As the name cleverly implies, the Excruci8 is an 8" subwoofer; it features a 2" voice coil and a very conservative input power rating of 250W continuous, 600W peak. Two 5.375" diameter Ferrite stacks make up the 2.75" (top plate to back plate) tall motor. Bryan from Addictive Audio was quite prompt in sending me several of these little monsters for a more hands-on examination.
Initial impressions: This driver screams versatility; aside from it's sheer weight my attention was drawn immediately to the traditional foam gasket extending from the mounting ring. This is an increasingly rare trend among car audio subwoofers, where mounting versatility tends to take a back seat to aesthetics. An emerging trend, however, is the direct wire-to-wire connection method of which the Excruci8 is a proud participant; two sets of tinsel leads follow the surface of the spider out to the edge of the basket, then continue out as pairs of 8AWG connecting wire. Upon arrival, the woofer's suspension was surprisingly stiff. The initial parameters prior to break-in (measured in series) were as follows:
Re: 7.418 Ohms
Fs: 61.91Hz
Qms: 6.18
Qes: 0.8205
Qts: 0.7243
Le: 2.445mH
The derived EBP (Efficiency Bandwidth Product) of 75.45, though indicative of a driver suitable for use in vented applications, is still sufficiently low to where a sealed or a 4th order bandpass alignment can be viewed as an option. The break-in process consisted of four 2 hour sessions with the woofer brought to 75% peak excursion at 20Hz:
After a several hour cool-down, the parameters were re-measured. One of the most commonly overlooked factors in benchmarking T/S parameters is the ambient temperature as well as the temperature of the voice coil; if the results are to be accurate, these conditions have to remain consistent from one test to the next. The final parameters following the break-in (again, measured in series) were as follows:
Re: 7.287 Ohms (-0.131 Shift)
Fs: 47.78Hz (-17.13Hz Shift)
Qms: 4.213 (-1.967 Shift)
Qes: 0.6415 (-0.179 Shift)
Qts: 0.5567 (-0.1676 Shift)
Le: 2.48mH (+0.035mH Shift)
As expected, we can observe a significant downward shift in the free-air resonant peak along with a decline in the driver Q which is proportional enough for the EBP to remain within ~0.9 units of the product derived from the initial measurement.
For the listening portion of this review, I decided to try a pair of the Excruci8s in a rear-loading horn that I designed around the most recently derived T/S parameters and the cabin geometry of my '91 Honda CRX. They were quite compliant and didn't impose any significant degree of ripple along the predicted efficiency curve; this made the task of countering the cabin's naturally occurring resonant spikes and nulls all the easier.
With the subsonic filter and bass boost disabled, the in-cabin performance was very rich, with a response that remained consistent well into the lower 20Hz region. The Excruci8s offered a very "large" presence; many times that of what you would typically expect with merely 45 square inches of effective piston area. Pressure-wise, the woofers sustained an average Term-LAB SPL reading of 143.8dB at the dash, with a peak of 147.1dB at 48Hz. Given an adequate degree of acoustic suspension, the Excruci8s handle themselves quite well; at peak each woofer was receiving approximately 1100W across the entire frequency range.
All in all, the Addictive Audio Excruci8 is a well engineered, well put together piece of hardware. At just 8.25" in outer diameter, it makes for a very surface-efficient solution, especially when mounting space is at a premium. If you're looking to strike up the "shock factor," I can vouch for the Excruci8 as an excellent woofer to design your system around. A pair of these in a proper enclosure can be sure to overwhelm just about any conventional front stage.
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