The objective of performing the
MATT test in your listening room is to determine where you
might move your speakers, listening position, and/or where
to add acoustic treatment to your room to obtain the highest
quality sound possible from the components in your listening
environment. This is done by recording the playback of a carefully
selected set of tones designed to evaluate the way in which
a loudspeaker system operates relative to its surroundings.
ASC MATT Test Analysis
For a modest fee ($50 + $25 per test),
ASC will analyze your MATT Test data and make suggestions
to help you deal with acoustic weaknesses in your
room. You provide us with a recording of the MATT
Test in your room and we'll take it from there. The
MATT signal is available on the Stereophile Test CD
2 (track 19) and on the PROSONUS Studio Reference
Disc (track 50). Or, download the
Mp3 file and burn it to a CD. To save the file
to your computer, right-click (Windows) or control-click
(Mac), then choose the save option. The diagram below
illustrates a typical MATT test set-up.
No gain control or equalization
should be used.
Use an omni-directional microphone
with a flat frequency response and place at the
listening position.
Do not stand behind or near the
microphone. It needs to be out in the open.
Record onto a cassette or DAT
recorder.
Label the tape before it is sent
to ASC for processing. A sketch showing the test
set-up would also be helpful.
Do You Need a MATT
Test?
Presented here is an informal
sample of the full MATT Test. For this particular test,
we have produced a .wav file that is similar to the first
third of the MATT test (available on Stereophile Test CD
2) to be used simply as a qualitative indicator of general
acoustic problems.
Stereophile reviewed the MATT Test in an article
called "Room Tuning: ASC TubeTraps & the MATT Test"
By Brian Damkroger • February, 2000. Check
it out here
Click HERE
to download the M.A.T.T. Test sound file in .mp3 format. (1700k)
How to begin the test:
First, audition the test through a pair
of headphones. You will hear a clear sequence of tones.
This is indicative of an ideal acoustic listening room where
all tones are distinct and articulate.
Now, repeat the test. This time send the
signal through your loudspeaker system and listen from your
usual listening position. You may be surprised at how unintelligible
an audio playback system can appear using this test.
Evaluating the sound:
During the playback of the test, you will
notice two types of sounds: clear articulate tone pulses "tat,
tat, tat" and garbled passages "buddula buddula
buddula". After listening to the test a few times you
should be able to easily identify the differences in sound
as the test progresses. When you feel ready, make a list of
the approximate track times during which garbled signals occurred.
Then, refer to the graph below to determine what frequencies
correspond to the times you noted. This will provide you with
an idea of any acoustic weaknesses within your room.
If you're not comfortable with your ears'
ability to hear the difference, purchase a simple sound level
meter to help you visualize the sound. You can get a fairly
good sound level meter from Radio Shack for under $40. Set
the weighting to "C scale" and "Fast"
acquisition. Be sure to adjust gain and volume levels so the
display does not peg the meter. First, hold the meter close
to one of the speakers and play the test. You should see the
indicator needle vibrate rapidly back and forth as it follows
the tone burst sequence. Next, move back to the listening
position and play the test again. Note that during inarticulate,
garbled passages the needle barely quivers unlike when it
was close to the speaker. This is a visual representation
of the difference between articulate and inarticulate sound
in your space.
What does the test tell me?
The MATT test provides two pieces of information:
how loud the sound is and how articulate the sound is. The
maximum readout on the sound level meter during a tone burst
is an indication, in decibels, of how loud your system is
at that frequency. The difference in readout between the highest
and lowest swing of the needle during a tone burst tells us
how articulate the sound is at that frequency. Generally speaking,
you can follow the following table to determine how articulate
your sound is at various frequencies.
15dB swing - excellent
10dB swing - good
5 dB swing - fair
3 dB swing - poor
1 db swing - bad
Examining your system's articulation levels
can help you determine whether or not acoustic treatment is
necessary. As a first level of treatment, try adjusting your
speakers or listening position and see if there is any improvement.
Also, try out your own "home-made" acoustic treatments
if you are so inclined. If, after you've experimented with
these level of treatments, you still notice a lack of articulation
in some frequency ranges, give us a call (1-800-ASC-TUBE)
and we can help you determine the best acoustic treatment
for your particular problem(s).
