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Polk Audio db521

5-1/4" 2-way car speakers

Item #: 107DB521

In Stock

65 Reviews


Price Break:-$30.00

Installation gear for most cars

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Polk Audio db521

Give your music new life

Good music becomes great when you hear it through Polk's db Series car speakers. Polk engineers use laser imaging to determine the ideal combination of speaker materials and design to eliminate distortion. The resulting technology produces speakers with smooth frequency response, sharp detail, and the ability to play music at high volumes without strain.

Polk's db521 speakers feature 5-1/4" woofers made from a polymer/mica composite and durable rubber surrounds that won't fall apart under stress from heat, moisture, or time. Liquid-cooled 3/4" silk/polymer dome tweeters use powerful Neodymium magnets to deliver precise high-frequency reproduction, enveloping you in bright musical detail. And you can even pivot the tweeters, aiming them at your ears for improved stereo imaging. The built-in two-way crossovers keep the high and low frequencies flowing to the proper drivers for seamless, efficient audio.

The stainless steel mounting hardware is built to last, while the muscular ABS grilles will look great in your car's interior. Whether you've got a factory radio or an aftermarket stereo, these efficient speakers will spice up your daily drive. And Polk certifies their db Series speakers for marine applications, so they're a great choice for your boat, motorcycle, or ATV.

Priced per pair

Product Highlights:

  • 5-1/4" 2-way cars speakers (pair)
  • Dynamic Balance polymer/mica composite woofer with butyl rubber surround
  • 3/4" pivoting liquid-cooled silk/polymer composite dome tweeter
  • Neodymium tweeter magnet
  • Kapton voice coil
  • built-in 2-way crossover network
  • marine-certified for use in boats, convertibles, motorcycles, and ATVs
  • ABS wheel-design grilles
  • stainless steel mounting hardware
  • power range: 4-45 watts RMS (135 watts peak power)
  • frequency response: 60-22,000 Hz
  • sensitivity: 93 dB
  • top-mount depth: 2-5/16"
  • warranty: 1 year
  • Our 60-day money-back guarantee

Why replace your car's original speakers?

The speakers that originally came in your car were made from inexpensive materials, designed to create acceptable sound at the lowest possible cost to the manufacturer. If you love music, you deserve better. Name-brand aftermarket speakers deliver fuller, richer sound with considerably more detail and nuance, and they're capable of playing louder and cleaner than factory speakers. Connect new speakers to your factory radio and you'll get the best possible sound from your dealer-equipped system. Pair them up with a new car stereo for a level of enjoyment that can rival a high-fidelity home audio experience.

Polk Audio db521 Reviews

Average Customer Review:

65 reviews
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Motorcycle upgrade

Written By Mike, West Virginia on Monday, August 10, 2015

Crutchfield Customer Review (What's this?)

Used to upgrade speakers on my Indian motorcycle. They made a big difference in the sound quality coming from the stereo. Really like the quality and sound.


Written By Eric, Wisconsin on Monday, July 20, 2015

Crutchfield Customer Review (What's this?)

Fit perfectly in my vehicle as stated. Sound great. Huge upgrade over the old stock speakers in my Jeep Wrangler. Took about 15 minutes to install. Easy.

Pros: Sound great. Good deal for the price.

Cons: None.

Great Speakers

Written By Ernie_E, Florida on Monday, June 01, 2015

Crutchfield Customer Review (What's this?)

Bought these speakers to replace the stock speakers on my '90 Tour Glide. They sound excellent should have done this a long time ago

Awesome fit/design

Written By Dawg Pound, Maryland on Monday, May 25, 2015

Crutchfield Customer Review (What's this?)

I purchased this set of speakers as an upgrade/enhancement for my motorcycle. The fit was perfect and easy to install (under 10 minutes). The real reason Polk was my #1 choice is due prior experience with Polk home & auto speakers. They perform as well as they look.

Pros: Well designed, fit and function is "top-notch"

Cons: I wish the cone was a flat black color, allowing to blend better with multiple colors.

Great sound for the price

Written By Stephen, Lebanon, PA on Sunday, April 19, 2015

Crutchfield Customer Review (What's this?)

For the price, the installation was made quite easy by Crutchfield with their directions and wiring harness. The sound is just what it needs to be at for its specs, may add some new Polk tweeters to add the higher pitch bur other than that they are great!

Pros: Clear sound, good price point, easy installation

Cons: Could use a higher pitch but that's what tweeters are for.

Good speakers for my Jeep

Written By Born2bogey, Alabama on Thursday, April 16, 2015

Crutchfield Customer Review (What's this?)

