Current optimized or voltage optimized speakers?


Just read a recent post from an old thread, and an old question, that has kicked around the Forum for some time. Back in "09," a member wrote:

"Read Atmasphere's posts and white paper. Amp choice [is] highly dependent on whether your speakers are current optimized or voltage optimized. Which strongly suggest[s] that at least a part of 'system synergy' can be predicted."

The question for the Forum is how can one know whether speakers are "current optimized or voltage optimized"?

My layman's understanding of Ralph's whitepaper is that most solid state amps are based on the "voltage paradigm" (voltage is constant and watts change with load) and that most tube amps are based on the "power paradigm" (voltage changes with load, but watts don't change very much) [or is it the other way around?? LOL]

The old post quoted above suggests that some speakers will work better with solid state amps and others with tube amps -- let's leave electrostats and maggies out of the discussion. I'm thinking about the vast array of dynamic speakers out there.

So . . . restating the question, how do we know whether dynamic Speaker X will work best with a tube amp or a solid state amp?
bifwynne
Bruce, keep in mind that there are many shades of gray in between the black and white extremes. And that applies to both speakers and amplifiers.

While there are some speakers that will clearly be mismatched when used with one or the other kind of amplifier, tube or solid state, there are a lot of speakers that will do reasonably well with either. In those cases, the two resulting presentations will certainly have different sonic characters, but the differences will be such that room acoustics, personal taste, and the intrinsic sonic characteristics of the particular amplifier will determine which is preferable.

And while ALMOST all solid state amplifiers will fall into the voltage paradigm category, tube amplifiers will fall into the power paradigm category to varying degrees, depending primarily on their output impedance (output impedances for 8 ohm taps being equal to 8 ohms divided by damping factor), and its relation to the impedance of the speaker that is being used. As a general guideline, which is applicable to the kinds of damping factors that are most commonly encountered (i.e., those greater than about 2 or so), and to the kinds of speaker impedances that are typically encountered (i.e., nominal values that are in the 4 to 8 ohm area or thereabouts), the lower the damping factor (or equivalently the higher the output impedance), the greater the degree to which the amplifier will behave in accordance with power paradigm principles. (That guideline but may not be applicable in some extreme situations where the numbers fall outside those limits). ARC amps tend not to be as far into the power paradigm category as a lot of other tube amps, I believe mainly because their use of feedback tends to result in lower output impedance.

Take a look at the impedance curve of the Harbeth M40.1. It fluctuates all over the map, yet that speaker is widely used very successfully with tube amps having significantly lower damping factors than yours.
I believe a Power Paradigm amp (tube) will put out the same wattage regardless of impedance peaks.
No, it won't eliminate variations in power delivery as a function of load impedance. What it will do is to REDUCE those variations, in comparison with a solid state amp. The degree of reduction will depend on the relation between the output impedance/damping factor of the particular tube amplifier and the impedance characteristics of the speaker.
But if I was starting from scratch and already owned the VS-115, should I have looked to match my amp with a different type of speaker; and vice versa, if I already owned the S-8s, should I have looked to match the speakers with a different type of amp.

I think that's the bottom line Q here. How does one make an informed decision?
We had a related discussion a little under two years ago in this thread. For comments that are specifically relevant to your situation, see my two posts in that thread dated 1-5-11.

Best regards,
-- Al
Thanks Al. As my system description says, I'm done with major changes and upgrades for now. Will still do some tweaking here and there, but my main focus will be on buying good quality vinyl and CDs. And then just enjoying what I have. As I've said before, ignorance is bliss, because I really enjoy whatever swill is coming out of my rig.

As I've also said before, something must be right because last night my wife came running into my man-cave/listening room and went nuts because the bass was shaking the floors. I think I was playing a new CD: T-Bone. Good music.

Funny thing is that my wife ran over to the sub and starting turning knobs and flipping switches hoping to turn the bass down. I "politely" [sic] invited her out of the basement. What she wound up doing was turning the gain on the woofer up to maximum. Ha Ha.

Well, I still find the technical side fascinating. So I hope guys like you don't mind my questions. I'm really trying to understand what makes audio sound good or bad.

Thanks to all and best wishes for Happy Holidays and a Happy New Year!!

Bruce
If you don't ask questions sometimes its harder to get answers :)

Enjoy the music.