I run the Uniden amplified speaker from my SDS100’s earphone jack without issue. But I agree with all who expect to see acceptable audio output levels provided for external speakers, even on the SDS100 and BCD325P2. I suspect inadequate levels of audio are partly due to marketing ( maybe get us to buy the SDS200 in addition to the ‘100?) ...and not solely a hearing protection concern. And of course, there are the laws of physics that must be observed. Handhelds are designed to perform on a temporary basis (they run on batteries), where conserving power is a concern while it allows for the portability of the product. There seems to be an expectation we should be able to plug them into AC power, connect an external speaker and antenna and magically turn our portable into a base station listening post. While having the ability to do that is nice, it was never the intent of what a handheld should be... and there’s the rub, the expectation of the vast majority of consumers, (which should be the driving force for manufacturers) is that the handhelds should support the expectations. It’s not a case of this expectation being right or wrong, no one cares if it’s wrong, it’s what they want. Its a case of satisfying the customer.
A workaround would be nice. It would allow those who wanted to increase the audio gain to do so at their own risk. It would deplete your battery quicker, but it’s a trade-off.