Garage
Shop
Account Icon
Account
Box Icon
Track
order
Telephone Icon
Call
Help Icon
Help
Door with Arrow Icon
Sign In
  1. Home
  2. Diamond Audio Store
  3. Diamond Audio Car Audio & Electronics
  4. Diamond Audio Car Speakers
  5. Diamond Audio 6.75" Speakers

Diamond Audio 6.75" Speakers for your 2011 Optima close

Exclamation Icon It’s a no-brainer.
 Get your speakers here.

Install kit discounts · Guaranteed fit · Full warranty
Filters
Diamond Audio ✕
Clear Filters
Reset Done
Show products that do not fit
Speaker Location
Speaker Size
Refers to the size of the speaker measured in inches. Every vehicle has standard application sizes. Please use our vehicle fitment guide for your vehicle's specific speaker sizes if you do not know them.
Design
The number of individual drivers in a car speaker. Speakers with 2 drivers are known as a 2-way, and 3 drivers are known as a 3-way. Component systems are often referred to as "separates" because the tweeter is not attached to the midwoofer (main speaker driver) and mounts separately in a location such as a door post. Component systems typically come with an external crossover so you can easily adjust the high and low frequencies sent to both the midwoofer and the tweeter. Center channel speakers are great for those looking to have surround sound in their vehicle.
RMS Power Handling
The RMS power is the amount of power the speaker requires to operate safely and properly. RMS Power Handling refers to the amount of power a speaker can handle on a continuous basis. We recommend powering your speakers or subwoofer with 80%-120% of its recommended RMS rating. The RMS power handling specification is typically rated per speaker unless otherwise noted.
Peak Power Handling
Peak power handling refers to the amount of power a speaker can handle during a brief musical burst. The RMS power range figure is a much more reliable rating for determining the speaker's power requirements. The Peak power handling specification is typically rated per speaker unless otherwise noted.
Sensitivity
An efficiency or sensitivity rating tells you how effectively a speaker converts power into sound. The higher the number, the more efficient the speaker and the louder it will play with the same input power. An efficient speaker helps you maximize your available power. Most sensitivity ratings measure the speaker's output with 1 watt of input, 1 meter from the speaker. Some speakers' sensitivity is measured with 2.83 volts of input, instead of 1 watt.
  Efficiency (1w/1m) is not an accurate indicator of a subwoofer's output capability and should not be used as a comparison to other speakers or subwoofers to determine which one is "louder".
Impedance (Per Voice Coil)
The load value (in ohms) that the speakers present to the amplifier per voice coil - the amount of resistance to the current flow. This is a key specification as subs wired in parallel or low impedances can create problems with your amplifier and potentially void all warranties. We encourage you to ask our support department prior to purchase if you do not understand which impedance level will suit your application best.
Shallow Mount Installation
This means that the subwoofer/speaker is designed to be installed in areas that do not have a lot of space. Shallow mount subwoofers are typically found under a seat or behind the seat in some trucks.

Shallow mount speakers will typically have a mounting depth of 2" or less, while shallow mount subwoofers will typically have a mounting depth of 3" or less.
Tweeter Design
Designs such as cone, dome, semi-dome, balanced dome, and whizzer are most popular. Cone tweeters are simple, efficient and typically are the most reasonably priced. Dome tweeters are used in most home speakers, and provide a smoother and more accurate sound. Semi-dome design is one with a dome placed inside a cone. A Balanced dome driver is a semi-dome with equal reproduction area given the cone and dome portions of the driver. A whizzer tweeter is a separate tweeter cone driven by the voice coil of the woofer.
Series
Many brands group their products into series or lines of products to help customers know the level of quality (good, better, best for example). You can filter by series and the brand using our guided browsing.
Deals
Promotions we have offer More Ways to Shop for items that are on clearance, last chance, special offer and sales, Made in America, and more!

