[Ben - TheStudioRI.com]

Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?

[Laurence Payne]

On 14 Mar 2007 09:02:35 -0700, "Ben - TheStudioRI.com"
wrote:

Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?

What happens if the speakers are further from the wall? And if you
move them closer to the listening position and work at a lower volume?

[Ben - TheStudioRI.com]

On Mar 14, 11:09 am, Laurence Payne lpayne1NOSPAM@dslDOTpipexDOTcom
wrote:
On 14 Mar 2007 09:02:35 -0700, "Ben - TheStudioRI.com"

wrote:
Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?

What happens if the speakers are further from the wall? And if you
move them closer to the listening position and work at a lower volume?

Did that... no change in the low end.

[[email protected]]

On Mar 14, 8:02 am, "Ben - TheStudioRI.com" wrote:
Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?

Ben,

I looked at the pictures of your control room. Those 824s are too
close to the boundries. They perform better if they can be kept away
from boundries. Do you have acoustic measurements for your room? If
not visit the following:

http://www.realtraps.com - lots of really good articles written by
Ethan Winer
http://www.acoustisoft.com (ETF5)
http://www.hometheatershack.com (Room EQ Wizard)

A Behringer ECM-8000 measurement mic will cost you around $50, be
reasonably adequate for the task and still be useful for recording
where an omni is appropriate and where noise floor isn't an issue.

When you have some hard data you will know much better what you need
to do to your room. Anecdote: From my experience Ethan's Mondo Traps
work much much better than foam bass traps.

bobs

Bob Smith
BS Studios
we organize chaos
http://www.bsstudios.com

[Scott Dorsey]

Ben - TheStudioRI.com wrote:
Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?


Okay, what's WRONG with the bass in the current configuration? If you
play a sweep, where do you hear the peaks and troughs at the listening
position? How much do they move around as you move back and forth
around the sweet spot?

And what are these "foam bass traps?" Foam and diffusion will do nothing
about the low end.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Ben - TheStudioRI.com wrote:
On Mar 14, 11:09 am, Laurence Payne lpayne1NOSPAM@dslDOTpipexDOTcom
wrote:
On 14 Mar 2007 09:02:35 -0700, "Ben - TheStudioRI.com"

wrote:
Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?

What happens if the speakers are further from the wall? And if you
move them closer to the listening position and work at a lower volume?

Did that... no change in the low end.

No change at ALL?
It didn't make the problems worse, even?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Ethan Winer]

Ben,

Did that... no change in the low end.

You already got the right advice - you need better bass traps than you have,
and likely more of them. It's impossible to get a small room like that
perfectly flat, though with enough real bass traps - not foam corners - you
can make a huge improvement. But skip the EQ because that only makes things
worse in a room the size of yours.

--Ethan

[Mark]

The traps work by splitting a
standing wave mode into multiple modes, each of which is less powerful and
troublesome than the original.


Is that true?
I thought bass traps worked by lowering the Q of the resonance by
ABSORBING energy. Not by deTUNING the resonance.
Mark

[Mike Rivers]

On Mar 14, 12:02 pm, "Ben - TheStudioRI.com"
wrote:
Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall.

You need to get them away from the wall, at least two, or better,
three feet out. When they're up against the wall, what would be the
back wave (which is all low frequency) gets reflected back into the
room, adding to the normal bass produced by the speakers.

If you have no other choice for placement, this bass buildup from a
boundary (try saying that fast) can be reduced by using an equalizer.
But this is the ONLY acoustic problem that can be helped by
equalization. This is what the Acoustic Space switch does. Have you
tried that in the Half or Quarter space position?

[Mike Rivers]

On Mar 14, 1:08 pm, "Soundhaspriority" wrote:

The traps work by splitting a
standing wave mode into multiple modes, each of which is less powerful and
troublesome than the original.

That's a description of a diffusor, sort of, not a trap. A trap
absorbs energy and doesn't let it bounce back to where you don't want
it.

[Norman[_2_]]

1) move speakers off the wall (atl least 2') -- bass builds up at room
bounderies, having your max acoustical energy there will encourage room
modes.

2) don't know what you are using for 'bass traps' -- there are some very bad
products (foam corner traps etc) on the market claiming to do things they
really don't. either go for membrane absorbers (specially made tubes with
membranes on the ends tuned to absorb low end), or better yet, build several
'panel absorbers'. if you google 'panel bass trap' you will find a site for
the design of these -- very effective if done right.

3) diffusion is great -- essential in control rooms, but will not deal with
room modes (bass buildup). in my control room i've designed angular panel
bass traps that are tuned for the room and function as diffusors at the same
time (as they are wedge shaped).

