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I own the latest parts express CBT36 version. I have slightly modified the design to encompass a 15" parts express sub and Digamoda DSP controled 3 channel amps.The sound is mind blowing. Much better than I heard at RMAF Not a easy build, but I have had many a reference quality speaker and these will hang with any of them regardless of price. They have some of the best imaging I have ever expierenced.Takes a little effort to tweek the speaker balance to your room / system. but WAY easy compared with tweeking standard passive crossovers.
Re the CBT 36 kit, are the cabinets completely unfinished I.e. you have to paint them yourself?Also some more comments on the difficulty of the build would be interesting. Bjorn?
...The manual suggests a Behringer DCX2496 crossover and also tells you how to set it up. You can also download the presets directly from Audioartistry's website. I would however recommend using a miniDSP 4x10 Hd or 10x10 Hd instead. The Behringer is a bottleneck when it comes to sound quality and it's not without noise when hocking up with commercial electronics...
"THE VERTICAL AND HORIZONTAL COVERAGE OF THE CBT36 GREATLY REDUCESCEILING AND WALL REFLECTIONS:The above-the-floor vertical coverage of the CBT36 is a narrow 28º which is extremely stable with frequency. This greatly reduces ceiling reflections as compared to a typical box style system. In addition, the horizontal coverage which is very broad narrows as you go around the side of the system, which also significantly minimizes side wall reflections.
EXTREMELY EVEN COVERAGE WITH NO SWEET-SPOT LISTENING AXIS:The system has extremely well-behaved and smooth coverage from locations well above the array to points even down at floor level, and at distances from directly in front of the speaker to points in the rear of the listening room. The horizontal coverage is extremely broad and uniform even out to plus-minus 90 degrees.
The CBT36's variation of loudness with, distance is also very unique. At standing height, the system's volume level hardly changes over a range from directly in front of the system to points 10 feet away!MAXIMUM SPL AND DISTORTION:The system can be played extremely loud and remains very clean and effortless at all levels. The large number of drivers minimizes distortion, and driven with powerful amplifiers the system can generate very-high instantaneous peaks.
SYSTEM REQUIREMENTS:The system must be bi-amped and requires a DSP-based speaker processor along with two stereo power amplifiers. For extended bass response below 45 Hz, one or two powerful subwoofers are required.
...Demmed with Jeff Rowland Design Group amplification and crossed over to an active woofer below 60Hz...
What is CBT36 sensitivity anechoic? I suppose CBT36 rate of decrease vs. distance differs from normal mono pole. For instance, monopole SPL decreases with square of increased distance, while dipole decreases at only one half mono pole rate.
Note: the raw sensitivity (no crossover or EQ) of the CBT36 is frequency dependent. It is roughly flat from 80 to 300 Hz and then rolls off at 3 dB/octave (10 dB/decade) up to 20 kHz. See later section “CBT36 Power Rolloff” in Appendix 2 for further explanation of this rolloff. For more details see Fig. 26 in this section. Here are some approximate sensitivity numbers at different frequencies:80 to 300 Hz: 94 dB800 Hz: 89 dB8 kHz: 79 dB
Do the above negative reports re. the 2496 derive from personal experience? If yes, please explain details. If this is only 2nd hand report to you it would be nice to know. This is critical because I contemplate 2496 for LP/HP @ 80 Hz only, in top level system.
The horizontal coverage of the CBT36 is a function of the horizontal off-axis angle and actually gets narrower as you go off-axis. Here’s a fig from my paper to illustrate that illustrates the sound field of a free-standing circular-arc CBT line array. Because the array is a ground-plane array the narrowing goes down to floor level, i.e. you get less and less illumination of the side walls as you go around the side. If you listen to the system on the side, it gets louder and louder as you squat down!So what’s the conclusion? Yes the CBT36 does illuminate the walls, but with essentially a spectrum that is quite flat and that decreases considerably with height at distances particularly close to the array.
Just so readers know, I have no affinity for and no regard for any speaker with mono pole, bi pole, dipole, nor omni pole radiation pattern. Any such speaker regardless of cost and complexity is wholly inadequate to reproduce musical sound in a domestic space. That's why I find this speaker so interesting. But certainly, from the image, at the mid vertical point, this CBT has extremely wide 180 degree dispersion pattern which inevitably increases reflections from the side wall at that vertical point and any furnishings on that line.
Thanks for the links.There is a unique array that simultaneously provides immersion equal to MBL and image precision equal to the world's best point source mini monitor. For a time I thought possibly this CBT might equal the array I describe above, but from this reading it apparently does not. The array I describe above also provides density of the best horn systems, transparency of the best planar, 96 dB sensitivity from high 30 Hz range up (in-room), and other unique benefits such as higher pitch accuracy from top to bottom and stage size 75' beyond front and side walls.
I heard the CBT at RMAF a few years ago and thought it was incredible. Completely unlike any other speaker. At that particular show, it was EQ'ed too bright, and the musical choices were just awful, but the sound was fantastic. They sounded huge, and projected a sort of forest of sound. Not the standard holographic imaging , but a different thing completely. A description probably can't do them justice. (If I had two criticisms: (a) like nearly all other speakers, the CBT's don't necessarily have -tone- completely nailed with those particular drivers, but you can't have everything -- I have speakers with perfect tone which are worse in just about all other respects than the CBT's, and (b) as amazing as they are, they don't "breathe" like a perfectly tweaked horn system, but those are -very- picky criticisms! It seems most people don't value those two things anyway.)
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