MOTM

I've been testing out my studio to see what acoustic treatments I need to
do. I don't have a Real Time Analyzer (RTA) so the next best thing is to
use a Radio Shack sound pressure meter and a bunch of test tones to figure
out the frequency response of the room. To make this easier for myself
(because by nature, I'm lazy), I wanted a track that would contain the test
tones needed and a simple announcement of the next frequency. I could list
the frequencies in a spreadsheet and record the values from the meter,
change something in the room or on the monitoring system and repeat the
process.

I sat down with SayIt from AnalogX and SoundForge and created a file with a
series of 10 second sine waves spaced from 10Hz to 20KHz with synthesized
announcements of each frequency. SayIt provided the announcements and
SoundForge allows you to synthesize a waveform with a specified frequency
and duration. Analog warmth was *not* desired here. I tended to bunch up
the frequencies in the low end around 100Hz since that seems to be where
there are lots of problems in studios. The test runs about 6 minutes and
change.

You can find these files at:

http://www.alt-mode.com/noise/TestTones.aif
http://www.alt-mode.com/noise/TestTones.wav
http://www.alt-mode.com/noise/TestTones.mp3

Note: The sine waves in these files are 0db Full Scale. In other words
LOUD! Since these cover the full spectrum, please be careful. I'm not
responsible for any damage to hearing, equipment, speakers, small animals,
or bodily functions!

The .wav and .aif files are 35MB and the .mp3 file is 6.3MB. I haven't
done any analysis to see if the .mp3 file is too lossy but I wouldn't use
it for critical testing.

Enjoy and let me know if this was useful for you. I've found some really
interesting problems with my room! Now I just have to figure out how to
handle them...

Eric

Man Eric - it sounds like you have a lot of time on your hands! Your
very lucky.

I really would just go beg, borrow or steal a RTA and do it in one
shot - also note: that room (or concert hall) analysis is most often
done with pink noise - not sine waves -so I don't necessarily know
where your going with that ?!?!

Also - you are already in possession of the finest piece of audio
test-gear that is know to mankind - and they are resting on both
sides of your head!

Acoustics appears to be a relatively misunderstood topic and many
folks go to great lengths for it only to find that they'not pleased
with the results.

I'd go hang out at a pro-studio and/or try and talk to guys who've
done this before - it will seriously cut down on the BS and get you
moving ahead quicker - unless, of course you're looking into
designing studios and soundrooms, etc...

Acoustics is (are) a tricky thing to fathom, especially when you're
dealing with a per-existing space - not one especially designed
for 'acoustics'.

People who can do this fairly well get the big bucks for it. Which
says once again - its a pretty eloborate topic for most folks to
apply effectively - unless you dig in a read yer hinny off - which is
a rather inexpensive - and in the long run valuable - way to go!

Best of luck - "Buck them standing waves!" (these are bad things)

Rog

Roger,

Actually, this didn't take much time at all. The file took maybe 20
minutes to generate and it confirmed what I was hearing so I could better
determine what changes to make. I thought about renting an RTA but this
seemed easier and yes, I know pink noise gets it all done at once but you
can certainly hear what is going on when you take it a few frequencies at a
time!

I've tried to gather as much as I can from folks and I have found lots of
BS. One of the things I found is that most of the mathematical solutions
don't work unless you can model things to the Nth degree. I downloaded a
room mode calculator from the web that covered the first several room
modes. I entered my room dimensions in and the modes it came back with
didn't match what my ears were hearing or what my tests were showing! Once
you start loading a room with equipment, and modular synths get pretty big,
any formulas based on just the walls of the room will start to break down.

Eric

From - Eric:
I've tried to gather as much as I can from folks and I have found
lots of BS. One of the things I found is that most of the
mathematical solutions don't work unless you can model things to the
Nth degree. I downloaded a room mode calculator from the web that
covered the first several room modes. I entered my room dimensions in
and the modes it came back with didn't match what my ears were
hearing or what my tests were showing! Once you start loading a room
with equipment, and modular synths get pretty big, any formulas based
on just the walls of the room will start to break down.


