OK, I am finally getting a chance to post my results from the earlier listening tests. It's clear from reading Alleric's posts that I am nowhere near as sensitive (or looney ) as he is. However, I listened to a variety of recordings over a total period of several hours and really tried my best to listen objectively.

Until now, my usual two-channel listening habits would be one of the following:

Full-range, two-channel only: for the majority of my listening, I run my Sierra-1s full-range with no subwoofer. I also installed Q-Plug B a while back to help with room modes and to extend the low bass response. For low to moderate listening levels (up to ~85 dB), I am very happy with the results.

Crossover applied, subwoofer used: even with the remarkable bass response of the Sierra-1s, there are times I want to reinforce the bottom octaves and feel the low end in my bowels. In addition, I occasionally like to crank to 90-95 dB for a short time and prefer not to ask the 5.25" woofers for lots of excursion since they must also deliver the mid-range with accuracy. I would apply an 80 Hz crossover (12 dB/octave slope) and let my 15" Rythmik do its thing with aplomb.

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Room size, listening distance, and speaker placement

12.5 ft. wide x 10 ft. long x 8.25 ft. high (average height) = 1,031.25 cu. ft.

My Sierra-1s are in a near-field arrangement on a computer desk. Unfortunately, the placement is arranged on the longer 12.5' wall, so I only have 10' to optimally position the speakers and listening chair. There is no other way. There are multi-shelf ranks directly behind my chair and I must use an entire wall for storage space. This room has to be an office and a home theater.

Listening position is typically 4.5 feet (1.37 meters) from Sierra-1s. This position is about 38% into the room measured from the back wall. Occasionally, I'll push the listening position back to about 6 feet (1.83 meters) from the Sierras for movies when I have a guest with me.

- rear port is 13.5" from the front wall
- Sierra-1s placed 38" apart, measured from left woofer (centered) to right woofer (centered)
- raised 2" from desk height on Auralex MoPads to boost the tweeter height closer to ear level when sitting (center of woofer is 36.5" from floor), and to control vibrations to the desk (although the cabinet is quite inert)
- toed in ~7 degrees

My Rythmik F15SE is front-firing and immediately beside the right Sierra-1, but on the floor on a ~3" high Auralex Great Gramma riser (for decoupling purposes). The Sierra-1 woofer and the Rythmik woofer are on the same horizontal plane, and the subwoofer is ~5 feet (1.52 meters) from the primary listening position. The sub is not corner loaded, but is 25" from the front wall and 55" from the nearest side wall (measured to center of cone).

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OK, now that you know more about my setup than you ever wanted to , I'll jump into my findings.

One of the things I love about my Rythmik is how fast, realistic, and tight the bass is compared to any other sub I've owned. I wanted a sub that could keep up with the Sierras rather than boom out one-note bass at 1,000 watts. When configured properly, it blends remarkably well with the mains, especially considering I have zero (zilch, nada) room treatments installed yet.

As per my usual listening configuration, my HTPC outputs unprocessed PCM (via TOSLINK) to my pre/pro in Direct mode, and then the pre/pro sends it directly to the amp with no DSP, no room correction, or any other digital manipulation. The only digital feature I used was Bass Management so I could apply a crossover.

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My pre/pro offers high-pass filters from 40 Hz to 80 Hz (in 5 Hz increments), and then up to 250 Hz in 10 Hz increments. It was extremely difficult to notice changes going only 5 Hz at a time, so I used 10 Hz increments. The changes I noticed here were nearly identical with all the recordings I used.

First, I played the specific demo track with no crossover, only full-range signal to the Sierras. I listened carefully to the low frequency content below 100 Hz for: timbre, punch, boom, smoothness, dynamics, etc. After this, I replayed the selected track and engaged an 80 Hz crossover to bring in the Rythmik. I would then begin to drop the crossover 10 Hz at a time, listening carefully to the resulting changes, going all the way back down to full-range/no sub. Then, I would go up the ladder: beginning again with full-range as a reference, I would then climb up the crossover settings until reaching 80 Hz. Here is a visual representation:

Test 1: full-range --> 80 Hz --> 70 Hz --> 60 Hz --> 50 Hz --> 40 Hz --> full range
Test 2: full-range --> 40 Hz --> 50 Hz --> 60 Hz --> 70 Hz --> 80 Hz --> full range


At 80 Hz: Sierras sounded a bit thin, possible to localize sub with some recordings. Fairly seamless blend.

