16 ohm speakers: Pros & cons

Even with solid state amps that put out more power into lower impedance loads, sometimes you get better sound driving a higher impedance load. I remember years ago building a homebrew that had two woofers, which of course I wired in parallel. Just for fun one day I wired the woofers in series on one of the speakers, scaling the crossover components accordingly and padding the tweeter way down to match sensitivities. Adjusting for equal volume, the 16-ohm version sounded better on my inexpensive NAD integrated amp than the 4-ohm version did. The sound was more effortless is my recollection (that was over 20 years ago). For some reason (better damping factor maybe) that particular solid-state amplifer sounded better driving a high impedance load. Since I didn't listen very loud and didn't need the extra headroom, I converted the other speaker to 16-ohm configuration and left them that way until the speakerbuilding bug bit me again a few months later.

Duke

Hi Eldartford,

You're right that I made a lot of changes in that system as described, but I didn't give all the details of what I did. I used a Nakamichi active crossover in comparing the 4 ohm and 16 ohm configurations, which took the passive crossover parts out of the equation and levelled the playing field quite a bit more. But I had to build the passive 16-ohm crossover to see if it would sound better than my (optimized) passive 4-ohm crossover, which I'd tweaked to sound better than the generic second order active filter.

Later on I built a subwoofer and once again found the 16-ohm configuration to sound better (tighter), presumably due to the amp's higher damping factor into the higher impedance load. In this case, I did miss the extra headroom that the 4-ohm configuration gave me over the 16-ohm configuration.

In both of these examples, I was using relatively cheap solid state amplification, so the trend may not hold up for better quality amplifiers.

Recently I did a fair amount of experimenting in the course of designing a homebrew speaker system to work well with my parents' little JoLida tube amplifier. In this case, I found that a 16-ohm speaker driven off the 4-ohm taps sounded the best (I experimentd with 4, 8, and 16 ohm versions of the speaker using either one or two small full-range drivers). The differences between the different speaker impedances were somewhat subtle, but the difference between the 4 and 8 ohm taps on the amp was obvious and dramatic. That being said, I am not claiming that the 4 ohm taps will necessarily sound best in anyone else's system - but they sure did in this one.

Duke

Hi Edlartford,

I don't have any dual voice coil drivers on hand. But you are right, that would probably remove all significant variables from the comparison between 4, 8, and 16 ohm formats. Unfortunately, I'm not nearly curious enough to buy a dual voice coil driver or two just for the experiment.

Cheers,

Duke