Author Topic: crossover point for Maggie horns  (Read 443 times)

mashaffer

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crossover point for Maggie horns
« on: June 10, 2019, 09:59:11 AM »
I have a pair of theae Magnavox horns that someone else salvaged from a trashed console. I can't remember what cap was connected to them when I got them. Can anyone give me an idea of the typical crossover point they usually used? Any idea of the approximate sensitivity?


electra225

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Re: crossover point for Maggie horns
« Reply #1 on: June 10, 2019, 03:38:37 PM »
The crossover caps on the horns in my Stereo Theater project are 16Uf at 50 volts non-polarized.  I'm not sure about crossover frequency and have no idea about sensitivity.   Good luck.   ;) ;) :) :)
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Motorola Minion

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Re: crossover point for Maggie horns
« Reply #2 on: June 13, 2019, 01:33:33 PM »
First photo -  I have two sets of these that I played around with before I settled on component values and then mounted them in a Peavey box with two 12" Pyle drivers. second photo - these are on a shelf in my garage, driven from a Sherwood S7800 (40 wpc). I have cranked it up past noon a few times but the horns keep on singing on key 8) I loaned them along with a Dynaco QS-300 (75 wpc x 4 ch) amp for a friend's wedding and the horns survived.

I started out carefully, as I have fried many a tweeter in 40 years of abusing my eardrums with SS equipment :-[
madisoundspeakerstore.com supplied a calculation page (which I used to select parts values I then ordered) but now offers a LEAP service.

Using my EICO 378 audio generator and an oscilloscope for voltage measurements, I found that the Magnavox horns, long 580069 and short 580088 BOTH are at risk of damage when driven below 1000 hertz. Current peaked somewhere near 700 Hertz. I selected a crossover point at 900 Hz and designed a

The solution is normally to place a 10 watt resistor in series with the 10-ohm horn, a first order filter using a coil and 16 mf NP capacitor as per the schematic I attached should be a good start. 
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Dave

Motorola Minion

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Re: crossover point for Maggie horns
« Reply #3 on: June 13, 2019, 02:13:32 PM »
pics follow but to finish last post, I designed a crossover similar to the Mag R204 schematic attached
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Dave

mashaffer

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Re: crossover point for Maggie horns
« Reply #4 on: June 14, 2019, 02:25:45 PM »
Thanks. So it sounds like 2kHz 2nd order should be OK.

Motorola Minion

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Re: crossover point for Maggie horns
« Reply #5 on: June 21, 2019, 01:47:39 PM »
The horn on the left in my picture is actually not a Magnavox but a plastic HF horn from one of the Peavey boxes. The other plastic one was cooked.
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Dave