What do you guys think of the MB Quart QL S1030? How do they compare to the M80's if anyone is knowledgeble with the speakers. Here the specs on the MB Quarts:
Impedance: 4 Ohms
Frequency Response: 28Hz - 32kHz
Sensitivity: 87 dB
Power Range: 110 - 200 watts
Crossover Freq: 200Hz/2.5kHz Hz
Crossover Slope: 12/12 dB/octave
Dimensions: 42 1/2"H x 9"W x 12 1/2"D (1079mm x 317mm x 228mm)

Notes:
The QL S1030 contains 2 6.5" bass drivers, 1 5.25" midrange and a 1" titanium dome tweeter

I remember several models of the MB Quart lineup, but not any specific models....this was sometime ago. They were ok if memory serves.

Looking at the specs you listed, a couple of things jump out:
1) they are very inefficient (87db - M80 listed at 98db)
2) crossover points located in difficult frequency points - although I would suspect the bass is again crossed over to utilize the dual woofers.

Are the MB's up for replacement?