Excellent speakers for the soundbar. Good sound, marine rated, good looking grills

Pros: sound, price, specs

Cons: none

Excellent Speaker

Written By Colin, Jersey Shore, PA on Tuesday, January 20, 2015

Crutchfield Customer Review (What's this?)

I purchased these to replace the blown stock speakers in my '03 Wrangler, they sound excellent from what I did have. I didn't take any stars away from them for not having enough bass though. They're small speakers I would never expect them to produce bass the way a larger speaker or even a subwoofer would. I don't know why Crutchfield said they don't fit my application. They dropped right into my roll at without any modifications.

Pros: Great mids and highs.

Cons: Not amazing bass but what I expected out of them.

Excellent speakers

Written By Bruce, Nashville, TN on Sunday, August 17, 2014

Crutchfield Customer Review (What's this?)

In my 2006 Dodge Ram regular cab truckI have a pair of Polk 6X9 in my doors and a pair of Polk 3.5 in my dash. I saved a little money initially with some Sony 5.5 behind the seat. MISTAKE Within or right at a year, the Sony could not keep up. I got these Polk 521 to replace them with and oh what a difference! Such clean sound! I can actually turn it up a little louder and it still sounds great! I will never buy another pair of Sony speakers again. I have Polk 6X9 in the rear of my car. I've become a pretty strong Polk fan for their speakers. I might be hard pressed to buy anything else.

Pros: Sound absolutely great! I had them installed as I'm not inclined to take the time to do that. I have a much cleaner and stronger sound coming from behind the seat now to complement the rest. Everything about this purchase was good so far.

Cons: When i find one then I will have to change this review. There are no downsides yet.

Great speakers

Written By tim, mckinney, tx on Friday, June 27, 2014

Crutchfield Customer Review (What's this?)

Great speakers. Sound great. Much better than factory. Installation was very easy.

Pros: Great range of sound

Great sound!

Written By Frank K, Southington CT on Sunday, May 04, 2014

Crutchfield Customer Review (What's this?)

Crutchfield got me my speakers quick and inexpensively. They have vastly improved the sound in my jeep.

Pros: Easy install, great sound, quick shipping.

Cons: None.

bd in jeep

Written By ash, west Jefferson nc on Monday, January 13, 2014

Crutchfield Customer Review (What's this?)

Good speaker but is lacking in the highs, also dissapointed by the speaker grills, barely touched it while screwing it in place and it chipped leaving an ugly black spot...would have thought it would take a little more to chip paint than that, it is marine rated after all and that should include everything , not just the speaker...

Pros: Sound

Cons: Needs to be run off an amp to show true potential, and grill cheaply made...

Good Replacement for Stock

Written By VA_Tim, Ashburn, VA on Thursday, January 02, 2014

Crutchfield Customer Review (What's this?)

Installed in a 2003 Jeep Wrangler Rubicon with OEM System (7-speaker). Solid replacement speakers for OEM rear speakers. Better response across the board. Bass won't knock you out of your seat, but hey, these are 5 inch speakers! Definitely better than OEM, and worth the price. Install was a breeze with Crutchfield instructions and wire harnesses. Took me 10 minutes! The Kicker speaker grills worked for me despite the instructions saying you had to use the stock covers.

Pros: Good Sound. Reasonable price. Super simple install. Great looks.

Cons: Not a top of the line speaker if that's what you want (but they are supposed to be either!)

They Rock

Written By Chris, Stuarts Draft, VA on Wednesday, January 01, 2014

These speakers rock, I had them installed in a Wrangler and even with the top down they sound great. Crutchfield did a great install job as well.

Would buy again

Written By KevinB, Asheville NC on Tuesday, December 31, 2013

Crutchfield Customer Review (What's this?)

Clean sound, excellent value, would buy again.

Easy Install for 2005 Jeep Wrangler

Written By Anonymous, Greenville, MS on Monday, November 25, 2013

Crutchfield Customer Review (What's this?)

These speakers went it flawlessly. I have never replaced a speaker in my life and was able to install these in less than 30 minutes.

Great replacement speakers for Jeep

Written By JohnD, Virginia Beach, VA on Friday, November 22, 2013

Crutchfield Customer Review (What's this?)

These speakers sounded great powered by an aftermarket head unit. Handle plenty of power and are a huge improvement over the factory speakers. It was an easy install in the roll bar/speaker pods of my 2003 Jeep Wrangler.

Pros: Great sound Plenty powerful Easy install in the Jeep Marine certified (so hopefully durable in the Jeep)

Cons: None

Polk Audio db521 Jeep TJ

Written By Jeffery S, Florida on Thursday, November 14, 2013

Crutchfield Customer Review (What's this?)

