Thank you for the response!
Let me ask you a few question (I’m sorry the more I learn the more questions I have!!)
1) I know the 803D can go as low as 3.2ohms, should I be using the 4ohms terminals instead of the 8ohms one?
2) You said that the 803D show “phase angle response of around 70° at 50 Hz” what does this mean?
3) My McIntosh MC252 has autoformers, doesn’t that help with ohms load or justify a better power supply than the MCA525?
I don’t want to make a mistake.
1) You can, but whether you should or not, depends on your actual "power" need.
2) At higher phase angles, such as 45° and higher, the amplifier will have to dissipated a lot of heat.
3) Mc uses those autoformers to lower the voltage to match the lower load impedance.
My two cents:
- I don't know where Verdinut got his 70° at 50 Hz, according to soundandvision.com, the 803 D measured:
B&W 803D Speaker System HT Labs Measures | Sound & Vision (soundandvision.com)
"Impedance reaches a minimum of 3.65 ohms at 99 Hz and a phase angle of –56.23 degrees at 50 Hz."
That's still quite high, so if you use the 4 Ohm tap the amp will run cooler but you will lose some dynamic output capability. That may not make any difference at all in terms of sound quality, depending on your actual power need, that you can use an online calculator to find out.
- Whether it is a "mistake" or not going from a MC252 to a MCA525 is a tough question as again it depends..
- The Mc amps have better specs than the Anthem but in an apple to apple comparison both should/will sound the same if used well below their output limits.
- You do have speakers that may be considered relatively hard to drive so in my opinion you important first step is to find out your power needs. The center speaker is likely worse in that sense (power demand).
Crown Audio - Professional Power Amplifiers
Peak SPL Calculator (homestead.com)
If you are not sure about the calculated results, post the screenshots and we can help verify and/or interpret them for you.