Your Vehicle

close
Checkmark Icon
Fits select locations in your 2011 Optima
Add vehicle details to confirm exact location or Update vehicle.
Update vehicle | Remove vehicle | Vehicle store

Shop the Category

filter-icon Filters & Sort

Diamond Audio DMDX675

300W Peak (100W RMS) 6.75" DMD Series 2-Way Cocentric Coaxial 4-ohm Speakers

DMDX675 big
Go to item page Right Arrow Icon of Right Arrow

Diamond Audio DMDX675

300W Peak (100W RMS) 6.75" DMD Series 2-Way Cocentric Coaxial 4-ohm Speakers

• 150 watts Peak Each, 50 watts RMS Each
• Dome Tweeters
• Treated Paper cone material
• Impedance: 4 ohm
• Sensitivity: 86 dB

shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $16.00 in rewards to spend later

install icon

Save $21 on install kits for this speaker

found car based on your search
Fits multiple locations in your Optima
$159.99 /pair

In stock.

Add to Cart
See all 6 special offers
 
    Clear all
    why-shoping-with-sonic

    We love people and we're ready to help you! See what separates us from our competition.

    Take advantage of our VIP rewards like 10% back on your purchases, free 2-day shipping, extended warranties, and free returns! Gain access to all of these rewards without any membership fees.
    Get great discounted (and possibly FREE) installation accessories with most car stereo purchases. This includes dash kits, wiring harnesses and antenna adapters that you will need to properly install your new car stereo.
    We are an Authorized Dealer for all the brands we sell, including the most premium brands in car and marine audio such as Hertz, JL Audio, NVX, Rockford Fosgate, Kicker, Alpine, Kenwood and many more.
    Shop Deals and get up to 30% off premium brands! Shop Now! We are always looking out for the best products and deals to offer our customers. Don’t pay too much by shopping elsewhere!
    We have information on brands, gear, and more for you to explore! Check out our YouTube Channel for helpful how-to videos, product reviews, and Q&As. For a more detailed look, also visit our Learning Center!
    Our trained experts are here to assist you! They are just a phone call or click away to help you get the right gear for you and your vehicle!
    Why Shop With Us?
    Save up to 10 different vehicles in your garage
    Vehicle
    Store     Delete

    2009 Subaru Forester

    2024 Ford Bronco

    2003 Toyota Matrix

    2011 Kia Optima

    2018 Jeep Cherokee

    2007 Lexus RX350

    2014 Lexus RX350

    2005 Buick Rendezvous

    2008 Lexus IS350

    1996 Lexus LS400

    Add vehicle Clear all vehicles
    Where to find vehicle info
    Are you sure you want to clear your garage?
    This action cannot be undone. Confirm

    Cancel

    This category was not designed for products.
    If you continue, you will be redirected to a category customized for your vehicle. Continue

    Cancel

    Shop your 2011 Optima
    Why Use a Vehicle Fit Guide?
    Change vehicle | Shop without vehicle
    Whoa! Slow down. Add your details below!
    additional information required
    Add vehicle details to confirm fitment
    Ignore fitment details
    Find stereos and more that work -- fast.

    Additional information:

    Remove

    Can't find your vehicle? Click here and we'll help.

    Where to find vehicle info

    Go to Fitment

    Didn't find your car?

    Submit your details and we'll help!
    Please enter the letters as they are shown in the image above. Letters are not case-sensitive.
    Identify your vehicle and submodel details
    • Owner's manual
    • Vehicle's insurance card
    • Vehicle registration
    • Vehicle produced after 2005: Inside driver's side door
    • Vehicle produced before 2005: Rear passenger doorjamb, glove box, center console, or engine compartment
    Car Info Side Door Icon
    Vehicle Registration Icon
    Vehicle Insurance Icon
    Back

    Modern vehicles often require specific brackets, wiring harnesses, and mounting solutions. A fit guide ensures:

    • You see only parts engineered for your exact vehicle
    • You avoid incompatible radios, speakers, or wiring
    • Installation is smoother, faster, and frustration-free
    • You get the correct accessories the first time

    Whether you're replacing a factory stereo or upgrading your entire audio system, the Fit Finder eliminates uncertainty.

    Back
    Track your order
    Call our experts
    Support Center
    Return & Exchanges
    Follow on Instagram Instagram logo
    Subscribe on YouTube YouTube logo