Setup with 300 MHz bass blockers and foam surrounds on an Alpine deck. Perform well at low volume level but when listening at higher volume levels these speakers loose their clarity rather quickly and become distorted. Build quality looks good and should hold up to outdoor use. Overall these are acceptable replacement speakers.

Pros: Marine Certified Good clarity at low volume

Cons: Poor clarity at higher volumes

Jeep upgrade

Written By dg144, Birmingham, AL on Tuesday, September 17, 2013

Crutchfield Customer Review (What's this?)

Product seems to be well made and had no fitment issues. The speakes sound good, but there is something about the "tone" i guess that seems a little low, just have to play with controls a little and i am using factory HU so they are probably underpowered. But they produce clean sound and are a mojor improvemt

Pros: well made, easy to install. sound great

Cons: maybe a little low in tone, could be my HU

'04 Rubicon Upgrade

Written By RDS, Lancaster, PA on Saturday, July 13, 2013

Crutchfield Customer Review (What's this?)

If your looking for an upgrade for your Wrangler sound bar - These are the Ones ! I highly recommend ! Easy upgrade, great price ! With the install accessories provide by Crutchfield, took less than an hour. I used the Polk speaker covers instead of the stock, and they look great in the sound bar. And the speakers sound awesome with my Kenwood head unit ! Bright, Crisp high end and a little extra punch on the low end. A real improvement from the stock speakers !

Fast Delivery ! Ordered Thurs, 9am - Delivered and Installed by Fri, 5pm.

Thanks Crutchfield And thanks Bryce for your help !

Pros: Great sound ! Great price ! Great Service !

Cons: None

Polk Audio db521

Written By Jewboy, Clarksville Tn on Saturday, June 08, 2013

Crutchfield Customer Review (What's this?)

Sounds great


Written By Todd M, Alpharetta, GA on Friday, April 26, 2013

Crutchfield Customer Review (What's this?)

Good sound Quality, Would Purchase again

Nice speakers

Written By Kirk, Oroville, CA on Friday, April 26, 2013

Crutchfield Customer Review (What's this?)

Great speakers and easy to install with minimal customization in place of 4x6 old OEM speakers. Especially like the cross overs on the speaker itself,

Pros: Sound good and quality construction

Cons: with that i could change cross over settings, but could find any.

Polk Audio db521

Written By hockey guy, Northern California on Monday, March 11, 2013

Crutchfield Customer Review (What's this?)

nice cheap speakers, unfortunately, the bellows tore very easily during installation, but doesn't seem to affect the sound too much.

Pros: cheap, reasonable sounding speakers

Cons: better be super careful during installation because of the fragile bellows.

Pretty Good

Written By Anonymous, Baltimore, MD on Friday, March 08, 2013

Crutchfield Customer Review (What's this?)

These were to replace my blown rear speakers in my 1991 Jeep Cherokee. Its hard to tell if they're better considering that my old ones never worked. Installed really easily thanks to the wire harness that came with them.

Pros: They were easy to install and work.

Cons: I don't know if its my head unit or what but I have the bass turned way down but still get distortion when I turn them up. It bothers me but it could just be that my truck is old.

Good Replacement Speakers

Written By Dave, Round Rock, TX on Friday, March 08, 2013

Crutchfield Customer Review (What's this?)

I purchased these speakers to replace the factory speakers in the soundbar. What a difference! First, they were easy to install with the wiring harness and easy instructions - maybe 40 minutes max (if I had better lighting, maybe 25 - 30 minutes). They sound tremendous and fit the bill for what I wanted. I used the soundbar's speaker covers instead of the covers that were supplied because I liked the appearance.

Pros: Great sound. Economical. Easy to install.

Sound great

Written By Keith D, Cleveland Ohio on Monday, March 04, 2013

Crutchfield Customer Review (What's this?)

Sounds goood

Pros: Sounds great price was good

Cons: None

Replacement Spks for 2006 Wrangler

Written By BSuber, Atlanta, Ga on Sunday, February 17, 2013

Crutchfield Customer Review (What's this?)

Definitely sound better than the factory cardboard speakers; but they do make a cracking sound and are just radio quality. I also got duped by Crutchfield with their "Buy One Get One Half Off" bc Amazon sold them for less with no sale.

Pros: Easy instructions for installation.

Cons: Not as clear as the brand used to be. They crack and are very "treble-ish". I'm a 40 yr old woman, so I'm not trying to have a concert on wheelie.

Polk's are Perfect for 2003 Jeep TJ

Written By Todd, Connecticut on Sunday, October 21, 2012

Crutchfield Customer Review (What's this?)

