what is this connected between the speakers?

[pula58]

Montgomery Ward Airline amp.
I have one in the shop for repairs. There is what looks like a choke mounted between the speakers inside the area of the cabinet where the speakers are. Inside the chassis there is an output transformer, with two wires headed out to the speakers, ie. looks fairly standard so far. But then there is this choke, or something, with two leads, each one connected to a terminal of each of the two speakers. I have not seen an arrangement like this before. What is this?

[NickC]

It sounds like a field-coil speaker.

[pula58]

Is it field coil speaker? There are only two wires headed-out of the OT to the two speakers. Then, this thing is mounted to the woooden cabinet, has two wires, one to each speaker. So, there is not separate power to the coil, it is simply connected between the two speakers.

[Structo]

That is strange.

Got a picture?

[Cantplay]

Depending on parallel or series a choke acts as 6 dB high or low pass crossover.

John

[pula58]

The two speakers are connected in series:

+
-
+
-

with the choke between the top "+" and bottom "-"

[Cantplay]

Then it acts as first order high pass filter.

The choke is eating some of the low bass.

John

[pula58]

Then it acts as first order high pass filter.

The choke is eating some of the low bass.

John

Yeah, I think this makes sense.

thanks