hint of agression. ... these Grados are hard to beat!" -WHAT Hi-Fi

Grado SR225i Features

Vented diaphragm

Non Resonant air chamber

UHPLC copper voice coil wire

Standard copper connecting cord

Grado SR225i Technical Data

Transducer type dynamic

Operating principle open air

Frequency response 20-22

SPL 1mV 98

Normal impedance 32ohms

Driver matched db .05