At 70 Hz: Not too much change from 80 Hz, although the total low-frequency output seemed slightly less. I may have a room mode in this range.

At 60 Hz: Very good, full sound. Sierras no longer seem thin. Could be happy here. Seamless blend between speakers and sub.

At 50 Hz: Perfect balance between Sierra bass output and Rythmik output for this room. The Sierra bass response has "weight" that could be felt, both tangibly and intangibly. I could not localize the sub. Everything just seemed to flow. A small amount of thump was lost from the Rythmik compared to 60 Hz settings. The 15" driver is more efficient at pressurizing the room than a 5.25" driver. An issue, but not a big one.

At 40 Hz: Sub may as well have been in another room; it was impossible to find, even moving around every area of the room. Sierra bass output had the most weight here. The only downside I heard was a slight drop in low-frequency output. I suspect it might be because the Sierras were approaching their frequency response limits, or it could be a room issue, or both.

For music, I'm settling on 50 Hz since that gave me the best balance with all factors: no localization, no thinness from speakers, seamless blend of speakers/subwoofer, and plays on the strengths of both components. For movies, I'm still going with the tried-and-true 80 Hz for all speakers except the Horizon center. It will stay at 60 Hz for movies since it has two dedicated low-frequency drivers, plus I want a bit more weight in the vocals/dialog. I'm still going to run full-range Sierras (for music) most of the time, but now I have a new crossover setting when I want a sub.

Oh, one other thing: while my pre/pro does have a "double bass" mode (full-range + sub), the option is not available in the latest firmware. I couldn't test this option unless I rolled back (a major pain to reenter all the settings, etc.).
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Music used during evaluation:

Track - Artist (Album) [notes]


Erase This - Evanescence (Evanescence) [lots of kick drum, bass, and guitars in this rock track]

Golden Bowls - Karma Moffett (Golden Bowls) [this track features deep, resonating Tibetan singing bowls]

Saragossa's Manuscript - Patrick O'Hearn (The So Flows Sessions) [deep, rhythmic bass from synth and strings]

Sun Gone Down - Protoculture (Sun Gone Down) [strong bass/synth/kick from this energetic vocal trance song]

Black Blade - Two Steps from Hell (Invincible) [lots of drums, bass, and brass]

If I Could Fly (Jaytech Remix) - OceanLab (Sirens of the Sea Remixed) [vocal trance, strong bass and kick drum]

Scar - Bear McCreary (Battlestar Galactica Season 2) [lots of drums]

Open Frequency - Between Interval (Radio Silence) [synth/bass electronica]

Upon Reflection - Darshan Ambient (Dream in Blue) [fantastic sounding bass guitar]

Ghosts of Africa - Darshan Ambient (Dream in Blue) [some of the most intense low bass pulse/kick I have ever heard]

Above All - Jon Jenkins/David Helpling (The Crossing) [awesome low bass synth, will shake the walls...in the next room]

To the Ends of the Earth - Jon Jenkins/David Helpling (The Crossing) [drums, synth bass, one of my favorite tracks on this album]

Prelude & Fugue in D Major - Bach/played by Douglas Marshall (Opus 1) [pure pipe organ sweetness!]

On Walks The Night - Jesse Cook (Free Fall) [great sounding kick drum and bass, one of my reference tracks for testing low-end]

Constantinople - Patrica Barber (Modern Cool) [gotta love that string bass]

Magnificent River - Patrick O'Hearn (Beautiful World) [excellent walking bass line]

So Flows The Current - Patrick O'Hearn (So Flows The Current) [excellent walking bass line]

Cherry Twist - The Crystal Method (Vegas) [synth bass/kick electronica]

Fast Cars and Freedom - Rascal Flatts (Feels Like Today) [great-sounding kick]
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Phew! I think this is one of the longest posts I've done here. I would end with "my $0.02," but I think I'm gonna need to take out a loan for this one!