A re-think on acoustics - long posting

[archive]

From: sjoerd@n...
Date: Sun Mar 4, 2001 11:22 pm
Subject: A re-think on acoustics - long posting

Some of you may have seen some pictures of the studio I am building at
the moment, where - especially the control room ? things look somewhat
?different?. As I am just writing an article for a pro audio magazine
on studio construction / acoustic treatment,
I thought you might be interested in an explanation of ?the reasons
why?. Here is a brief version of the article; sorry it is so long,
it?s a brief version ? really!

I have over the last 30 odd years worked in many studios, on both
sides of the Atlantic. In addition I have done a lot of
troubleshooting for studios as well as studio design firms / builders.
As a result I have formed a number of conclusions, as well as a whole
lot of likes and dislikes (a whole bunch of the latter!).

Now, finally, I am building a place for myself. The reasons? 1). I?m
sick of traveling around. 2). I would like to work in a place where I
have everything I need, the equipment of my choice. 3). One of my main
hates ? ?gotta finish this project ?coz we?ve must be out of this
studio in 2 weeks?. 4). I would like to create an environment where
artists (and me) feel at home, a place that inspires creativity.

The building:
Starting with one of my dislikes. Most studios, especially those build
in the last 20 years, have been build to a set of defined design
principles. Nothing wrong with that, especially when it comes to
control rooms. A dead end ? live end room build to set principles of
delay, diffusion and absorbsion works ? often, not always (surround
sound requires a re-think there). But, tracking rooms?.., these used
to be BIG. Often just because more people used to play live in a
studio, and there were a bunch of recording with real orchestras. Any
of you who have ever recorded in a big tracking room (if it was a good
one), will know that it simply is the most wonderful way to record.
Want it to sound smaller? Use some baffles. Want it bigger sounding?
baffles gone and your room mikes sound wonderful. The difference?
natural sound which is pleasing and easy on the ears. Now most
tracking rooms are small, dead and horrible. Hey! we can add anything
you like artificially!!
So, my priority was to find a building with plenty of space,
especially with plenty of height, in which we could get the sounds we
wanted by good microphone placement. Also, a strong preference for a
building without to many square angles, to avoid standing waves
requiring plenty of acoustic treatment. My favorite studios all have
rooms like this ? plenty of ceiling height, uneven surfaces etc. (The
Church, Manor Studio, Abbey Road, Record Plant, Island). After a long
search we found what we thought was the ideal place, a 1 acre property
with a house, a large ?Dutch barn? a smaller barn, a cottage and 2
workshop / sheds. This suited our needs 100%, it allows us to have
one large tracking room, 2 control rooms and a writer / composer room,
all linked to a central machine room.

The environment
One thing I noticed over the years. When spending long hours in a
studios, I get headaches quite often. Not a good thing if you?re
trying to be creative. First I thought it was the sound and/or the
work. But then, I didn?t get headaches if I worked at home on music
for equally long hours? So I started taking mental notes. In some
studios, like Virgin?s old Manor House in the UK, I simply never had a
headache. There were other places I worked with the same thing ? no
headache. And then there were places where I always had a headache
(sometimes it could have been the people I worked with :>). What was
the difference? Over time I managed to narrow it down to two main
features.
1)
Air. Bad air conditioning systems. They suck! Most systems do not
pull any fresh air from outside. You?re in what is basically a sealed
space with a bunch of people, breathing the same air for hours. When
it finally dawned on me that air might have something to do with
headaches and lack of energy (duh!!), I asked a friend of mine, a
professor at Loughborough University, to come and do some analyses as
a student project. The results were scary. The one place they
measured had no fresh air intake at all, the air quality was so bad
that he stated ?everyone in there should have gotten ill? The second
place was one which, so I?d been told, had a fresh air intake on the
ventilation system, but definitely a studio where I felt bad if I
spend more than 6 hours at the time. Here the air was even worse. My
friend didn?t understand this; so 2 students went back and did some
more research. The ?fresh air? intake was in the attic, where the
blower was placed. This place was quite damp, and filled with mold
and fungi. The system was therefore blowing spores around the whole
place non-stop.

2)
Having done the above, I started looking at other options. There were
many places with good ventilation, but where I still didn?t ?feel
well?. After a couple of years I found the answer, the acoustic
treatment. The more chemically manufactured products in a studio, the
worse I felt. Please note ? I didn?t just go on my own experiences.
Some research into foams, composites etc. Man! Most of that stuff has
some crap in it! The problem is that it doesn?t measure it in great
quantities; it releases ?things? over a long period of time, sometimes
for the lifespan of the product. Nice things, like formaldehyde and
such beauties. The lesser amount of such materials in a studio, the
better I felt after long days / hours. Another lesson learned.

