View Single Post
  #9   Report Post  
Posted to rec.audio.opinion
Arny Krueger Arny Krueger is offline
external usenet poster
 
Posts: 17,262
Default Subwoofer capable of killing the listener?

"John Atkinson" wrote
in message
ps.com
Arny Krueger wrote:
"John Atkinson" wrote
in message
ups.com
Arny Krueger wrote:
"MvonB" wrote in message

http://www.eminent-tech.com/RWbrochure.htm

Note that true subwoofer fanciers like Nousaine rate
woofers in terms of output on the order of 120 dB @ 10
Hz.


The Eminent can do that easily. See, for example,
http://blog.stereophile.com/cedia2006/091906soundfield/
and
http://blog.stereophile.com/cedia2006/091606thigpen/


In the first photo, the subwoofer is outputting 8Hz at
115dB spl in the room next door.


Trivial observation: 115 120.


Correct, but that was the level in the other room,
according to a spectrum analyzer. I also witnessed a IHz
tone at the same level, but I found it compeletly
inaudible.


When reproduced with sufficient acoustic power, not heard but definately
sensed.

Bandwidth extended up to 25-30Hz, so this is a
a true_sub_woofer.


Agreed - and this is a consequence of the method of operation.

Second observation, delivering 115 dB to a hotel room
doesn't take as much effort as delivering 120 dB to a
good-sized listening room.


True, but the room the Eminent subwoofer was operating
into
was neither small nor a hotel bedroom. It was ameeting
room measuring around 15' x 25', if I remember correctly.


Agreed that 15 x 25 is a decent-sized listening room. It is like mine if you
further specify a 9 foot ceiling.

Third observation, distortion is only speced at a
relatively weak 90 dB SPL.


I couldn't hear any harmonics along with the 8Hz tone,
though there may have been some masking from the
noise of the furnishings/walls/ceiling rattling :-)


Agreed, those are natural consequences of deep bass at a loud enough level.

Harmonics visible on the spectrum analyzer were in the
few per cent.


If it can do say 120 dB @ 10% THD, why don't they say it?

And remember, this is with _one_ drive-unit and 30W
of amplification. No reason (other than financial) to
use multiple units.


The 30 watt number is misleading. This is a speaker driver that works on the
principle of modulation. I see no specification for the power input to the
motor that provides the airflow that is modulated.

What did you think of this subwoofer when you heard
it, Mr. Krueger?


I didn't have the pleasure. Was it demoed at HE2005?