Overview
Boston Acoustics SPG555.
SPZ redefines absolute top-level mobile audio performance. Outstanding bass extension
thanks to nearly 1-inch of peakto-peak excursion along with the smoothest, most
accurate octave-to-octave tonal balance ever give this system bragging rights unlike
any other. Factor in an innovative design that’s as stunning to look at as it is
simple to install, and you’ve got sound and style that will awe even the most experienced
audiophile.
- 6½" glass fiber composite cone woofer
- Nearly 1” (22mm) of peak-to-peak excursion for great midbass from
factory locations
- Cast aluminum woofer basket with TwinStage™ and RadialVent®
- 1 ½” voice coil for great power handling
- Compact neodymium magnet structure
- 1" Type-M1 aluminum alloy dome tweeter with off-Axis AMD™
- 360° Full Rotation Axis Mount plus flush & surface/angle tweeter
mounting kit
- VariMount™ Adapter rings allow installation in 6 ½”, 6”, and 5
x 7” locations without customization
- 24dB system-specific crossovers with extrusion cases

AMD™ (Amplitude Modification Device)
This patented tuning device uses precisely sized hollow tubes positioned in front
of the tweeter to refocus short wavelength energy and create an extremely smooth,
ruler-flat response. How flat you ask? 2kHz to 30kHz ±1dB without added equalization.

TwinStage™ heat sink
Effectively pulling heat away from the voice coil, two separate aluminum heat sinks,
working together as one, improve power handling and reliability. The first heat
sink is located inside the voice coil; the second surrounds the woofer magnet assembly.

1-1⁄2-inch
voice coil
Oversized 1-1⁄2-inch voice coil increases overall powerhandling and reliability.
Neodymium magnets The compact size of the magnet allows SPZ speakers to be installed
where others can’t. It offers an extraordinary powerto-weight ratio: approximately
10x more magnetic strength than a conventional iron-ferrite magnet of equal size.

System-specific
crossover
Housed in an aluminum case that pulls heat away from the components for increased
powerhandling; the SPZ crossover features low DF/ESR polypropylene capacitors, G-10
circuit boards, 24dB octave slopes, and unique equalization settings that deliver
optimized system performance in both infinite baffle enclosures and reduced volume
enclosures.