4) you will have to go to great lengths to make a decent control room with
only about 850 cubic ft to work with -- will never be great (the 7' ceiling
is very unfortunate).

have to go now, but if you sent me a quick sketch of the room and set-up i
would gladly give you my 2 cents on panel absorber placement.

cheers, Norman



"Ben - TheStudioRI.com" wrote in message
ups.com...
Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?

[Mike Rivers]

On Mar 14, 4:48 pm, "Soundhaspriority" wrote:

No, diffusors do not absorb energy. They reduce the coherence of the
reverberant sound field without reducing the power of that field.

Yes, I know that. Diffusors reflect the energy back in multiple
directions rather than a single direction that a flat wall would.

A trap (ideally) does not reflect any energy.

You wrote:
The traps work by splitting a
standing wave mode into multiple modes,

That doesn't really mean anything to me. It essentially eliminates the
standing wave in whatever mode hits the trap. It doesn't split
anything.



Bob Morein
Dresher, PA
(215) 646-4894

[Chris Hornbeck]

On Wed, 14 Mar 2007 13:08:23 -0400, "Soundhaspriority"
wrote:

There is, however, a solution:
1. Remove all the bass traps, because they simply complicate the room
response. Keep the diffusers.
2. Use electronic equalization.
3. use monitors that feature an overdamped woofer design. In a larger room,
such speakers are identified by anemic bass, but with excellent timbral
accuracy.

I strongly disagree with the first two. The third is
irrelevant to the issue. ("It's not irrelevant; it's
a hippopotamus!")

All good fortune,

Chris Hornbeck

[Laurence Payne]

On 14 Mar 2007 09:44:26 -0700, "Ben - TheStudioRI.com"
wrote:

What happens if the speakers are further from the wall? And if you
move them closer to the listening position and work at a lower volume?

Did that... no change in the low end.

No change at all in bass when you move them away from the wall?
Strange.

[Scott Dorsey]

Soundhaspriority wrote:
"Mark" wrote in message
oups.com...

The traps work by splitting a
standing wave mode into multiple modes, each of which is less powerful
and
troublesome than the original.


Is that true?
I thought bass traps worked by lowering the Q of the resonance by
ABSORBING energy. Not by deTUNING the resonance.
Mark

All bass traps are tuned to some degree. There are low bass, mid, bass, and
high bass traps. The tuning is necessary in order to couple the undesired
mode to the absorber. It absorbs some energy, but it also detunes the
troublesome mode by coupling to it.

None of these are actually good examples of what is going on.

See, reflections occur when the acoustical impedance of the medium that
sound is flowing through changes. If you produce a wave, it goes through
the air and it will go right out through the window because the impedance
of the air inside and the air outside are the same.

If you produce a wave and it strikes a wall, it will be reflected back
because of the impedance discontinuity.

What a bass trap is doing is building a solid box whose input impedance
is the same as free air. Waves flow into it, and they don't come out.
Now, this being the real world, the low frequency corner of the bass trap
is determined by its size among other things. That is, the lowest frequency
at which the impedance is actually close to that of free air.

But, a bass trap is NOT a helmholtz resonator and it is NOT a tuned cavity
device like some people claim.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Ty Ford]

On Wed, 14 Mar 2007 12:02:35 -0400, Ben - TheStudioRI.com wrote
(in article . com):

Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?


Ben,

Specifically, what is the problem?

Regards,

Ty Ford


--Audio Equipment Reviews Audio Production Services
Acting and Voiceover Demos http://www.tyford.com
Guitar player?:http://www.youtube.com/watch?v=4RZJ9MptZmU

[Mark]

..... a bass trap is a tuned cavity
that has been detuned to some extent by filling it with a lossy material........

DeTUNED is NOT the same thing as DE Q'd. Frequency is NOT the same
thing as Q. Lossy material does not deTUNE, lossy material de Q's.

Mark

[kooz]

On Mar 15, 8:58 am, Ty Ford wrote:
On Wed, 14 Mar 2007 12:02:35 -0400, Ben - TheStudioRI.com wrote
(in article . com):

Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?

Ben,

Specifically, what is the problem?

Regards,

Ty Ford

--Audio Equipment Reviews Audio Production Services
Acting and Voiceover Demoshttp://www.tyford.com
Guitar player?:http://www.youtube.com/watch?v=4RZJ9MptZmU

This thread started with an earlier post. Ben was asking for advice
on "better" monitors to replace his Mackie HR824s with, since the
mixes he is making on his Sennheiser headphones "translate better" and
"have better imaging." It seems the group has convinced him to
examine his "professionally designed/treated" control room/mix suite
acoustics, but his "years of engineering experience" are suggesting
that his current set-up is adequate.