Eric,

It sounds like you've already realized what I was getting at! Then
you're well ahead of the game. And I didn't mean to imply anything
less than helpful. And you are absolutely correct about the math
formulas, etc...which is one of the biggest reasons (I think) that
the "acoustical sciences" are rather misunderstood. Those freakin
formulas are scary - even if you CAN determine what the coefficients
are! And every little stupid mass that gets put in the room, whether
reflective or absorbent, throws the formulas out the window which is
why I've never felt the need to really use them!

Yes I find math to be over-rated! There I said it - and I suffered
through a LOT of it at engineering school. Did pretty well with it
at the time - but it doesn't really help me do anything artistically
speaking, yet it does seem to come in handy for some aspects
of 'synth module design', etc - so you can't escape it!

My studio, though not specifically 'designed' to be a studio
acoustically speaking, sounds pretty darn good, yet I know that it
tends to emphasize the bass freqs more and I just have to roll-off
the lows when 'mastering'- which I am no expert in. What I've found
though, and which works quite successfully is the use of 'nearfield
speakers' - the whole point of which is do not have to worry about
room acoustics - easy enough! I've got 2 pairs of DynAudios that I
bought (when I still had money...), and they are quite heavenly.

Yet as I have only recently (last 2-3 years) gotten 'serious' about
mixing/producing/mastering and now have the tools to tinker, I'm
still lightyears away from having the 'Bernie Grundman' magic ears -
these guys get paid amazingly to do what they do and mastering is
probably the most 'mystical' of the production phases - yet can turn
things into gold or better yet platinum! And that is reason alone to
dig in and just learn as much as you can from wherever you can!

Its quite an artform I feel - very little science - and the better
you get at becoming friends with, and can identify, frequencies/or
freq bands - the closer you get to having magic ears I believe. I am
finding this to be true - after banging my head against the walls for
years wondering what the hells all this 'compression' about, and why
can't I hear it change when I turn the little knobs!

(note: it is fairly well known and documented that we humans lose
some degree of freq response with age - what is lesser known, is that
we also lose our ability to perceive relative loudnesses - hence my
compression impairment.)

These are only my opinions, however, and I am very lucky, as I have a
lot of friends in the biz who I talk 'tech' with and am learning
SOOOOOO much at a mad rate I sometimes think my heads gonna fall off -

But these are a few of the pleasures I've found which give me good
reason to do this "whole music thing" for the rest of eternity!

It's just one huge, endless game - with amazing perks -and the end
results (most of them) are things that this planet really needs.

And this whole synth DIY thing - is yet another little microcosm
within - that is an absolute riot too.

Its funny cause when I was first getting into the whole MIDI thing,
back at the time whenit was still just a new thing, I used to get
frustrated and say "Geez you gotta be a freakin engineer to
understand this stuff!" and oddly enough, I already was!

The point being is that my BSEE didn't really help too much with
these artistic, yet rather 'technical' things. (I didn't go to get my
BSEE for musical reasons - at least thats what I told my folks who
were growing rather thin on patience with my 'musical endeavors')

But every little bit helps - huh?

Onward Acoustic Solder!

Rog

On Oct 27, 2003, at 10:09 AM, Chris Walcott wrote:

> Another thing to check out is the recording.org forum on acoustics.
> One thing I learned is that no amount of foam is going to work as a
> bass trap (and I wish I had figured that out before I bought 2 boxes
> of 12" foam.)

What did you end up using? I've been looking at MiniTraps from
RealTraps. The seem to have gotten decent reviews. If anyone has had
positive or negetive experience with these please speak up! Bass is a
huge problem in my little studio. When the motm hits the resonant
frequency of the room it quite literally shakes the house.

--mikes

Real Traps are highly recommended. They sell panel resonators that are literally just
2x3s, ply, and some owens corning rigid fiberglass. Stuff works wonders.

They'll also sell you bulk fiberglass that you can use to build your own bass traps, if
you are thrifty and able-bodied.

Max

--- In motm@yahoogroups.com, Mike Estee <mikest@a...> wrote:
> What did you end up using? I've been looking at MiniTraps from
> RealTraps. The seem to have gotten decent reviews. If anyone has had
> positive or negetive experience with these please speak up! Bass is a
> huge problem in my little studio. When the motm hits the resonant
> frequency of the room it quite literally shakes the house.
>
> --mikes

FFT measurements such as those provided by SmaartLive provide much more meaningful data than an RTA. Traditional Real Time Analysis shows a buildup of acoustic information over time so the knowing what to look for is important.

