Which amplifier tap... 4 ohm or 8 ohm

Randy Myers

Randy Myers

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I have a new pair of Harbeth arriving today. My McIntosh amplifier has 2, 4, and 8 ohm speaker connections. The Harbeth are 6 ohm. Which tap should I use 4 or 8? I know the normal answer is to try both and see which I like better. I have always used the 8 ohm connection on this amp, but I am asking opinions. Would the 4 or 8 connector be better, and why would you think so.

Thank you
 
I'm not familiar with your amp but I thought many of the Mac amps used autoformers where the speaker impedance wouldn't matter.

I've always heard the Harbeth are easy to drive although inefficient. My thought would be to use the 4 ohm tap which would be designed to handle lower impedances than your other taps. 4 ohm should just produce a bit more current which I feel is a good thing.

I once had a CJ power amp with the option of 4 or 8 ohm taps, I also had 6 ohm speakers, I was told by CJ to use the 4 ohm tap.
 
Mr Peabody said:
I'm not familiar with your amp but I thought many of the Mac amps used autoformers where the speaker impedance wouldn't matter.

I've always heard the Harbeth are easy to drive although inefficient. My thought would be to use the 4 ohm tap which would be designed to handle lower impedances than your other taps. 4 ohm should just produce a bit more current which I feel is a good thing.

I once had a CJ power amp with the option of 4 or 8 ohm taps, I also had 6 ohm speakers, I was told by CJ to use the 4 ohm tap.
Click to expand...
Thank you sir. The McIntosh does have autoformers, but also has 2, 4, and 8 ohm terminals. I will try the 4 ohm :)...
 
I talked to McIntosh and he basically said that either would not be an issue. He did suggest, as you did, to try both. He also said to see if I could find a review where they ran impedance tests on the speakers. I did and here are the results.
1746722479820.png
I would tend to think that the speaker never drops down to the 4 ohm range, and when they state that the speakers are easy to drive this is probably what they are referring to. I would also conclude that the 8 ohm connection is probably the best to use to start with. I also see what McIntosh is saying; that either would probably work just fine.

Agree?
 
I usually listen to each tap for awhile before I decide. The higher impedance tap will be louder so you have to adjust the volume to compensate for that. Looks like either the 4 or 8 ohm tap will work just fine.

To me that looks like an 8 ohm speaker with just a small dip below that.
 
So far playing using the 8 ohm and they are working great. I agree, it definitely look more like a 8 ohm speaker. Harbeth rates them at 6 ohm, but they might be a little closer to 8 than 6.
 
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