Acoustic treatment
Now you might think that the above gave me a first class dislike of
modern acoustic treatment materials. Well, not really. Its there to
do a job, right? A chainsaw makes a rotten noise; you still use the
thing if you need to. It isn?t the above that makes me dislike foams
and composite panels to that degree, it just emphasized my dislike of
them.
What are the other reasons? In my opinion they are used too much,
sometimes the material does not need to be there in such quantities,
sometimes they are used to mask faults in design which should have
been addressed in the construction stage. Why? You might think I?m
crazy in stating this but; I think they sound REALLY BAD!
How on earth did I reach that conclusion? I have been lucky in that
from a very early age, 15 years to be precise, I started touring,
first as a musician, than as a front-of-house engineer, this in
addition to working in studios. It taught me a lot about acoustics, I
leaned to listen to rooms, from clubs to theaters, from concert halls
to sports arenas and football stadiums. In the early ?70?s, in
addition to listening, I had to add science to it and started taking
measurements, as well as listening. The reason? Quadraphonics. For
about 5 years I toured with some gigantic live quad systems. The
combination of ears and science taught me a whole lot, especially the
effect of different structures and materials on sound.
Sometime people thought I was quite mad, when for instance I pointed
short and long throw midrange horns in all sorts of weird directions,
everywhere but directed towards the audience. Until they heard the
result ? and then they really didn?t understand it anymore. I found
that, where a building had a particular strong reflective surface, one
that effected the PA?s sound in a bad way, I could use that surface to
become the main source of the sound and improve overall sound quality
and dispersion dramatically. The key lessons I learned from all this
were:
1)
Resonance, in particular resonance with some damping, is something you
can use to your advantage. Vibration on the other hand is bad.
2)
Natural materials, like wood and stone, sound infinitely better then
any ?man-made? materials.
3)
Positioning sound generating equipment ?to suit a space? is a major
factor in getting good sound.

Back to the studio
Go into almost any new(ish) studio, be it a home studio, or a
full-blown commercial one. What do you see? Man made panels, foam,
and fibers, covered in nylon or acrylic materials. These panels and
materials work, no question about it ? just look at all the test
reports and all the scientific data. Got some flutter here? This
piece of foam will suck it right out. Some standing waves? Cover the
wall with acoustic panels. But one thing seems to have been
forgotten; IT DOES NOT SOUND GOOD ANYMORE!
Then why is it used all the time? Is it cheap? In my (not so humble,
I?m an opinionated bastard) opinion it is a cheap fix, considered
difficult to screw up. Hold on, did I say cheap fix? Well, that is
another thing, cheap it is certainly not. Apart from that, think
about the effects on your health? If you want to be creative you have
to feel good!

Conclusion
If you are thinking of building a studio, whatever size it may be,
think before you build. There is a lot you can do with natural
materials, like wood, stone, slate etc. It is cheaper, stronger,
sounds better, feels better and is better for your health. Study
things like Helmholz resonators. It is so easy to put a sheet of ply
on a frame, and it does the same job as buying an expensive trap, or
covering a wall with horrible looking pieces of foam.
Need absorbsion and / or diffusion? Nothing on this planet works and
sounds as good as straw. Cloth covering? Jute / Burlap is still
unbeatable, because it is a natural, uneven fiber, we just bought the
?minimum order? quantity from an importer, 150 feet of the stuff for
$140,00, enough to do the whole studio. Use natural dyes and color it
anyway you like. Consider using tongue-and groove wood, looks good,
sounds good, the grooves get rid of flutter and standing waves if you
apply the planks in a pattern suitable to the room.
Don?t get me wrong, I?m not saying never use any modern materials,
they do their job. If you do use them, use them sparingly and with
much thought. Visit some lumber yards, stone masons and building
suppliers, look at all the natural materials available, and ask
yourself if there is an alternative to using foams and composites.
As I am building our own place, I finally had the chance to put my
money where my mouth is. We just finished doing the first sound tests
in the control room, which has timber walls, straw panels and plywood
covered resonating panels. After that, two engineers with ?good ears?
and myself went to 2 established commercial studios with renowned
control rooms and monitor systems, armed with three tracks of high
definition audio and a top DA converter, played the tracks and
returned to our new place. The difference was quite amazing, with the
new control room scoring hands down. The new room sounded clearer,
tighter, we could only describe it as more accurate, a higher
definition of what really was on the tracks.
Perhaps we need to rethink the way we use acoustic materials and the
way we build / design studio space?

