8 ohms or 4 ohms?

[max11499439z]

My setup:
Rotel 1070 CDP
McIntosh MC2205
Martin Logan Ascent Speakers
SiganlCable Ultra cables

Is it sonically better to use the amp inputs to drive the speakers at 8 ohms or 4 ohms? I could even go down to 2 or 1 ohms. I'd appreciate your thoughts.

[basite]

use the 4 ohm taps on the Mac...

the Martin logan Ascent are 4 ohms nominal, and they dip to 1,2 ohms at 20khz...
so, 4 ohms would be the best match, theoretically, but experiment with the 2 ohms tap too (maybe...)...

4 ohm tap should/could make an audible difference compared to the 8 ohm tap...
Keep them spinning,
Bert.

[max11499439z]

Thanx for your helpful input. Could you expain the reason for potentially better sound with 4 ohm output. Is it that the impedences of the amp and speaker are better matched with the 4 ohm output?

[basite]

the Mac works with output transformers, this is something you usually only find with tube amps, because tubes have a much higher output impedence (like 800 ohms or so), which wouldn't work at all for driving speakers, so they have to transform the impedence so it can be used to drive a speaker.
insert: output transformer, or autoformer, as Mac calls it...

Mcintosh also uses these output transformers on their solid state amps, which also contributes to the Mc house sound. Transistors (solid state), don't acutally need these transformers to work properly to drive speakers, but it does give a very stable power output, and as I already said, it contributes to the Mc house sound.
the transformers need to be matched to the transformers though (otherwise, the whole idea of the transformer is pretty much lost...), so try matching the output taps to the speaker's impedence...

it could be that you won't hear a difference at all, could be that your jaw immediately drops to the floor too... it all depends on your speakers.

Keep them spinning,
Bert.

[Kevio]

Match as best as you can as per Basite's suggestion. If you use too low of a tap, it won't be as loud as it could be. If you use too high of a tap you'll potentially overload the output transformer and it will overheat and/or produce excessive distortion.