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1981 733i
Speakers guaranteed to fit your vehicle.
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Products in these categories contain items that carry a guarantee to fit your BMW 733i (change vehicle)
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All Alpine Car Speakers

Discover Alpine's entire lineup of high-performance car speakers.

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Alpine Speaker Installation & Accessories

Get the best from your Alpine speakers with our installation accessories.

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Alpine Vehicle Specific Speaker Kits

Tailor-made speaker kits by Alpine for your vehicle.

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Alpine 6.5" Speakers

Alpine's 6.5” speakers are engineered for balanced, high-quality sound.

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Alpine 6x9" Speakers

Enjoy powerful, expansive sound with Alpine's high-performing 6x9” speakers.

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Alpine 4" Speakers

Compact and potent, Alpine's 4” speakers ensure quality sound in a small package.

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Alpine 5.25" Speakers

Alpine's 5.25” speakers balance size and performance for superior audio.

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Other Alpine Car Speakers

Explore Alpine's variety of speakers for every car audio need.

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Alpine Tweeters

Alpine tweeters enhance high frequencies for crisp, clear audio.

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Alpine Speaker Packages & Bundles

Speaker packages and bundles for a complete Alpine audio upgrade.

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Alpine Marine Speakers

Weather-resistant Alpine speakers designed for the marine environment.

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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.
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Alpine S2-S50

340W Peak (110W RMS) 5.25" S-Series Hi-Res 2-Way Coaxial 4-ohm Car Speakers

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Alpine S2-S50

340W Peak (110W RMS) 5.25" S-Series Hi-Res 2-Way Coaxial 4-ohm Car Speakers

• 170 watts Peak Each, 55 watts RMS Each
• Hi-Res Audio Certified
• 3/4" Cloth Soft Dome tweeters
• Polypropylene, Glass Fiber and Mica cone material
• Impedance: 4 ohm
• Sensitivity: 87 dB

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Install kits available for most vehicles

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Fits the following location in your 733i
  • Rear Deck Corner
2
List price $160.00
-19% $129.95 /pair

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Alpine S2-S50 (2-Pairs, 4-Total)

680W Peak (220W RMS) 5.25" S-Series 2-way Coaxial Car Speakers (2-Pairs)

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Alpine S2-S50 (2-Pairs, 4-Total)

680W Peak (220W RMS) 5.25" S-Series 2-way Coaxial Car Speakers (2-Pairs)

• 170 watts Peak Each, 55 watts RMS Each
• 3/4" Silk Dome Tweeters
• Polypropylene cone material
• Impedance: 4 ohm
• Sensitivity: 87 dB

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Fits your 733i
2
List price $320.00
-19% $259.90

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• 170 watts Peak Each, 55 watts RMS Each
• 3/4" Silk Dome Tweeters
• Polypropylene cone material
• Impedance: 4 ohm
• Sensitivity: 87 dB

Alpine SPS-M601

220W Peak (70W RMS) 6.5" 2 Way Coaxial 4-ohm Marine Speakers (Silver)

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Alpine SPS-M601

220W Peak (70W RMS) 6.5" 2 Way Coaxial 4-ohm Marine Speakers (Silver)

• 110 watts Max Each, 35 watts RMS Each
• 7/8" PEI Titanium Balanced Dome tweeter
• Polypropylene cone material
• Impedance: 4 ohm
• Sensitivity: 89 dB
• Mounting Depth: 2-9/16"

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1
List price $180.00
-17% $149.95 /pair

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Only 1 Left!

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• 110 watts Max Each, 35 watts RMS Each
• 7/8" PEI Titanium Balanced Dome tweeter
• Polypropylene cone material
• Impedance: 4 ohm
• Sensitivity: 89 dB
• Mounting Depth: 2-9/16"

Alpine SPS-M601W

110W 6-1/2" 2-Way Type-S Marine Coaxial Speakers - White

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Alpine SPS-M601W

110W 6-1/2" 2-Way Type-S Marine Coaxial Speakers - White

• 110 Watts Max, 35 Watts RMS
• Poly-Mica Woofer Cone
• Santoprene surround
• 4 Ohm Impedance
• Sensitivity: 89 dB
• Centrex 813-coated grilles included

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List price $180.00
-17% $149.95

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Alpine MRN-S88-LB

900W Peak (150W RMS) 8.8" 2 Way Coaxial Marine Speakers with Black LED Grilles

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Alpine MRN-S88-LB

900W Peak (150W RMS) 8.8" 2 Way Coaxial Marine Speakers with Black LED Grilles

• 450 watts Peak Each, 150 watts RMS Each
• 1-1/4" Silk Dome tweeters
• Carbon Fiber Hybrid cone material

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List price $900.00
-11% $799.95 /pair

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• 450 watts Peak Each, 150 watts RMS Each
• 1-1/4" Silk Dome tweeters
• Carbon Fiber Hybrid cone material

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

    • You see only parts engineered for your exact vehicle
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    Whether you're replacing a factory stereo or upgrading your entire audio system, the Fit Finder eliminates uncertainty.

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