B-52 (USA) Professional MX-1515 - Dual 15" Two-Way Speaker System, 600W RMS each

Description

B-52 Professional MX-1515 - Dual 15" Two-Way Speaker System, 600W RMS each - Made in the USA
The cabinets are in excellent shape, were placed since new in a clean, virus-free and air-conditioned room. They were never moved outside the house so there are no surface blemishes and no internal or external defects. In fact they look like out of the box. The choice of quality parts and materials is evident as is the quality of execution.
The speakers never saw more than 300W RMS (limited by the amp driving them) - and that was for tests only, but most of the time they were used below 100W musical. We managed to overheat the original tweeters while testing  them with a signal generator at high power so we decided to fully upgrade the drivers (see below). The speakers are now well broken in and do sound better than new. They work quite competently for critical music listeners with room and loudness corrections and provide a large dynamic range and decent transparency even for classical music.
For about 0 in parts only, we made several professional upgrades to the original cabinets as follows:
Upgraded the original tweeter drivers to the robust 1.7" coil Selenium D220Ti-8 (titanium, 8 ohms, 160W musical program - or 80W RMS max, 1kHz to 21KHz frequency response). This also improved the perceived sound definition with musical content.
Installed internal speaker circuit breakers (reversible fuses) that protect the tweeters separate from the woofers
Mounted 4 double-wheel casters (2 with brakes) on each cabinet (2x Middle Atlantic Caster Kits)
Added acoustic damping material inside the cabinets.
To the upgraded pair we added 2x 32ft heavy duty Dayton Professional Speaker Cables (11 gage, 4 conductors each) with 4-pole Neutrik SpeakOn connectors. These are expensive but dependable cables made (not only assembled) in the USA, with a 0.53in external diameter and 14lb weight, robust, flexible and low loss. With these cables one can reliably take both the high power and sound quality across the stage.
Provided are also 2 new Selenium diaphragm replacements, for those inclined to "cook" their tweeters
From the manufacturer:
The B-52 MX-1515 speaker from the MX-Series combines substantial SPL handling and accuracy from a very compact 2-way cabinet. The 1" exit titanium compression driver delivers smooth and detailed highs while the dual B-52 15-85 woofers produce tight, punchy low end. The MX-1515 audio speaker can be used as a stand-alone system or in combination with the MX-18S subwoofer.
The B-52 speaker is designed for live sound, small venue installations and mobile DJ/KJs. B-52 components include high-performance loudspeakers and 1" exit titanium diaphragm compression drivers. Each rugged cabinet features metal bar handles, 16-gauge perforated steel grille, rubber feet and protective metal corners. Input connectors include 2 - 1/4" metal phone jacks and a genuine Neutrik NL4 connector. Each speaker enclosure is finished with impact-resistant black carpet.
Nominal Impedance: 4 Ohms
Frequency Response: 40-19kHz
High-Freq. Dispersion: 90 x 40
X-Over Points: 1.6kHz
Power Handling: 600 watts RMS
SPL @ 1w1m: 99 dB
Peak SPL: 130 dB
Birch plywood construction for durability and sound quality (these are not the inexpensive MDF enclosures)
Black Carpet Cover
Chainable
Dimensions (W"x H" x D"): 19 x 45 x 18
Weight (lbs): 98 lbs
The original specs are at:
http://www.b-52pro.com/products/MX1515.html
http://www.b-52pro.com/products/Components.html