Before reading any further, if your Jeep, Truck or car does not have a sub woofer, the Polk Audio db521 speakers will leave you a bit wanting in the bass category. However, if you do have supplementary kick, then these are a great upgrade for the price, especially over the paper factory speakers and installation in the roll bar of my TJ was a breeze. Despite what the note suggests on Crutchfield's website and installation instructions, you CAN use the Polk Audio speaker grills instead of the original factory covers, which are a definite aesthetic upgrade.

Pros: Great sound, especially mid and high Value for money Easy installation Speaker covers provide a nice visual punch

Cons: Bass....but this really isn't a Con because it's only a 5.25" speaker. Be realistic with your expectations and you'll love these speakers.

Polk db521 5 1/4 speakers

Written By Adrian, Dixon, CA on Tuesday, August 14, 2012

Crutchfield Customer Review (What's this?)

I installed these in the bow of my boat. I had to go with 5 1/4 because that is what would fit. These speakers are a great addition to the four Polk db651s that are on the tower. I wasn't expecting much bass from these little speakers but I was pleasantly suprised. Now even the people in the front of the boat can rock out when we are traveling at top speed. (4 3/4 hole saw worked great for the holes!)

Pros: Sound quality, size, marine certified, appearance

Cons: None

Better than factory but not as good as I was hoping

Written By Elliott, Tampa, FL on Tuesday, July 31, 2012

Crutchfield Customer Review (What's this?)

They replaced the 1999 factory speakers along with a Kenwood Excelon KDC-X796 head unit. Sound improved but didn't get the depth and clarity I was hoping for. Granted, these are small speakers but I was hoping for a better sound - maybe I was just expecting too much. Fair speaker and fair price.

Pros: Clearer than stock speakers.

Cons: No bass.

Polk Audio db521

Written By Anonymous, Huntington, CT on Sunday, June 03, 2012

Crutchfield Customer Review (What's this?)

Sound great and easy to install!

Polk Audio db521

Written By Ramon, Doral, FL on Thursday, May 10, 2012

Crutchfield Customer Review (What's this?)

Excellent Product, Sound is clean .... I Installed on My Land Rover LR3 without problems. I Replaced OEM speaker and sound change 100%

Pros: Great Sound with amplifier

Cons: Nothing !!


Written By Acura tls 2007, 43206 on Wednesday, May 09, 2012

Crutchfield Customer Review (What's this?)

This I a great speaker. Great sound and clarity. Just to let you know, it does fit the front door location for a 2007 Acura tl s type. I had to use a speaker ring bracket (included) to mount in baffle but very simple. Took 10 minutes. Crutchfield claims this won't work but it does

Pros: Great highs and mids with about 40 watts rms

Cons: None yet

Polk db 521, Great in My Harley.

Written By Mike B., Henrico County, Va. on Thursday, April 26, 2012

Crutchfield Customer Review (What's this?)

I bought these to replace the original speakers on my '04 Harley Electra Glide. The motor has 75k miles on it and the speakers were not doing good. Thanks to some friends I spoke with and the help from Crutchfield website and online help, I decided on these speakers. They were going in my motorcycle fairing and would be subject to rain so the marine rating is what I need. I do basically ride 12 months a year and I do occaisionally get wet. The speakers were installed this past weekend. I rode from Stafford, Va to my home near Richmond and was very surprised how well they work. For the first time on my motorcycle, I could hear music as it is intended, which I could not even when the motor was new. Only had the volume half way up and could hear them clearly at 70mph.(no headphones and half helmet) I tried many stations to include country, soul, r&r, talk show and even Bach. True I have only had them installed a couple days so we will see after a couple months on the road in sun AND rain. I can only imagine how they will sound when I update the radio.

Pros: I heard the music as it was intended. The high background notes as well as the low. They fit the Harley fairing without any alterations or additional brackets.

Cons: I heard noises and thought the motorcycle was acting up. After turning the radio on and off a couple times, I realized the tapping and all, was not the motor, but part of the music.

Great Speaker Awful bracket - 2007 Civic EX

Written By rmc, Phoenix, AZ on Friday, December 23, 2011

I bought these speakers to compliment my db651 speakers for my 2007 Honda Civic EX. The front door speakers were pretty simple to install and were great sounding so I decided to purchase these for the rear speakers. The only issue I have with them is that installing the rear speakers should have been about a 10-15 minute job, but it turned out to be 1.5 hours+ due to the brackets that crutchfield shipped with these: model # 142 SAC656 - these are complete garbage and do not fit well at all. You have to snap off the edges and remove the screw threader that is already in place. The customer service rep was very helpful and helped me get started, but if they just would have shipped the same style bracket that I got with the 651s this would've been cake.

The speakers themselves sound great so far though.

Pros: Sounds great, decent price.

Cons: Mounting Brackets

2002 Jeep Wrangler

Written By Sumo, Annandale, VA on Wednesday, September 07, 2011

Crutchfield Customer Review (What's this?)

