SIERRA HORIZON

SIERRA HORIZON FEATURES

• All Sierra Horizons are hand assembled, tested and packaged at our factory in Orange County, CA.
• A serialized production line frequency response measurement is included with each speaker.
• 7 year manufacturer's warranty + 30-day satisfaction guarantee.

Cabinet:

• Exclusive 3-ply vertically laminated bamboo cabinet construction dramatically reduces cabinet resonance for a cleaner, more detailed, and transparent performance.
• Cabinet is a stunningly beautiful natural hardwood finish, there are no veneers and as such, no need to be concerned about peeling veneers or wraps or veneer cracks.
• Cabinet is fully environmentally friendly as the bamboo we source is a completely renewable resource.

Bass Woofers:

• Injection molded mineral-filled polypropylene cone provides excellent stiffness and superior self-damping.
• Long-throw design for high power handling and extended bass.
• Cast aluminum frame for a exceptional rigidity and reduced resonance.
• Exceptionally large magnet system for improved damping and lifelike dynamics.
• Pure copper shorting ring to reduce distortion, linearize magnetic flux, and dramatically reduce inductance.
• Vented pole-piece and vented spider for enhanced air-flow and cooling, minimizing compression artifacts.

Midrange Woofer:

• Injection molded mineral-filled polypropylene cone provides excellent stiffness and superior self-damping.
• Extreme low mass design for improved transient reproduction and lower stored energy.
• Underhung voice coil for exceptional linearity and lower distortion.
• Large metal phase plug for improved dispersion and enhanced cooling.
• Inverted surround eliminates edge resonance.
• Pure copper shorting ring to reduce distortion, linearize magnetic flux, and dramatically reduce inductance.
• Vented pole-piece and vented spider for enhanced air-flow and cooling, minimizing compression artifacts.

RAAL 70-20 Ribbon Tweeter:

• Fully custom true ribbon tweeter manufactured by RAAL in Serbia to our specifications.
• True ribbon tweeter has no voice coil, the pure aluminum ribbon is the only electrical conductor and the only moving part.
• Extremely low moving mass design, typically less than 1/50th the mass of a dome tweeter, enabling near instantaneous acceleration / deceleration, and no stored energy all combined to provide near perfect transient reproduction.
• Class-leading horizontal dispersion width provides a huge soundstage and precise imaging.
• High powered neodymium magnets in a unique homogenous design (equal strength magnetic field throughout the entire ribbon area) provides lower distortion and less stress on the ribbon diaphragm.
• Critically damped rear chamber to absorb the back wave of the ribbon diaphragm, improving frequency response linearity and overall transparency.
• Amorphous core transformer as opposed to ferrite reduces saturation and compression for much improved micro-dynamics and detail.

NrT Dome Tweeter:

• 26mm high-definition soft dome custom manufactured by SEAS of Norway and exclusive to Ascend Acoustics.
• Integrated elastomer wave guide.
• Axially magnetized neodymium ring magnet with large damping chamber dramatically lowers the resonant frequency and effectively eliminates back-wave radiation.
• Underhung voice coil for reduced distortion and improved transient reproduction.
• Wide surround and low-viscosity magnetic fluid for higher power handling and improved transients.

Crossover:

• Large open topology with proper inductor spacing and orientation to reduce mutual inductance and saturation.
• Heavy gauge pure copper traces to reduce resistance and provide higher power handling.
• Featuring metallized polypropylene capacitors.
• Air-core inductors in the direct signal path.

SIERRA HORIZON SPECIFICATIONS

SIERRA HORIZON MEASUREMENTS

*All measurements taken using DRA Lab’s MLSSA system with RCAI, calibrated ACO Pacific 7012 ½” free field measurement microphone with associated pre-amp and power supply and an automated Outline turntable.

Full-range quasi-anechoic on-axis frequency response:

Horizontal and vertical off-axis graphs plus listening window:

Listening window is the averaged response of 5 separate measurements, on-axis, +/- 15 degrees horizontal and +/- 15 degrees vertical. Note: due to the measurement technique, the response below 200Hz is invalid, as represented by the above and below horizontal green bars.

45 degrees off-axis horizontally is within +/- 6dB of on-axis up to 8 kHz, which is about the best there is in a horizontally configured center speaker. The horizontal listening window is +/- 45 degrees, which translates to nearly 20 feet wide (10 feet to left of center, 10 feet to right) at only 10 feet back from the speaker, which is remarkable.

Vertical response is extremely symmetrical, considering this is not a vertically symmetrical driver array, with a +/- 20 degree vertical listening window. This translates to a vertical listening window of ~7.25 feet at 10 feet back, approx 3.5 feet above listener and 3.5 feet below listener. This means the speaker won't sound different if you are sitting or standing and offers great placement flexibility (above or below the TV), while also not being too wide such that floor and ceiling reflections are causing problems.

Polar Response:

5 degree increments from 0 degs to a full 90 degs off-axis. Note how the critical midrange response remains linear and consistent with uniformly decreasing spl as frequency increases. Also note the lack of tweeter bloom as far off-axis as 45 degrees. Horizontal off-axis shows zero evidence of comb filtering (lobing) at any off-axis angle. This represents an exceptional off-axis response.

Impedance and electrical phase:

Note the extremely clean impedance response (free from wrinkles which would represent various forms of resonances) and linear phase with minimal phase angles. The mild phase angles ensure that this speaker is an easy load for even basic receivers.

Energy Time Curve:

This measurement is a good indication of overall transient accuracy and stored energy. The graph displays the decay time of a full range impulse. The impulse occurs at approx 2.8ms and decreases uniformly to the noise floor (-45db) by 4.4ms. This represents a decay time of 1.6ms, which is superb. Large diameter woofer cones, woofers and tweeters with poorly designed motor systems and/or heavy mass and poorly constructed cabinets will often contribute to far greater decay times which damage transient accuracy, coherency and overall resolution.

Cumulative Spectral Decay:

This measurement is similar to the energy time curve but displays a 3 dimensional view such that we can examine the decay time with reference to frequency. It is an exceptional tool to reveal transient accuracy and indicate various problem areas with respect to resonance and stored energy. The CSD of the Sierra Horizon is exceptionally clean with good uniformity.

SIERRA HORIZON SUMMARY

A high-performance center speaker is critical to any home theater system, it is the single most important speaker for this type of system.  The performance of our Horizon is well known, offering remarkable dialogue intelligibility from low volume levels to reference level volumes, even when sitting far off-axis. The Horizon offers best-in-class off-axis horizontal dispersion, while providing a smooth and detailed presentation with stunning dynamics.

Suitable for use as a center with any of our left/right speakers, and much like our Towers, the Horizon is a true end-game speaker, finding better center channel performance, regardless of price, would be most challenging.

SIERRA HORIZON GALLERY