Dynacord Stereo System manual When Controlled Coverage is Needed, Use of Subwoofers

The EVID C4.2 is just such a 4” speaker. The effect of the C4.2’s wider dispersion is indicated in the figure at the right. In applications where reverberation is not an issue, the C4.2 (shown with coverage pattern “A”) offers greater overlap and, thus, more uniform coverage than an 8-inch unit (coverage pattern “B”). When specifying a

new system, you can take advantage of the C4.2’s wider dispersion to decrease the number of speakers required to cover a given area. This will result in even greater savings.

Of course, a 4-inch unit will typically be somewhat less sensitive than a comparable 8-inch: for equivalent motor assemblies, the difference is on the order of 3 dB. The 4-inch will also have slightly reduced low-frequency capabilities.

A= C4.2 4-inch speaker @ 4000 Hz B=Typical 8-inch speaker @ 4000 Hz

Neither of these factors is a significant problem in most distributed systems, however. The C4.2 is conservatively rated to handle far greater power than most standard 8-inch units so its continuous SPL output will be more than adequate. Moreover, its reduced output below 150 Hz actually gives it an edge in intelligibility, since low-frequency energy is most likely to excite ambient reverberation. For these reasons, the C4.2 represents a great way for you to improve the performance of your distributed systems while maintaining a competitive edge in price quotes.

When Controlled Coverage is Needed

In some installations coverage control is clearly essential to maintain intelligibility and listenability. In these cases a speaker which provides controlled coverage over as wide a bandwidth as possible is needed. In live room environments the reflection of sound off of walls can be a major cause of intelligibility problems. The two examples below illustrate the effect of speaker dispersion in a room. The first example is the EVID C8.2 speaker with it’s 110 degree coverage pattern at 1kHz. The next illustration is the controlled coverage EVID C8.2HC unit with it’s 75 degree spec. As you can see the effect of the controlled coverage in the C8.2HC has a dramatic effect on the energy spilled onto the walls. The result will be a more intelligible installation using the C8.2HC.

C8.2 Speaker Coverage at 2kHz C8.2HC Speaker Coverage at 2kHz

The Use of Subwoofers

Subwoofers are an important part of an outstanding business music system. Light background or foreground music might not require subwoofers; however, even in systems where the bass doesn't need to be a dominant factor, having clear low frequencies can make a big difference in the customers' enjoyment of the music.

The number of subwoofers to use, where to position them, how to set the taps (on 70V/100V subs) and how loud to run them vary depending on the characteristics of each installation. Criteria

ElectroVoice/Dynacord BGM Guide Page 20