External speaker doesn't disable internal?

[Msingewald]

On the XPR4550, there is no way, aside from opening the radio and unplugging the speaker, to disable the internal speaker when using an external speaker? Can that be right?

Michael

 

[N4KVE]

That is correct, & I have been told it's not bad for the radio. The external speaker is so much louder, I never hear the internal speaker. GARY

 

[com501]

The US's largest rental company routinely modifies their rental fleet by adding a 1/8" mono jack on the housing next to the speaker to attach an external speaker instead of using the rear accessory connector. I dislke this approach, as it does two things: One, it brings the A+ voltage out from the audio stage and exposes it directly on the jack ring surface. If it gets grounded accidentally, things get very hot and evertually go poof (OTL floating audio). Second, an open circuit or an incorrect impedance load across that external jack with the internal speaker bypassed can damaged the audio output of the radio, an equally bad outcome.

 

[escomm]

On the XPR4550, there is no way, aside from opening the radio and unplugging the speaker, to disable the internal speaker when using an external speaker? Can that be right?

Michael

Yes of course it's right, Motorola's exceptionally competent and experienced engineers, who have been around Motorola radios for a very long time and remember best practices from prior model design, decided to put the front and back speakers on the same audio bus

 

[N4KVE]

Years ago I tried running a Maxtrac with the internal, & external speakers at the same time. It was very obvious the radio was not happy doing this, but I didn't cause any damage. I disconnected the internal speaker, & then the external one sounded fine again. But after 2 years of running my 4550 with both speakers, it still sounds great, & the external speaker drowns out the internal one. GARY