I hire out and install 100V horn systems a fair bit.

Firstly, am I right in thinking that you’re using 130 horns on each side, i.e. 260 horns? Or did you mean something else? As that’s a hell of a lot of horns!

How have you got them arranged? You mention that it is too quiet 2km away from the centre. Are they just in a massive cluster, left and right, or do you have them arranged on poles, evenly spaced along the full distance?

Does it look like this??

What is the maximum rated power for the horns. 5W is very low – what’s the maximum tapping on the transformer. Could you not get away with using fewer horns but on the higher power tapping?

Also, projecting clear sound 2km is asking a lot from any PA system.

Finally, what the hell is this for???!!

that pic cheesweasel posted is actually from Malaysia (any link to the article? I don’t understand Malay buy has my mum come over to visit and she does). I suspect this rig is also put there to do what mfrardan wanted, if it were for music they’d use the same speakers as Westerners do, but near it is clearly too loud. the chaps stopping their ears look like they are Malay.

in some countrys they put the horns up at high level at the minaret (or similar tall structures used by other faiths where it is permitted to use loudspeakers ) but there are often safety and planning rules against this.

This could also be a semi-portable system for the larger Friday prayers, which are held in the open air rather than at a smaller mosque. so there may not always be a nearby minaret, or an easy way of putting speakers up there. For instance until the projects ended, there was a large Friday prayer assembly at the British Telecom research centre, for the benefit of the engineers who had come from South Asia and were Muslims (not all of them were, some followed other religions). I am not sure how the call to prayer was given (probably over some sophisticated IP network to smartphones) but they certainly wouldn’t be allowed to put horns up at the Orion tower, as it would din the ears of half of Martlesham and as far as Kesgrave and Rushmere St Andrews :laugh_at:

the content sent down these rigs is already equalised for the limited bandwidth of horn speakers. A few years ago a friend from the Punjab said that “pop music” was not explicitly banned by his form of Islam, but it was not right to let it distract you from prayer or family duties. He did also like reggae and Dutch gabber! I am not sure how he got introduced to the second though suspect it might even have been through the mosques of the Netherlands as there are many Indonesian chaps there.

Another method used for long distance PA is to send the low level audio on fixed telephone lines or radio links and use more smaller local amplifiers, powered by the easiest available electricity supply. But I appreciate that the OP is not currently in the most politically stable country, (Malaysia has had some rough times in the past too), and that is also why they want to keep the speakers in the same area as they could be prone to theft and sabotage.