Hope you find the above usefull, comments welcome, and remember, I
told you I?m an opinionated bastard. Comments welcome :>)

[archive]

From: Douglas_E._Haeussler@f...
Date: Mon Mar 5, 2001 9:09 pm
Subject: Re: [acoustics] A re-think on acoustics - long posting

Hello Sjoerd, been noticing your posts. Very thoughtful insights. Question
- where, on the 'net, can pictures of your studio be found?

Thanks,
Doug Haeussler
Rohnert Park, CA USA

[archive]

From: sjoerd@n...
Date: Mon Mar 5, 2001 11:51 pm
Subject: Re: A re-think on acoustics - long posting

--- In acoustics@y..., Douglas_E._Haeussler@f... wrote:
>
> Hello Sjoerd, been noticing your posts. Very thoughtful insights.
Question
> - where, on the 'net, can pictures of your studio be found?
>
> Thanks,
> Doug Haeussler
> Rohnert Park, CA USA

Hey Douglas, pics can be found on John Sayers website (Australian
engineer / producer / studio designer of some repute) Very worthwhile
to browse around his site!! Address is:
www.lis.net.au/~johnsay/Acoustics
I'll update the pictures with some new ones showing progress later
this week.

[archive]

From: Douglas_E._Haeussler@f...
Date: Tue Mar 6, 2001 4:05 pm
Subject: Re: [acoustics] Re: A re-think on acoustics - long posting

Thanks, Sjoerd. I'll take a look...
PS, I forgot to ask in my last post... what publication are you going to
have your article appear? I'd like to pick up a copy.

Regards,
Doug Haeussler
Rohnert Park, CA USA

Hello Sjoerd, been noticing your posts. Very thoughtful insights.
Question
> - where, on the 'net, can pictures of your studio be found?
>
> Thanks,
> Doug Haeussler
> Rohnert Park, CA USA

Hey Douglas, pics can be found on John Sayers website (Australian
engineer / producer / studio designer of some repute) Very worthwhile
to browse around his site!! Address is:
www.lis.net.au/~johnsay/Acoustics
I'll update the pictures with some new ones showing progress later
this week.

[archive]

From: SRF7@a...
Date: Tue Mar 6, 2001 6:09 pm
Subject: Re: [acoustics] A re-think on acoustics - long posting

In a message dated 3/4/01 6:26:57 PM Eastern Standard Time,
sjoerd@n... writes:

> Some of you may have seen some pictures of the studio I am building at
> the moment

Yeah sure .. blah blah blah .... tell us more about the Babe in the pics ...
if she were President she'd be Babeham Lincoln.

snip

>
> But, tracking rooms?.., these used
> to be BIG.

Oh alright .. lets talk studiotips ... couldn't agree more. Big is
beautiful, I once renovated an old 1920's theater into a night club and in a
perfect world that place would be my studio ... wood stage with brick wall
behind, 50' high stage fly, massive plaster presidium, sloped stage wings,
30' high ceilings, sloped floors, a small mezzanine with full width loge, 30'
x 20' projection booth / control room .... would have been great.

That room sounded wonderful. You could put a cheap boom box on center stage
and fill the room with sweet sounding music. Of course doing this on a
small scale is impossible but the lesson is "build as big a tracking room as
you can", for me this was a 27' x 20' room with 10' walls vaulting to a 12.5'
ceiling ... not the same but workable.

Your tracking room looks sweeeeeet .. those barn height ceilings should make
for great drum recording.

>
> Now most
> tracking rooms are small, dead and horrible. Hey! we can add anything
> you like artificially!!
>

The more you think about this trend ... the stupider it is.

"We saved money on the room so we could buy crappy black boxes that put back
later (after you leave) the room sound that should have been there in the
first place (but wasn't)."

Boy that's sure to motivate the artist to give the performance of a lifetime.

>
> Most systems do not pull any fresh air from outside.

I'm having a real problem with this ... I end up opening the front door and
turning the bathroom fan on every chance I get. I'm going to have to bring
my HVAC man back and install an air exchanger ... fortuneately the mechanical
closet has a wall common with the exterior so this shouldn't be too big a
deal ... but this one could be a real pain in the ass for some to retrofit
... good idea to do it up front.

> for the lifespan of the product. Nice things, like formaldehyde and
> such beauties. The lesser amount of such materials in a studio, the
> better I felt after long days / hours. Another lesson learned.

