MATT™ - The ASC Acoustic Test Signal

....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.  

To explore the musical intelligibility and the sonic image-ability of your audio system......

How It Works

How to Run the MATT™ Test

See MATT Test  for training on how to setup and run the MATT test.  

Load CD into player, select Track 1 and adjust levels.  Select Track 7 and play the standard MATT test.  

Record the sound played through the system and room at the listening position.   

Track Listing for MATT Acoustic Test CD (2014) 

1.  0:33  Pink Noise Reference (decorrolated)

2) 0:42  Pink Noise (correlated) 

3)  0.42  Pink Noise (decorrelated)

4) 0.42  STC Noise (100 Hz - 5k Hz)

5) 4:27  Narrowband Noise Bursts (25 Hz - 5k Hz) 

6) 1:44  Low Frequency MATT (25 Hz - 250 Hz) 

7) 1:31  MATT ℗ 1986 Noxon  (18 Hz - 792 Hz)

8) 5:20  MATT Tutorial

 

MATT Test Analysis

The easiest way to display the results of the MATT test is sit in your listening position while holding an analog sound meter right in front of you.  Set meter to C-weighted and the averaging speed to Fast.  Play a little of the track and adjust the meter scale to match the sound level in the room.   Restart the MATT test.  Watch the movement of the needle as you listen to the MATT test and you can literally see what you are hearing in real time.  When your room is delivering a tone sequence that is strong and clear, the needle swings wildly.  When it becomes garbled, the needle only quivers.   

Most sound meters have an AC output, which is how you use the meter as a mic preamp.  If you get a more expensive sound meter that has a DC output then you have something like a 10 mV/dB signal out that is directly proportional to the needle movement, the sound level in the room.  You can plug that signal into a mechanical strip chart, similar to the old B&K 2306 and set pen speed to fast, or into your sound card if you can find a strip chart download that is fast enough for a slew rate of 70v/sec.  Modern phones have a sound meter app that includes a sound level strip chart.  One way or another print the DC output vs time.  The whole test lasts 90 seconds.  See the section MATT Test Analysis.

If you don't have the equipment to display the MATT test results, make a recording of the test with mic set at your listening position.  Do not use voice recorders because of AGC and limited bandwidth.  Sound meters are good mic preamps.  Use music type recorder to get a good signal.  Send CD recording or email a WAV file of the audio track to us at ASC.  We will process the data and send the strip chart test results back to you.  We also explain what we see in the test data, what's good about your room setup and what's not so good.

 

 

Benefits

Now you can just listen to your sound system and tell if it is working right or not. The MATT test track is "Go/No-Go" type of audio test and it doesn't take electronic analyzers or a computer program to tell you if your room sounds good. You just use your ears and they tell you what's up with your system.

In addition, the ASC Acoustic Test CD contains a standard pink noise track and frequency sweep, both of which are used to measure the steady state performance of the room. The MATT test track is a dynamic test, as it tests how quickly the room can respond to sound level changes. Also included is a convenient STC test track which is useful to determine the STC soundproof rating of large surfaces such as a wall, floor or ceiling, door or window.

Prices

ASC MATT & Acoustic Test CD: $19