Polk Audio Book Shelf or Tower Kit Dual 5.25 woofers 2 Way
Price: $57.50
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(5 out of 5 with 1 vote)
Product Description:

Polk Audio Book Shelf or Tower Kit

Components to build two speakers

This is a super kit, consisting of top quality components. Each was selected to give you a fantastic sound. It is a upgraded version of our Polk Kit, we swapped out the crossover for one that is much better.

You will get the components to build One Dual Woofer Center Speaker, as  follows.

Components in the Kit

  • (4) 5 1/4" Polk Audio Woofers (4 ohm) Shielded
  • (2) 1" Silk Dome Tweeter (8 ohm) Shielded
  • (2) Two Way Crossover 12db 
  • (2) Terminal Cup
Over All Specifications to expect
  • Power 20 to 150 Watts RMS Per Channel at 8 ohms
  • Impedance 8 ohms
  • Frequency response 40 Hz. to 20 kHz.
  • Efficiency 90 dB at 1 watt at 1 meter
Woofer Specifications
  • 5.25" Polly Cone Shielded Woofer
  • Impedance 4 ohms (you wire in series to get you 8 ohm load)
  • Weight 3 pounds each
  • Revc - 3.4679 ohms
  • Fs - 56 Hz.
  • Zmax - 68 ohms
  • Qes - 0.4969
  • Qms - 9.2893
  • Qts - 4717
  • Le - 0.3484 mH (at 1 kHz.)
  • Vas - 0.3586 Cu. Ft.
  • BL - 0.1401 N/A
  • Sensitivity - 90 dB
  • Frequency response 40 Hz. to 7 kHz.
Tweeter Specifications
  • 1" Silk Dome Soft Tweeter
  • 8 ohms
  • Power 45 watts (80 watts max.)
  • Ferro Cooled Voice Coil
  • Neodymium Rare Earth Magnet
  • Sensitivity - 91 dB
  • Frequency response 1.4 kHz. to 20 kHz.
  • Weight .5 pounds each
2 Way Crossover Specification
  • 12 db slope
  • Good from 1 watt to 500 Watt RMS
  • Crossover point is at 3500 Hz.
  • Our Mavin superior performing T-201
  • Made from high quality electronic components

Misc. Information ( remember, speaker components only, no cabinet )
  • Cabinet requirements are pretty basic. Keep it about .5 cf. to .75 cf. and you should be fine, ported is what we prefer.
  • Wiring, the crossover to the speakers is very straight forward, you will be putting the woofers in series. Solder leads to your crossover, make them long enough to connect easily to the speakers. Allow for working through the speaker holes in the cabinet.
  • Take the lead from the woofer positive on the crossover, to the positive terminal of woofer number 1. Next you will need a piece of insulated wire to run from the negative terminal of woofer number 1, to the positive terminal of woofer number 2. Finally the negative wire from the woofer connection on the crossover, attaches to the negative terminal on woofer number 2.
  • Connecting the tweeter is easier, you use the tweeter leads you soldered to the crossover for this.  The positive lead goes to the positive terminal on the tweeter, and the negative  lead from the crossover goes to the negative terminal on the tweeter.
  • This is a upgraded version of the kit with a much nicer crossover.
  • For best response use a tweeter TWW design (vertical layout), see picture below.
Layout for a Center Design
Tower / Book Shelf Layout
Click on an image to enlarge


More Detail

Brother Build
  • Rating 5/5 Stars.
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Brian Raulerson (Florida) - July 18th 2020
I built these and the Polk Audio center channel for my brother. With John's help I made my enclosure ported. 30" tall and 7"x7" on width and depth. I added a reinforcement about 1/3 up from the bottom. Put some acoustic foam in the top. Made an 18" red oak front baffle stained in "Gunstock" to match the center channel. Again I recessed the drivers with a trim router. I did make some legs and put spikes in them because they seemed a bit top heavy. The port was a clearance B52 port from Parts Express.

I got them all hooked up at my brother's house. He 'tested' them by playing some marching band video so loud that the nuts on the speaker spikes started to loosen and rattle. Perfectly clear, no clipping or cone break up. I had to remind him that they were brand new speakers and he may want to consider turning them down a bit until they break in all the way.

With this and the center channel kit, all the involved materials, wood, MDF, glue, stain, screws, spikes, metal for legs, paint so on, so forth ..... I probably spent $200. I would challenge you to find better sounding speakers anywhere on the planet for less. It was great fun to put them together and sound really nice.