Amplifier circuitry-4 ohm vs 8 ohm


Obviously there are different wires leading into the four or eight Ohm taps on the back of an amplifier from the one amplifier.  The single amplifier at some point splits the signal going into either one of these Ports.  What differences are there in the circuitry?

Maybe this will help me better understand the difference between these two taps. I believe 4 ohms is a wider more open path for voltage to flow. So when you're speaker attempts to go lower, which requires more power, the 4 ohm more easily allows this to happen with a better outcome. Or maybe I got this wrong.

 

 

 

emergingsoul

I believe tubes represent a more even profile of the harmonics, elevating the harmonics in the upper range better than solid state.

@emergingsoul 

This is incorrect. Tube amps tend to make more the lower ordered harmonics, the 2nd and 3rd, which is the source of their 'richness'. These two harmonics are at a high enough level in tube amps that they are able to mask the higher ordered harmonics, which are heard otherwise (if not masked) as harshness and brightness. The class D amp I'm playing at home does exactly the same thing, and since the distortion signature of any amplifier is the way that amplifier sounds its not a surprise that this amp sounds exactly like a very good tube amplifier.

I have ARC amps from 1995, 2018 and 2023, and they all have 16, 8 and 4 ohm taps. My ELS speakers impedance curve indicates about 30 ohms at 20Hz and 3 ohms at 20kHz. The 16 ohm taps sound excellent. The 8 ohm taps do too, but with a different balance and therefore dynamic.

@emergingsoul:

I doubt any two amps, especially a tube amp and a class D amp, sound "exactly like"....

@williambf

Very interesting, you make up above.

It seems the impedance curve of a speaker is very important in assessing Ohm range throughout the frequency range. And there by it seems selecting the proper tap somewhere within the ohm range on the curve would influence how each tap may perform.

 

Very important and I’m gonna get the impedance curve for my speakers which seems a good idea, because I like to think I’m somewhat smart about this sort of thing albeit very slow

@williambf Wrote:

I doubt any two amps, especially a tube amp and a class D amp, sound "exactly like"....

I agree 😎

Mike