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RBernst929
 
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Default small room and bass.

Hi everyone. If i have a small, square 11'x 11' listening room am i doomed to
have no bass? No matter whether i add a subwoofer or two? Can i never get any
better bass than 50hz? -Bob Bernstein.
  #2   Report Post  
MIKE
 
Posts: n/a
Default small room and bass.

Small spaces are usually good for bass (automobiles for example) but a
square room is not good. I would try a (one) sub woofer and experiment
with location.

-MIKE
  #3   Report Post  
Wylie Williams
 
Posts: n/a
Default small room and bass.

The idea that "some rooms are too small for bass" is widespread. It has
something to do with wavelengths and the space required to support specific
frequencies. Lacking any training in physics I have always wondered
wondered how this logic could be true. What if it were applied to
headphones? Given a distance from diaphragm to eardrum of maybe an inch
headphones shouldn't produce bass, or even midrange.
I believe that you can get good bass. A square room can create
problems, but there are solutions. I can refer you to Acoustic Sciences
Corporation, a leader in room treatment.
http://www.acousticsciences.com/ascmain.htm Maybe they have what you need.
Of course there are many other companies in the field and some DIY
solutions, but solutions offered by ASC's experts just might be worth the
money.

Wylie Williams
The Speaker and Stereo Store

"RBernst929" wrote in message
...
Hi everyone. If i have a small, square 11'x 11' listening room am i

doomed to
have no bass? No matter whether i add a subwoofer or two? Can i never

get any
better bass than 50hz? -Bob Bernstein.

  #4   Report Post  
Stu-R
 
Posts: n/a
Default small room and bass.

Subwoofer placement in the room is probably the problem. Many years
ago, I had a friend who used Altec theater systems with a 400 watt
Crown amplifier. He complained about the lack of bass at his
listening position ... which it turned out, was in a null. At other
room locations, the bass levels were so high they were intolerable.

To find your best subwoofer location, first place the subwoofer at
your listening position. Then, while feeding it a low frequency
signal, walk around the room, listening along the walls, at the height
the sub woofer would be, either by ear or with an SPL meter, for the
loudest location. Then relocate your subwoofer to that location, and
you should have the problem solved.

On 19 Apr 2004 05:06:13 GMT, (RBernst929) wrote:

Hi everyone. If i have a small, square 11'x 11' listening room am i doomed to
have no bass? No matter whether i add a subwoofer or two? Can i never get any
better bass than 50hz? -Bob Bernstein.


  #5   Report Post  
Stu-R
 
Posts: n/a
Default small room and bass.

Subwoofer placement in the room is probably the problem. Many years
ago, I had a friend who used Altec theater systems with a 400 watt
Crown amplifier. He complained about the lack of bass at his
listening position ... which it turned out, was in a null. At other
room locations, the bass levels were so high they were intolerable.

To find your best subwoofer location, first place the subwoofer at
your listening position. Then, while feeding it a low frequency
signal, walk around the room, listening along the walls, at the height
the sub woofer would be, either by ear or with an SPL meter, for the
loudest location. Then relocate your subwoofer to that location, and
you should have the problem solved.

On 19 Apr 2004 05:06:13 GMT, (RBernst929) wrote:

Hi everyone. If i have a small, square 11'x 11' listening room am i doomed to
have no bass? No matter whether i add a subwoofer or two? Can i never get any
better bass than 50hz? -Bob Bernstein.




  #6   Report Post  
Dick Pierce
 
Posts: n/a
Default small room and bass.

(RBernst929) wrote in message ...
Hi everyone. If i have a small, square 11'x 11' listening room
am i doomed to have no bass? No matter whether i add a subwoofer
or two? Can i never get any better bass than 50hz?


This is a common and, to some, and intuitive conclusion. The
assumption is that if you can't fit a wavelength in it, the room
can't support that frequency.

Intuitive as it may seem, it's wrong.

I wrote an extensive article debunking this myth in a recent
AudioExpress issue. Rather than going into that level of detail,
let me summarize the principles and conclusions.

