Speakers Bass response.

[rollo]

  So how low should a speaker go ? What is full range to you ? Why do not all speakers go from 20Hz to 20,000 Hz ?
   Besides organ and a handfull of instruments go below 20Hz or close too, why do we need subwoofer output. Ambiance ? Harmonics ?  Actual music content ? Air movement. What ??
  Opinions please.


charles
   
   

[BobM]

Bass is absolutely necessary for the accurate presentation of dynamics. And to my mind both micro and macro dynamics are necessary before you can begin approaching real unamplified acoustic sounds.

Now there are several types of bass but they seem to generally divide into:
- air moving / chest thumping, and
- tuneful, open panel/baffle

Each seems to do one thing that true bass has, but somewhat falls short in terms of the other department, IMO. Very few speakers or subs get both right.

Also, deepar and "better" bass somehow also has an effect on how I hear and discern the treble region. It balances things out and can make an otherwise sharp sounding system sound more even and natural. Must be some kind of aural trick our ears play on themselves.

[richidoo]

Why do not all speakers go from 20Hz to 20,000 Hz ?

WAF

why do we need subwoofer output

Instinctual craving

[mfsoa]

I always felt (pun intended) that along with the bass fundamental comes a subsonic "oomph" of air.

I have no idea of the frequency (DC almost?) but when a bass guitar is thumped, or a bass drum is whacked, or acoustic bass string plucked, I like to sense that impact shakin the ol' monkey-bone.

Could be totally wrong here 

[bhobba]

One issue is room reinforcement.  Its actually not necessary for speakers to be flat down to some low hz say 30hz or 25hz because the room will reinforce it anyway.  My speakers are flat to 25hz in a typical room but measured free air have a bit of a roll off.  Speakers that dodn't do this need to be well away from a wall which is not really practical in many situations.

I remember many years ago I was interested in getting a small sealed speaker made by VAF that was reviewed well in the local electronics mag at that time.  They commented on its weak bass and that sort of turned me off a bit.  I rang the manufacturer and he explained something along the lines of what I wrote above but I was still a bit uneasy.  I shouldn't have been - I spoke to a guy years later who got a pair and when correctly set up near a wall its bass was fine. 

Thanks
Bill

[Face]

Excellent software in regards to room reinforcement. 

http://audio.claub.net/software/jbabgy/BDBS.html

[_Scotty_]

I have found bass response to 20Hz useful when reproducing classical music. When an orchestra is recorded in a large hall one of the cues telling you how big an acoustical space is, is the low frequency reverberation time. If an orchestral piece has parts in it played by instruments with low frequency fundamentals or overtones then the entire acoustical space is energized at very low frequencies.
 If this is captured when the recording is made and subsequently reproduced in your listening room via a loudspeaker with low frequency response adequate to the task, then the sense of being at the venue where the performance took place is much more complete.
 Also as my system does duel duty for music and home theater, 20 Hz extension with headroom for explosions without loudspeaker destruction has come in handy.
 As the number of modern recordings done completely in the digital domain in my collection of classical music has increased I have noticed that more of them have successfully captured the low frequency concert hall ambiance that is present at the recording venue.
 The classical music I have on vinyl is mostly missing this sort of information due to the conflict between the need for time on a record side
and the space that 20Hz frequency extension takes up in groove width.
 Full frequency response to 20 Hz might require 4 sides instead of 2 making it economically impractical to implement just to start with.
Scotty