5 knowledge points about subwoofers

                                  5 knowledge points about subwoofers

In many home theater system construction cases, the selection and adjustment of the subwoofer is the most easily overlooked.

Many users don't even understand why a home theater system must have a subwoofer? Can't the main speaker replace the subwoofer? Or if you have no idea when choosing a product, the bigger the subwoofer, the better the effect? How to adjust the subwoofer phase? For practical purposes, in this issue, we will directly interpret the doubts or problems encountered by friends.

01

Subwoofer is a must

Whether it is the built-in Dolby Digital and DTS in the early DVD, or the current Dolby Atmos, Dolby HD, DTS True HD and other audio coding, there are planned independent subwoofer channels.

That is to say, under these regular multi-channel audio coding specifications, one or more active subwoofers must be used in order to show the midrange, bass and even subwoofer in the audio. band.

02

Don't judge a subwoofer by its size

The size of the subwoofer is related to factors such as the driving power of the subwoofer itself, the type of cabinet, the efficiency and instantaneous performance of the monomer.

Although a large-sized subwoofer can push the air with a larger area, thereby producing a more powerful low frequency, it has a much heavier cone weight than a small-sized subwoofer. If you want to push it out to a stronger low frequency, In the part of the amplifier circuit, it must first have a stronger output power.

In addition, the instantaneous performance of large-sized subwoofers is often not as good as that of small-caliber subwoofers, so the sense of speed during low-frequency transmission is often not fast enough, and even the phenomenon of "smearing" of the sound will occur. Therefore, a large-sized subwoofer may only provide a larger low-frequency component, and it may not be as light and agile as a small-sized subwoofer in the sense of speed.

03

Main speakers instead of subwoofers? Sound effects for a discount

A home theater system cannot determine whether the mid-bass range (especially the low-frequency part) of the entire combination is sufficient based on the size of the speaker alone. Give the subwoofer the responsibility. For users who do not consider buying a subwoofer, they can also set the main speaker to full frequency through the settings.

However, such a setting is bound to cause a greater burden on the amplification circuit of the main speaker and the theater power amplifier itself. In addition, the subwoofer can also independently adjust the volume, crossover point and phase, and can also adjust the position according to the size of the space. For a home theater system with a subwoofer, the overall adjustment is more flexible.

04

Subwoofers are phase sensitive

Simply put, in the placement adjustment of the subwoofer, when the subwoofer and the left and right channel speakers both sound in the same direction, the sound phase of the two should belong to an angle close to the same phase.

If the subwoofer is placed in the position of "confronting" the speaker, the subwoofer will form a 180-degree anti-phase state with the left and right speakers. At this time, if the phase of the subwoofer backplane is not set at 180 degrees (anti-phase), it will not only cause the subwoofer low frequency to always be emitted from the rear of the sound field, or part of the frequency band between the subwoofer and the speaker will be Cause phase inconsistency, even because of phase overlap or offset, some low-frequency bands increase or disappear and so on.

When we adjust the positive and negative phases of the subwoofer, it can be based on the sense of low-frequency volume heard at the listening position. That is to say, when we play a song with full sense of low frequency, you can sit at the listening position, and then switch the positive and negative phases of the subwoofer in turn, as long as you can feel a strong low frequency effect at the listening position, then The phase of is the phase that can make you feel the low frequency.

05

The low frequency is a mess, how can I debug it?

Generally speaking, subwoofers often cancel or increase the frequency bands and phases in the space, resulting in the disappearance of some frequency bands and the excess of some frequency bands.

First of all, when we adjust the subwoofer, we can start with the four parts of subwoofer position and angle, phase selection, volume and crossover point as adjustment items. During the initial debugging, we can adjust the volume first, and finally adjust the appropriate volume. After the problem of low-frequency confusion is improved to a certain extent, then use familiar music and movies as playback detection. After several adjustments and settings in this way, the effect of the subwoofer will be improved to a certain extent.