"Sound," as detected by the ear, is the pysiological response to
movement of the eardrum. For the eardrum to move in response to
acoustical stimuli requires a periodic chnage in the difference
in pressure on one side of the eardrum vs the other. This is
germaine to your question, because what is says is simply that
you need a change in pressure of a sufficient amplitude and
within certain frequency limits to hear the sound.

Now, we do not "hear" wavelengths, we hear pressure variations.
So, to perceive a sound, all we have to have is the pressure
variations in the air in the vicinity of our ears, variations,
again, of sufficient pressure and within a certain range of
frequencies in order to hear something.

SO, all the loudspeaker has to do is cause those pressure
variations to happen, That's it. It doesn't make ANY difference
how big the room is. In fact, consider the lowly headphone if
the "intuitive" conclusion was correct, it would be impossible
for headphones to have ANY information below a few thousand Hz,
being that the size of the "room" they are working into is only
a couple of inches in its largest dimension.

Another example of how it is possible for "bass" to exist in a
very small enclosure is the Bruel & Kjaer pistonphone
calibrator, used for calibratiing microphones. It has a chamber
which is on the order of 3/4" in it's largest dimension,
suggesting a lower limit, using your rule of thumb, of about
9000 Hz. Yet it operates quite nicely at its design frequency of
250 Hz and, in fact, can be slowed down to a few Hz. Above the
frequency where simply air leaks dominate (a fraction of a Hz,
the response of this "room" is essentially flat from about 5-10
Hz to about 800 kHz, where is stops working in pressure mode and
starts working in various resonant exitation modes.

And that's what's happening in your 11' x 11' room. About 50 Hz
is the frequency where HOW the room works changes. At and above
50 Hz, it's operating in various resonant modes. Well above
50Hz, it's essentially operating in a diffuse field mode. Below
50 Hz, it's operatring in pressure mode, down to the frequency
where the room "leaks" (determined by the volume of the room and
the size of the leaks).

But, most assuredly, you can have bass at and well below 50 Hz
in such a room.

  #8   Report Post  
Dick Pierce
 
Posts: n/a
Default small room and bass.

(RBernst929) wrote in message ...
Hi everyone. If i have a small, square 11'x 11' listening room
am i doomed to have no bass? No matter whether i add a subwoofer
or two? Can i never get any better bass than 50hz?


This is a common and, to some, and intuitive conclusion. The
assumption is that if you can't fit a wavelength in it, the room
can't support that frequency.

Intuitive as it may seem, it's wrong.

I wrote an extensive article debunking this myth in a recent
AudioExpress issue. Rather than going into that level of detail,
let me summarize the principles and conclusions.

"Sound," as detected by the ear, is the pysiological response to
movement of the eardrum. For the eardrum to move in response to
acoustical stimuli requires a periodic chnage in the difference
in pressure on one side of the eardrum vs the other. This is
germaine to your question, because what is says is simply that you
need a change in pressure of a sufficient amplitude and within
certain frequency limits to hear the sound.

Now, we do not "hear" wavelengths, we hear pressure variations.
So, to perceive a sound, all we have to have is the pressure
variations in the air in the vicinity of our ears, variations,
again, of sufficient pressure and within a certain range of
frequencies in order to hear something.

SO, all the loudspeaker has to do is cause those pressure variations
to happen, That's it. It doesn't make ANY difference how big the
room is. In fact, consider the lowly headphone if the "intuitive"
conclusion was correct, it would be impossible for headphones to have
ANY information below a few thousand Hz, being that the size of the
"room" they are working into is only a couple of inches in its largest
dimension.

Another example of how it is possible for "bass" to exist in a very
small enclosure is the Bruel & Kjaer pistonphone calibrator, used for
calibratiing microphones. It has a chamber which is on the order of
3/4" in it's largest dimension, suggesting a lower limit, using your
rule of thumb, of about 9000 Hz. Yet it operates quite nicely at its
design frequency of 250 Hz and, in fact, can be slowed down to a few
Hz. Above the frequency where simply air leaks dominate (a fraction
of a Hz, the response of this "room" is essentially flat from about
5-10 Hz to about 800 kHz, where is stops working in pressure mode
and starts working in various resonant exitation modes.

