|Definitive Technology BP3000TL Loudspeakers|
|Home Theater Loudspeakers Floorstanding Loudspeakers|
|Written by Bryan Southard|
|Monday, 01 July 2002|
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The Definitive Technology BP3000TL loudspeaker is a floor-standing tower with an earth-shaking frequency response of 15 Hz to 30 kHz, thanks to support from a built-in powered subwoofer. The BP3000TL is the largest in Definitive Technology’s line, measuring 55 inches tall, nine inches wide, 19 inches deep and a stout 155 lbs. per speaker. They are available in either piano-gloss black or cherry finish, and sell for $4,500 and $4,700 per pair, respectively.
The BP3000TL has a bipolar design with two front-firing six-and-a-half-inch cast-basket bass/midrange drivers, and a front-firing one-inch aluminum dome tweeter. The rear of the speaker features an array of drivers identical to the front, the essence of the bipolar design. The BP3000TL has an integrated 18-inch subwoofer powered with an internal 1000-watt MOSFET power amplifier. The cabinets are constructed and braced with MDF. This ultra-rigid high-density Medite material is used for the front baffle in an effort to minimize cabinet resonance that can color music reproduction. The BP3000TL is covered in fabric, with optional finish on the top plate. The review models were black and had very respectable fit and finish.
There are a couple of design philosophies that separate the BP3000TLs from most other high-performance loudspeakers. The bipolar design is not unique, but it is rarely implemented in higher-priced performance speakers (Mirage is another good example of a high-end bi-polar application). Many manufacturers employ a rear-firing tweeter to improve overall spaciousness and ambience, but there has long been a taboo associated with both bipolar and dipole designs. Perhaps the biggest fear is the loss of accuracy associated with cancellation from reflected information. It is important to understand the difference in the two designs. Dipole is a design that employs an out-of-phase response from the rear of the speakers, opposite to that of the front. The theory is that the two signals will intersect and cancel one another, providing a narrow radiation pattern. The philosophy of the bipolar design is quite different. It provides a rear response that is in phase with the information coming from the front of the speakers, thus delivering a greater dispersion and overall sense of spaciousness when executed correctly. Many purists argue that the only accurate information from a speaker is the information radiating directly from the loudspeaker and any reflection will cause negative interaction. My opinion is that all speaker designs have inherent pros and cons and it is the implementation or execution that is of utmost importance.
The powered subwoofer is equally unique to high-performance sound reproduction. Due to speaker efficiency and necessary amplification, most loudspeakers fall short of providing the lowest frequencies needed in a kick-ass theater system. An integrated subwoofer represents a compelling philosophy that, if carried out properly, can deliver soul-shaking low-end reinforcement in a convenient, space-efficient package. Sandy Gross of Definitive Technology argues that this speaker is "not a loudspeaker with a powered subwoofer, but a full-range speaker assisted by a low-frequency driver and internal amplifier."
Since the BP3000TLs have side-firing bass drivers, you can either position the drivers facing the inside or the outside of the speaker. I played with both configurations and found my preference for my listening environment was to place the drivers facing inwards. This served to minimize sidewall reflections and cancellation from reflective standing waves. I recommend that purchasers of this speaker play with both configurations to find what works best in a particular room. Definitive suggests a placement that is close to the front wall (behind the speakers). In playing with location, I preferred a position that was approximately four feet from the front wall. Although this may not be practical in many environments, it provided the best and smoothest response in my room. The BP3000TLs provide a variety of connection options. For speaker connections, there is tri-wiring capability. This means that you can have three sets of speaker wires, one set connected to the sub, one to the bass/midrange drivers, and one to the high-frequency drivers. There are few people who dispute the advantages of having separate runs of wires to your speakers. Whether it makes more sense to have a single run of high-quality wire, or three independent runs of considerably less expensive wire, is a personal call that you will need to make. In my setup, I have a single run of very expensive Transparent Reference speaker cable and have utilized the bridging straps provided with the BP3000TLs to connect the three sets of terminals.
There are two additional ways to connect to the subwoofer on the BP3000TLs. You have the option of connecting to a full-range low-level input either from the subwoofer output, from the preamplifier output of your A/V preamp processor or receiver, or to connect via the optional LFE input on the BP3000TLs.
The subwoofers on the BP3000TLs have only a volume adjustment, as the crossover frequency has been preset to blend with the rest of the drivers. I used an inexpensive SPL meter from Radio Shack to set the volume to the appropriate level, something that I would suggest as a minimum to assure proper setup and balanced bass response.