Evaluation Criteria	Rating (1-5)	Summary Comments
Part I: General Information/Features
Packaging Solution	4.00	Package is protective of the subwoofer, and should withstand most rough handling during shipment.
Owner's Manual	4.50	Well written and comprehensive, with good diagrams and instructions on using the Room Compensation settings and all other controls.
Size/Weight	4.50	Very manageable size and weight.
Floor Interface Solution	4.50	Blunt spiked metal screw-in feet, or optional soft rubber stick-on feet, or the option of no feet at all.
Aesthetics	5.00	Really stylish, modern, and handsome design cues and unique cabinet shape.
Fit/Finish	5.00	The silver metallic paint was smooth and lustrous and there are no flaws anywhere in the finish.  The amp and woofer were well fitted and all screws were properly torqued and seated.
Available Finishes	4.50	Painted silver/black two-tone paint and cherry or maple wood veneers should match most decors.
Part I: Raw Score	4.57
Part II: Amplifier Controls/Features
Amplifier Class		ICEpower.
Amplifier Power		200 watts continuous.
Front Panel Controls		No.
Remote Control		No.
Main Power Switch		Yes: 2 way rocker.
User Replacable Fuse		No.
Detachable Power Cord		Yes.
Auto-On	0.25	Yes: 2-way toggle with green/red indicator light.
Low Level Inputs	0.25	Yes: Left/Right RCA jacks.
Low Level Outputs	0.25	Yes: Unfiltered and 80 Hz high passed.
High Level Inputs	0.25	Yes.
High Level Outputs	0.25	Yes.
Low Pass Filter	0.25	Yes: 45-200 Hz continuously variable, 4th order slope.
Low Pass Filter Defeat/Bypass	0.00	No.
0/180 Phase Switch	0.00	No.
0-180 Variable Phase	0.50	Yes.
Overdrive Protection	0.25	Yes: attack/sustain limiter, clipping, thermal.
Boundary Gain Compensation Controls	0.75	Yes: Three position settings - Narrow, Normal, Wide.
Single Band PEQ	0.00	No.
Multi-band PEQ (external or on-board)	0.00	No.
PEQ with Auto EQ	0.00	No.
Digital Signal Processing (DSP) Chip	0.00	No.
Servo Feedback System	0.00	No.
Part II: Raw Score (this section is additive)	3.00
Part III: Objective Testing
Quasi-Anechoic Frequency Response	3.75	26-190 Hz +/- 3 dB in Wide mode.
Deep Bass Output Compression	2.00	Exhibits 7 dB of deep bass compression at "maximum sweep level" as defined in the formula section.
10% THD Output Limits 14-80 Hz	-
10% THD Output Limits 16-80 Hz	-
10% THD Output Limits 18-80 Hz	-
10% THD Output Limits 20-80 Hz	2.13
10% THD Output Limits 22-80 Hz	2.29
10% THD Output Limits 25-80 Hz	2.67
10% THD Output Limits 32-80 Hz	3.20
10% THD Output Limits 40-80 Hz	3.63
Bandwidth Linearity 14-80 Hz	-
Bandwidth Linearity 16-80 Hz	-
Bandwidth Linearity 18-80 Hz	-
Bandwidth Linearity 20-80 Hz	2.50
Bandwidth Linearity 22-80 Hz	3.50
Bandwidth Linearity 25-80 Hz	4.00
Bandwidth Linearity 32-80 Hz	4.50
Bandwidth Linearity 40-80 Hz	5.00
Group Delay	5.00	Holds GD below 1 cycle over the entire pass band.
System Ringing and Stored Energy Release	5.00	Very short ring time at a low frequency.
Part III: Raw Score	3.51
Part IV: In-Room Evaluations
In-Room Frequency Response	4.00	Digs to about 21 Hz in-room and then rolls off.
HT Performance	3.38
Music Performance	4.40	Outstanding music performance.
Part IV: Raw Score	3.93
Parts I-IV Weighted Total Score	3.68	74%
Final Score: Total Score With Price Considered	3.68	74%

For details on how these numbers were calculated, see the Subwoofer Benchmark Formulae document located here.

Conclusions

I liked the modern appearance, silver metallic and black color scheme, and unique cabinet shape of the Canton Vento AS 850 SC subwoofer; this is a very attractive and well-finished product that will look great in art deco, contemporary, or postmodern décors. 

The sophisticated ICEpower amp is cool-running and efficient and has effective overload prevention and distortion reduction circuitry.  And the new Canton 12" woofer provides much more clean output than previous versions.  The innovative room compensation settings allow the user to tailor the deep extension points and roll-off provide to best match the acoustic transfer function of the room. 

On the objective performance front, the Canton has a very flat mid/upper bass frequency response and better than average distortion-limited output.  The Wide Room compensation setting provides a gradual anechoic roll-off and a very wide F6 bandwidth which results in excellent transient response and phase characteristics, particularly for a bass reflex design.

In-room, the Wide Room compensation setting proved to be a near-perfect match for the acoustic transfer of my evaluation room, with the in-room response extending flat to 21 Hz - 22 Hz.  On HT applications in a mid-size room, the 850 SC exhibits good mid/upper bass dynamics and will play loud enough to satisfy the subhuman cravings of most enthusiasts.  My only two reservations at higher playback volumes are audible port chuffing on deep bass passages which contain little or no masking content, and occasional deep bass compression on the really gnarly stuff.  Stepping up to dual collocated 850 SC will provide an additional 6 dB of headroom, and should largely ameliorate both of these concerns, so hard-core HT enthusiasts who really like to push things on movie night should consider this option.

On popular music – where the average playback volume is much lower and the subwoofer is relatively unstressed – I can recommend the 850 SC without reservation.  This subwoofer sounds flat-out fantastic on music, with a perfect combination of balance, coherence, articulation, and well-preserved pitch.  Much of this great music performance can be attributed to the superior transient response and the in-room frequency response, which extends to 21 Hz - 22 Hz without displaying the rising low-end response typical of many other deep-playing bass reflex subwoofers.  The result is a subwoofer which stays light on its feet, with excellent rhythm and pace with no bloat or overhang.
 

- Ed Mullen -