For passive speakers a stereo or AV receiver or a mini or integrated amp. What is your budget? What is a nearby town or zip I can search for used options? Reply here or chat.

The compact 4" Klipsch R-41M passive speakers are for a small room?

Klipsch R-41PM are the powered version with a built in speaker amp and Bluetooth.

Or lower cost Klipsch KD-400 $149 powered speakers with Bluetooth.

Mini amps to power the passive R-41M. These 2 amps have 3.5mm input instead of RCA so use the correct cable or adapter:

• Fosi Audio BL20A $68 has a remote, subwoofer output and Bluetooth.
• Fosi Audio DA2120A $126 has a remote, subwoofer output, USB and digital optical inputs and Bluetooth.

Or RCA input mini amp Aiyima A08 $139 has a subwoofer output and Bluetooth.

Plus speaker wire, pure copper oxygen free 16 AWG or optional thicker 14 AWG. Then How To Strip Speaker Wire and How to Install Speaker Wire.

Audio Guides, Speaker Placement, Accessories and Vinyl Care

Receiver plus passive speakers sounds like something you don't need. Do you think you would want this in the future?

R-41PM for 299 (239 on ebay unopened box in texas or opened in cali), or R-51PM for 328 should sound hot and not take up extra space (249 for the R-51PM on ebay located in michigan)

Some of the larger Edifier would probably work, Maybe the PSB AM5, Klipsch R-41PM, AudioEngine apparently makes some decent pieces as far as active speakers

I might consider a separate amp and passive speakers though

RT81 to Spinbase, you can use either phono preamp:

• Turntable switch set to LINE > speaker LINE input.
• Turntable switch set to PHONO > speaker PHONO input.

However the older RT81 is not worth buying anymore since the newer improved RT82 for $50 more adds a $100 increase in component and performance value since it adds the new optical sensor speed controlled motor for lower wow and flutter and speed variation and the speed won't drift since the senor is monitoring the speed 400 times a second. Connect the RT82 to the Spinbase PHONO input. Pass on the RT83 since the cartridge is not any better.

For the speakers consider that for $85 less you could get a pair of compact 4" mid bass driver speakers that gives you stereo separation, imaging and sound stage for better sound and performance than the single SpinBase.

4" Klipsch KD-400 $159 powered speakers plus Art DJ Pre II $65 phono preamp that should be better than the one in the RT81 or Spinbase.

Or for $20 less than the Spinbase, 4" Klipsch R-41PM $279 have a built in phono preamp.

Audio Guides, Speaker Placement, Accessories and Vinyl Care

I meant North America? Europe?

the Edifer are apparently OK. https://www.amazon.com/Edifier-R1280T-Powered-Bookshelf-Speakers/dp/B016P9HJIA

The Klipsch are better https://www.amazon.com/Klipsch-R-41PM-Powered-Bookshelf-Speaker/dp/B07FK48JW8

Those speakers do not include a built in pre-amp, some speakers that do include it are the Klipsch R41PM (on sale now) or the Kanto YU6 (not on sale)

Or you could get the Edifier with an external pre-amp (Pyle or ART)

Whats your current TT, why does it need upgrading?

The r-51m are passive speakers and would need an amplifier.

You would need powered speakers like the r-51pm or r-41pm if you are stuck on klipsch.the turntable is a good starter