[Ben - TheStudioRI.com]

On Mar 14, 12:08 pm, "Soundhaspriority" wrote:
"Ben - TheStudioRI.com" wrote in oglegroups.com...

Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?

If the linear dimensions of a room are at least one half wavelength, the
room can support at least one standing wave. The traps work by splitting a
standing wave mode into multiple modes, each of which is less powerful and
troublesome than the original. This comes from the theory of coupled
harmonic oscillators.

But when the room is smaller than 1/2 the problem wavelength, the room does
not resonate. Instead, each pulse of the speaker cone pressurizes the entire
room almost uniformly. In this case, bass traps cannot work, because there
are no modes to split.

With a dimension of 9 feet, this gives problem wavelengths of 60 Hz, 180 Hz,
300 Hz, 420 Hz, and up.

Diffusers are not for bass anomalies. They work on mids and up.

There is, however, a solution:
1. Remove all the bass traps, because they simply complicate the room
response. Keep the diffusers.
2. Use electronic equalization.
3. use monitors that feature an overdamped woofer design. In a larger room,
such speakers are identified by anemic bass, but with excellent timbral
accuracy.

Bob Morein
Dresher, PA
(215) 646-4894



ok, first off... you all have great advice. I've been through most of
that with sound professionals and I even had auralex do the numbers on
the standing waves and nodes, etc. Despite adding traps, moving
speakers, moving furniture, etc. I still have this dramatic dip
around 400hz, boost around 60hz and similar problems near the
frequencies that Bob pointed out. I have two sets of Genesis traps
from Auralex in the front and back of the room. I also have a custom
6'x4'x10" fiberglass filled trap right in back of the monitors. I
know the room has problems because of its size, but I cant make the
room any larger. I'm trying NOT to use EQ to compensate, but I
recognize that I may have to. The notion that the room is not
resonant may be in the right direction as I can FEEL the pressure from
the speakers when i'm listening. It's an unnatural listening
pressure.

So, If I wanted to add an EQ, what would you suggest? and if I wanted
to pay someone to come and analyze the room with the right equipement,
where can I find someone around here and how much would it cost?

p.s., I'm still not happy with the mackies lol.

[Ethan Winer]

Mark,

I thought bass traps worked by lowering the Q of the resonance by
ABSORBING energy. Not by deTUNING the resonance.

Bass traps do three things, all via absorbing reflections:

1) They reduce the level of peaks
2) They reduce the depth of nulls
3) They reduce modal ringing times

A side effect off adding absorption into a room is the resonant frequencies
are shifted a little lower.

Bass traps can be tuned or broadband. Sometimes they're both. That is, tuned
traps can be designed to have a relatively low Q to work over a useful range
of about an octave.

Some of the explanations I see in this thread miss the fact the while
ringing is always due to the room and its dimensions, peaks and nulls also
occur at non-modal frequencies due to simple comb filtering. This is why
broadband absorption is generally preferred to tuned absorption. Especially
in the smaller rooms many people use these days. When all of the room
boundaries are nearby, the reflections are stronger yielding larger peaks
and deeper nulls.

Also, peaks and nulls due to comb filtering have two fundamentally different
causes. One is SBIR - Speaker Boundary Interference Response - where the
peak and null frequencies are related to the speaker's distance from each
boundary. The other is LBIR - Listener Boundary Interference Response -
which relates to the distance from your ears to each boundary. So that gives
MANY DOZENS of individual peak/dip sets for each situation (speaker or
listener) and each boundary distance.

--Ethan

[David Grant]

ok, first off... you all have great advice. I've been through most of
that with sound professionals and I even had auralex do the numbers on
the standing waves and nodes, etc. Despite adding traps, moving
speakers, moving furniture, etc. I still have this dramatic dip
around 400hz, boost around 60hz and similar problems near the
frequencies that Bob pointed out. I have two sets of Genesis traps
from Auralex in the front and back of the room.

I'd avoid foam like the plague... In my experience it doesn't do a whole
heck of a lot. My room's a similar size and I made it sound much much better
by adding 4" thick panels of fabric-covered rigid fiber glass strattling
every corner. The stuff isn't that expensive, and it's only a day's worth of
fabric-work and hanging.

If you do that, and pull your monitors out from the wall by at least a foot,
you'll probably be blown away by the difference.

Keep some foam for side wall absorption to tame the higher frequencies, but
other than that, toss it!



--
Posted via a free Usenet account from http://www.teranews.com

[[email protected]]

On Mar 15, 11:33 am, "Ben - TheStudioRI.com"
wrote:
On Mar 14, 12:08 pm, "Soundhaspriority" wrote:



"Ben - TheStudioRI.com" wrote in oglegroups.com...

Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?

If the linear dimensions of a room are at least one half wavelength, the
room can support at least one standing wave. The traps work by splitting a
standing wave mode into multiple modes, each of which is less powerful and
troublesome than the original. This comes from the theory of coupled
harmonic oscillators.

But when the room is smaller than 1/2 the problem wavelength, the room does
not resonate. Instead, each pulse of the speaker cone pressurizes the entire
room almost uniformly. In this case, bass traps cannot work, because there
are no modes to split.

With a dimension of 9 feet, this gives problem wavelengths of 60 Hz, 180 Hz,
300 Hz, 420 Hz, and up.

Diffusers are not for bass anomalies. They work on mids and up.

There is, however, a solution:
1. Remove all the bass traps, because they simply complicate the room
response. Keep the diffusers.
2. Use electronic equalization.
3. use monitors that feature an overdamped woofer design. In a larger room,
such speakers are identified by anemic bass, but with excellent timbral
accuracy.

Bob Morein
Dresher, PA
(215) 646-4894

ok, first off... you all have great advice. I've been through most of
that with sound professionals and I even had auralex do the numbers on
the standing waves and nodes, etc. Despite adding traps, moving
speakers, moving furniture, etc. I still have this dramatic dip
around 400hz, boost around 60hz and similar problems near the
frequencies that Bob pointed out. I have two sets of Genesis traps
from Auralex in the front and back of the room. I also have a custom
6'x4'x10" fiberglass filled trap right in back of the monitors. I
know the room has problems because of its size, but I cant make the
room any larger. I'm trying NOT to use EQ to compensate, but I
recognize that I may have to. The notion that the room is not
resonant may be in the right direction as I can FEEL the pressure from
the speakers when i'm listening. It's an unnatural listening
pressure.

So, If I wanted to add an EQ, what would you suggest? and if I wanted
to pay someone to come and analyze the room with the right equipement,
where can I find someone around here and how much would it cost?

p.s., I'm still not happy with the mackies lol.

Check this link out for some DIY solutions:

http://forum.studiotips.com/viewforum.php?f=8

Give some more details like exactly what kind of trap you have and
what kind of material is used. Bass Trap is very ambiguous and
doesn't really tell you much. Do some research and figure out the
modes in your room and where they are located. This helps you in
placement of solutions.

What kind of bass traps are in the corners, foam or fiberglass? Fill
your corners with fiberglass not foam. For the walls try making poly
cylindrical diffusors of various sizes and filling them with
fiberglass. This will reflect highs and mids and absorb lows.

What is on your ceiling? What kind of floor do you have? If your
floor is reflective you should make your ceiling completely absorptive
by hanging fiber glass panels from it. Especially since your ceiling
is only 7 ft. I bet those problems are from your ceiling. You said
you only have some diffusion over your mix position. Treat the entire
ceiling with absorption not diffusion, especially if you have a
reflective floor. If you have carpet replace it with something
reflective and make the ceiling completely absorptive. Carpet is like
foam but worse.

Foam won't do anything for that 60hz problem. Probably better off not
using foam at all as it will absorb the mids and highs and leave you
with the lows like carpet. For that 60hz problem if you try all the
above and it's still there then build a Helmholtz resonator to absorb
it at it's pressure points in the room. Figure out all your modes and
where they are located. Place the Helmholtz resonator where the 60hz
mode is supposed to have it's highest pressure point.

[Edwin Hurwitz]

In article ,
"Soundhaspriority" wrote:



Scott, rather than get into symantecs,

What does virus protection have to do with all this?

:-)

Edwin

[Norman[_2_]]

"Ben - TheStudioRI.com" wrote in message
oups.com...
On Mar 14, 12:08 pm, "Soundhaspriority" wrote:
"Ben - TheStudioRI.com" wrote in
oglegroups.com...

Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?

If the linear dimensions of a room are at least one half wavelength,
the
room can support at least one standing wave. The traps work by splitting
a
standing wave mode into multiple modes, each of which is less powerful
and
troublesome than the original. This comes from the theory of coupled
harmonic oscillators.

But when the room is smaller than 1/2 the problem wavelength, the room
does
not resonate. Instead, each pulse of the speaker cone pressurizes the
entire
room almost uniformly. In this case, bass traps cannot work, because
there
are no modes to split.

With a dimension of 9 feet, this gives problem wavelengths of 60 Hz, 180
Hz,
300 Hz, 420 Hz, and up.

Diffusers are not for bass anomalies. They work on mids and up.

