Comments
Jim Tavegia's picture

I have never had a rig close to the low noise floor you use, but it is amazing when you put on your headphones during recording takes, what you can hear and becomes very distressing.

I have more trouble with our HVAC system(s) at church recording our Steinway. Why they put the units on the roof right next to our beautiful sanctuary is beyond me. Trying to find it and eliminate it takes cooperation...as you have found. Stuff going on across the street and next door is more problematic. Thanks for the science. I'm curious, would not the green trace be 24 bit?

John_Atkinson's picture

>Thanks for the science. I'm curious, would not the green trace be 24 bit?<

It does look that way, Jim, but if you perform an RMS sum of all the frequency components that make up the green trace in this graph, you do end up with the -96dB noise floor typical of a 16-bit PCM system. A 24-bit system would have individual components around the -160dB level.

>Why they put the units on the roof right next to our beautiful sanctuary is beyond me.<

Probably to cut down on the ducting costs. But the mechanical noise from the compressors will then drive the roof like a large diaphragm. I had a similar problem when I recorded Cantus in Sioux Falls. The hall was permeated with an acoustic 120Hz hum. It turned out to be due to the transformers for the emergency lighting system, which were mounted above the ceiling and were vibrating it at 120Hz. :-(

Jim Tavegia's picture

Thanks for the free lesson.

  •  
  •  
  • Site Map / Direct Links