They will work fine - I probably wouldn't go to maximum volume on any amplifier as you get more distortion but the 1900 produces an honest 30W with higher peaks and as most music at normal volume uses about 1W, no issues! 

They are very big though!!

Do you have any suggestions for a good speaker system that will fit the 1900?  Something smaller would be better but honestly I just need to know what will work.  The connecting outlets on the 1900 seem very specific.

Hi Todd,

We can get ANY speakers (either powered or unpowered, B&O or other brands) working with your Beomaster 1900!  For example, the newer powered Beolab 6000 or 8000 speakers are good value at the moment and these can link to the Beomaster via a simple converter:-

You can connect nearly any Beovox passive speaker to the BM 1900, I would go for Beovox S 45 early model or S 45-2, both 3 way speakers floor standing, or one of my favorites P 45 3 way speaker wall hanging

Any idea where I could get any of those speakers?  I checked eBay but to no avail...

Any idea where I could pick up any of these speakers?  I checked eBay but couldn't find anything.

Keep checking they will be there sooner or later, but be careful that you choose a good seller and be prepared that any speaker this age will need some work.

S45-2 speakers would be the best but seriously, you can use any passive speakers you like. You just need the right plugs for the amplifier. I use BBC LS3/5A speakers rather that B&O.