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Blaupunkt GTb 8A

8" 75-watt powered subwoofer

2 Reviews

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Item # 023GTB8A

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Our take on the Blaupunkt GTb 8A

Get ready to rock with Blaupunkt's GTb 8A powered subwoofer. You'll feel the bass you've been missing as the 8" spun-paper woofer pumps out the low-end thump. Its built-in 75-watt RMS amplifier keeps you from having to match up a separate amplifier — you just wire this sub up to your system and you're good to go. At under 11" deep, this compact sub will fit in some pretty tight places.

I upgraded my auto stereo system with component front & rear speakers & equalizer yet was lacking the low bass and decided to try this sub. I primarily listen to lower volume settings and this sub is just right. Easy to install and provides the much needed "bottom end".

Bob, Lincoln, NE

What's in the Box:

  • Subwoofer enclosure loaded with one 8" Woofer and built-in amplifier
  • 7.5 amp ATO fuses (installed)
  • Wiring harness (16.5' Power and speaker level input/ 3' Ground)
  • Instruction manual

Product Highlights:

  • powered subwoofer with 8" woofer
  • built-in 75 watt RMS amplifier (150 watts maximum)
  • frequency response: 30-200 Hz
  • dimensions: 10-1/2"W x 10-3/8"H x 11-5/8"D1 x 8-7/8"D2
  • warranty: none (Crutchfield's 60-day satisfaction guarantee applies)
  • Our 60-day money-back guarantee

Blaupunkt GTb 8A Reviews

Average Customer Review(s):

(2 Reviews)
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Hands-on research

Features and Specs

Enclosure Type Ported
Finish Material Carpet
Grille Metal Rods
Connector Type RCA/Molex
Bi-amp Inputs No
Woofer Size (inches) 8
Woofer Material Spun Paper
Passive Radiator ---
Width 10-1/2"
Height 10-3/8"
Depth 11-5/8"
Second Depth 8-7/8"
Parts Warranty 60 Days
Labor Warranty 60 Days
Frequency Response 30-200
Amplifier Power (RMS) 75 watts
Maximum Wattage 150 watts
Sensitivity N/A
Impedance N/A
Second Voice Coil Impedance N/A
Crossover Point 70-200

Product Research


Overview: The GTb 8A amplified subwoofer features a 75-watt RMS (150-watts max) amp and an 8" subwoofer housed in a ported enclosure.

Auto Turn-on: The amplifier automatically turns on when it detects a signal on the line or speaker level inputs. After approximately 60 seconds with no input signal, the amplifier will turn off.


  • Level: rotary dial to set the amplifier input gain; variable from 300mV to 8V for the line level inputs and 700mV to 19V for the speaker level inputs
  • Frequency: rotary dial to set the low-pass crossover frequency; variable from 70 Hz to 200 Hz
  • Phase: rotary dial to set the subwoofer phase; variable from 0° to 180°


  • Power: the included harness has two 16.5' power and two 3' ground wires (all should be connected and the power wires should be fused at the battery)
  • Speaker Input: the included harness also has 16.5' left and right speaker level input wires
  • Line Input: stereo RCA jacks


  • Width: 10-1/2" (including 5/8" protrusion of the control knobs)
  • Height: 10-3/8"
  • Depth (bottom): 10-5/8" (the grille, two steel rods, adds approximately 1" to the depth)
  • Depth (top): 8-7/8"

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.