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Polk Audio Signature Reference SR5250

5-1/4" component speaker system

6 Reviews

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Item # 107SR5250

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Our take on the Polk Audio Signature Reference SR5250

Polk Audio has taken elements from their highly-acclaimed LSi Series home speakers and brought them to your car. The award-winning Signature Reference Series component speakers will impress you with sound that's detailed, dynamic, and realistic.

Polk Audio has taken elements from their highly-acclaimed LSi Series home speakers and brought them to your car. The award-winning Signature Reference Series component speakers will impress you with sound that's detailed, dynamic, and realistic.

The SR5250 5-1/4" component speaker system features special-design tweeters that broadcast accurate, natural high frequencies, with no annoying frequency spikes to color the sound. If installation space is limited, these versatile tweeters can even be mounted directly on the woofer cones to make outstanding 2-way speakers.

The air-injected polypropylene woofers kick out gutsy lows with superior control, and their extended frequency response allows them to blend smoothly with the tweeters. Butyl rubber surrounds form a rugged suspension for the cones, while the cast aluminum baskets eliminate resonances that can degrade sound quality. The powerful, compact neodymium magnets exert superb control over cone movement, while freeing up installation space.

High-performance crossover networks stabilize impedance as they distribute signals to the woofers and tweeters. The result — extremely accurate sound. Each crossover features four tweeter output levels — plenty of adjustment options to ensure well-balanced highs.

Priced per system

Product Highlights:

  • component speaker system includes woofers, tweeters, and crossovers
  • 5-1/4" aerated polypropylene woofer with UV- and temperature-resistant butyl rubber surround
  • 7/8" ring radiator tweeter with multiple mounting options
  • die cast aluminum woofer basket
  • 2-way external Zobel crossover network (3100 Hz, 18 dB/octave high-pass and 12 dB/octave low-pass) with four tweeter level settings
  • power range: 50-100 watts RMS (200 watts peak power)
  • frequency response: 60-30,000 Hz
  • sensitivity: 90 dB
  • top-mount depth: 2-1/4"
  • warranty: 3 years
  • Our 60-day money-back guarantee

What's in the Box:

  • Two 5-1/4" woofers (with installed phase plugs)
  • Two 22mm ring radiator tweeters (with attached 10" length of speaker wire)
  • 2 Tweeter flush mount cups (installed)
  • 2 Tweeter angle mount cups
  • 2 Crossover networks
  • 2 Coaxial tweeter posts
  • 2 Woofer grilles
  • 2 Woofer grille mounting rings
  • 2 Tweeter grilles
  • Two 5x7/6x8 Woofer adapter plates
  • 2 Adapter plate plugs
  • 2 Tweeter flush mount clamps
  • 2 Tweeter angle mount clamps
  • 2 Woofer mounting gaskets
  • 2 Rubber grommets
  • 2 Woofer spacer rings
  • 4 Speaker terminals
  • 4 Clear plastic speaker terminal insulators
  • Strip of grille adhesive
  • 8 Speed clips
  • Tweeter install tool
  • 2 Pan-head machine screws (#6 x 1/4")
  • 2 Split-ring lock washers (#6)
  • 4 Flat-head sheet metal screws (#8 x 1")
  • 8 Pan-head sheet metal screws (#8 x 1/2")
  • 8 Pan-head sheet metal screws (#8 x 3/4")
  • 8 Pan-head sheet metal screws (#8 x 1-1/2")
  • Owner's Manual (English/ Portuguese/ Italian/ German/ Spanish/ French)
  • Woofer mounting template
  • Tweeter mounting template
  • On-line product registration information
  • Letter of congratulations from Matthew Polk
  • Polk Audio vinyl decal

These speakers are phenomenal, yeah they might cost more, but who cares. You don't even need a sub with these things. I'm so glad I got these, I wish all speakers sounded like these.



Polk Audio Signature Reference SR5250 Reviews

Average Customer Review(s):

(6 Reviews)

Excellent high-end speakers

RG from Wisconsin on 4/15/2011

2000 Toyota Tundra
Crutchfield Customer Review (What's this?)

I am still waiting for these to fully break-in. Already I can tell that they are excellent, balanced speakers. My only regret is that Polk does not sell the 6500 anymore as those would have some better low frequency response; the bass on these isn't that great but you really shouldnt be looking into these without a subwoofer. The plus side is better blending with the tweeter (I imagine, haven't actually heard the 6500), and the speakers fit well in tight spaces. These do well what they were meant to do: make excellent, seamless mid-high range sound that is natural. After spending months researching speakers, I noticed that these were consistently lauded for their quality and rich sound, even compared to speakers costing thousands more. I would have consider Focal but then it seems like you are spending more for similar quality speakers. These sure do impress and they complement the subwoofer perfectly. The crossovers on these are large (did not fit in my doors) and very solid. Overall, all the components seem very well built. setup: Tundra access cab truck with these in front sharing a Rockford Power 600-4 with a 10" JL 10w3v3-4 in a home-made sealed enclosure. All running off of a simple pioneer deck with a 4v preout.