I replaced the stock speakers in my dash and sound bar with these Polks. They are powered by the head unit only (Pioneer DEH-33HD) and are loud enough when I'm at speed with the top up. I would recommend them for anyone who wants to do a speaker upgrade in their car. I mainly listen to heavy metal, rock, rap, and talk radio. These speakers are fine for that.

Great rear fill speakers

Written By Blaine, Louisiana on Monday, September 05, 2011

Crutchfield Customer Review (What's this?)

I am using these as rear fill speakers in a 99 Mustang GT. They are powered by a Boston Acoustics GTA-504 amp. I do not need bass from these...that's what subwoofers are for. They sound smooth and clear just how I expected them to. Great product.

Wrangler - Good As expected

Written By Frank M., Atlanta, GA on Friday, August 26, 2011

Crutchfield Customer Review (What's this?)

Installed incredibly easy into my 2003 Jeep Wrangler - Front and Top Bar. Sound is a definte improvement over stock speakers, but lack base as expected due to their size. Once I replace the subwoofer, this should be a pretty decent system - especially for the cost and time involved to upgrade. Would recommend as a great stock replacement.

Just okay

Written By Chris, WV on Friday, July 08, 2011

Crutchfield Customer Review (What's this?)

To be honest I wasn't blown away by these speakers. I installed two in the soundbar and with a little modification, two in the dash of my 1999 Jeep Wrangler. I bought them because my dash speakers were blown. I did a comparison when the left soundbar speaker was installed and the right was still factory. I didn't think there was that much difference to be heard which was pretty surprising considering the factory speakers are cardboard.

Of note to other wrangler owners: The biggest difference I heard was after I put poly fill in the soundbar. With either the factory or the Polks.

Excellent choice for Jeep Wrangler

Written By Mike, Hudson, Ohio on Thursday, June 16, 2011

Crutchfield Customer Review (What's this?)

With the help of the folks at Crutchfield I paired these up with the Polk db421's in the dash along with a Bazooka BTA8100 8" 100 Watt Powered Sub behind the rear seat. I also replace the head unit with the Kenwood KDC-X395 CD Receiver. The system sounds great. I have a nice full sound at an awesome price.

I did NOT use bass blockers as some have commented about because the receiver actually allows you to specify the frequency that is is passed to each speaker. The polks have great mids and highs and the bass tube fills in the lows perfectly. This is an excellent combo.

2005 tj

Written By chris, kc Mo. on Wednesday, May 18, 2011

Crutchfield Customer Review (What's this?)

I just installed these and the 4" in the dash. The guys at cruchfield know what they
are talk'n about, these little guys rock. I could'nt beleve the amount of bass they put
out for what they are. If you have a jeep wrangler these are what you want. I might
add that i added bass blockers to the dash speakers.

2003 Jeep Wrangler TJ

Written By 2003TJ, Alabama on Tuesday, March 29, 2011

Crutchfield Customer Review (What's this?)

Just installed two pairs of these speakers this in my daughter's 2003 Jeep
Wrangler TJ. The jeep had the original factory 4x6" speakers in the dash and
5 1/4" speakers in the sound bar.

I did purchase adapters for the 5 1/4" speakers to fit in the dash, but no
problem with that. Install was a breeze with the included "freebies" (master
sheet instructions for removing old speakers, factory wiring adapters, etc...)
from Crutchfield.

Also, replaced the factory radio with an Alpine CDA-105 CD receiver.

I realize that the stock radio and speakers were eight (8) years old, but the
difference is incredible. My daughter can now hear music clearly with the soft
top flapping, or with the entire top down.

Sound is excellent for these speakers. One should not expect alot of bass
from small speakers, but the sound quality is excellent, very little distortion at
louder volumes; the bass from the head unit does need to be reduced at
louder volumes, but the speakers still sound excellent; very clear and crisp
highs and mid-range.

Again, thanks Crutchfield. Spent less that $300 for a new head unit and two
pairs of speakers. About 3 hours of time spent. Money will spent. I have to say
a 200% improvement over the stock radio/speakers.

Nice upgrade

Written By Eric B, Dyer, in on Saturday, February 19, 2011

Replaced 4 stock speakers in a 2008 Saturn Vue, Not quite a "system" but a
definite upgrade. I'd buy them again.

Worth buying!

Written By KT, Bellevue, WA on Monday, February 14, 2011

Crutchfield Customer Review (What's this?)

I purchased these based on others' reviews for my 04 Wrangler. They're obviously a
much better quality item than the stock paper speakers in the soundbar, and after a very
simple install, they're a big sound improvement.

