Zöllner kiel makrofon rebuilding

Hi!
The story goes like this, I got this horn as a gift. It is not much, the sound is high-pitched (girly). My idea is to rebuild it, if possible, I would like to get the classic strong sound of the train trumpet. For me I’d make a new bell and a new diaphragm, but I do not know from which materials and which dimensions, so I would like to ask for suggestions. Any kind of tips welcome.

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Welcome to the forum.

The size of the horn indicates to me that the primary frequency will be high, somewhere around 700 Hz. That horn was probably used as an industrial alarm, not as a train horn.

That horn will never produce a deep train sound. It will probably be very loud and will garner attention.

The first steps would be cleaning the parts, taking care to not alter the shape or dimension.

It looks like the threads that set the trumpet length have been moved. There is an ideal position for that adjustment that is set by the manufacturer during assembly. It is probably possible to set that adjustment by ear, or a microphone and spectral anayzer could be used.

Welcome to the forum.

The size of the horn indicates to me that the primary frequency will be high, somewhere around 700 Hz. That horn was probably used as an industrial alarm, not as a train horn.

That horn will never produce a deep train sound. It will probably be very loud and will garner attention.

The first steps would be cleaning the parts, taking care to not alter the shape or dimension.

It looks like the threads that set the trumpet length have been moved. There is an ideal position for that adjustment that is set by the manufacturer during assembly. It is probably possible to set that adjustment by ear, or a microphone and spectral anayzer could be used.

Cool… ze Germans are coming!
That sucker looks like it has a solid brass back end … very nice! The driver looks beautiful. You should clean it all up to bring out some shine.

By the photos it looks like their 660Hz model (M75F/660 UIC). You can find out more from the manufacturer here:
http://www.zoellner.de/en/locomotive/zoellner-makrofon/

If you want to make the horn sound deeper, all you need is to develop a larger longer trumpet - … not trivial but it is possible. The nice thing with your horn seems to be that the driver and trumpet parts are threaded (i.e. detachable) which would make it a reasonable task to attach a new trumpet front end. There are some custom plans around for making train horns from PVC. Do some Googling for PVC K5LA to get some ideas on how you can use plastic parts to make a large trumpet.