JOHN from WISCONSIN on 1/28/2011

These speakers are phenomenal, yeah they might cost more, but who cares. You don't even need a sub with these things. I'm so glad I got these, I wish all speakers sounded like these.



Loud and Clean

Gary from Oakland, CA on 4/14/2009

2004 Honda Element
Crutchfield Customer Review (What's this?)

These are some of the cleanest sounding speakers I have ever heard. I'm a big fan of crisp clean highs where you can almost feel like you're right there with the musician. With these speakers, I hear sounds I don't even hear on other speakers. These speakers have some awesome clarity in the highs. As for the lows, I feel you still need a sub to completely complement the sound. Without a sub, the music feels a little lacking in depth and bass. But you really can't expect a 5-1/4" to compare to a 12" subwoofer.



Excellent components

Jason from Clover, SC on 3/24/2009

2008 Chevrolet Impala
Crutchfield Customer Review (What's this?)

Great speakers! I am running them with 130 watts per side, thinking about bi-amping them with 260 per side later on after they break in. The woofer is very capable, easily surpassing cheaper components I have had from Infinity (reference and kappa series) and other manufacturers over the years. The tweeter is very smooth and makes the whole setup sound phenomenal. The crossover is huge, but necessary for higher end speakers. Overall, I am very happy. I am still breaking these in and also tuning them. They are VERY clear and detailed, and handle power well. I am using the stock crossover (maybe go active later), with the tweeter at -1.5db. I have them high passed at 63hz, with my Polk SR104-DVC running everything lower. Very pleased.



Excellent Speakers!!!

Russ from Drumore, PA on 2/2/2008

1995 Chrysler Lebaron
Crutchfield Customer Review (What's this?)

I decided to try these speakers in my 95 Le Baron conv. in an effort to get the best sound possible in my doors and rear pillars beside the rear seat. It took a little work to mount them in the rear, but it can be done! Also the huge crossovers were a trick to get into the front doors, but there is a spot. The sound is awsome to say the least! With my alpine 90watts per channel driving them, and the 3.5 Infifnity's in the dash, and the 10" sub in the trunk we are rockin!!! You will really be happy with these speakers!!!



no contest

kris from boston on 5/31/2006

my entire home theater is polk LSi, and now I've upgraded my car stereo to the signature reference series (which contains the same technology as the LSi home speakers), and yet again, polk does not disappoint...I have the 5.25's in the front and 6.5's in the back and they sound fantastic...I've listened to many other top of the line speakers including focals, Boston's, MB's, etc. and none of them even come close; factor in the price on top of the sonic quality, and the gap grows even wider...polk makes the best speaker out there for any application, home or car, you simply cannot go wrong with these guys...




Hands-on research

Features and Specs

Speaker Size
Design 2-way
Tweeter Design 22mm Ring Radiator
Impedance (Ohms) 4
Tweeter Composition Fabric
Woofer Composition Aerated Polypropylene
Woofer Surround Butyl Rubber
Parts Warranty 3 Years
Labor Warranty 3 Years
Sensitivity (1W at 1 meter) 90
Sensitivity at 2.83 volts N/A
Frequency Response 60 - 30k Hz
Minimum RMS Wattage 50
Maximum RMS Wattage 100
Peak Power Handling (Watts) 200
Top-mount Depth (Inches) 2 1/4
Bottom-mount Depth (Inches) N/A
Cutout Diameter or Length (inches) 4 3/4

Product Research

Woofer Features
Tweeter Features
Crossover Features

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.


Tweeters (mounted separately):

  Straight Flush Mount 15° Angled Flush Mount
Mounting Height 0.388" (incl. grille) 0.826" (incl. grille)
Depth 0.897" 0.603"
Frame Diameter 2.242" 2.333 Width, 2.375 Depth
Cutout Diameter 1.949" 1.502"

Crossover: The crossover dimensions are:

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

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.