@phays245 You might should have led off with your last post. Your problem, as you describe it now, is that you are unsatisfied with the sound of your current speakers. Given the fact the bass drivers in a ported two-way design are only 7 inches in diameter, there may be no amp on earth that can help you get the sound you seek from that speaker. You might be happier with a sealed acoustic suspension design or an open baffle speaker. If I were in your shoes, I would try to expose myself to different types of speakers, and save up for something truly worthy of your amplifier. Dealers, friends, audio shows could all give you such exposure. As other have said, look for a sensitivity in the upper 80’s or above.
The wattage rating of a speaker simply describes its power handling abilities. Most of the time, at normal listening levels, you are unlikely to exceed 25 Watts; only when you really crank it up does the power handling become an issue, and only then when the power being required by the speaker (at the volume selected) exceeds the amp’s ability to deliver it. If your amplifier doesn’t have the ability to sense that you are trying to over drive it, you can’blow up the amp, or the speakers, or both. I’m not sure if the Marantz has this circuitry or not. It’s a question worth asking. Speakers and motors (actually a speaker is a motor of sorts) are dumb; they will destroy themselves trying to do what you ask of them. 

Roughly speaking, a 100W/ch amp will play 5dB louder than a 30W amp, unless the smaller amp has extraordinary peak capabilities. It's also.likely the larger amp.will be more comfortable with complex low impedance speakers. As far as upgrades go, the new KEF Q7 Meta is a lot of value for $2k a pair. The Monitor Audio Silver 300 7G are a bit more, $26-2800, but are a step up in overall quality, especially the cabinets. These are two clear leaders in this price range, but you may find others from Revel or the Polk Reserve line to your liking. These are are middle/middle speakers: middle speaker from the middle tier of these very high quality and well known brands. 

My take: 

(1) 50K-foot level overview in general:… repost…

Audio - amps vs speakers 

The philosophy is clear. An affordable speaker with decent amplification (and source) makes a lot more sense than an expensive speaker with a cheap amp (and source.)

 Amplifier power ratings

Another word on power:, if your speakers are demanding to drive you’ll need a suitably muscular amplifier to support them.

Don’t look only at the posted headline power figure - watts per channel  (wpc) in isolation are meaningless.

Do consider It’s available “grunt ” ,,,,(ergo  the amplifier’s available current measured in amps that matters most. )

Go see what happens when the speaker impedance drops to four ohms. If the number nearly doubles, then your amplifier has good current delivery and will be capable of driving more demanding speakers.

(2) Lots of background reading available…. Do your own research , here is just a sampler.

What Specs Really Matter in Audio Amplifiers?https://www.youtube.com/live/vw1SG9tGun0?si=O0QjaCq2Z5q8zKEK

Clearing Up The Mystery & Confusion With Amplifier Power Ratings

https://www.prosoundweb.com/clearing-up-the-mystery-confusion-with-amplifier-power-ratings/

Thank you to everyone's help and suggestions.I will read those helpful links.