Axiom Home Page Forums General Discussion Stereo M80's with Outlaw RR 2150 receiver

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with another dip of 3db or so at 120-150db or so.

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Ian has explained this dip before.

"In reference to the little dip and rise at 150 Hz in the M80 compared to the M60; it is just the microphone positioning being up right under the tweeter and only 2 meters back in the anechoic chamber giving it an increased angle of attack on the very tall M80s."

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We can see that beginning at 60hz and down the M80’s are already off by 3db

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This too has been explained.

"The chamber is accurate to 85 Hz and then there is a correction applied below that. For heightened accuracy of measurements below 85 Hz we measure out on our pole in mid air. The pole puts the product and microphone up about 20 feet in the air. The sub graphs above are from the pole. You can see in the NRC graph above of the M60 the bass rolls off quickly below 37 Hz and this trend lines up with the pole measurements of the bass response of an M60, hence the 37 Hz spec."

Peak SPL calculator

I am planning on crossing over my M80's at 60 Hz. My room has a resonant peak at about 63 Hz. I use a dbx 31 dual channel 31 band graphic equalizer to tame this peak. The Outlaw RR 2150 has a bass management selector switch which allows the cross over to be at 60,80, and 100.

I now have JBL S38 speakers which work fine with the 60 Hz crossover point and the dbx equalizer.

sir: I can NOT imagine listening at those sound levels!!!!!!

Of course, if we are talking about peak power, then, maybe, that factor of 20 -25 between peak and average may enter into the picture.

I didn't get the impression that he was listening at those levels, but rather the computed theoretical max SPL of a single M80 (at 95dB / 1W per meter) driven with 100 and 500 Watts. Add another M80 for the pair gives another 3dB.

I was also wondering about your house. Your room should be great for music. In our great room, where the M80's are going, recordings of pipe organ really sound nice with room for the low pedal notes to breath.

I find that in my case different kinds of music sound better on different sound systems. My favorite for lots of my listening is still my pair of Carver Platinum Amazing speakers. I really like the dipole sound. They have served me well for over 20 years.