Ashdown 410H wiring

[Mick Bailey]

I have an Ashdown Magnifier 4x10 + horn cab that's missing it's input/switch plate. I've got the replacement, but it's just the plate with sockets and switch. Can anyone tell me what the high/off/low horn control switch wiring is? presume its just switching resistance.

[Jazz P Bass]

Hmmm.

Have you tried contacting Ashdown?

[Mick Bailey]

I would have done, only it's one of those jobs that ended up suddenly getting urgent over the weekend and I wanted to get it done by Monday (there was also the amp to fix too). Was expecting the plate to be pre-wired. I should have checked with Guy in spares when I ordered it.

As they say, Never assume anything. Assume makes an ASS of U and ME.

[Enzo]

I just looked through their schematic files, and all I see is electronics, no speakers.

But I am sure it is nothing cosmic or unusual, the woofers run full range, and a rudimentary crossover is somewhere inside? Unless the horn is a piezo, it needs a crossover. I suspect any attenuating resistors would be on that. Is there a crossover board hiding in the cab somewhere?

My first weapon might be to look at other brand similar cabs and see what they did. Doesn't really matter if you do it exactly the same so long as the results are good.

I just skimmed through my Fender/SWR/Sunn stuff, and all of them use the Foster horn and an L=pad. The crossover would work, but you need a switch instead of a dial.

I just can;t think of who had the hi/lo/off horn switch.

[Mick Bailey]

I took it apart to take a closer look and now I've extracted the (very) stuck tweeter I can see how it works. Just a piezo tweeter with attenuating resistors on the back as you suggested. I was missing a third lead, which happened to have dropped back inside the cab.

Just for info the circuit is;

Black lead - ground
Red lead - High connection to switch
Orange Lead - Low connection to switch

Centre contact of switch connects to common +ve speaker connection

Just two 15R WW resistors and a 2.2uf NP cap in series - high is 15 ohms, low is 30 ohms.

[J M Fahey]

Please draw the actual tweeter/attenuator circuit, an image is worth 1000 words.
Thanks.

[Mick Bailey]

Here it is;