Water intrusion and speaker grills

[TDR-94]

How do the speakers on the portable radios keep water out? Is there a water resistant material between the speaker and the grill or is the actual speaker cone used to block the water?

 

[Radioman96p71]

These speaker cones are typically made out of some robust plastic like PET or PVC with no vent holes and the rim of the speaker frame is epoxied or sealed to the case with something water tight. A big concern there is making the case water tight also makes it air tight meaning temperature swings can cause pressures inside, blowing out the seals or creating a vacuum that can actually implode the seals allowing water in. Most modern radios have a small pinhole somewhere with a diaphragm that allows the case to breathe a little to avoid that.

 

[TDR-94]

I see something in between the speaker diaphragm and the plastic grill.It's looks like some kind of foam?Is it for vibration dampening?

What about those two 'white' circular areas under the rear plastic cover, above the battery compartment? Are those possibly for venting?

With the ease that these case fronts develop cracks it makes you wonder if it even really matters.All 3 of my P7xxx/P5xxx series radios have case fronts that have now formed cracks from just sitting on a desk! They don't get manhandled and haven't even seen any real outdoor exposure.Two radios were practically new out of the box!!! Ironically,the P5100 light grey case front held out the longest and was the oldest.....go figure.

It just starting developing a crack under the retaining lug a few days ago.The P7100 and P7200 have little cracks developing between that little area between the screen and the UDC connector.