For easy acoustic treatment solutions the following company has done a good job of packaging a system that works in most small studios:

http://www.msr-inc.com/studiopanel.html

Ivan

At 10:26 AM 10/27/2003 -0800, Mike Estee wrote:

>On Oct 27, 2003, at 10:09 AM, Chris Walcott wrote:
>
> > Another thing to check out is the recording.org forum on acoustics.
> > One thing I learned is that no amount of foam is going to work as a
> > bass trap (and I wish I had figured that out before I bought 2 boxes
> > of 12" foam.)
>
>What did you end up using? I've been looking at MiniTraps from
>RealTraps. The seem to have gotten decent reviews. If anyone has had
>positive or negetive experience with these please speak up! Bass is a
>huge problem in my little studio. When the motm hits the resonant
>frequency of the room it quite literally shakes the house.

One thing I noticed is that the moderator for recording.org is the founder
of RealTraps.com. I don't know if there is a conflict there or not but at
least it was disclosed on the realtraps.com web site.

I am seriously thinking of getting some minitraps though. They do seem to
make more sense than the foam solutions and seem to be more "affordable".

Thanks to all for the tips and comments.

Eric

> One thing I noticed is that the moderator for recording.org is the
> founder
> of RealTraps.com. I don't know if there is a conflict there or not
> but at
> least it was disclosed on the realtraps.com web site.
>
> I am seriously thinking of getting some minitraps though. They do
> seem to
> make more sense than the foam solutions and seem to be more
> "affordable".

I too am considering them, the physics make more sense to me than
auralex foam. Auralex seems to work great for high frequency
reflections, but it doesn't do squat for low or end. I'd be curious to
hear about your first hand experiences when you do get these panels.

--mikes

sorry for the late response, been really busy and haven't been able to keep
up with all my lists.

I ended up using 12" foam from Auralex. I now wish I had done some more
research. This is what I wish I had gotten:

http://www.rpginc.com/products/modex/index.htm

- chris

> -----Original Message-----
> From: Mike Estee [mailto:mikest@...]
> Sent: Monday, October 27, 2003 10:26 AM
> To: Chris Walcott
> Cc: MOTM List
> Subject: Re: [motm] Testing your studio
>
>
> On Oct 27, 2003, at 10:09 AM, Chris Walcott wrote:
>
> > Another thing to check out is the recording.org forum on acoustics.
> > One thing I learned is that no amount of foam is going to work as a
> > bass trap (and I wish I had figured that out before I bought 2 boxes
> > of 12" foam.)
>
> What did you end up using? I've been looking at MiniTraps from
> RealTraps. The seem to have gotten decent reviews. If anyone has had
> positive or negetive experience with these please speak up! Bass is a
> huge problem in my little studio. When the motm hits the resonant
> frequency of the room it quite literally shakes the house.
>
> --mikes

Those are some pretty expensive bass traps! I ordered some MiniTraps from RealTraps.com today. I'll let you all know how it works out. I was impressed with what I have read on recording.org forum on studio and control room acoustics and had some nice email exchanges with Ethan, the head of RealTraps.com before ordering. So far, so good.

Eric

At 10:07 AM 11/3/2003 -0800, Chris Walcott wrote:

sorry for the late response, been really busy and haven't been able to keep
up with all my lists.

I ended up using 12" foam from Auralex. I now wish I had done some more
research. This is what I wish I had gotten:

http://www.rpginc.com/products/modex/index.htm

- chris

> -----Original Message-----
> From: Mike Estee [mailto:mikest@...]
> Sent: Monday, October 27, 2003 10:26 AM
> To: Chris Walcott
> Cc: MOTM List
> Subject: Re: [motm] Testing your studio
>
>
> On Oct 27, 2003, at 10:09 AM, Chris Walcott wrote:
>
> > Another thing to check out is the recording.org forum on acoustics.
> > One thing I learned is that no amount of foam is going to work as a
> > bass trap (and I wish I had figured that out before I bought 2 boxes
> > of 12" foam.)
>
> What did you end up using? I've been looking at MiniTraps from
> RealTraps. The seem to have gotten decent reviews. If anyone has had
> positive or negetive experience with these please speak up! Bass is a
> huge problem in my little studio. When the motm hits the resonant
> frequency of the room it quite literally shakes the house.
>
> --mikes