External speaker? YES, on both models.
Update? It's EASY. Go to the Minelab Equinox downloads page, here: https://www.minelab.com/usa/metal-detectors/all-purpose-use/equinox-800?view=downloads
Download and run the file; once it's downloaded and it runs, it will open a window, that will prompt you to connect your machine to your computer (using the supplied charging cable). Then, install the upgrade (takes about 2 minutes), and you are done. That simple (in 99% of cases, barring outdated Windows operating systems, or anti-virus/firewall issues).
As for the REAL differences between the 600 and 800? Mainly "bells and whistles," largely surrounding ability to further customize/tweak certain settings. The only hard-wired operating difference is that on the 800, you can choose to run either 20 kHz or 40 kHz as a SINGLE frequency, whereas on the 600 you can only choose 5, 10, or 15 kHz in single-frequency mode...and likewise there is a "gold prospecting mode" on the 800 but not on the 600. The only hardware difference is that the 800 has a "user profile" button, on the side of the control box, where you can save a "custom" program for quick retrieval. This button is not included on the 600. In terms of accessories that come in the box, the 800 includes wireless bluetooth headphones, while the 600 includes wireless bluetooth CAPABILITY, but not the bluetooth headphones themselves (just a corded pair of headphones). Finally, the 800 also includes a small, portable, clip-on wireless MODULE, to which you can attach any corded pair of headphones you wish -- but still not be "tethered" to the machine (only tethered to that small portable module). This module, should you want it, must be purchased separately if you purchase the 600 model. Most folks who own the 800 though don't even use the module, but use wireless Bluetooth headphones instead. Otherwise, the machines are essentially identical, and offer identical performance (when set up with the same settings in an "apples to apples" way).
Bottom line -- the 600 is an outstanding value, for the price paid, in terms of the amount of performance you get; meanwhile, if you wish for a bit more customization ability, for wireless headphones to be included, and for the ability to run the machine in 20 kHz or 40 kHz single frequency mode (or gold mode), the 800 may be your choice.
Steve
