JL Audio Fathom

Make try the 2 ohm tap on the McIntosh. 

@rauliruegas where does the Sabrina go as low as 1.1 ohms? I’ve seen 2+ but not anything as low as you state. I think the MA8950 would drive them well just as @upstateaudiophile says as it will drive 2,4,8 ohm loads with 200W regardless of which tap is used. I disagree that the MA8950 is a mediocre integrated amp.

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.