Woofer Features
Tweeter Features
Crossover Features
Dimensions

Woofer Features

Aerated Polypropylene (APP) Cone: The Polk Audio SR5250's woofers are constructed of Aerated Polypropylene, a mineral-filled polypropylene that has been "puffed up" with injected air to form a honeycomb-like structure. The result is a stiff, lightweight material with excellent damping qualities.

Surround: The cone is bonded to the basket with a soft butyl rubber surround. The injection-molded butyl rubber is tuned to absorb unwanted cone resonance. In addition, the surround is resistant to ultraviolet rays, temperature extremes, and humidity to add to the speaker's reliability and longevity.

Phase Plug: The bullet-shaped phase plug in the center of the driver ensures a smooth, flat, off-axis frequency response by preventing the high frequency sound waves emanating from one side of the cone from interfering with sound waves from the other side of the cone. The phase plug can be removed to convert the SR5250 into a coaxial speaker.

Basket: The woofer features a high-mass cast aluminum basket. The basket and magnet cover are one piece with heat sink fins that draw heat away from the voice coil, increasing power handling and reliability.

Voice Coil: The voice coil is wound around a 1-1/2" diameter low-mass, high temperature polyimide former. The large diameter coil contributes to the high bass output and high power handling of the driver.

Neodymium Magnets: The speaker uses a Neodymium magnet, which has a similar magnetic flux density to a ceramic magnet 10 times its size.

Mounting Rings: Mounting rings are included which reduce the mounting depth and increase the mounting height, both by 0.36 inches. The effective frame diameter of the woofer when using the mounting ring is 6.298", meaning it covers a 6-1/2" or 6-3/4" speaker opening, but the screw holes don't match either standard application.

5x7/6x8 Adapters: The woofers can be mounted in many 5x7/6x8 applications when used with the supplied adapters.

Terminals: The woofers have typical quick-slide terminals, and also have screw terminals which will accept bare wire or spade terminals.

Tweeter Features

Ring Radiator Tweeter: The SR5250 has a 22mm (7/8") Ring Radiator tweeter, the same type as used in high-end audiophile home speakers. The Ring Radiator's ultra-light woven diaphragm is supported at two pivot points, with the voice coil attached approximately midway between the two pivots. Since there is a very small diaphragm area that is unsupported, there is less opportunity for the development of performance-robbing resonance. The phase plug, similar to the one found on the woofer, prevents phase cancellations, so you get a flat, smooth frequency response, both on- and off-axis.

Extended High Frequency Response: The tweeter's frequency response goes well beyond 20kHz; to 40kHz overall and to 30kHz at -3dB. This drives resonant peaks beyond audibility, and gives the speaker more overall detail and lower distortion levels.

Dual Neodymium Magnets: The tweeter has two Neodymium magnets to provide a powerful magnetic field for the voice coil, while still maintaining the tweeter's compact dimensions.

Faraday Cap: The motor structure includes a copper Faraday Cap on the pole piece to flatten the impedance curve, lower distortion, and extend and improve high frequency response.

Mounting Options: The tweeter can be mounted a variety of ways. When the speakers are mounted as separate components, the tweeter can be mounted in a straight flush-mount cup or in an angled flush mount cup. In addition, you can remove the woofer's phase plug and mount the tweeter on the woofer as a coaxial speaker. When configured as coaxials, the tweeter speaker wire is threaded through the magnet and adds approximately 1/16" to the mounting depth. The tweeter adds a little over 3/4" to the mounting height, for a total of 1.141 inches. The tweeter can also be mounted in the 5" x 7" adapter.

Crossover Features

High Quality Components: The SR5250 crossover uses 1% tolerance resistors and capacitors to ensure the woofers and tweeters are perfectly matched to provide a solid, stable, and consistent stereo image. Air Core Inductors with Oxygen-free copper wire are used for wider dynamic range, contrast, and punch.

Zobel Network: The crossover includes a Zobel network, which flattens the system's impedance curve for a more efficient power transfer and flatter response.

Bi-Amping: The crossover's circuit board includes two jumpers which can be configured for single amplification or bi-amping. You can independently drive the woofer and tweeter with separate amplifier channels when the jumpers are removed. If driving the woofer and tweeter from the same channel, the jumpers should remain installed.

4-Position Tweeter Levels: You can adjust the output level of the tweeter at the crossover by positioning a jumper to one of four positions: -3dB, -1.5dB, 0dB, or +2dB.

Crossover Slopes: The crossover includes a 2nd order, 12dB per octave low pass filter for the woofer, and a 3rd order, 18dB per octave high pass filter for the tweeter. The crossover frequency for both high- and low-pass filters is 4600 Hz.

Tweeter Protection: The crossover's Tweeter Protection device limits the current flowing into the tweeter, preventing damage to the tweeter when it is operated beyond safe operating levels.

Heat Sink: The crossover is housed in a heavy-duty solid cast aluminum chassis which acts as a heat sink for cooler operation and longer reliability.

Dimensions

Tweeters (mounted separately):

Crossover: The crossover dimensions are:

• Width: 6.767"
• Height: 1.585" (chassis) / 1.890" (overall, including knobs)
• Depth: 4.518"