This is a great reason to stay away from foam products altogether ... also,
considering that fiberglass is cheap, non-volitile, easy to work with (though
a bit scratchy) and inert (rats and roaches don't chew on it or live in it,
and it won't rot) I figure its the way to go when you have to add absorbant
material. That said, you can get a lot sound sucking from a pair of comfy
couchs ... or a pile of hay bales if you're in a barn ;-]

>
> 1)
> Resonance, in particular resonance with some damping, is something you
> can use to your advantage. Vibration on the other hand is bad.

True ... just keep in mind that even while resonation would diminishes the
level of reverb for the sympathetic frequencies it can make them more
persistent.

2)

> Natural materials, like wood and stone, sound infinitely better then
> any ?man-made? materials.

I dunno about this one ... aesthetically I can see your point, but
acousticly???

For instance, concrete or plaster (man made) can make up the major surfaces
of a room that sounds great and I think it'd be hard to hear the difference
between a split face concrete block wall and a stone wall (though the later
might look better it would cost ten times as much). I would agree strongly
that natural materials help create a pleasent environment, and that we should
all think outside the box when it comes to designing our acoustic spaces ...
making them pleasing to look at enhances the experience.

> 3)
> Positioning sound generating equipment ?to suit a space? is a major
> factor in getting good sound.
>
>

Didn't they nail the mic stands to the floor at the Motown studio once they
found the "sweet spot"?

> Go into almost any new(ish) studio, be it a home studio, or a
> full-blown commercial one. What do you see? Man made panels, foam,
> and fibers, covered in nylon or acrylic materials. These panels and
> materials work, no question about it ? just look at all the test
> reports and all the scientific data. Got some flutter here? This
> piece of foam will suck it right out. Some standing waves? Cover the
> wall with acoustic panels. But one thing seems to have been
> forgotten; IT DOES NOT SOUND GOOD ANYMORE!
> Then why is it used all the time? Is it cheap? In my (not so humble,
> I?m an opinionated bastard) opinion it is a cheap fix, considered
> difficult to screw up. Hold on, did I say cheap fix? Well, that is
> another thing, cheap it is certainly not. Apart from that, think
> about the effects on your health? If you want to be creative you have
> to feel good!
>

I used a number of 703 squares that I covered with black burlap .. I can't
say they look great, but they were cheap ... they are also fairly inocuous
and inert ... I wanted something cheap and easy to break up the reflections
off the cc block walls and that's what I got. In long run, I hope to furr
off the cc block and put in a finished wall system ... I like the idea of the
resonate panels mounted on welding rods concept you described in a prior
post. If one used stained hardwood veneer panels such a wall system could be
both practical and beautiful (and natural for that matter ... well sorta, is
plywood a natural material?).

>
> Cloth covering? Jute / Burlap is still
> unbeatable, because it is a natural, uneven fiber, we just bought the
> ?minimum order? quantity from an importer, 150 feet of the stuff for
> $140,00, enough to do the whole studio. Use natural dyes and color it
> anyway you like.
>

Yep this is what I used (black burlap ... don't know about the dye's
naturalness but it is black ... didn't smell chemical anyway). Bought it at
a discount cloth store by the 48" bolt ... 40 yards was about $50 I dimly
recall ($1.15 per yard?).

Good Luck

Scott R. Foster

[archive]

From: BASSMANCP@A...
Date: Tue Mar 6, 2001 6:33 pm
Subject: Re: [acoustics] A re-think on acoustics - long posting

In a message dated 3/6/01 1:12:28 PM Eastern Standard Time, SRF7@a...
writes:

<<
I dunno about this one ... aesthetically I can see your point, but
acousticly???

For instance, concrete or plaster (man made) can make up the major surfaces
of a room that sounds great and I think it'd be hard to hear the difference
between a split face concrete block wall and a stone wall (though the later
might look better it would cost ten times as much). I would agree strongly
that natural materials help create a pleasent environment, and that we
should
all think outside the box when it comes to designing our acoustic spaces ...
making them pleasing to look at enhances the experience.
>>

Phillip Newell discusses how to get "tuned" (my term not his)
refraction from cement blocks and stone. He shows how to get
different refraction qualities by using different block and stone
laying and pointing techniques. "Recording Spaces" and "Project
Studios: A More Professional Approach" both give a good insight
to using these natural materials. There are big differences in the
sound of a block wall vs. a stone wall and you can't deeply point
plaster.

Chris Preston

[archive]

From: SRF7@a...
Date: Tue Mar 6, 2001 8:20 pm
Subject: Re: [acoustics] A re-think on acoustics - long posting

In a message dated 3/6/01 1:36:11 PM Eastern Standard Time, BASSMANCP@A...
writes:

> Phillip Newell discusses how to get "tuned" (my term not his)
> refraction from cement blocks and stone. He shows how to get
> different refraction qualities by using different block and stone
> laying and pointing techniques. "Recording Spaces" and "Project
> Studios: A More Professional Approach" both give a good insight
> to using these natural materials.

