Rega RX Speakers match

Good evening,

Regarding these speakers RX Five (Rega) https://ibb.co/hySQ9s8

• System: 2.5-way
• Impedance Nominal: 6 ohms
• Sensitivity: 89dB
• Power Handling: 110W per channel

I was hoping to get some advice on the ideal matching for these speakers to achieve a good pairing. I admit I'm not very familiar with calculating the optimal power ratio (greater or equal to the power handling of the speakers) for the best match. I also understand that there are other factors beyond just technical specs, such as space, frequency peaks, and so on, that can influence this choice.

That being said, based on my past experience, I would prefer to avoid amplifiers with power output lower than 100W. Lately, I've been using a 65W amplifier on 6 ohms, and I believe this underpowering might have contributed to damaging a tweeter, even though I never noticed any significant audible distortion before the failure.

I like to push my system to fairly high levels, reaching a maximum of 90-96 dB of volume, with the speakers about 2.5 meters away from the listening point.

Given this, I am deciding between two vintage amplifiers and would like to understand the ideal pairing based on their power:

• Yamaha M4: https://hifi-wiki.com/index.php/Yamaha_M-4 

  • Continuous power (at specified distortion):
    • 8 Ohm: 2x 120 W
    • 4 Ohm: 2x 170 W
  • Dynamic power:
    • 8 Ohm: 2x 135 W
    • 4 Ohm: 2x 210 W

• Yamaha M2​: https://hifi-wiki.com/index.php/Yamaha_M-2

  • Continuous power (at specified distortion):
    • 8 Ohm: 2x 244 W
    • 4 Ohm: 2x 380 W
  • Dynamic power:
    • 8 Ohm: 2x 400 W

1. The M4 paired with my speakers would provide roughly:

   • Continuous power at 6 ohms: ~145W per channel
   • Dynamic power at 6 ohms: ~172.5W per channel
     This should already provide a good amount of headroom.

2. The M2 would deliver about 325W per channel at 6 ohms. I imagine that almost tripling the power compared to the speakers' rating might be risky at certain frequencies and SPL levels?

3. What are the precise calculations needed to determine the ideal ratio between speaker power handling and amplifier power?

I look forward to your kind clarification.

Thank you