Speakers

About Speakers for organs in General.......
The provision of the correct amplification and speakers is one of the most important aspects in any Hauptwerk or indeed any pipeless organ installation. Of course, pretty much any speaker set-up will produce "a sound" but there are some fundamental rules to be considered when trying to produce believable pipe organ sound in any environment. 

The use of P.A. speakers and amplification is generally not recommended in most cases because this types of speaker is designed to project sound as far as possible into an auditorium. Whilst this is all very well for a pop group or rock band it is not suitable for pipeless organ sound. 

Of prime importance is the positioning of any speakers used in any installation and the bad placement of speakers regardless of how good the speakers themselves ar, will result in disappointment. In large instruments (possibly with a faux pipe or grille front) the front will usually act as a diffusion baffle which helps break up the direct nature of speaker produced sounds. Where no such baffle exists, positioning speakers indirectly to bounce sound off walls and ceilings can help to produce a more authentic sounding result. Experimentation and prior experience is the order of the day here.

With the exception of some very loud stops, most organ stops are relatively quiet. Individually, pipes do not produce very high volumes and it is only when they are combined with others that a greater volume is produced. In a real pipe organ, the combining of several individual pipes at the same pitch does not in itself produce a marked increase in overall volume and it has long been known that it requires as many as 10 pipes of the same pitch (speaking in a similar manner and individual volume) to double the overall volume of the individual stop. However, the addition of a pipe at half the original pitch (ie; the octave above) has the effect of increasing the volume of the original single pipe considerably. This is caused by the fact that a pipe at say 64Hz added to a second pipe at 128Hz produces not only both the pitches of the basic fundamental but also reinforces the "base" fundamental by the addition of a "resonant" tone generated by the difference between 128Hz and 64 Hz (= 64Hz). This phenomenon carries onwards and upwards as additional pitches are added according to the physics of sound. Every additional basic pitch above the original fundamental one will continue to reinforce the original fundamental and this is what causes the glory of the pipe organ sound as we have come to know it.

Unfortunately speakers do not operate in exactly the same way as physical pipes and all sorts of complicated factors come into play such as inter-modulation distortion. Short of providing a speaker for the equivalent of every pipe in an organ, all solutions must be seen as a compromise and all that we can do is try to get as close to nature as possible. Fortunately, we don't have to go quite so far as providing an individual speaker for every pipe but the closer we can get to this, the more convincing and authentic the resulting sound will be. In order to emulate the true pipe organ, the first thing is to provide as many speakers and amplification channels as possible. This is not ostensibly to produce volume of sound but rather to reduce the problems of the conflicting inter-modulation distortion and other factors such as "point source". Put simply, the more amplification channels and speakers that are used brings one closer to the ideal of one speaker per pipe. Every reduction in the amount of channels and speakers used will produce a less accurate end result. 

The sound of any individual pipe when heard up close can be very unpleasant indeed since there are all sorts of spurious components such as noise and clashing harmonics. It is the damping action of air, absorption of frequencies by the room fabric, distance and several other factors that results in the sound that is heard by the listener. Basically the environment in which the pipe speaks is filtered and modified by its surroundings. Therefore, the concept is to produce the basic sound of a real pipe through the limited resource of a speaker and allow the room and other factors to create the desired sound as far as is possible. P.A. speakers tend to throw out the original sound (together with all of the original and unmodified undesirable sound components) as far as possible which results in a loud noise but retains much of the unpleasantness of pipes listened to at close quarters. Whilst this is possibly desirable for the lower pitched stops which rely on the movement of large quantities of air for their effect, they have less higher harmonics and are therefore much less affected by their environment, it is definitely not suitable for the higher pitched voices.

We feel that the provision of multiple channels of amplification and tonally uncoloured speakers provides the most accurate means of producing convincing pipe organ sound which is why we advocate the use of studio monitor speakers. In themselves, these speakers are not particularly powerful but in combination, they produce something approaching the desired effect.

There are a number of excellent speakers on the market which meet the requirements above and will adequately fulfil the needs of most installations at a reasonable cost. Like any "tech" product, speaker models change on a regular basis and therefore it is impossible to recommend specific models and manufacturers except on a day to day basis. The choice of speakers in each installation is governed by what is currently available and what the requirements are for each location.
SOUNDBARS
 
A relatively recent development in speaker technology, the "Sound-bar" was designed for home cinema applications. Most soundbars consist of a single unit which contains several small speakers often together with a separate sub-bass unit. Using soundbars is a slightly different approach and the main advantage is that the units are relatively unobtrusive and small enough that several can be used in a multi channel environment without taking up too much space. Quality varies enormously and price is no guarantee of how good this quality might be when applied to organ sound. Therefore some research is needed as to the best models available at the time. An additional factor to be taken into consideration when making a choice is that many soundbars have unsuitable facilities such as optical inputs only.
Many soundbars are capable of producing a stereo effect regardless of listening perspective thanks to their unique design. They are also capable of projecting sound a considerable distance from source without the characteristic "flaw" of P.A. speakers and we have used them successfully in a number of large rooms. We have found that using soundbars to handle upperwork and mixtures in conjunction with other speaker units is very effective. Another useful application is for chamber organs where their small size and acoustic characteristics are ideal.

SUBWOOFERS
       
These tend to be considerably more expensive than "normal range" speakers and often offer far less "bang for the buck" than their prices might suggest. There are plenty of companies that claim to produce sub woofer speakers but few actually come up with the results that warrant such a description. The main requirement of any subwoofer is to produce a firm and accurate bass down to the bottom notes of a 32' at 16hZ and some are capable of remarkable results from units that take up very little space indeed. However, even the cheapest models are relatively expensive and more capable models (in terms of power) can only be considered in situations where cost is not the main issue. 

A suggested guideline in pricing for active speakers suitable for use in a Hauptwerk instrument would be from £300.00 - £400.00 per pair. For subwoofers, a starting price would be from about £500 for a single mono unit. Please note that since bass sounds tend to lack specific stereo field information to an extent, many consider that a mono bass speaker is sufficient. Whilst the foregoing statement is true to an extent, we still believe that in terms of organ sound (in all but a few situations), dedicated left and right speakers and amplifiers are preferable.

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