There is, however, a solution:
1. Remove all the bass traps, because they simply complicate the room
response. Keep the diffusers.
2. Use electronic equalization.
3. use monitors that feature an overdamped woofer design. In a larger
room,
such speakers are identified by anemic bass, but with excellent timbral
accuracy.

Bob Morein
Dresher, PA
(215) 646-4894



ok, first off... you all have great advice. I've been through most of
that with sound professionals and I even had auralex do the numbers on
the standing waves and nodes, etc. Despite adding traps, moving
speakers, moving furniture, etc. I still have this dramatic dip
around 400hz, boost around 60hz and similar problems near the
frequencies that Bob pointed out. I have two sets of Genesis traps
from Auralex in the front and back of the room. I also have a custom
6'x4'x10" fiberglass filled trap right in back of the monitors. I
know the room has problems because of its size, but I cant make the
room any larger. I'm trying NOT to use EQ to compensate, but I
recognize that I may have to. The notion that the room is not
resonant may be in the right direction as I can FEEL the pressure from
the speakers when i'm listening. It's an unnatural listening
pressure.

So, If I wanted to add an EQ, what would you suggest? and if I wanted
to pay someone to come and analyze the room with the right equipement,
where can I find someone around here and how much would it cost?

p.s., I'm still not happy with the mackies lol.


ok...first off i think you have two problems...and you know it. the room
needs to be dealt with, and you don't like the sound of your monitors.
although you clearly have room issues, i disagree that you wouldn't be able
to distinquish those from not being happy with the tambral quality of your
monitors...to some extent.

so...to the monitor issue, since you will never completely deal with the low
end in your room, no matter what you do, you will be better off with a
nearfield monitor that rolls off pretty high -- 60 - 80 Hz. work with that
and check low octave on headphones or in another room. i think only your
ears will be able to determine which monitor is best for you. if you like
the 'sound' of the HD600's, then that's a hint that you are looking for an
'accurate' monitor. still, 'accuracy' and speakers are not words that
should be used in the same sentance, so....probably the best advice it to
find a way to check out the usual suspects on the 'more accurate' or
higher-end side of things -- quested, PMC, dynaudio, klein & hummel, adam,
and my personal favorite...ATC. none are cheap, but most make good models
in the $1000 per speaker range. still, which one's of those will work for
you, only you can determine.

as for the room...i looked at your photo's and....well, i don't know what
'textbook' you were looking at when you placed your monitors, but trade it
in for 'the master handbook of acoustics' by F. Alton Everest. in my
opinion, a) you got bad advice from Auralex who were more concerned with
selling you their products than solving your problems, and b) you just
haven't gone far enough and combined enough of the suggestions here to get
the best possible results.

first, as was discussed with some technical back and forth, it is clear that
the size of your room prohibits you from ever making it 'great'...but i do
believe you could make it much better. my control romm is 11' w X 19' l X
8' h -- so although nearly twice the cubic footage of your space, i share
some of your issues because of the low ceiling height and less than
desireable width. i built a modified live-end / dead end room with great
success, and use 3 way PMC's that are flat to 25 Hz with no eq and no
serious room mode issues -- but, i t was A LOT of work...and if you are
serious, i don't think there are any real shortcuts or pre-fab solutions,
sorry to say.

what i did was:

1) build the room with the long dimensions canted from front to back (10' in
the front or dead-end, 12.5' in the rear, or live-end) -- this minimized the
specificity of the 11' mode, and prvides a better diffusion pattern as a
base.

2) hung the ceiling using resiliant channel on the studs -- this not only
increases transmission loss, but makes the ceiling into a big 'panel trap'
of sorts, functioning at very low frequencies.

3) built big low Q panel traps at a variety of dimensions covering 20 Hz -
400 Hz. sizes from 3' X 8' to 2' X 4' ranging in depth from parallel 4" &
6" to wedge shaped at a variety of angles from 4" to 10" to 4" to 24".
placed them around the room at about 1' intervals in a pattern designed to
achieve maximum diffusion, including the ceiling, with 703 board covered in
fabric (dead-end), or half circle tube diffusors of various diameters
(live-end), placed in between. you end up with a variagated wall and
ceiling surface 2/3 of which is panel trapped -- no 'foam' in this room at
all -- very overrated product.

4) set the room up, moved the speakersand listenig position around, and
adjusted placement of diffusors and traps until it sounded 'right' -- takes
some thought, and a lots of time, but i've been told by good engineers that
that the room sounds as good as many 'high-end' rooms costing many times as
much $. BTW, i ended up with my main monitors on stands 3' off the back
wall, and 20" off the side walls. listning position with my head roughly 6'
off a very well diffused back wall.

hope this helps,

Norman

[Mike Rivers]

On Mar 15, 2:06 pm, "Norman" wrote:

ok...first off i think you have two problems...and you know it. the room
needs to be dealt with, and you don't like the sound of your monitors.