I liked them enough to try them out in the front panel of the Jeep (using a special bracket
for 5.25" speakers). Huge difference over the 4x6 paper speakers, and they fit perfectly.
I'm now getting ready to order a second set to round out the sound. I purchased a
Kenwood deck from Crutchfield, and it's powering these speakers just fine. Thanks
again Crutchfield!

Dan K

Written By Dan K, Lake Havasu Az on Sunday, February 13, 2011

Crutchfield Customer Review (What's this?)

Really easy install with good instructions and good quality sound for the money.

Polk Audio db521

Written By Franklin, Tyrone, pa on Sunday, January 16, 2011

Crutchfield Customer Review (What's this?)

i replaced all the speaker's in my ridgeline using the full range speaker's in the rear
door's and the component speaker's in the front door's polk audio realy made my first
time buying after market speaker's worth doing.


Written By Hunter, Baton Rouge, LA on Thursday, December 09, 2010

Crutchfield Customer Review (What's this?)

Bought a pair of these to replace the cardboard and foam rubber Mexican-made speakers
in my TJ's soundbar. Installation was simple with the included wiring harness. The sound
is worlds better than the stock speakers. I'd put sound quality right between Infinity
Reference and Kappa. A little better than Ref, but not quite up to Kappa. Highly
recommended, especially at this price.

Tight Tight Tight

Written By Glenn, Cincinnati. OH on Sunday, June 20, 2010

These dropped into my doors without much effort. The fronts took some juggling, but
the rears dropped in like they were made for the car. The sound is much more than I
expected, very tight and handle power without any whining at all. May add a sub, but the
bass is impressive. I have used Polk products before and have been impressed with
each purchase. Great value.

2004 Jeep Rubicon

Written By Dennis, Pinole, Ca on Thursday, March 25, 2010

Crutchfield Customer Review (What's this?)

My Rubicon came with an infinity 7-speaker system that sounded pretty good but my
CD's skipped with the big tires on my rig rolling down the road, so I purchased the
Kenwood KDC-MP342U CD Receiver with the iPod USB controller and decided to
upgrade the rollbar speakers. I have to tell you these rock! Extremley smooth and loud. I
now hear instruments in the music that I did not hear before. These are a definate
upgrade to the stock inifinity speakers. I highly reccomend! Easy upgrade, great price!

Highly Impressed

Written By Ken, Atlanta, GA on Sunday, March 14, 2010

I bought a set of these for my 2000 Wrangler in June of 2008, they have now been installed for over a year and a half and have left me nothing short of impressed. They're currently being powered by a 600w 4ch amplifier (Polk's in the roll bar, Infinity Kappa 4x6's in the dash) with channel 1 set for the left side, and 2 for the right. 3 and 4 are bridged for my 10" Rockford sub and together they all make a beautiful medley of sound. The Polks don't distort at all at high volume, the highs are clear and yet they provide enough of a low end that the highs don't screech in your ears, which is great because I can ride with the top and doors off and still blast my music loud enough to hear it at 65mph on the interstate. If I could give these speakers a higher rating than a 5 I would. Definitely worth the money.

Jeep replacements

Written By Winston, NJ on Saturday, January 23, 2010

Crutchfield Customer Review (What's this?)

I put 2 of these in my 99 Jeep Wrangler's roll bar speakers and it sounds phenomenal. They might not provide ground shaking bass but there is definitely noticeable low end and almost no distortion coming from these speakers. In fact, i noticed that these speakers sound better the louder they are. These speakers are perfect for a Jeep Wrangler.

These Polks Rock

Written By Tony, Long Island, New York on Wednesday, July 08, 2009

I just installed these Polk db521's in the front doors of my '07 Accord and all I can say is wow! These really pick up the highs as hear a lot music. I have these along with 6x9 rear Alpines being driven off the stock head unit. When the folks at Crutchfield say the first thing to do for better sound is to change the stock factory speakers, believe it. These speakers require a little more effort to install as mounting holes have to be drilled because the stock units are spring clipped in. Not a big deal just a little more time. I have installed head units and speakers for the last eight years all bought from Crutchfield. Their sales, service and tech support are second to none.

'00 Jeep Wrangler

Written By waechter, York, PA on Wednesday, March 11, 2009

Crutchfield Customer Review (What's this?)

I purchased the combo of db 4 x 6 for the dash and 5 1/4 for the roll cage and couldn't be happier with the crystal clear rich sound they provide; at this time I have the factory head unit with XM radio. I will eventually get a new cd player and would like to add a small sub for a little added bass but until Crutchfield came through again. I will definitely buy the other components from them! Thanks to customer service for answering all my questions; stellar job.

Oh and the install couldn't have been easier with the wiring harness included. All I needed was a Phillips screwdriver and 15 minutes...done!

