Hi,
What are your thoughts on Linns reasoning regarding their center channel "Majik 112" deploying only one bass driver.
Short background and attached their paper on single bass driver design.
small.linncdn.com/product-catalogue/documents/Linn_Majik_112_Key_Technology.pdf
(I can't post a link but past this into the browser and you will see the paper)
BACKGROUND
Most commercially available centre channel designs employ symmetrically loaded bass units. The main reason for this appears to be primarily cosmetic, as in many designs there is compelling acoustical evidence for deploying only one bass driver.
The ideal centre channel loudspeaker should provide a broad horizontal spread and narrow vertical dispersion to ensure a consistent listening experience from all positions. Column loudspeaker arrays used in public address systems achieve this 'ideal' dispersion using between 6 and 10 identical full range drivers in a single vertical enclosure. However, a vertical column represents the worst possible physical dimensions for a centre channel as it would obviously obscure the screen. Vertical columns may be good for churches, not so good for home theatre.
A typical centre channel employing two symmetrically positioned bass drivers can be considered as a small column array lying on its side. This would suggest that the loudspeaker will provide broad vertical dispersion with a narrow horizontal spread; exactly what you do not want from a centre channel.
Lower frequencies are generally less directional than higher frequencies, so the bandwidth over which the bass drivers are required to play must be considered.
The higher the frequencies the bass driver is required to produce, the greater the likelihood of 'beaming' affecting the output. Beaming is commonly used to describe the effect of constructive and destructive interference caused by differences in path length between acoustic sources (drive units) and a receiver (your ears). When these path differences are similar in length to the wavelength of the sound being produced, the directivity pattern will exhibit lobes and nulls (peaks and dips),as shown in fi gure 3 on the next page.
The strongest lobe will be directed forward with a null on each side. As frequency increases and the wavelength of sound gets shorter, more and more lobes and nulls will be produced, but always with the strongest lobe directed forward, thus the term beaming.
In addition, beaming occurs at lower frequencies the further apart identical drive units are placed. By using a single drive unit the distance between units is removed and the effects of beaming are eliminated over the bandwidth of the driver.