And that's what's happening in your 11' x 11' room. About 50 Hz is
the frequency where HOW the room works changes. At and above 50 Hz,
it's operating in various resonant modes. Well above 50Hz, it's
essentially operating in a diffuse field mode. Below 50 Hz, it's
operatring in pressure mode, down to the frequency where the room
"leaks" (determined by the volume of the room and the size of the
leaks).

But, most assuredly, you can have bass at and well below 50 Hz in
such a room.

  #14   Report Post  
Rui Pedro Mendes Salgueiro
 
Posts: n/a
Default small room and bass.

RBernst929 wrote:
Hi everyone. If i have a small, square 11'x 11' listening room am i doomed to
have no bass? No matter whether i add a subwoofer or two? Can i never get any
better bass than 50hz? -Bob Bernstein.


Take a look at the white papers about bass and rooms on the harman web page:
http://www.harman.com/wp/index.jsp?articleId=122
http://www.harman.com/wp/index.jsp?articleId=1003

--
http://www.mat.uc.pt/~rps/

..pt is Portugal| `Whom the gods love die young'-Menander (342-292 BC)
Europe | Villeneuve 50-82, Toivonen 56-86, Senna 60-94

  #15   Report Post  
Nousaine
 
Posts: n/a
Default small room and bass.

(Buster Mudd) wrote:



(Nousaine) wrote in message
...


This is all easily equalizable with even a 1/3 octave equalizer. A single

cut
at 50 or 62 Hz will most likely cure things.


...at some position in the room, sure. But 8" to the left, that single
cut @ 50 or 62Hz will have so dramatically skewed the low frequency
response it'll make your head swim when you lean over to pick up your
beer.

You can never completely address temporal artifacts with frequency
adjustments. Peaks & nulls in the low frequency response of small
rooms are due to standing waves & acoustic interference...these are a
direct result of the physical dimensions of your room. Changing the
frequency response of the material you playback into that room does
not change the physical dimensions of the room; there will still be
standing waves at certain frequencies, there will still be peaks &
nulls in the room's response, & you will have simply sacrificed some
valuable amplifier headroom by trying to smooth out those anomalies
with an equalizer. You will also have sacrificed some valuable cash by
buying that equalizer in the first place.

Better to spend that cash on acoustic treatment to smooth out
interference & lessen the effects of room modes. A modest investment
in broadband absorbers & bass traps will do more to flatten the room
response of any playback equipment than even the most expensive
equalizer.


It's remarkable that when you get a problem (too much energy in a given
frequency band) that is treatable with a widely available inexpensive device
the old audiophile 'fear of EQ' strikes.

In an 11 X 11 X 8 room there will be too much energy at 50-70 Hz in any of the
better listening/woofer positions (there just aren't that many in a room this
size) because the modal peaks stack up there. I know this because I've response
mapped low frequency performance in 2 of these spaces. It's a job, perhaps one
of a few, perfectly suited for a 1/3 octave EQ.

OTOH I've never seen a case where bass traps have effectively been used to
address such a problem in a room this size. And I don't see that a broadband
absorber would address this problem in any way.

But overall I'd say that the original posters worry that he wouldn't get enough
bass in a small space should certainly have been ameliorated by now.


  #16   Report Post  
Steven Sullivan
 
Posts: n/a
Default small room and bass.

Buster Mudd wrote:
(Nousaine) wrote in message ...



This is all easily equalizable with even a 1/3 octave equalizer. A single cut
at 50 or 62 Hz will most likely cure things.


...at some position in the room, sure. But 8" to the left, that single
cut @ 50 or 62Hz will have so dramatically skewed the low frequency
response it'll make your head swim when you lean over to pick up your
beer.


Fortunately, I don't do that much leaning over when I'm sitting in
my standard listening position...even after a few beers.

I would bet that most serious audio hobbyists tend
to 1) listen alone and 2) sit in a 'sweet spot' to which their
setup has been tailored. For them, knocking down bass peaks
with EQ has merit.

