6moons fullrange measurements - Lowther vs. Fostex

[planet10]

Originally Posted by siavashr

think what Martin King find so magical about these speakers is due to their high ( IMHO unacceptable) 2nd order harmonic distortion.

I'm gonna guess you don't know who Martin is.

dave

[siavashr]

Originally Posted by planet10

Did you do this blind. As in before you saw the distrotion curves?

Geddes studies have shown the distortion needs to reach some serious levels before it is audible.

dave

Its good that you asked. It does not take golden ears to tell the difference between even order and odd order HD or the absence of them . I believe every one can do it with a little experience and training. You just have learn their effect on the sound. I actually try to predict the HD levels of speakers before testing them and I'm right most of the times. Except for high-end drivers with very low HD. For those I have no clue!

I think some people enjoy certain types of HD in their systems. I think it is a matter of personal preference and the type of music one listens to.

A while back, I actually did some experiments where I added different levels of odd order and even order HD to a song using Matlab to see their effect. They actually confirmed my previous perception of the effect of HD. I can send you the music files if I find them.

I also noticed on your website that you live close by. I should drop by to give a listen to your speakers!

[planet10]

You should come over for VI diyFEST this summer.

An aside to the distortion thing is that the amp + speaker can have less measured distortion than either separtely. One of our (dutch?) members has shown this.

dave

[siavashr]

I was always searching for such an event in Vancouver area but never found one! I would love to attend!

I also think it is possible for the amp + speaker combination to have a lower HD than each one alone. Since HD is a result of non-linearity in the transfer function of systems, I think it is possible that the non-linearities in the transfer functions of a certain amp and a certain speaker to cancel out to give a more linear transfer function for the whole system.

I was actually thinking on a DSP system just for the purpose of non-linearity compensation, then I searched the internet and found out I'm not the first person to think of it...damn!
AES E-Library: Simplified Loudspeaker Distortion Compensation by DSP

[siavashr]

There is also this patent!
Method and apparatus for compensating for nonlinear distortion of speaker system - US Patent 7359519 Description