Duetta Rattle!

[Dloper]

Having read a bit about the dreaded rattle from older Apogee panels I was disturbed the other day when, after moving my Duettas by 'walking' them over the floor, one of them began to rattle when fed low bass.

I lived with it for a few days but one afternoon the sunlight was reflecting off the speakers in a way that highlighted something I did not expect to see - the outer cover was visibly vibrating. I grasped the bottom of the outer cover and squeezed it against the panel frame - no more rattles.

As a temporary solution, I have used small g clamps to gently squeeze the speaker covers against the panel frames along the bottom of the speakers. The rattle has gone. At some point I may take the covers off and see where the original fixing has gone awry as there does seem to be a bit of movement between the cover and the frame but meantime, they're singing again.

[Graz]

There is a layer of foam around the perimeter of the upper clamp set that touches the edge of the bass cut-out on the main case front. This foam is fitted to the speaker when new, and actually is the same type of foam that is used around the bass ribbon, above and below it all the way around it. Over time the foam breaks down, a process that usually takes around 15 years from new, but it is a gradual process.

If you have had a result by setting a clamp device on the case front, you may extend the play life by replacing the foam on the upper clamps. BUT in all cases I have seen the degradation in the upper foam is actually mirrored in the other layers of foam around the panel so the improvement will likely be short lived. The lower foam sets are only accessible during a bass ribbon replacement.

[Dloper]

That's useful to know. I don't have much history for this particular pair, but there is some damage to the periphery of the mdf panel at the bottom and the covers are loose, as if the fixing of the main case to the panel is adrift. I don't have time to investigate how the cases are fixed to the panels at present, but I'm hoping it's the mechanical coupling between the two rather than foam degradation causing the loose fit.

[Graz]

In the early Duettas the case front is not structural, and attempting to lift the speaker by the case front can cause it to split. The actual fixings are small almost submerged cap bolts along the top edge of the chassis board that act as a "hook" that locate in small routs on the inside of the top case front edge. The actual closing of this is at the bottom, usually with two #8 wood screws that screw through the case front bottom edge into the bottom edge of the chassis board. There are also patches of velcro located on the inside of the case front that mate with velcro on the upper clamp set.