Unless he's heard those monitors in a good room, he doesn't know what
they really sound like, so how can he rightfully not like their
sound?

[Mark]

DeTUNED is NOT the same thing as DE Q'd

False.

Frequency is NOT the same thing as Q.

True.

Lossy material does not deTUNE, lossy material de Q's.

The two are equivalent.


TUNING refers to FREQUENCY
Q refers to QUALITY FACTOR

deTUNING means to "change the FREQUENCY of a resonance"
de Q ing means to "lower the quality factor of a resonance"

A lower quality factor implies a wider bandwidth and lower gain
resonance i.e. less sharp resonance of lower gain

These are the definitions an electronics engineer would use.
If you think these definitions are wrong then we are working from two
different dictionaries.


thanks
Mark

[Mike Rivers]

On Mar 15, 4:41 pm, "Mark" wrote:

Q refers to QUALITY FACTOR

A lower quality factor implies a wider bandwidth and lower gain
resonance i.e. less sharp resonance of lower gain

Q actually, in practice, means two things. Electrically, it's
reactance divided by resistance. A device that has reactance but low
resistance will behave more like a pure reactance and less like a
resistor, which suggests a higer quality component.

The way you're using it, it's related to bandwidth.

The way that these two tie gogether is that if you have a tuned
circuit consisting of an capacitor and inductor, and both have a high
Q, the resonance will be sharp. If the components have resistance
that's significant compared to their reactance at the resonant
frequency, this tends to broaden the resonance.

An acoustical trap functions as a resonant circuit, but a mechanical
one. The resistance in this case is the absorption, the equivalent of
electrical loss. If you have a lot of absorption, the resonant peak
will be lower and broader.

[Norman[_2_]]

"Mike Rivers" wrote in message
ups.com...
On Mar 15, 2:06 pm, "Norman" wrote:

ok...first off i think you have two problems...and you know it. the room
needs to be dealt with, and you don't like the sound of your monitors.

Unless he's heard those monitors in a good room, he doesn't know what
they really sound like, so how can he rightfully not like their
sound?


i find that with nearfeild monitors (such as his are) i can tell whether or
not i like their basic tambral quality by listening at 1 meter at 65 - 75 db
even in a bad room. might not be able to tell about the low end, but i can
judge the quality of the mids and highs -- i assume he has done this.

[Arny Krueger]

"Soundhaspriority" wrote in message

"Mark" wrote in message
oups.com...


DeTUNED is NOT the same thing as DE Q'd

False.

Frequency is NOT the same thing as Q.

True.

Lossy material does not deTUNE, lossy material de Q's.

The two are equivalent.


TUNING refers to FREQUENCY
Q refers to QUALITY FACTOR

deTUNING means to "change the FREQUENCY of a resonance"

No, it does not.

Yes it does.

de Q ing means to "lower the quality factor of a
resonance"

Well, at least you got one right.

A lower quality factor implies a wider bandwidth and
lower gain resonance i.e. less sharp resonance of lower
gain

Never properly used a full parametric analyzer, have you?

These are the definitions an electronics engineer would
use.

No, they are not.

Yes they are.

[Don Pearce]

On Thu, 15 Mar 2007 16:50:05 -0400, "Soundhaspriority"
wrote:


"Mark" wrote in message
roups.com...


DeTUNED is NOT the same thing as DE Q'd

False.

Frequency is NOT the same thing as Q.

True.

Lossy material does not deTUNE, lossy material de Q's.

The two are equivalent.


TUNING refers to FREQUENCY
Q refers to QUALITY FACTOR

deTUNING means to "change the FREQUENCY of a resonance"

No, it does not.


Yes it does - tuning refers to the frequency of operation. When an
instrument is out of tune, its frequency or pitch is wrong - it isn't
too loud or too soft.

de Q ing means to "lower the quality factor of a resonance"

Well, at least you got one right.

A lower quality factor implies a wider bandwidth and lower gain
resonance i.e. less sharp resonance of lower gain

These are the definitions an electronics engineer would use.

No, they are not.

Oh yes they are.

d

--
Pearce Consulting
http://www.pearce.uk.com

[Don Pearce]

On 15 Mar 2007 13:52:57 -0700, "Mike Rivers"
wrote:

On Mar 15, 4:41 pm, "Mark" wrote:

Q refers to QUALITY FACTOR

A lower quality factor implies a wider bandwidth and lower gain
resonance i.e. less sharp resonance of lower gain

Q actually, in practice, means two things. Electrically, it's
reactance divided by resistance. A device that has reactance but low
resistance will behave more like a pure reactance and less like a
resistor, which suggests a higer quality component.

