While building custom amplifiers over 20W I found that my bookshelf speakers were too weak to handle the power and I never test amplifiers on my good home stereo speakers so it was time to build a custom set just for testing amplifiers over 50W. The result was a modest 80W RMS 3-Way speaker system.
In the photo you can see the completed set sitting with the Prototype Power Amplifier on the right speaker and my 5-Disc CD Player sitting on the floor to the right of that.
I found the actual drivers on clearance through MCM Electronics. The wood is dense particle board from an old display cabinet from a retail store. The speakers are Onkyo brand, and are rated at 80 Watts RMS in a 2 cubic foot sealed enclosure. These enclosures were matched perfectly to these speakers and sounded great! The whole system topped out at over 100 Watts peak (85W RMS)!
Two things you can't see in the photo are that both speakers have insultation for dampening as well as caulking in all the joints to properly seal the cabinets. There are also rubber gaskets around not only the drivers, but the speaker terminals in the back. To my knowledge these speakers are still in use today in NY.