These installed perfectly fine in my '00 roll bar, nothing extra needed....maybe a little different than the '05.

Polk Audio db521

Written By Namsag, Appleton, WI on Saturday, February 14, 2009

I installed these in the front of my 2005 Jeep Wrangler. The two rear speakers in the sound bar are factory. My Jeep has the factory stereo and
also comes with a factory sub woofer. Please keep that in mind as I rate this.......

WOW! Major difference over the stock speakers. Much cleaner, clearer and significantly louder. I hear sounds I never heard before. These are awesome low cost speakers. Sound much better than I had expected. The original two-piece speakers are not even close. They help give the system the needed highs and mid ranges that the factory speakers just didn't have.

If this is your price range I highly recommend these speakers.

NOTE FOR JEEP OWNERS: These are not the same size as the factory two-piece speakers and will not fit without the required adaptor plates.
Crutchfield will list these as not fitting as they do not fit without the adaptors. It is really easy to upgrade to these speakers with the adaptors
and well worth it.

not better than stock Harley speakers

Written By Steve, Fort Morgan, CO on Tuesday, February 10, 2009

Crutchfield Customer Review (What's this?)

I purchased these speakers for my '06 electra glide classic. they do not measure up to the stock speakers, they do not have the clarity and they distort at volume levels quite a bit lower than the stock ones. However in their defense, Harley uses high quality speakers as stock so the bar is set pretty high.

Polk Audio what else do you have to say

Written By Chase, Morgan City, LA on Wednesday, January 14, 2009

These speakers are great. I have to in my front doors and the db 6x9's in the rear doors. These speakers are the best I have heard by far. The sound clariety is amazing. I just order two Polk MoMo 10 inch subs to add to my system. If anyone is wondering what brand of speakers to go with I will tell you, you cant go wrong when you get Polk.

not impressed

Written By greenwald, boy from illinois on Monday, September 29, 2008

Crutchfield Customer Review (What's this?)

i put these in my 95 ram p/u and am disappointed. i installed the baffles as well that were recommended, and must say they are weak. i even went all out and ran new speaker wire (16ga monster cable) to them from my deck. i dont know, was expecting more. i had a chevy 1500 with 4x6s sound better. maybe one day when i am bored, i shall remove the baffles, and hope for the best. until then.

I'd buy them again!

Written By Jeff, Lafayette, CA on Thursday, September 25, 2008

Crutchfield Customer Review (What's this?)

This is the 3rd set of Polks I have purchased from Crutchfield, these always
sound great and add to any existing system.

Nice set of speakers

Written By Andrew, Little Ferry NJ on Monday, September 08, 2008

Crutchfield Customer Review (What's this?)

My friend recommended I buy these speakers for my 26 foot Searay Boat. We bought a brand new Clarion Marine Head Unit and I had 4 (probably factory) 5 1/4 speakers in my boat. I bought 2 pairs and installed them on my boat. With the baffles, these speakers are excellent. They are a perfect mid level marine speaker that produces very nice sound. I am happy with the purchase and installation was easy. Pretty good bass response out a little 5 1/4 speaker. I would recommend these for your marine application.

Good clean sound

Written By baggett, Clarksville Tn on Thursday, September 04, 2008

Crutchfield Customer Review (What's this?)

I replaced my factory speakers on my 97 jeep wrangler, you can beat the performance of these speakers in which you can clearly hear going down the road with the top down. I would recommend to any jeep owner.

sweet addition

Written By William, Rogers, AR on Monday, August 18, 2008

Crutchfield Customer Review (What's this?)

I replaced my 4, 4" speakers in my boat with these 5 1/4" Polks and WOW! I have paired these speakers with the Kenwood marine rated compact
amp/10" sub combo to my JVC head unit with no additional amp pushing the Polks. The sound is crystal clear, even when we're tied up at the cove
cranking out the tunes. Lots of compliments, even from those guys who really forked out the bucks for much more expensive systems. Good choice,
right price!

Perfect upgrade for Jeep soundbar

Written By Tyler, Clemson, SC on Friday, August 01, 2008

I put a pair of these in the sound bar of my '03 Wrangler, and they are exactly what I was looking for. VERY easy to install.

The sound is clear even with volume up loud enough to hear while driving at highway speeds with the top down; more than the stock speakers could ever handle...

Without replacing the head unit (for now) this is a necessary upgrade for any Jeep owner, especially if you drive with the top down a lot. I ordered a pair of Polk MOMO 4"x6" to compliment these, and can't wait to get them installed.

Great job Polk!

Truly Amazing!!!

