In-Room Frequency Response: I placed the UFW-12 in the front left corner of my 2,000 ft³ evaluation room, which is acoustically treated and bass-trapped. I connected the software signal generator to an analog stereo input on the SSP and measured the combined frequency response of the mains speakers and subwoofer at the primary listening position.

For digital bass management, the main speakers were set to Small with a crossover frequency of 80 Hz. The digital bass management circuit imposes a 2nd order high pass filter on the speakers, and a 4th order low pass filter on the subwoofer. Accordingly, I used the LFE Direct input, which bypasses the low pass filter on the subwoofer. I set the phase control to 0 degrees and manipulated the subwoofer distance setting in the SSP to obtain the best phase integration with the mains.

The in-room frequency response showed a peak in the 60-70 Hz region. This peak results from a combination of the anechoic FR (which also shows a peak in this bandwidth), a possible floor/ceiling mode, and asymmetrical filter slopes in the digital bass management circuit. As shown in the graph below, I used R-DES to eliminate this mid-bass peak.

My evaluation room provides some room gain below about 35 Hz, and this resulted in a response peak at 25-30 Hz. Since the human ear grows progressively less sensitive to deeper frequencies, many people will subjectively perceive a mildly rising deep bass response as even sounding. This room gain peak can also add impact on HT passages, so I left it intact for the movie evaluation and saved this curve in R-DES.

For music however, this room gain peak can upset the overall octave-to-octave balance and overwhelm the 22-23 Hz region. So I used R-DES to eliminate the room gain peak for the music evaluation, and saved this second curve in another R-DES memory location.

With Movies

I played several action-oriented DVDs, evaluating the UFW-12 for mid-bass dynamics, audible artifacts (muddiness, cone cry, rattling), deep extension and output compression.

To determine the maximum clean playback level in my 2,000 ft³ evaluation room, I increased the master volume until I started to notice audible distress, doubling, compression, or loss of deep extension. Then I backed off a bit and monitored sound pressure levels at the listening position with a B&K SPL meter set to C-weighted Fast. The amp limiter did a very good job of keeping the UFW-12 well composed under hard use, while allowing a respectable 103-106 dB bass peaks at the listening position.

My overall subjective home theater ratings for the UFW-12 are provided in the table below, with a rating of 5 being the best score:

Evaluation Criteria	Rating (1-5)	Summary Comments
Mid-Bass Dynamics	3.50	Decent mid-bass dynamics, with good output at/above 30-35 Hz.
Audible Artifacts	4.00	The amp limiter and steep HPF are very effective in preventing overload. There is only minor audible distress when pushed really hard.
Deep Extension	3.50	Digs to 23-24 Hz in-room. R-DES can help subjectively improve deep extension by flattening room gain peaks.
Deep-Bass Compression	3.00	In order to protect the subwoofer at high volumes, the amp limiter will moderately compress high amplitude deep bass peaks.

Provided below are my listening notes and a few spectral frequency charts, from the extended edition of Lord Of The Rings – Return Of The King in DTS 6.1 ES-Discrete. These spectral color charts were electronically recorded directly from the DVD, and show where the deep bass occurs on a given passage, with dark red and pink colors being the highest amplitude. These spectral charts were provided courtesy of Ilkka Rissanen.

Minas Morgul Tower Shoots Green Fire Into Sky (Disc 1 0:57:06); 103 dB. Here the tower of Minas Morgul erupts with ominous green fire, signifying the Witch King’s emergence. The UFW-12 added good depth and foundation to this passage.

 

Orc General Side Steps Trebuchet Boulder (Disc 1 02:02:57); 103 dB. General Gothmog has no choice but to step aside or be crushed by the massive boulder flung from the Gondor Battlecry trebuchet. The UFW-12 punched out some decent room pressure, handling this passage well.

 

Orc Battering Ram Hits Gate (1st Time) (Disc 1 02:06:20); 104 dB. The Orcs get serious about breaching the gates of Gondor, and break out the battering ram. The big Rocket sub dished out a solid punch on the first ram strike, with only a bit of dynamic compression.

 

Oliphants Stomping (Disc 2 0:32:07); 105-106 dB. Here the Oliphants wreak havoc in the Battle Of Pelennor Fields, effortlessly sweeping aside or simply crushing man and horse alike. The Oliphant stomping is primarily centered in the 40-50 Hz region, and at these frequencies the UFW-12 feels muscular, belting out 105-106 dB at the seats.

 

Oliphants Collide (Disc 2 0:34:06); 104 dB. A well-placed spear strike by Eomer of Rohan ultimately causes an Oliphant to lose control and collide with another. This is easily the most demanding passage in the entire movie, containing very loud bass from 16-50 Hz, with a peak occurring at 25 Hz. The UFW-12 played the upper bass regions of this scene well, only missing the infrasonics below about 25 Hz.

 

Witch King Battle Mace Hits Ground (2nd Time) (Disc 2 0:39:04); 105 dB. Eowyn barely dodges a blow from the Witch King’s fearsome battle mace. The UFW-12 felt dynamic on this scene, whacking the room with an impressive thud.

 

Frodo’s Heart Beating At Mount Doom (Disc 2 1:22:22-48); 101 dB. With a pounding heart, Frodo fights the evil power of the Ring at Mount Doom. This is the deepest passage in the movie, with loud bass extending to 16 Hz. The UFW-12 played the heart beat overtones in the 25-50 Hz region, only missing the very deepest infrasonic underpinnings.

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