Interesting ... I'd like to take a look at that. I once laid out a design
for a brick wall in a primitive root sequence thinking about making it
"diffusive" ... but the lack of well walls made me wonder about its
effectiveness.

On the same lines, there is also a product line out there called
"acoustablock" or something similar that is meant to be laid out in a
quadratic pattern to achieve diffusion, and also has slots to create large
scale Helmholtz arrays.

There are big differences in the

> sound of a block wall vs. a stone wall and you can't deeply point
> plaster.
>
> Chris Preston

Yep. very large ... or none at all ... depends on the type of stone, how it
is laid, vs. the texture of the block, how the block is laid, and what
coating (if any) you put on the block.

Obviously unpainted cc block has lots of holes in it thus the reletively high
LF Sabine numbers ... but so does limestone. A split face block has a highly
irregular surface and lots of small holes, but so does coquina. A flag
stone, or similar smooth stone will as you point out (pardon the pun)
generally not have these qualities (many small holes and large surface
irregularity) but could be set with a raked joint or a weeping joint which
would yield a fairly irregular surface.

This could easily be reproduced (acousticly) with masonry and/or plaster. In
fact it is done all the time ... imitation stone walls are made out of out
of layers of different colored plaster (stucco) cut with a tool to the shape
of a raked joint. S'true you don't "point" plaster, but as far as shape goes
plaster is unbound ... people have been using plaster to make virtually
anything you can imagine as far as surfaces on walls and ceilngs for ages
(including things like heavy crown mouldings, medallions, column wraps that
make it look like naked men are holding up the roof and the vast range of
plaster textured ceiling / wall treatments from stalagtites to crow's feet to
double knock down).

My point is simply that "natural" stone is not intrinsicly superior to "man
made" cementicious products ... it just often looks better.

Scott R. Foster

[archive]

From: sjoerd@n...
Date: Tue Mar 6, 2001 8:59 pm
Subject: Re: A re-think on acoustics - long posting

--- In acoustics@y..., BASSMANCP@A... wrote:
> In a message dated 3/6/01 1:12:28 PM Eastern Standard Time, SRF7@a...
> writes:
>
> <<
> I dunno about this one ... aesthetically I can see your point, but
> acousticly???
>
> For instance, concrete or plaster (man made) can make up the major
surfaces
> of a room that sounds great and I think it'd be hard to hear the
difference
> between a split face concrete block wall and a stone wall (though
the later
> might look better it would cost ten times as much). I would agree
strongly
> that natural materials help create a pleasent environment, and that we
> should
> all think outside the box when it comes to designing our acoustic
spaces ...
> making them pleasing to look at enhances the experience.

> Chris Preston

Chris, there is a HUGE difference between stone and concrete block
walls, it is really not possible to put them in the same bracket, or
even compare them. The uneven shape and high density of stone creates
an acoustic ambiance which avoids problems (like standing waves,
flutter etc.), and makes for a "big sounding" room. Therefore it is
often refered to as the best kind of room to record acoustic
instruments and drums / percussion. A good example can be found on
www.thebreenagency.com/stuj/htm
Concrete block is not something I would personally see as a preferred
acoustic treatment. An outer wall, yes. An inner wall - maybe, but
then only with a lot af caution. Writing this I just realised that # 1
to 6 of the most expensive to fix problems I have encountered in my
time troubleshooting studios were problems caused by concrete block
(cracks, sand leakage, vibration etc.)
As a side note, if anyone uses concrete block for any studio wall,
inside or out, don't use normal mortar. Plasticized mortar works, even
better is mixing sand with a 2:1 cement - lime mix. The same goes for
a stone wall, it avoids cracks.

[archive]

From: BASSMANCP@A...
Date: Tue Mar 6, 2001 10:18 pm
Subject: Re: [acoustics] Re: A re-think on acoustics - long posting

In a message dated 3/6/01 4:02:30 PM Eastern Standard Time,
sjoerd@n... writes:

