Quote:
Originally Posted by santosh.s  Nope, I believe I am NOT confused. I think damping (both speaker or amp) and total Q are different ways to look at one and same thing. The contribution of amp's damping factor (more accurately its output impedance) is to increase electrical Qe of the speaker (and hence its total Q). In ideal case when amp has zero impedance, original Qe will remain unchanged. Even if Qe increases, it may not affect total Q much if Qm was dominating. And I suspect Qm might be dominating in tweeters while Qe in subs. |
Sorry Santosh, there were some wires crossed earlier today. Now I get what you are talking about. I re-read all the posts and even the ones after the one quoted above and not that we are on the same page let me add....
Yes it is obvious that a woofer mechanical Q is much higher (huge spider/surround) in fact in many cases Qms = 10 Qes; and in a tweeter the electrical Q is higher and Qms < Qes or often Qms is 0.5 Qes.
However what happens here is that Qts in a woofer is almost = Qes (since Qms is much higher) and in a tweeter Qts is "about" 0.5 Qes (since Qes and Qms are about equal or atleast not of the order of 10x). Also when the speaker is put in a closed box (lets keep it simple and assume a closed box) the Qtc is always the woofer's Q in the box. The tweeter being sealed is not in the mechanical circuit.
So the damping factor (ratio of speaker's imprdance over amp's impedance) really affects the bass more.
FYI. remember because damping factor is dependant on the amplifer AND speaker in question it is never really just one number (so many manufacturers quote a damping factor approaching 100 as if 100 is some magical number). To a lesser extent DF will also depend on the type of music you play and how loud you play it. So where do manufacturers get this magical number from?
Seach me. I just use this number as a generic guide to explain things to my friends. A high dampoig factor really means a amp with a very low output impedance not nescarrily a good souding amp (just ask any valve amp aficionado).
Santosh, since you have read SL's website You must have also read that of John K. (Zaphaudio). John has tested a bunch of drivers for IM and THD and all sorts of stuff. Fostex's fared rather poorly in these tests.
Der Alte, Tube amps are so dependant on their "iron" it is their weakest link. Even today finding good iron is hard. Building a good OTL is harder still.
LBM, talking about just a maximally flat frequency response does not divluge the full picture. Impluse response, decay etc. are also to be considered.