Written By Robert, Garner, NC on Monday, May 26, 2008

I got these little gems. I put these
in the door of a 1996 Dodge Dakota knockaround truck. I also got a pair of
Polk 5x7's to put behind the seat. With an Alpine amp pushing these two
sets of speakers--the sound is rich, full and vibrant.

I have alwyas utilized higher end speakers in my car stereo applications.
But I could not have asked for better sound reproduction in the small area
of my truck.

if you are looking for an affordable set of speakers with excellent sound
reproduction--get some Polks. You'll be just as impressed as I am.


Written By yaumno, Atlanta, GA on Thursday, January 03, 2008

I purchased a pair of these along with a pair of Polk MOMO 4'' x 6'' speakers for my BMW 328i. With only the power from my receiver at 30/50 volume they make my ears bleed. If you are looking for loads of midrange and highs with some extra bass then pick a pair of these up as soon as possible. They are really easy to install and are amazing for the price. Way to go Polk and thanks Crutchfield!

Really tight - great speakers

Written By Douglas, Milwaukee WI on Wednesday, November 07, 2007

I purchased a pair of the 6x9 and 5 1/4" speakers to install in my vintage 1971 speedboat. Coupled with the infinity bass link and a Jensen head unit the system really rocks - hard! I have received a number of compliments on the sound system - for the sound and looks. Everyone likes the speakers - the grills are very nicely done - nothing overstated or cheesy with chrome. They have received a fair amount of splashed water and it hasn't damaged them. I wouldn't submerge them; however, they do prove to work well in a boat. I will be adding a pair of these to my 2007 Accord because the sound is amazing. On a boat the last thing you want is distortion at high volume to overcome the motor sound - these puppies really crank - loud and clear - and at lower volumes when we are tied up on a sand bar - look out you will get lots of people asking how did you get that to sound so good!!! It's fun - and the speakers are priced right!

Hands-on research

What's in the box?

Download owner's manual

  • Two 2-way speakers
  • 2 Grilles
  • 8 Self-tapping screws (length=1")
  • 8 Speed clips
  • Owner's Manual (Eng/Span/Fren/Ger/Ita/Port)
  • Online registration sheet

Features and Specs

Design 2-way
Tweeter Design 3/4" Dome
Tweeter Composition Silk/Polymer composite
Woofer Composition Polymer/Mica composite
Woofer Surround Butyl rubber
Parts Warranty 1 Year
Labor Warranty 1 Year
Sensitivity 93 dB at 1 watt
Frequency Response 60 - 22k Hz
RMS Power Range (Watts) 4-45
Peak Power Handling (Watts) 135
Impedance (Ohms) 4
Top-mount Depth (Inches) 2 5/16
Bottom-mount Depth (Inches) N/A
Cutout Diameter or Length (inches) 4 3/4

Product Research


Dynamic Balance: Dynamic Balance is a proprietary Polk Audio technology using laser imaging to determine what combination of speaker materials create the least amount of resonance. Eliminating resonance in speakers results in a wide, smooth response and low distortion.

Woofer Cones: Each speaker features a Dynamic Balance polymer/mica composite mineral-filled cone. The cones are stiff and lightweight for big sound and low distortion.

Butyl Rubber Surrounds: For a smoother response and improved durability, the woofers use butyl rubber surrounds.

Kapton Voice Coil Former: The low-mass two-layer 25mm Kapton Voice Coil former is lightweight for high sound output. Kapton's high melting temperature (725°F) ensures high power handling and longer reliability.

Silk/Polymer Composite Tweeters: The 3/4" liquid-cooled, silk/polymer composite tweeters provide clear, detailed highs. The tweeters use neodymium magnets.

Pivoting Tweeter: The tweeter pivots, allowing you to aim it toward your listening position for better imaging.

2-way Crossover Network: The built-in 2-way crossover network sends the appropriate frequencies to each driver for cleaner sound and better imaging.

Flat Spider: The speaker utilizes a flat spider for faster, longer excursion linear motion.

Pole Plate Heat Sink: The speaker's pole plate heat sink promotes better heat dissipation for superior power handling and reliability.

Woven Leads: The speaker features flexible woven leads sewn directly into the spider for greater reliability.

Basket: The speaker is housed in a solid, acoustically inert stamped steel basket finished in rustproof gun metal gray.

Grilles: Strong ABS plastic grilles are included. These computer optimized grilles are based on exclusive MOMO designs.

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.

Product reviews from the Crutchfield Labs

What are the Labs?

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Polk Audio db5251

Polk Audio db5251


In Stock

$129.99 After $60.00 Price Break

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Components sound better

The Polk Audio db5251 offers these features:

  • separate 1" silk composite dome tweeters for a clearer, more detailed stereo image
  • 2-way external crossover network with 3-position tweeter level control
  • lower frequency response for better mid-bass