Lots of theory here, but talk to the maker, Jim Salk. He's been exhibiting with tube maker McGary audio. Here, the speakers are 87 db driven by a 30 watt amp.
https://theaudiobeatnik.com/california-audio-show-drews-picks-for-the-5-best-rooms/I asked Jim exactly these questions when I bought my Salks. No problem driving them with a 30 watt tube amp, he said. At first, I was going to buy his little 82 db Wow1 monitors. He said this about 82 db monitors:
"I would look for a minimum of about 100 watts for solid state and 30 watts for a tube amp (the more the better in both cases). The reason is that the way these amps clip is different. The solid state amp will be linear until it reaches its maximum output and then clip, becoming overly bright and edgy. As you increase the gain (volume) with a tube amp, it is linear to a point near its maximum output. As you increase it further, it acts somewhat like a compressor and simply limits the maximum output. So it is “soft” clipping as opposed to “hard” clipping. For that reason, you can get by with less wattage with tube amps. People who love tube amps love the liquid-smooth midrange they provide. But they don’t have quite as tight a grip on the bass. If you want tighter bass, then solid state becomes more attractive. The bottom line, then, becomes “what is more important to you...liquid smooth performance or tight bass performance.” Other than that, as long as the basic amp design is good, wattage becomes the most important (since amps are very accurate compared to speakers)."
What this says to me about your present 88 db Salks is that you should be fine IF Raven is well made, again depending on how loud you want to go. And it may be an open question how well they grab the bass. But you have a sub, right?
Talk to Jim.
