Double down, good or bad?


I came across this article on Atma Sphere's website:

http://www.atma-sphere.com/papers/myth.html

In short, Atma Sphere believes having a power amp that is capable of doubling its power when impedance is half is not necessarily a good thing because speakers in general do not have a flat impedance across all freq range.

On paper, it does make sense. Though I am sure speaker designers take that into consideration and reduce/increase output where necessary to achieve the flatest freq response, that explains why most of the speakers measured by Stereophile or other magazines have near flat responses.

But what if designer use tube amps to design his speakers, mating them with solid state should yield higher bass output in general? Vice versa, tube amps yield less bass output at home?

I have always been a tube guy and learned to live with less bass weight/impact in exchange of better midrange/top end. Will one be better off buying the same exact amp the speakers were "voiced" with, not that it will guarantee good sound, at least not to everyone's ear.
semi

Showing 3 responses by gregadd

I always thought that doubling down was the sign of a technically correct amp that could handle the "WICKED LOADS" (without oscillating or otherwise becoming unstable) rather than a requirement.
I would never go so far to say it should be avoided. Ralph knows a lot about amps. By his own admission he pushes the technical envelope and is quite a design radical. His amps don't double down. I am sure he has had to explain that to a lot of potential cutomers.
We can conclude then that a technically correct amp is good. Doulbe down if done right is good. See(hear?) Bryston amps. It depends on where you are going and how you want to get there.
If you pass on Ralphs' amps merely because they don't double down you are making a mistake. On the other hand there are speakrs that should not be mated with Atmasphere.
Ralph just thinking off the top of my head.Because most speakers report "nominal" impedance and thier real impedance curve is all over the place, a doubling down amp would create serious spectral balance problems.
Looking at a frequency versus impedance curve like my Martin Logan CLS the high frequencies(2 ohms) would be driven 800 watts where the Low frequencies (8ohms) would be driven at 200 watts. Intuitively this would seem to cause spectral balance problems.
Does this make any sense?