You can never completely address temporal artifacts with frequency
adjustments. Peaks & nulls in the low frequency response of small
rooms are due to standing waves & acoustic interference...these are a
direct result of the physical dimensions of your room. Changing the
frequency response of the material you playback into that room does
not change the physical dimensions of the room; there will still be
standing waves at certain frequencies, there will still be peaks &
nulls in the room's response, & you will have simply sacrificed some
valuable amplifier headroom by trying to smooth out those anomalies
with an equalizer. You will also have sacrificed some valuable cash by
buying that equalizer in the first place.


Better to spend that cash on acoustic treatment to smooth out
interference & lessen the effects of room modes. A modest investment
in broadband absorbers & bass traps will do more to flatten the room
response of any playback equipment than even the most expensive
equalizer.


I kinda doubt Tom N. needs a lecture on room acoustics and bass.

--

-S.

"They've got God on their side. All we've got is science and reason."
-- Dawn Hulsey, Talent Director

  #17   Report Post  
Buster Mudd
 
Posts: n/a
Default small room and bass.

(Nousaine) wrote in message ...

It's remarkable that when you get a problem (too much energy in a given
frequency band) that is treatable with a widely available inexpensive device
the old audiophile 'fear of EQ' strikes.


'Taint fear; simply common sense: an equalizer is the wrong tool for
the job.

In an 11 X 11 X 8 room there will be too much energy at 50-70 Hz in any of the
better listening/woofer positions (there just aren't that many in a room this
size) because the modal peaks stack up there. I know this because I've response
mapped low frequency performance in 2 of these spaces.


Cool. I've analyzed 3 such spaces. Between you & me we probably have
just enough data to get any serious acoustician to raise their head
long enough to snort in disgust.

It's a job, perhaps one
of a few, perfectly suited for a 1/3 octave EQ.


That's a band-aid. You've addressed the symptom, not the problem.
Eliminating the problem passively not only prevents

OTOH I've never seen a case where bass traps have effectively been used to
address such a problem in a room this size.


Talk to John Storyk, or Fran Manzella, or Ethan Winer, or Russ
Berger...between just those four esteemed control room designers they
probably have a file of real-world case studies documenting not just
the benefits, but the mandatory need for bass trapping in small
listening rooms.

And I don't see that a broadband
absorber would address this problem in any way.


By broadband I mean as opposed to a Helmholtz resonator or tuned panel
type absorber, devices which target a specific frequency or narrow
band of frequencies. Broadband absorbers that affect an entire octave
or more would not only tame that excess energy @ 50-70Hz, but would
also address the 102 Hz axial modes that would plague an 11' x 11'
room.

But overall I'd say that the original posters worry that he wouldn't get enough
bass in a small space should certainly have been ameliorated by now.


Absolutely!

  #20   Report Post  
McLaughlin Web Design
 
Posts: n/a
Default small room and bass.

Your best bet is to go with room treatments. There is only oe company that
comes to my mind that can help you out very in expensively. www.roomtune.com
They really can do wonders for your room.
"RBernst929" wrote in message
...
Hi everyone. If i have a small, square 11'x 11' listening room am i

doomed to
have no bass? No matter whether i add a subwoofer or two? Can i never

get any
better bass than 50hz? -Bob Bernstein.



  #22   Report Post  
Rui Pedro Mendes Salgueiro
 
Posts: n/a
Default small room and bass.

RBernst929 wrote:
Hi everyone. If i have a small, square 11'x 11' listening room am i doomed to
have no bass? No matter whether i add a subwoofer or two? Can i never get any
better bass than 50hz? -Bob Bernstein.


Take a look at:
http://www.harman.com/wp/index.jsp?articleId=122
http://www.harman.com/wp/index.jsp?articleId=1003

--
http://www.mat.uc.pt/~rps/

..pt is Portugal| `Whom the gods love die young'-Menander (342-292 BC)
Europe | Villeneuve 50-82, Toivonen 56-86, Senna 60-94
  #23   Report Post  
Nousaine
 
Posts: n/a
Default small room and bass.

