Car Subwoofers
MM840
8-inch single voice coil subwoofer
8" woofer
20.32cm woofer
MM840
If you’re looking for an introduction to the joy of real bass, bass that takes your music to the next level, yet doesn’t take up much space, the MM840 8-inch subwoofer is your choice. Using composite baskets, powerful motor structures with oversized voice coils, the MM840 punches out real tight, real serious bass you’d usually find only in the most expensive loudspeaker systems. With 250 Watts continuous/500 Watts peak power handling, we recommend the MM840 for small sealed (.35 cubic foot) enclosures.
Designed to Perform
The MM840 high performance 8-inch subwoofer maybe compact for a subwoofer but it cranks out waves of bass. As a result of 3 years of Polk research and development, every woofer and driver in the MM Series has been designed to offer unparalleled sound quality with exceptional fit to meet virtually any application. Borrowing technology from our flagship SR Series, the MM Series offers outstanding performance for your mobile audio dollar. With 250 Watts continuous/500 Watts peak power handling, the MM840 is recommended for small sealed (.35 cubic foot) enclosures.
MM840 Features:
New polymer woofer cones and butyl rubber surrounds will not break down over time and will survive the rigors of harsh automotive environments.
High temperature copper voice coil (51mm) and polyamide former withstands the most rigorous use while maintaining extremely low distortion for bass punch and output.
Heavy duty input terminals accommodate speaker wire up to 8 AWG or twisted pairs of 12 AWG.
Advanced carbon composite basket based on the spokes of a wheel is lightweight, will not flex during peaks and looks great! Don’t be afraid to show off the back of your woofer.
Klippel optimized components using a state-of-the-art Klippel distortion analyzer, Polk engineers were able to optimize the woofer’s motor structure, voice coil alignment and suspension for the best possible performance, even at extreme listening levels.
Available matching grille complement the wheel spoke design.
Dual voice coil configuration (MM840DVC) also available.
All Polk products are made using the best materials and the most advanced manufacturing techniques. They pass the industry’s most exhaustive quality tests, including drop testing, extreme signal response and UV & salt exposure testing. Polk loudspeakers are built to perform for a lifetime.
Driver Complement | |
|---|---|
| Subwoofer | |
| Quantity | 1 |
| Diameter | 8" (20.32cm) |
| Type | Dynamic Balance poly composite woofer |
Electrical | |
|---|---|
| Minimum Impedance | 3.3 |
| Total Frequency Response | 26-200Hz |
| Nominal Impedance | 4 ohms |
| Efficiency | 90 dB |
| Power Handling | |
| Continuous | 250 watts |
| Peak | 500 watts |
| Voice Coil | |
| Driver Diameter | 1 1/2" (3.81cm) |
Thiele / Small Parameters | |
|---|---|
| Resonant Frequency | 35 Hz |
| Xmax | |
| Xmax Linear | .75 |
| LE | 2.3 mH |
| SD | 35.65 sq in/230 sq cm |
| VAS | .54 cu ft/15.4L |
| QTS | .6 |
| QES | .7 |
| QMS | 5.5 |
Dimensions | |
|---|---|
| Cut-Out Diameter | 7 1/8" (18.10cm) |
| Driver Mounting Depth | |
| Top Mount | 4 1/8" (10.48cm) |
| Bottom Mount | 4 11/16" (11.91cm) |
Shipping | |
|---|---|
| Unit of Measure | each |
Warranty | |
|---|---|
| Speaker Warranty | 1 year parts and labor (original purchaser) |
Specifications, dimensions and features subject to change without notice. For more information call us at 1-800-377-7655 (USA and Canada). Outside of North America call +1 (410) 358-3600.
Customer Reviews
2 reviews with an average of 4.5
Write your own reviewby Mike, February 2, 2010
101 out of 155 people found this review helpful.Strengths:
Cleanest sub I've ever heard. I've only got 160 RMS going to it and it gets loud with no distortion or sloppiness to it. Great looking too. It's a shame I have to stuff it behind my seats so no one can see it.
Weaknesses:
NONE, terrific sub if you're cramped on space but don't wanna sacrifice sound quality
Review:
Great sounding sub. Clear and clean and awesome.
by adam, August 6, 2012
3 out of 3 people found this review helpful.Strengths:
Great sound, tight, responsive, great low end for 8's. They sound better than the 3 JL10W3's I had 15 years ago.
Weaknesses:
Composite basket seems cheap, but strong enough. I dont like using a small allen wrench to tighten a sub to a box, which is what is provided. Biggest problem is the nice compression terminals. They are too close to the edge of the sub. Makes fitting it into the box challenging. Also the terminals are rated for 8 gauge wire. I have supposedly true 8 gauge wire and I have a few strands that stick out.
Review:
I have 2 of the single 4 ohm ran in 2 ohm mono with around 300-350 watts. The box is about 1.3 cubic feet sealed. Optimal Q was 0.67 cu ft per Polk tech support (per sub).
MM840 Media
MM840 Literature
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