Put simply you get more for your money. But it is more - not just sound - but, in a correctly designed system, better quality of sound.
We may not all realise it, but the effect of "horn-loading" is well known to every one of us. We only have to cup our hands to our mouth, so creating a rudimentary megaphone, to realise a simple example of the resultant increase in loudness. Our hands act as what we might term a "natural amplifier", converting the high pressure, low amplitude signal at the narrow end close to the source, to a low pressure, high amplitude signal at the broader open end which is a much better "impedance match" to the surrounding air. This illustrates the benefits of the horn as an acoustic coupling device, as a means of greatly increasing the efficiency of signal transfer.
If we now consider a similar situation, but substituting a loudspeaker signal for the human voice and a horn for our cupped hands, the benefits for hi-fi sound reproduction become clear. The purpose of the loudspeaker transducer is to transform the movement of the diaphragm, or cone, into the air pressure waves that are the sound we hear. The very different physical properties of the cone and the air that it has to excite, however, mean that in the case of a conventional direct radiating cone loudspeaker, this process is hugely inefficient. A horn loaded device can transfer this energy far more efficiently. As they have to work much less hard than a similar direct radiating device to generate any given volume of sound, they can thus be constructed with lighter, more responsive cone/diaphragm assemblies, and these can operate with reduced excursion, which in acoustic terms means a vastly improved transient response and lower distortion. Their efficiency also makes them far easier to drive, allowing not only much lower power amplifiers to be used but also their operation with increased headroom and consequently less distortion.
So if horn loading offers us such benefits, why isn't everybody doing it?
The lower the frequency to be reproduced the larger the horn required, and whilst high and mid freqency horns can be of perfectly domestically acceptable dimensions, bass horns can be, to say the least, a little on the large side! In order to achieve acceptable bass performance in wideband home audio systems horns many metres in length and with very large mouth openings would be required, and in normal circumstances these simply cannot be accommodated. A means of making horn loaded systems more space efficient must therefore be sought.
A good compromise can be found in the use of "hybrid" systems, in which the upper frequencies are horn loaded and the lower registers are handled by more conventional transducers, but if the benefits of horn loading are to be felt across the entire frequency range then a more ingenious approach is required. Whilst preserving their cross section at all distances from the driver source, the horn can be cleverly folded into a cabinet that takes up much less space, and, as in the case of the CN-191 corner horn, these can also utilise the architecture of the listening room to further expand their effective size and achieve even deeper bass response.
Considerably reduced in size though these solutions might be, small they most certainly are not, so we must accept the trade off that comes with the use of horn loading. We strongly believe that it's a trade well worth making, and that discerning audiophiles agree; sharing the understanding that music replay is best experienced via a horn loaded loudspeaker system.