New efficient speakers - best way to keep noise floor down?

good point, I do have a passive preamp (well in tube mode it has 1DB gain). My phono preamp does have adjustable gain settings. Right now I'm on the 48db setting, I suppose with the new speakers being efficient I could lower that to the 42db setting or even the 32 db setting (has the best SNR of all 4 settings). Keep forgetting my phono has those adjustable gain settings... This makes me feel better :)

The status quo for tonearm to phono stage cable’s is horribly flawed. You can help keep the signal free of interference by changing from “shielded” cables that use one of the signal-bearing conductors as “shield” to shielded twisted pair cable and XLR connectors. The shield on this cable is connected to the tonearm ground, and is grounded at your phono stage. This is your best opportunity for rejecting  induced noise on a vinyl playing system. 

Edit: lowrider57 said it more succinctly

I have very efficient speakers too (96 db/Watt), in a vinyl-only system, and have struggled with this. If your vinyl source is quiet with normal speakers, it will be equally quiet with efficient speakers - i.e. the efficiency of your speakers has no bearing on your perception of source noise. This is because you simply adjust your preamp’s volume control to get the signal level you need to achieve listening levels - and for efficient speakers, this will necessarily be a much lower volume setting, which rejects the source’s noise floor exactly in proportion to its signal (i.e. the signal and noise get equally attenuated, and then equally "amplified" by your sensitive downstream amp & speakers). Your vinyl source’s noise floor is a function of the quality of your phono stage combined with the output of your cartridge.

Where you can run into problems elsewhere in your setup is if your preamp and amp don’t have an adequate signal/noise ratio. That’s because these are your active stages downstream from your volume control - so any unused gain is going to contribute to your noise floor, with no chance to reject it via volume dial. This is going to be most egregiously demonstrated by tube preamps, especially ones with high gain. My tube amps are VERY sensitive amps (275 Watts / 1V input) so any residual noise from the preamp is going to be made extremely apparent. I’ve tried more than a few tube preamps, and the only one so far that’s been dead quiet in my setup is the Audio Research Ref 6 - very impressive! Stereophile posted some nice measurements of the REF 6 in their review, so I’d make sure to have a preamp at least matching its signal/noise.

In recap - use a preamp with as high a signal/noise ratio as possible, keep its gain on the lower side as much as possible, and if you can utilize amps with a lower input sensitivity (or add attenuators to the inputs if you have excess system gain to spare) then that will help too.

@sleepwalker65 brings up salient points. While you may not have much control of these factors, a low noise floor requires (systemwide) a proper grounding scheme. Including shields and tonearm internal wiring.

Note: this refers to *how* the wiring is implemented *not* how fancy the material are.

No efficient is not the key ,it is the quality of the drivers , 
the quality of the crossover, as well as the cabinet design .
i owneda Audio store  and some of the most efficient we’re actually some of the worst when put under a complex load .
the sum of the total  as is mentioned  means the most .
for example a Accuton ceramic driver has lessmoving mass 
then a paper cone and far less distortion , but because of its magnetic structure ,voice coil ,spider not as efficient to drive .
also much more expensive to make.