Stereo Sound Test Method Skills

                                      Stereo Sound Test Method Skills

The placement of the speaker in the room usually has an impact on the low frequency of the speaker. Therefore, when checking the placement of the speakers, pay special attention to the low frequency of the speakers. The following is a small editor to share with you the stereo sound test method skills, welcome to read and browse.

1. Phase calibration of main speakers

(a) Play the 45th to 49th tracks on the test CD, which are the pink noise signals of the left and right channels, first play in phase for 5 seconds (s), then play in reverse phase for 5 seconds (s), and finally play in phase for 5 seconds (s).

(b) Use your ears for phase judgment. First of all, you need to make sure that you are sitting at the listening point. If the signal is in phase, you will hear more low frequency signals, and the sound is also from a fixed point between the speakers. If the signal is out of phase, the sound image will lose the low frequencies, the sound image will become diffuse, and the directional information will become blurred.

You can also use RTA software to measure the phase.

2. Check the placement of the speakers

(a) The placement of the speaker in the room usually has an impact on the low frequency of the speaker. Therefore, when checking the placement of the speakers, pay special attention to the low frequency of the speakers.

(b) We use the low-frequency sweep signals of the 31st to 39th tracks in the test CD to check the speaker placement.

(c) During the sweeping process, you will hear a "beep" sound, which tells you that the signal is passing through a certain ISO center frequency. Two consecutive "beeps" indicate that the signal is passing through the center frequency of an octave, and one "beep" indicates that the signal is passing through the center frequency of a 1/3 octave.

(d) Use only one loudspeaker at a time to play the signal.

(e) Listening with your ears, if positioned properly, without any frequency coloration, you will hear a smooth gradual rise in pitch (remember, the frequency response of the human ear is not flat). If certain frequencies are boosted or attenuated relative to others, note the approximate frequency range. This frequency point should be just above the crossover point of your selected main speaker and subwoofer.

(f) If you really can't find a suitable placement, you can consider improving the acoustic conditions of the room. If you have pre-processing equipment, you can also consider equalizing to obtain a smoother frequency response. But remember: EQ can never make up for poor acoustics.

(g) If you have adjusted the balance, please come back after 15 minutes (min) and listen to the music you are familiar with. At this time, the first impression obtained from the speaker is very important, because long-term listening will change the perceived tone. Make sure the first impression is the sound you need.

3. Calibrate the main speakers

(a) The purpose of calibrating the speakers is to ensure that, under the condition of inputting the same signal, each speaker will play back at the same sound pressure level at the listening point. Once calibration is complete, lock the input signal level at the preamp.

(b) Set the master volume knob to the normal setting position.

(c) Play track 12 or 23, which is bandpass pink noise at 500Hz~2kHz. Only measure one speaker at a time. Use a sound level meter to measure the sound pressure levels of the sounds played by the two speakers at the listening point, and adjust the gain of each speaker so that the sound pressure levels of the two speakers are the same.

(d) Note that when measuring sound pressure, please select C weighting in the sound pressure meter or software.

(e) For speaker calibrations for audio production, input pink noise at -20dBFS and calibrate to the following SPLs:

Movie 83dB(C) TV 78dB(C) Music 78~93dB(C)

If there is a subwoofer, please proceed to the following steps.

4. Check the positioning of the subwoofer

(a) We use the low-frequency sweep signals of the 31st to 39th tracks in the test CD to check the speaker placement.

(b) During the sweeping process, you will hear a "beep" sound, which tells you that the signal is passing through a certain ISO center frequency. Two consecutive "beeps" indicate that the signal is passing through the center frequency of an octave, and one "beep" indicates that the signal is passing through the center frequency of a 1/3 octave.

(c) Use only the subwoofer to play the signal at a time, and mute the other speakers.

(d) Listen with your ears, if positioned properly, without any frequency coloration, you will hear a smooth gradual rise in pitch (remember, the human ear's frequency response is not flat). If certain frequencies are boosted or attenuated relative to others, note the approximate frequency range and make adjustments to the subwoofer's position. If you use a sound level meter for measurement, please set the weighting to the LIN position. If the sound level meter does not have the LIN option, select C weighting.

5. Check the crossover point and the gain of the subwoofer

(a) Turn on the low-frequency management function of all speakers and power amplifiers. But only one channel is tested at a time. Start with the left channel.

(b) Play the low-frequency sweep signal (31~42 tracks) in the CD, listen to the frequency response, or use the sound level meter/RTA software to measure. If you use RTA software, you can play the pink noise of the whole frequency band, observe it with a spectrum analyzer, and adjust the gain of the subwoofer to make the response on both sides of the crossover point consistent.

(c) If the crossover point is not suitable, please go to the power amplifier and choose a suitable crossover point.

(d) After checking one channel, check the next channel. The last two channels are calibrated simultaneously.

6. Phase check

(a) This check is to ensure that the phase of the subwoofer is consistent with that of the main speaker.

(b) Turn on all speakers and bass management. Play track 46 on the CD. The test signal is 20~200Hz bandpass pink noise, which is played in the order of in-phase, anti-phase, and in-phase.

(c) If the phase is reversed, you will feel that the low frequency is missing and the loudness will be weakened. If in phase, the sound is full. Note the order of the pink noise. Stereo Sound Test Method Skills