The way you're using it, it's related to bandwidth.

The way that these two tie gogether is that if you have a tuned
circuit consisting of an capacitor and inductor, and both have a high
Q, the resonance will be sharp. If the components have resistance
that's significant compared to their reactance at the resonant
frequency, this tends to broaden the resonance.

An acoustical trap functions as a resonant circuit, but a mechanical
one. The resistance in this case is the absorption, the equivalent of
electrical loss. If you have a lot of absorption, the resonant peak
will be lower and broader.


The Q or quality factor of a resonator actually has just one
definition, which leads indirectly to all the others - the number of
cycles of operation needed to dissipate half of the stored energy. If
you do the maths, this turns out to equal the centre frequency divided
by the bandwidth.

d

--
Pearce Consulting
http://www.pearce.uk.com

[Scott Dorsey]

Mark wrote:
These are the definitions an electronics engineer would use.
If you think these definitions are wrong then we are working from two
different dictionaries.

I believe that Mr. Morein is not only using a different dictionary but is
in a different universe altogether.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mark]

An acoustical trap functions as a resonant circuit, but a mechanical
one. The resistance in this case is the absorption, the equivalent of
electrical loss. If you have a lot of absorption, the resonant peak
will be lower and broader.

Thats what I was saying and
I agree with the addition of one clarification

If you have a lot of absorption, the resonant peak
will be lower (lower in amplitude not lower in frequency) and
broader.

Mark

[Mark]

On Mar 15, 4:57 pm, (Don Pearce) wrote:
On 15 Mar 2007 13:52:57 -0700, "Mike Rivers"
wrote:





On Mar 15, 4:41 pm, "Mark" wrote:

Q refers to QUALITY FACTOR

A lower quality factor implies a wider bandwidth and lower gain
resonance i.e. less sharp resonance of lower gain

Q actually, in practice, means two things. Electrically, it's
reactance divided by resistance. A device that has reactance but low
resistance will behave more like a pure reactance and less like a
resistor, which suggests a higer quality component.

The way you're using it, it's related to bandwidth.

The way that these two tie gogether is that if you have a tuned
circuit consisting of an capacitor and inductor, and both have a high
Q, the resonance will be sharp. If the components have resistance
that's significant compared to their reactance at the resonant
frequency, this tends to broaden the resonance.

An acoustical trap functions as a resonant circuit, but a mechanical
one. The resistance in this case is the absorption, the equivalent of
electrical loss. If you have a lot of absorption, the resonant peak
will be lower and broader.

The Q or quality factor of a resonator actually has just one
definition, which leads indirectly to all the others - the number of
cycles of operation needed to dissipate half of the stored energy. If
you do the maths, this turns out to equal the centre frequency divided
by the bandwidth.

d

Agreed...specifically the -3 dB bandwidth...
Mark

[Ty Ford]

On Thu, 15 Mar 2007 10:45:42 -0400, kooz wrote
(in article .com):

On Mar 15, 8:58 am, Ty Ford wrote:
On Wed, 14 Mar 2007 12:02:35 -0400, Ben - TheStudioRI.com wrote
(in article . com):

Ok, here we go. my control room measures 9x13x7. the speakers are
against the 9 back wall. I've done EVERYTHING I know how to do to
tame the bass. I have bass traps in every corner, a custom 8" bass
trap on the back wall behind the speakers, foam bass traps along the
rear wall, diffusers above the mix position, etc. nothing has really
helped. aside from redesigning the entire room (which I would do, but
only if nothing else helps), what are your suggestions?

Ben,

Specifically, what is the problem?

Regards,

Ty Ford

--Audio Equipment Reviews Audio Production Services
Acting and Voiceover Demoshttp://www.tyford.com
Guitar player?:http://www.youtube.com/watch?v=4RZJ9MptZmU

This thread started with an earlier post. Ben was asking for advice
on "better" monitors to replace his Mackie HR824s with, since the
mixes he is making on his Sennheiser headphones "translate better" and
"have better imaging." It seems the group has convinced him to
examine his "professionally designed/treated" control room/mix suite
acoustics, but his "years of engineering experience" are suggesting
that his current set-up is adequate.


Hmm, classic case of which one's right. Chances are neither are totally
right, but since "fixing" the headphones isn't really an option, you start
thinking room.

I have nodes in my room. I know where they are. I know how much more to
expect from them. I go to them to check mixes. If I'm hear more than X in
them, I have to pull back the LF EQ.

