Monitor 45B

Two-way bookshelf loudspeaker

15 3/4" H x 7" W x 12" D
40.01cm H x 17.78cm W x 30.48cm D


$36995 per pair

Available Finishes:
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The new standard for classic performance

High efficiency design in a dual-driver bookshelf size gives you more options for high performance audio. Let the 45B reveal the classic Polk sound (open, spacious and clear) in mid- to large-sized rooms (driven by even a modestly-powered amp or receiver). The 45B mounts on the wall, or on stands (available separately).

Monitor 45B Features:

1-inch (25mm) silk/polymer composite Dynamic Balance® dome tweeter with powerful neodymium magnet structure delivers clear and detailed high frequency response for realistic reproduction of vocals and instruments.

Dual 5 1/4-inch composite Dynamic Balance drivers are lightweight and stiff with good damping for high efficiency, excellent bass and midrange clarity with lower distortion.

Small-diameter driver design delivers wide dispersion, better mid-range, and more detailed bass response for an open, "box-less" three-dimensional sound.

Non-resonant all-MDF enclosure construction with 3/4-thick baffles ensures cleaner, clearer, more lifelike sound quality.

Crossovers use mylar bypass capacitors for more detailed high frequencies.

5-way binding post connectors, allowing for more secure hook-up options.

Monitor Series speakers are modern living accessories that make a stylish statement in either black or cherry wood grain finish, with Titanium faces.

Critically tuned flared port minimizes port noise (chuffing) for good low frequency extension with low distortion, resulting in natural, full-bodied sound with rich bass.

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

Diameter1" (2.54cm) 
TypeDynamic Balance silk/polymer composite dome 
Diameter5 1/4" (13.34cm) 
TypeDynamic Balance bi-laminate composite cone driver 


Total Frequency Response47Hz-25kHz 
Upper -3dB Limit24 kHz
Lower -3dB Limit57 Hz
Nominal Impedance8 ohms
Efficiency89 dB
Recommended Amplifier Power20-125 watts per channel
Inputs5-way binding posts 


Cabinet Dimensions
Height15 3/4" (40.01cm) 
Width7" (17.78cm) 
Depth12" (30.48cm) 
Product Weight (each)16.00 pounds


Unit of Measurepair 
Total Shipping Weighttbd pounds


Speaker Warranty5 years 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.

Monitor 45B Media

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Monitor 45B Accessories