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Infinity Primus 503F Primus Series 5-1/4" 2-way car speakers

Item # 108P503F

Infinity knows what music should sound like in the car, and their Primus PR503F 5-1/4" 2-way...

Find what Fits your vehicle

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Infinity knows what music should sound like in the car, and their Primus PR503F 5-1/4" 2-way...

Item # 108P503F

Every order includes

  • Free lifetime tech support
  • 60-day price-drop protection
  • 60-day returns

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Get questions answered fast & free

Expert help 400+ hours training Virginia-based

About the Infinity Primus 503F

Alexander H.

Product highlights:

  • 5-1/4" 2-way car speakers
  • Plus One+ polypropylene woofer cone with hi-roll rubber surround
  • 3/4" edge-driven silk dome tweeter
  • 3-ohm impedance for extra power (compatible with virtually all factory or aftermarket car stereos)
  • handles up to 40 watts RMS (120 watts peak power)
  • frequency response: 75-20,000 Hz
  • sensitivity: 91 dB at 2.83 volts
  • grilles not included
  • warranty: 1 year
  • MFR # INFSPKPR503F
  • Item # 108P503F
  • California customers: Please click here for your Proposition 65 WARNING.

What's in the box:

Infinity Primus 503F owner's manual

If you need assistance accessing this owner's manual, please give us a call.
  • Two 2-way speakers
  • Two 9" Lengths of speaker wire (each has female quick-slides on one end and tinned wire on the other)
  • Eight 1" Screws
  • 8 Speed clips
  • 2 Adhesive backed foam gaskets
  • Template and specs on box

More details on the Infinity Primus 503F

Pat M.

Features & specs

General
Speaker Size 5 1/4
Driver Design 2-way
Woofer Design Plus One Cone
Woofer Material Polypropylene
Woofer Surround Rubber
Midrange Design ---
Midrange Material ---
Tweeter Design Dome
Tweeter Material Silk
Super Tweeter Design ---
Super Tweeter Material ---
Impedance (Ohms) 3
Weather-resistant No
Grilles Included No
Parts Warranty 1 Year
Labor Warranty 1 Year
Specifications
Sensitivity (1W at 1 meter) N/A
Sensitivity at 2.83 volts 91
Frequency Response 75 - 20k Hz
Maximum RMS Wattage 40
Peak Power Handling (Watts) 120
Top-mount Depth (Inches) 1 13/16
Bottom-mount Depth (Inches) N/A
Cutout Diameter or Length (inches) 4 7/16
Mounting Height (Inches) 0.293
Frame Width 5.083
Frame Length 5.083
The Infinity Primus 503F replaces these items:

Product Research

Features

Plus One Woofer Cones: The Plus One speaker cones offer more surface area than many other speakers that fit in the same size opening. This is accomplished by using a new basket design and hi-roll surround. The result is greater bass output and an increase in efficiency.

Voice Coil: The Primus Series speakers feature 3-ohm voice coils to compensate for the high in-line resistance of small gauge factory wiring. They extract every watt from the factory receiver, increasing overall system output and efficiency (relative to 4-ohm speakers). The speakers also benefit from increased power when you upgrade the wire and add aftermarket amplifiers capable of powering a lower impedance load.

The Infinity Primus 503F replaces these items:


Adding...
  • Plus One+ polypropylene woofer cone with hi-roll rubber surround
  • edge-driven, textile dome tweeter
  • handles up to 40 watts RMS (120 watts peak power)

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Customer Q&A

2 questions already asked

Q
Do these speakers require anything else? Or is it as simple as out with the old (stock) and in with the new?
trevor  Nov 03, 2024
1 answer
A
Hey Trevor, so typically its out with the old and in the new though depending on your vehicle there may be harnesses or brackets that are going to be required to get them mounted in place. For details on installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on what you will need for an installation.
red  Nov 03, 2024 (Staff)
Q
What is the Outside diameter measurement my stock speakers are 6 1/2" outside diameter?
danny  Oct 26, 2024
1 answer
A
Greetings Danny. Thank you for your question. The outside diameter without the screw holes is 5.083 inches. With the screw holes diagonal is 5.8 inches.
thomas  Oct 26, 2024 (Staff)

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Infinity Primus PR503F
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