Upgrading the Definitive Technology BP2000 Speakers

[Big Daddy]

I recently performed surgery on my Definitive Technology BP2000 speakers and replaced all their drivers with completely different (in my opinion better) drivers. The BP2000 speakers are bipolar and use very sophisticated design. Their wiring is not very easy to follow. Every inch of my body hurts from carrying these massive speakers. It would probably be useful to start with some introduction.

The Definitive Technology BP2000 speakers were introduced in 1995. They were among the first speakers that had built-in powered subwoofers. The built-in subwoofers were not LFE subwoofers. They were meant to provide the speakers with low frequency extension. The 15 inch subwoofers are not the typical subwoofers with an upper bass frequency limit of around 150Hz - 200Hz. They extend way beyond that to have a seamless . The subwoofers are meant to be fed with full-range signal. You can use speaker wires or an RCA cable to feed full-range signal to the subwoofers. A sophisticated Linkwitz Riley crossover system takes care of the frequencies between the subwoofers and the midrange/tweeter drivers. They have a level control and a low frequency equalization control. The level control works in conjunction with a gain sensitivity button to vary the overall level of the subwoofer section in relation to the rest of the system. The gain sensitivity button varies the input sensitivity to give you a greater range of levels.

The BP2000 speakers are bipolar. They have two 6.5 inch midrange drivers and a one inch aluminum driver on the front and exactly the same drivers on the back of the speakers. They use MTM (D’Appolito) driver arrangement with the tweeter placed slightly to the side of the front and rear baffles so that the two woofers are closer to each other. The cabinets of the speakers are very solid with plenty of braces. Plenty of foam and polyfill are used inside the cabinet to provide enough sound dampening. The drivers on the front and back are separated from each other and the subwoofer has its own dedicated chamber.

Specifications

Dimmensions: 50"H, 9"W, 16 7/8 /8 "D
Weight: 120 lbs each
Frequency Response: 15Hz - 30kHz
Efficiency: 90 dB
Impedance: Compatible with 4-8 ohm outputs
Built-in Subwoofer Amplifier: 300 watts RMS
Tweeters: Two 1" (25 mm) aluminum dome tweeter (one in the front and one in the back)
Midrange: Four 6 ½" (17 cm) high definition cast-magnesium basket polymer drivers (two on the front and two on the back)
Subwoofer: One 15" (38.1 cm) subwoofer on the side


Some Images and Detailed Information:

Reviews:

The reviews of BP2000 speakers were excellent. I myself found out that the speakers are extremely well made. The cabinets are very rigid with lots of bracing and dampening material. Their performance was far better than speakers that cost several times more. Although the price of $3,000 a pair in 1995 sounds like a lot, these were among a few high-end speakers that were worth every penny. There are plenty of outrageously-priced speakers around with absolutely nothing significant in their design or performance that can justify their price. A lot of credit should be given to the Definitive Technology founder/designer, Sandy Gross.

The following reviews of BP2000 speakers were by the late Julian Hirsch in Stereo Magazine (September 1995) and Brent Butterworth in Home Theater Technology magazine (November 1995):