JL Audio Fathom

Dear @jastralfu  : In a critical 90hz frequency and does not matter what that 8950 can't handled it and the problem is all what surrounded that reproduced 90hz frequency as the overtones/harmonics that puts colorations in the mid range and even in the HF and obviously in the mid-bass.

No single amplifier where the audio signal must pass through transformers/autoformers instead directly to the output bipolar devices could be considered up to the task.

Sorry @upstateaudiophile  but I'm not talking of what you like it but what is rigth and what's wrong because these are the facts the " I like " has no objective foundation it's just what we like but facts are way different.

R.

@rauliruegas I’m not entirely sure of what you are saying. You mentioned low impedance as a limiting factor that the Mac can’t handle then switched to the autoformers can’t recreate the frequency without some sort of coloration. I have an admittedly limited understanding of how the autoformer works and why it is used however I have never read anything that indicates that it’s incapable of effectively recreating an audio signal in a particular frequency. I believe the Macs are relatively linear in their output. I’m sure the engineers at McIntosh have sorted this all out and know better than you or I, so I will defer to their expertise. My ears tell me they have done an excellent job. If there is some literature you can point me to that explains your position I would be happy to read it.

Just use the 2 ohm tap. the autoformers are use to match the load to the amp so it does not need to work as hard. Using the 2 ohm tap should make the highs sound a touch softer, effectively making the bass louder.

if you want a deep dive into how a Mac work the stereophile review of the MC462 is a good read… it also has near perfect measurements.

Dear @jastralfu  : Look, Mac works with autoformer from 1967 but that just not says they are perfectly rigth about because it's not. Any additional device in an ampp design ( as the autoformer ) only degrades the MUSIC signal no matter what.

No, that Mac is not really ready to handled with aplomb that 1.1 ohm speaker impedance.

Those are facts that I can see or you don't understand very well or you have a misunderstood about.

@james633  is rigth: " autoformers are use to match the load to the amp " but not for that to low 1.1 ohm impedance in a critical and very often present in MUSIC as 90hz and wha surround that 90hz.

That's the issue.

R.

@rauliruegas you keep saying the same thing over and over without explaining what you mean.  There is also no 1.1ohm impedance in the curve for the Sabrina that I have seen.  Sorry, I'm hijacking this thread and I don't want to do that.  I understand the autoformer matches the load that's how it is able to consistently deliver the same wattage regardless of load.