I haven't been in a studio yet that doesn't have audible nodes somewhere;
walls, corners and other places. Try not to get hung up on nodes. I don't
know where you have the Mackies in relationship to the corners walls and
ceiling. Could yo post a jpg of an overhead view?

In a related note: I'm breaking in my Acura RSX speakers as translation
speakers and find a BIG difference between them and my JBL L100. Driving me a
bit nuts on the present project, but I'll get it.

Regards,

Ty Ford


--Audio Equipment Reviews Audio Production Services
Acting and Voiceover Demos http://www.tyford.com
Guitar player?:http://www.youtube.com/watch?v=4RZJ9MptZmU

[Ethan Winer]

Bob,

First you should measure, with oscillator or a Stereophile Test CD, and a
lowly Radio Shack SPL meter. If the room is pressurizing below a certain
frequency, the measured SPL at or below that frequency will be independent
of position. As you go up in frequency, you should see the modes. Chart
them out in 1/3 octave steps.

Third octave tests are not useful in small rooms. I've seen peaks and
adjacent nulls closer than a musical whole step. This is not only common,
but typical. So third-octave is mostly a "spot check" here and there, and
completely misses the true response and the mode frequencies.

I made the suggestion, not terribly well received, that you rip out the
bass traps. The reason I made this suggestion is that you are going to use
a parametric equalizer, with a limited number of bands, to fix what you
can.

It was not well received because it's not a great idea. :-)

Seriously, the ONLY viable solution is bass traps. EQ is at best a band-aid,
and as often as not makes things worse as much as better. Again, I'm talking
about small control rooms like people use these days.

As to what type of eq to use -- there are digital, there are analog, I
suggest staying away from anything "automatic."

I hate being argumentative because that's not my style and it's never
productive. So instead I'll just explain why "automatic" is in fact better,
with the caveat that EQ is not a great idea in the first place.

This article compares the effectiveness of EQ versus bass traps:

http://www.realtraps.com/eq-traps.htm

In this case the EQ was adjusted manually by a guy who does this for a
living and is IMO competent. But for all his fancy test gear, and working at
it for more than an hour, he was unable to exactly nail the frequencies. So
at one frequency he actually added substantial ringing.

This article debunks the claim that sophisticated DSP can do a better job at
room "correction" than EQ:

http://www.realtraps.com/art_audyssey.htm

As you will read, even the really expensive Audyssey device (which has been
lauded by an ignorant and uncritical audio press) does no more good than EQ.
But at least it works automatically and can hit the right frequencies. The
best (hypothetical) room EQ would be automatic but could also be overridden
manually.

--Ethan

[Scott Dorsey]

Soundhaspriority wrote:
"Ethan Winer" ethanw at ethanwiner dot com wrote in message
m...
Bob,

First you should measure, with oscillator or a Stereophile Test CD, and a
lowly Radio Shack SPL meter. If the room is pressurizing below a certain
frequency, the measured SPL at or below that frequency will be
independent
of position. As you go up in frequency, you should see the modes. Chart
them out in 1/3 octave steps.

Third octave tests are not useful in small rooms. I've seen peaks and
adjacent nulls closer than a musical whole step. This is not only common,
but typical. So third-octave is mostly a "spot check" here and there, and
completely misses the true response and the mode frequencies.

I'm giving him a methodology for which the tools are cheap and simple.
If I were doing the job, I would use a spectrum analyzer.

Third octave noise bands and warble tones aren't any more expensive than
third octave tones.

But a hand-sweepable oscillator is the most convenient way of doing this.

But you're wrong about the traps. His room is too small, and the problem
too severe.

Time to call in the backhoes, then.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[hank alrich]

Soundhaspriority wrote:

But you're wrong about the traps. His room is too small, and the problem
too severe.

In that case all you can do with EQ is make it worse.

--
ha
Iraq is Arabic for Vietnam

[Mike Rivers]

On Mar 16, 6:46 pm, "Soundhaspriority" wrote:

I'm giving him a methodology for which the tools are cheap and simple.

What good is it if it doesn't work? What Ethan's saying is that the
chance of working (that the problem frequencies in the room fall in
the equalizer bands) is unreasonably small. It's not even worth a try.
I suppose any peaks than can be reduced with EQ might be worth it, but
not at the expense of making the room worse overall.

If I were doing the job, I would use a spectrum analyzer.

With what resolution?

[Ethan Winer]

Bob,

But you're wrong about the traps. His room is too small, and the problem
too severe.

In fact, the smaller the room, the great amount of bass trapping it needs.
I'm curious as to what negative result you believe will occur from adding
bass traps.

--Ethan