Ashdown Acoustic Radiator 2, amp

It was only when I saw the IEC on the rear that I realised it was not 1960s, scuffed red mock leather covering, large thick leather handle, "ivory" knobs , that cream stove enamel used on a lot of medical kit etc of the era after the crackle finish of the 40s/50s. Now I've seen it all. To get the amp out you need to remove a speaker to release the speaker wires internally. But its a dummy speaker, presumably the 2 in the model name means 2 speakers. Basket , suspension , kevlar looking skirt, and cone , only. No pig tails or holes for pigtails or Voice coil or magnet. So if these were off a production line, how were they further processed? 4x3 sets of holes in the basket for what I would have thought were screw holes for a magnet , but sealed off by the seated cone. Would they glue in VC to the cone and magnet glued in to the basket with some sort of active monitoring of sound output , while posistioning in the uncured glue? Problem is the otherwise Ashdown Bass amp common symptom of loss of output , returning a few minutes later, but this one will then continue for an hour or more with no drop-out. Not had a chance to power up yet , to investigate

Reply to
N_Cook
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The answer is in the name. It's not a dummy speaker, but a passive 'acoustic radiator' Surely you have seen one of these before? They are not uncommon.

Ron

Reply to
Ron Johnson

1960s,

knobs

after

presumably

Voice

cone.

the

output ,

hour

investigate

Never seen one . I've seen holes in boxes called adiabatic resonators , yes, so I'd believe anything was possible. What is an active loudspeaker , if not an acoustic radiator? The company blurb refers to 2 speakers which to my mind implies 2 of the same sort of speaker . Eiter 2x active speakers or 2x passive speakers which would likely result in a lot of returns

Reply to
N_Cook

If you only had two passive speakers, no sound would come out! You could save a lot of money on the amplifiers mind ;) The passive radiator is a way of lowering the tuning of the cabinet whist keeping a small volume (hence size) and without resorting to bass ports

Ron

Reply to
Ron Johnson

Normal passive has no coil, but it might be there to damp, mostly over and under resonance. Most effective below resonance, so the cabinet does not cause overextension below driver resonance.

Greg

Reply to
gregz

"Ron Johnson"

** Ha, ha.

** A passive radiator is simply another form of tuned port - instead of the moving mass being simply the air enclosed by the tube, the cone of the radiator acts as the moving mass. The spring is always provided by the air trapped in the box.

The main advantage is that it allows small cabinets to be tuned to low frequencies and with a large moving surface area.

In such cases, a similar frequency air only port would be inconveniently long and have a too small a surface area - the result of which is a high level of chuffing noise and strong third harmonic generation.

As with an air only port, the cone motion of a radiator supports the output of the cabinet in the lowest octave and will be the main source of sound at box resonance.

... Phil

Reply to
Phil Allison

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