Sapphire Audio Sapphire XLs Frequency Response, Dynamic range, Delayed Resonance Control

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systematically engineering and refining the Sapphire XL to optimize performance. Please note the following factors:

Frequency Response:

For a speaker to be considered “accurate” it must have a smooth frequency response that is free of major dips, peaks, troughs or plateaus. The Sapphire XLs exhibit exceptionally flat response throughout the range from below 48Hz to 20kHz. In fact, from 60-20Khz the variance is less than 1.5db! The cast-frame woofer provides excellent bass performance at all but subwoofer frequencies.

Of nearly equal importance is the off-axis response of the speaker. This response from 15 to 45 degrees off the axis of the speaker determines the smoothness of the early reflections from the wall surfaces. In most domestic listening situations this energy is nearly equal to the on-axis response in determining the balance of the system. The off-axis response should show a gradual decrease in output with increased frequency but should not show major dips or peaks which will color the overall sound. Again, the Sapphire XL gives an exemplary off-axis dispersion pattern.

Tight quality control procedures are necessary to assure that your Sapphire XLs sound every bit as good as our lab samples. Incoming shipments of raw parts including cabinet materials, drivers and crossover components are subject to extensive testing to verify that they meet our exacting standards. Precise quality control is critical for the best stereo imaging. Drivers are selected to closely match the standard, and crossover components are hand selected to better than 1% tolerance.

Dynamic range:

Dynamic range in a speaker requires;

∙Adequate sensitivity so that it may be driven to realistic levels with available amplification. The C- weighted sensitivity for the Sapphire XL is 85.5db. This is a very reasonable rating considering the size and bass response of this speaker.

∙An easy load for the amplifier. A speaker can have a high sensitivity number but may present a difficult load for the driving amplifier. The Sapphire XL has a nominal impedance of 6 ohms. The minimum impedance is 4.5 ohms and the maximum impedance is 26 ohms. Some speakers have wildly varying impedance phase curves that can cause problems for amplifiers. The phase of the Sapphire XLs impedance helps make the Sapphire XL an easy load for any amplifier.

∙Low distortion drive units are necessary to keep the music from becoming edgy or gritty as the volume is turned up. The drive units used in the Sapphire XL have very linear suspensions, which reduce distortion components to inaudible levels and contribute to the excellent sense of “clarity”. The crossover used keeps low frequencies out of the tweeter and protects it from over-excursion at resonance, which would otherwise cause increased distortion.

Good power handling is a requirement if musical peaks are to be reproduced cleanly and without damage to the speaker. The drive units in the Sapphire XL are extremely rugged and will cleanly reproduce the dynamics of live music.

Delayed Resonance Control:

The ultimate control of delayed resonance required extensive use of Cumulative Spectral Decay analysis coupled with accelerometer testing of the cabinet wall surfaces. This extensive testing allowed us to develop the most cost-effective internal bracing to create the vault like solidity of the Sapphire XL. The entire cabinet is formed of an incredibly inert and well-damped medium density fiberboard (MDF) specified at 49.3 pounds per cubic foot density. All drive units were designed with effective resonance control in mind.

We’ve attempted to show you some of the important design considerations that go into the Sapphire XL system. To fully document the design process would require many hundreds of pages. We haven’t even discussed the extremely high level of quality control that must be exercised in the drivers, crossovers and enclosure to maintain the design standards. But the most important point is that the Sapphire XLs are designed and built by and for music lovers. You must hear the Sapphire XL system reproduce your favorite music over a period of time to appreciate how fine these speakers are.