Help with speaker plug

For domestic use I would replace the three pots with conventional spindle types with knobs.

It says 5mm captive screw

Quote Features

Inputs: Balanced or unbalanced stereo on a captive screw connector; unbalanced stereo on RCA connectors and a 3.5 mm stereo mini jack

Speaker Outputs: 5 mm captive screw connector

Very possibly

BTW rapid electronics may have the other plugs for the back of that box The example below may not be the right size (they come in different sizes)nor the correct number of ways but it may give an idea of how the two mating halves look like

Bare wires. Its captive screw connections (chocolate block)

I see it as the mating half of a captive screw socket/plug combination with the socket half being the back panel connection and just having a recessed pin. The screw connection will be on the plug.

Maybe the box is supplied with the mating plug(s)?

Are you certain those Bose speakers don't need an amp with the response tailored to them? Most do.

Being a class D amplifier (switching amp) I expect that the load (speakers) will also determine the overall performance of the amplifier.

What earthly reason would make you say that?

Sometimes terminals also have banana sockets in their centres as well. I had an amp made by Tandberg once but it used the most ridiculous speaker plugs on the planet. Din speaker plugs, with the big flat bit and the pin.

Not very robust. Brian

All the rage at one time. At least you can't get the speaker polarity wrong. My Armstrong had DIN plugs all round, so you couldn't muddle the left and right channels for low level input/output either, as you can with Merkin phono plugs, which hark back to mono days. And how are blind people going to tell red from white?

Only if you *want* people fiddling with them after you have set them up; instead of using preamplifier controls.