Atma-Sphere MA60's with Proac Speakers

Need more info on your room size, but it looks reasonable based on 91 dB, 8 ohm nominal/4 ohm min impedance. If you can find an impedance curve that would provide more information. FWIW, Merlin VSMs are 89 dB, 6 ohm impedance w very flat curve and they are a great match. For more info I'd check w Ralph Karsten at Atma-Sphere. He is one of the good guys in this business and will give you an honest answer.

I'd worry a bit about the dip to 4 ohms min impedance. But I also second the recommendation of checking with Ralph. It may be that buying the Speltz Zeros would be a good move with those speakers and the M60.

I don't know about those particular ProAcs, but the gentleman who sold me the S-30 I used to own (now owned by the poster right above me) used to drive either Response 2 or Response 2.5s with the little Atmas.

You may be fine with the m60s.

If the speaker has a 4 ohm dip at the crossover frequency I would have no worries. In this case we have have two woofers in parallel to create the 4 ohm impedance- that is not a dip. So a set of ZEROs is recommended as this is not an eight ohm nominal speaker, it is more like a 4 ohm nominal speaker.

Now my comments are based on what I have been able to find on the web, and I did not find an impedance curve. If the woofer region of the speaker's impedance curve is indeed 8 ohms then the ZEROs will not be needed.

Thanks for all the insights