New A/C compressor whines on acceleration?

Hi,

I had a shop install a new A/C compressor and dryer I supplied on my vehicle listed above T5. I bought Genuine Volvo parts from a Volvo dealer. My shop installed these new parts on July 8th. Around July 25 I realized my compressor started to whine (it did not before), only when the RPMs are up. Like 2,500 RPMs or so, I hear a whine. Only when the compressor engages. If I have the A/C off, it will not whine. Diagnosing more myself, I took a tube and ran it from my ear to belt tensioners, my alternator, and A/C compressor, while I had a family member rev the motor. I came to the conclusion that the A/C compressor was the only thing making the whine. Belt tensioners are new and so is the Alternator. Now, I have a replacement A/C compressor from the supplier. My shop today is installing it, when they saw the car, the technician said the noise, I'm hearing he has heard before and would consider it "normal." What do you say?

Thanks,
Vince