Subwoofers

Factual Questions
21

Anyone have any idea about that? Will subsonic sounds create a feeling of upset, edginess, etc.?

Same thing I was wondering in the Heinlein reference above. (the sixth column, or whatever the story was called)
These old links are still around, anyone know anything about the validity?

http://www.borderlands.com/newstuff/research/gavreaus.htm
http://www.borderlands.com/newstuff/research/infra.htm

22

The term “nondirectional” is bullshit. Omnidirectional is not. It has been well-understood in the field of sound reinforcement for oh, about 70 years or so.

The way we hear has approximately jack-shit to do with bass being omnidirectional. This is approaching the question from the wrong end. A mic and level meter will prove the same thing. Any introductory book on sound reinforcement will concur.

As roksez touched on and I attempted to explain, subs may be corner loaded. This is possible because a sub suspended in mid-air puts out an (almost) equal amount of acoustical energy in a 360 degree sphere.

A moment’s thought should reveal why if you are standing inside such a sphere it would become difficult to determine where the sub is located.

For further elucidation, may I suggest visting www.electrovoice.com and download ArraySHOW. Choose the EV Sx200 speaker with the mic at about 100 feet out or so. At anything below about 125Hz – not even low bass, the polar response will be nearly spherical – the lower you go, the closer to a perfect sphere it becomes. Then choose 20kHz. It’s darn near a beam of sound.

Not for nothing but there is a slight chance I know what I am talking about given I run sound every weekend and own 6 1200W 18" EV subs.

23
      • I am informed that the way commercial music is recorded, is to separate the medium and higher frequencies and combine the low frequencies. This was started originally decades back, because most home stereos weren’t very powerful and the quality sounded much better if the lower frequencies were combined rather than separated, so both speakers could work together at making bass notes. In other words, whether bass is omnidirectional or not is kind of mute, because music CD’s are engineered so that bass reproduced from them is omnidirectional - if it was originally or not.
      • I don’t recall all the technical language, but a high-school electronics teacher demonstrated the principle by hooking up a 15 Hz. signal generator to a 300 watt amp and four 18-inch speakers, one in each corner of the room. The setup allowed switching between speakers. If you stood in the center of the room, you couldn’t tell which speaker was being used at that moment. -And it didn’t really sound “loud” in the normal sense, but you could hear it everywhere. It seems odd but it’s true. You DID hear a lot of things rattling, if you got near them. We didn’t get a lot of time to play with it, because everybody else in the building, and many people in the adjoining buildings could hear it also.
  • I doubt many stereos could approach the effect but checking would require a CD with a clean 15 Hz. signal on it, and I don’t have one. Simply blasting “Snoop Homey Jail Thug’s Greatist Hits” because it’s got Super Bass Mix isn’t a resonable test. - MC