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 peterayer

I have a Pass XA.5. Its output doubles as impedance is halved. It replaced a Pass XA amp. Its output was constant. In my system, there is no comparison between the two. The XA.5 sounds much better. There is now much better control of the lower frequencies. Bass is more articulate, fuller and deeper. I'm sure results will be different for different amps and different speakers.

I wasn't aware that Nelson Pass thought his X series amp was perfect. That is a very interesting statement, er, question you pose.
Atmasphere,
Could you please elaborate a bit about the point in your last post where you say some speakers are more effectively driven by tubes and others by transistors. I do not see much written about this and am curious as to why. Thanks.
Ralph,Thank you for that explanation. I agree with your assertion that human hearing is the most important aspect of audio. I have found lately, that the speaker/room relationship or room acoustics may be the second.

I have not thought of or previously read about the "Power Paradigm" vs. the "Voltage Paradigm". It is interesting to view it from the speaker designer's point of view. I used to drive my Eggleston speakers with a Pass XA160 which had constant power to all loads, but I now use the Pass XA100.5 which doubles down as impedance is halved. The speaker's nominal load is 6 ohms, which means that the amps have about the same power. The latter combination sounds much better to me. From your explanation, am I to understand that the XA160 follows the "Power Paradigm" while the XA100.5 follows the "Voltage Paradigm" and that Eggleston probably designed the speaker with the latter in mind? It must sound better to me because the amp is better able to handle the load of the speaker. Or is it also because this paradigm places more value on low distortion, and that sounds better to me? This sounds overly simplified. Pardon me for my ignorance, but I'm interested and would like to better understand the issue. I'm fairly new to the hobby and don't have the technical background. Thanks.