--- In acoustics@y..., BASSMANCP@A... wrote: No he didn't ;-)
> In a message dated 3/6/01 1:12:28 PM Eastern Standard Time, SRF7@a...
> writes:
>
> <<
> I dunno about this one ... aesthetically I can see your point, but
> acousticly???
>
> For instance, concrete or plaster (man made) can make up the major
surfaces
> of a room that sounds great and I think it'd be hard to hear the
difference
> between a split face concrete block wall and a stone wall (though
the later
> might look better it would cost ten times as much). I would agree
strongly
> that natural materials help create a pleasent environment, and that we
> should
> all think outside the box when it comes to designing our acoustic
spaces ...
> making them pleasing to look at enhances the experience
<<
Chris, there is a HUGE difference between stone and concrete block
walls, it is really not possible to put them in the same bracket, or
even compare them. The uneven shape and high density of stone creates
an acoustic ambiance which avoids problems (like standing waves,
flutter etc.), and makes for a "big sounding" room. Therefore it is
often refered to as the best kind of room to record acoustic
instruments and drums / percussion. A good example can be found on
www.thebreenagency.com/stuj/htm
Concrete block is not something I would personally see as a preferred
acoustic treatment. An outer wall, yes. An inner wall - maybe, but
then only with a lot af caution. Writing this I just realised that # 1
to 6 of the most expensive to fix problems I have encountered in my
time troubleshooting studios were problems caused by concrete block
(cracks, sand leakage, vibration etc.)
As a side note, if anyone uses concrete block for any studio wall,
inside or out, don't use normal mortar. Plasticized mortar works, even
better is mixing sand with a 2:1 cement - lime mix. The same goes for
a stone wall, it avoids cracks.
>>

That was not me who wrote that, I replied to the above statement.
I recommended Phillip Newells books that have a good explanation
of the very real differences in block and stone. Incidentally, cement block
that is made for acoustic absorption (the kind with the slots in it and
the inside filled with Fiberglass) is excellent in smaller rooms. I have
used this in smaller spaces, usually on one wall with very pleasing
acoustic results. It lays up just like regular block, but it is less dense
and more porous. I have used both stone and block in all different
kinds on ways and they all sound different, but you can use them to
your advantage in almost any situation.

Chris Preston: The guy who didn't write that ;o)

[archive]

From: SRF7@a...
Date: Wed Mar 7, 2001 12:25 am
Subject: Re: [acoustics] Re: A re-think on acoustics - long posting

In a message dated 3/6/01 4:02:26 PM Eastern Standard Time,
sjoerd@n... writes:

Don't blame Chris ... he also disagrees ... this was from my post.

> Chris, there is a HUGE difference between stone and concrete block
> walls, it is really not possible to put them in the same bracket, or
> even compare them.

I disagree .. cc block can (and is) installed in ways very similar to stone.

>The uneven shape and high density of stone creates an acoustic ambiance
which avoids problems (like standing waves,
flutter etc.), and makes for a "big sounding" room. Therefore it is
often refered to as the best kind of room to record acoustic
instruments and drums / percussion.

Grout filled cc block has a HUGE density ...upwards of 80 lbs. per SF... I
used this method in my studio and a 1,000 watt bass rig can't make it wiggle
.... we're talking 8"s thick of pure rock (albeit manmade rock) ... slap
plaster on it and you are well over 100 lbs. per sf.

As to surface irregularity, split face block has a highly irregular surface
... equal to anything vaguely stone wallish in terms of irregularity (short
just dumping rocks in a pile with no grout). For that matter you could just
set painted block or brick in an irregular pattern (like quoin corners but
different).

As to Sabine numbers

MATERIAL SABINS/Sq FOOT AT (Hz) 125 250 500 1k
2k 4k Avg.

PLASTER ON LATHING 2 2 3 4
4 3 0.03
HOLLOW CINDER BLOCK, UNPAINTED 36 44 31 29 29
25 0.32
HOLLOW CINDER BLOCK, PAINTED 10 5 6 7
9 8 0.08
CONCRETE/MARBLE FLOORS 1 1 1 2
2 2 0.02
CONCRETE/STONE WALLS 2 2 2 3
4 4 0.03

Hard to say what style block or variety of stone are represented here (I got
most of these from Everest), but obviously generic hollow cc block is
slightly more absorbent than the generic stone chosen for sampling ... grout
filled cc block would be stiffer - more reflective ... if you wanted even
more reflection, this could be diminished more with another coat of paint or
even plaster. It appears cc block also has a flatter Sabine curve and is
tilted more to to LF damping than stone, but these numbers are so small
material choices elsewhere in the room could easily compensate (put a 5x9
oriental rug on the floor to pick up more HF for example).

> A good example can be found onwww.thebreenagency.com/stuj/htm

That is one cool looking room.

> Concrete block is not something I would personally see as a preferred
> acoustic treatment.

Well I'd prefer cypress paneling and marble floors with Persian rugs .. but
you know how it goes.

