….play it first over headphones and then in your room. You hear a scale of rapid tone bursts that any HiFi system should be able to reproduce. Your system could but it can’t because the room keeps getting in the way. Then concentrate on the sound stage. It’s a mono signal and the image should stay stage center, tight and focused. But it doesn’t.
This test is a rapid gated slow sine sweep. It demonstrates the musical clarity vs frequency of the HiFi system in your room. In some ranges of sound you will hear strong rapid dynamic sound level changes while in other ranges the tone bursts blur together in reverberant chaos. You can also hear the more familiar peaks and valleys of your room. Then play it again but this time close your eyes and concentrate on the sound stage of this perfectly mono signal. In some tone ranges the image stays put; stage center, small and tight, where it belongs. But the next tone range sees the image lose focus and fluff up into a ball of fog. And yet another sees the image up and wander off, flying around the sound stage like Peter Pan.
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.
To explore the musical intelligibility and the sonic image-ability of your audio system…
How fast is your room? Most audiophiles know how loud they can play their room before it begins to breakup. Even the speakers have a breakup threshold, above which we begin to hear cone breakup and box buzz. The MATT test is an easy way to ring out your room without risking doing damage to structure or gear due to sustained power at one frequency. At lower sound levels it checks out the room acoustic part of your listening experience, sorting out clear dynamic bandwidths from blurred bandwidths.
The MATT signal is available on the Stereophile Test CD 2 (track 19). Or, download the file and burn it to a CD. File is in compressed folder and will automatically download when you click on the link.
The diagram on the right illustrates a typical MATT test set-up.
For a small fee, ASC can analyze your MATT Test results and provide a report along with recommendations for acoustic improvements. You provide us with a recording of the MATT Test in your room and we’ll take it from there.
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 CD, or email an uncompressed WAV file.
Label the tape before it is sent to ASC for processing. A sketch and photos showing the test set-up would also be helpful.
Musical Articulation Test Tones (MATT)
Musical articulation is one basic requirement that must be met by nearly every hifi and pro audio system. This test has been developed to record and display the “fast tracking” capability of the audio chain. If you listen to the test signal over headphones you will hear what the fully articulate signal really sounds like.
The graph to the right is the analysis of the test signal:
In the following diagrams, the test signal has been played and recorded at various listening positions. Figure 2 and figure 3 show how the test signal was actually received at each position. Some portions of each graph will look and sound articulate. This is recognized by sections with a wide vertical “zig-zag” pattern similar to the articulate signature of the test tape printout.
Areas of poor articulation are evidenced by sections of small amplitude zig-zag. The room slurs and garbles the sound of the discrete test tones. Make a copy of each original recording and play it over headphones while studying the printout from the same test. You will quickly learn how the variations in intelligibility as shown in the printout are really very audible.
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
The MATT Test is Designed for Critical Music Playback Environments
Mix Down Rooms
Audiophile High-End Listening Rooms
Dedicated / Custom Home Theaters
Listen to the tone scales of the MATT test, first over headphones and then in your room. The difference is astounding. Watch how your room turns musical clarity into dynamic blur and image stability into a wandering fog bank. Add acoustics and track the changes you make. Your audio system is great, it’s the room that keeps getting in the way.
MATT Test Audio Files & Audio Tutorial
Trouble getting the test signal into your stereo system? Try burning a CD using the file you just downloaded. Or, plug your laptop/phone’s output into an auxiliary stereo input. If Bluetooth connection is an option, try streaming the test signal. Still no luck? Contact us to mail you a classic CD for a small fee.
MATT Test Tutorials:
A short tutorial has been prepared to illustrate the effects that the listening room has on the perception of the MATT, an articulation test signal. Here we introduce the tutorial tape and display hard copy printouts to accompany listening to the actual signals on the tutorial tape.
Listen to audio tutorial file on using the MATT Test
The articulation test signal is a rapid series of tone bursts held steady at 8 bursts per second. The tone of each burst is different, on a sliding scale. This demo tape presents only the last half of a real test. It fades in when the tone is about 780 Hz, in the middle of the test and follows the signal down to 28 Hz, its lowest frequency. Each tone burst sequence lasts about 45 seconds. Altogether there are 6 parts to the demo tape.
The room where the tape was made is a heavy wall, 2000 sq-ft listening room, built for research and testing at the ASC factory. It has a concrete floor with sheetrock walls and ceiling. All acoustic recordings were made in a professional manner with a crossed pair of mics for stereo and placed at the listening position. The speakers were placed in a typical HiFi setup. The 6 tracks are as follows:
Lightly treated room
Well treated room
Well treated room
Accompanying each track is an introductory comment by the recording engineer that identifies the track. Here we present the printout of each test. The audio signal is passed through a dB meter circuit so the level changes associated with each burst can be tracked.
It is clear that playback articulation is a direct function of acoustic conditioning in the last link of the audio chain, the listening room.
0:07 – Original signal
The first sequence is the music articulation test recorded directly from the test oscillator.
1:01 – Lightly treated room
The next sequence is the music articulation test recorded in a room with light acoustic treatment.
1:53 – Well treated room
The next sequence is the music articulation test recorded in the same room with a complete TubeTrap acoustic treatment system.
2:44 – Bare room
The next sequence is the music articulation test recorded in a bare room.
3:37 – Original signal
The music articulation test recorded directly from the test oscillator.
4:33 – Well treated room
The music articulation test recorded in a room equipped with a complete Tube Trap TM acoustic system.
Demo the Defect – Room Articulation
The MATT (Musical Articulation Test Tones) contains an audio test signal designed to test the fast-tracking ability of the listening room. The room acoustic is the last link in the audio chain. It is responsible for most of the deterioration of playback quality. A simple, quick and very effective A/B demo to this effect is available with the MATT signal.
The clean signal is best audited over a set of headphones. The signal path distortion is minimal with this type of acoustic coupler. Once the rapid set of distinct ascending and descending tone bursts are familiar, take the headphones off and listen to the room acoustic playback version of the same signal.
During room playback a number of different effects will be audible.
Ta-Ta-Ta-Ta, the sound of an articulate group of tone bursts. There will be usually some 8 to 10 clean bursts in such a group, lasting about one second. A typical room will have only a few of articulate groups of signals in the 75 second test.
Tattle-Tattle-Tattle-Tattle, the tell-tail sound of the room’s double-tongue response. Large spans of the tract will have this sound. Notice that the tonal pulse rate is really twice that of the real signal. Too much energy occupies the dwell period of the test signal.
Toodle-oodle-oodle-oodle, the sound of the garbled room. Notice that it is a softer, less impacted sound. It’s close to a slurred, double-tongue response.
Tathump-Tathump-Tathump, is a more accurate presentation of the TA-TA. The “thump” is the turn-on and turn-off transient effects. This subtle transient coloration becomes totally inaudible with anything but articulate room playback. The thump is a damped 45 Hz ringing with only 2 oscillations of presence following each burst transition.
These effects, all distinct, audible and measurable are controlled by the room acoustic. More importantly, the “demo the difference” experience leads the auditor to observe firsthand the significance of the acoustic interconnect. Then the auditor will realize and accept the impact the listening room has on the otherwise accurate, fast-tracking audio chain.
Audio is no longer satisfied with launching a clean wavefront through grill cloth and calling the job done. The room acoustic is clearly the last and weakest link in the upscale audio chain. Now, you can demo the defect and upgrade the interconnect.