RBernst929 wrote:

Hi everyone. If i have a small, square 11'x 11' listening room am i doomed

to
have no bass? No matter whether i add a subwoofer or two? Can i never get

any
better bass than 50hz? -Bob Bernstein.


The problem you have is too much 50 Hz. If you have an 8-foot ceiling you have
the axial length and width moded stacked up at 50 Hz followed closey with the
ceiling mode at 70 Hz.

But you will get wonderful lower frequency room reinforcement below 50 Hz (12
dB per octave as frequency falls.) However because you have so much at 50 Hz
you just can't appreciate the lower stuff. If you think about how deep your
voice sounds when you sing in the shower you get an idea of how bass works in
small spaces.

The smaller the easier it is to get bass. In a small room however, especially
with identical dimensions things get complicated by the modal range. In yourt
case the modal range starts at 50 Hz and runs to about 300 Hz. In a medium
sized room it usually starts around 30 Hz and runs to 300 Hz.

In a car the modal range is shifted up an octave (60 too 600 Hz) which makes
it easier to get low bass but complicates acoustics in the midrange.
  #24   Report Post  
Wylie Williams
 
Posts: n/a
Default small room and bass.

"Rui Pedro Mendes Salgueiro" wrote
If i have a small, square 11'x 11' listening room am i doomed to
have no bass?


I didn't read your links and I have no training in physics. Nevertheless I
say that if you can have deep bass in the space between a headphone
diaphragm and your eardrum, or in a car, you can have bass in your room. The
size isn't the problem, but the dimensions may be. Have you actually had a
problem or are you just asking?

Wylie Williams
The Speaker and Stereo Store

  #25   Report Post  
andy
 
Posts: n/a
Default small room and bass.

"Wylie Williams" wrote in message news:YktFc.16946$IQ4.8231@attbi_s02...
"Rui Pedro Mendes Salgueiro" wrote
If i have a small, square 11'x 11' listening room am i doomed to
have no bass?


I didn't read your links and I have no training in physics. Nevertheless I
say that if you can have deep bass in the space between a headphone
diaphragm and your eardrum, or in a car, you can have bass in your room. The
size isn't the problem, but the dimensions may be. Have you actually had a
problem or are you just asking?

Wylie Williams
The Speaker and Stereo Store


What about medium- and large-sized room? I listen music in a 5.5 * 6
mt with 4.5 mt ceiling. I expect excess bass at around 344/4 = 86 Hz
which i tame with a digital equalizer. Should it be better to dump the
mode with a passive absorber (in principle it it easier to build a
bass absorber at a higher frequency)

Regards



  #26   Report Post  
Wylie Williams
 
Posts: n/a
Default small room and bass.

I have no clear idea whether equalizing or absorbing a bass peak is better.
I definitely believe that buying an using a digital equalizer with its
associated microphone would be, for me, more achievable than learning how to
build a bass absorer that would be just right for the frequency and
amplitude of the bass peak. Not that I have used such an equalizer, but I am
considering buying and trying. However, before spending I would like to
hear of some RAHE contributor experiences in this area.

Wylie Williams

"andy" wrote in message
news:yKdGc.28707$Oq2.26503@attbi_s52...
"Wylie Williams" wrote in message

news:YktFc.16946$IQ4.8231@attbi_s02...
"Rui Pedro Mendes Salgueiro" wrote
If i have a small, square 11'x 11' listening room am i doomed to
have no bass?


I didn't read your links and I have no training in physics.

Nevertheless I
say that if you can have deep bass in the space between a headphone
diaphragm and your eardrum, or in a car, you can have bass in your room.

The
size isn't the problem, but the dimensions may be. Have you actually had

a
problem or are you just asking?

Wylie Williams
The Speaker and Stereo Store


What about medium- and large-sized room? I listen music in a 5.5 * 6
mt with 4.5 mt ceiling. I expect excess bass at around 344/4 = 86 Hz
which i tame with a digital equalizer. Should it be better to dump the
mode with a passive absorber (in principle it it easier to build a
bass absorber at a higher frequency)

Regards


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