> An outer wall, yes. An inner wall - maybe, butthen only with a lot af
> caution. Writing this I just realised that # 1
> to 6 of the most expensive to fix problems I have encountered in my
> time troubleshooting studios were problems caused by concrete block
> (cracks, sand leakage, vibration etc.)
> As a side note, if anyone uses concrete block for any studio wall,
> inside or out, don't use normal mortar. Plasticized mortar works, even
> better is mixing sand with a 2:1 cement - lime mix. The same goes for
> a stone wall, it avoids cracks.
>
>

Bad motar, or poor masonry could be a real problem ... I'm glad I was there
when my walls went up to ask that the mason make sure he overfilled all the
joints .. but this would apply for either material.

I would never sand fill or pearlite fill a cc block wall (drill a hole or get
a crack and the stuff runs out), but pumping grout is a different matter ..
you end up with a solid heavy wall.

Scott R. Foster

[archive]

From: BASSMANCP@A...
Date: Wed Mar 7, 2001 12:47 am
Subject: Re: [acoustics] Re: A re-think on acoustics - long posting

In a message dated 3/6/01 7:27:35 PM Eastern Standard Time, SRF7@a...
writes:

<< Hard to say what style block or variety of stone are represented here (I
got
most of these from Everest), but obviously generic hollow cc block is
slightly more absorbent than the generic stone chosen for sampling ... grout
filled cc block would be stiffer - more reflective ... if you wanted even
more reflection, this could be diminished more with another coat of paint or
even plaster. It appears cc block also has a flatter Sabine curve and is
tilted more to to LF damping than stone, but these numbers are so small
material choices elsewhere in the room could easily compensate (put a 5x9
oriental rug on the floor to pick up more HF for example).

>>

I think most people get this kind of info. from Everest. That is why
I suggested Newell's Books. He takes a different approach on why
he uses stone where he uses it. I don't think his work is definitive by
any means, but it is a different approach than most text books I've
read. His clients seem to approve.

Chris

[archive]

From: "Dave Martin" <dave.martin@n...>
Date: Wed Mar 7, 2001 1:00 am
Subject: Re: [acoustics] Re: A re-think on acoustics - long posting

From: <sjoerd@n...>
:
: Chris, there is a HUGE difference between stone and concrete block
: walls, it is really not possible to put them in the same bracket, or
: even compare them. The uneven shape and high density of stone creates
: an acoustic ambiance which avoids problems (like standing waves,
: flutter etc.), and makes for a "big sounding" room. Therefore it is
: often refered to as the best kind of room to record acoustic
: instruments and drums / percussion. A good example can be found on
: www.thebreenagency.com/stuj/htm

I didn't realize that you were talking about the Masterphonics Tracking Room
until just now. I haven't recorded there, but I remember that the first
drummer to use the stone room when the facility originally opened, Milton
Sledge, said that it was the worst sounding drum room he'd ever been in (and
this is a guy who's been on a bunch of records, including all of the Garth
Brooks albums).It just goes to show that different guys have different
tastes...

Dave Martin
DMA, Inc.
Nashville, TN

[archive]

From: "Danny Stinnett" <danny@p...>
Date: Wed Mar 7, 2001 2:18 am
Subject: Re: [acoustics] Re: A re-think on acoustics - long posting

Hi, Question folks... I have seen some walls where you basically have
flagstone applied, in a mortar type base. Will this give the acoustic
benefits?? I would still have a double wall behind it for the actual
soundproofing. Danny

[archive]

From: sjoerd@n...
Date: Wed Mar 7, 2001 2:47 am
Subject: Re: A re-think on acoustics - long posting

--- In acoustics@y..., "Dave Martin" <dave.martin@n...> wrote:
> From: <sjoerd@n...>

> I didn't realize that you were talking about the Masterphonics
Tracking Room
> until just now. I haven't recorded there, but I remember that the first
> drummer to use the stone room when the facility originally opened,
Milton
> Sledge, said that it was the worst sounding drum room he'd ever been
in (and
> this is a guy who's been on a bunch of records, including all of the
Garth
> Brooks albums).It just goes to show that different guys have different
> tastes...
>
> Dave Martin
> DMA, Inc.
> Nashville, TN

Yup right! I know quite a lot of rooms like that in Europe, the MF
one was just one that came to mind in the US. I have heard both good
and bad things about it. Personally I think its a bit of overkill on
the stone (to much of a good thing.....)
The best sounding stone room I have recorded in was not a studio, but
Lindesfarne Castle in the UK.

[archive]

From: sjoerd@n...
Date: Wed Mar 7, 2001 9:18 am
Subject: Re: A re-think on acoustics - long posting

> Chris Preston: The guy who didn't write that ;o)

*grin* totally forgiven :>)))))

[archive]

From: sjoerd@n...
Date: Wed Mar 7, 2001 9:22 am
Subject: Re: A re-think on acoustics - long posting

> Don't blame Chris ... he also disagrees ... this was from my post.

> I would never sand fill or pearlite fill a cc block wall (drill a
hole or get
> a crack and the stuff runs out), but pumping grout is a different
matter ..
> you end up with a solid heavy wall.
>
>
> Scott R. Foster
>
I don't blaim Chris, I don't I don't honestly I don't!!! :>))))
Grout works wonderfull. Unfortunately in the '70's people seemed to
love filling the bloody things with sand.

[archive]

From: sjoerd@n...
Date: Wed Mar 7, 2001 9:26 am
Subject: Re: A re-think on acoustics - long posting

--- In acoustics@y..., "Danny Stinnett" <danny@p...> wrote:
> Hi, Question folks... I have seen some walls where you basically have
> flagstone applied, in a mortar type base. Will this give the acoustic
> benefits?? I would still have a double wall behind it for the actual
> soundproofing. Danny

To be honest Danny, I've never used flagstone. I did use slate once
on a wall, and that was a bit of a disaster. It might be a bit to
flat and cause reflections - like the slate wall I build for someone
and had to take down again (at my own expense grrrrrrrrr)
Scott?

[archive]

From: "Billy Teichmiller" <b.teichmiller@w...>
Date: Wed Mar 7, 2001 2:51 pm
Subject: Re: [acoustics] Re: A re-think on acoustics - long posting

I worked a session at Jeff Cook's studio and played the house drum set that
Milton had tuned in the mid 80s. The toms and snare sounded great in the
little drum booth but the kick had no depth. The young man eng kept telling
me to hit it harder and I was coming off the stool already. I don't think it
was Miltons fault he was working with a single ply batter head and a throw
pillow that would have worked in a large tracking room but in a small booth
the sound has to come off the drum it self. They should have used a 2 ply
head and muffled close to the rim to help bring out the fundamental pitch,
and the young fellow engineering didn't understand cutting in the mid range
to get rid of the boxy sound.
Billy T.

the first
> drummer to use the stone room when the facility originally opened, Milton
> Sledge, said that it was the worst sounding drum room he'd ever been in
(and
> this is a guy who's been on a bunch of records, including all of the Garth
> Brooks albums).It just goes to show that different guys have different
> tastes...
>
> Dave Martin
> DMA, Inc.
> Nashville, TN

[archive]

From: SRF7@a...
Date: Wed Mar 7, 2001 3:35 pm
Subject: Re: [acoustics] Re: A re-think on acoustics - long posting

In a message dated 3/6/01 7:49:56 PM Eastern Standard Time, BASSMANCP@A...
writes:

> I think most people get this kind of info. from Everest. That is why
> I suggested Newell's Books. He takes a different approach on why
> he uses stone where he uses it. I don't think his work is definitive by
> any means, but it is a different approach than most text books I've
> read. His clients seem to approve.
>
> Chris

I shouldn't credit / blame Everest for all of the data in my Sabine
worksheet... some came from Doug's site, some from a University in Australia,
and the data in my last post from Malcolm Chisolm's site

<A HREF="http://www.mcs.net/~malcolm/">http://www.mcs.net/~malcolm/</A>

In any event I'd be interested in learning about a different approach to the
question ... maybe I'' pick up one of newell's books.

Scott R. Foster

[archive]

From: BASSMANCP@A...
Date: Wed Mar 7, 2001 3:52 pm
Subject: Re: [acoustics] Re: A re-think on acoustics - long posting

In a message dated 3/7/01 10:36:35 AM Eastern Standard Time, SRF7@a...
writes:

<< I shouldn't credit / blame Everest for all of the data in my Sabine
worksheet... some came from Doug's site, some from a University in
Australia,
and the data in my last post from Malcolm Chisolm's site

<A HREF="http://www.mcs.net/~malcolm/">http://www.mcs.net/~malcolm/</A>

In any event I'd be interested in learning about a different approach to the
question ... maybe I'' pick up one of newell's books.

Scott R. Foster
>>

I certain don't mean to diminish any of Everest's work, I hope
I didn't give that impression. I have read all his books including
now the latest "Acoustics" Ed. He is definitely one of "the"
authorities. He also makes his knowledge accessible to people
who may not have a huge background in math (as opposed to
someone like Olson). I thought Newell's books were along the
same accessible lines. Definitely worth the cost.

Cheers
Chris