Now first of all our ears were designed to hear up to 20,000 cycles there-abouts if not perhaps more, a scientific fact I can't really argue against.  So I find it difficult to accept a proposition that we don't enjoy listening to sounds from 2,000 Hz on. 

What seems much more likely is that you don't like the way that your tweeter sounds, and the more tweeter you hear, the more intolerable you find the music.  So you are rolling it off to avoid the horrible screeching. 

Could the rta be inaccurate?  Maybe.

You could try substituting other speakers or other tweeters and seeing if you still have the same reaction.

In any case, just tune your system the way you like it best. 

Adrian

stuck.wilson wrote:

I just started using RTA as a method of evaluating my results with my own 2 way speaker system, and I'm finding that I'm ending up liking the sound of my system a GREAT DEAL MORE without the absurd notion that 20-20k is what we 'need to hear'.. but it seems even more extreme than this.

2 way speaker system can not be 20-20k. It can hardly be 63-12.5K…

stuck.wilson wrote:

where it gets strange is-- after 2k-- if i'm still pleased with the sound-- rolls off DRAMATICALLY-- where i'm at LEAST 10db down by 10k, and further from there-- to where it looks as if it's rolling off a total of almost 20db from 2k- 20k!  when i lessen the reins on the horn-- the sound is SO agressive and unlistenable (on a BMS 4552nd -- the opinion of which you've shared) that i can't stand it.  upper midrange HELL. period.

It might be because many reasons but never take electricity out of accounts. The 4552nd has ligh cone and they uselessly becomes very flat but aggressive with bad electricity.

stuck.wilson wrote:

so i wonder if it's the 'chicken' of 20-20k being a myth, or the 'egg' of my misuse of a 2 way horn/direct radiator... a BUNK driver,  or in fact, just all three. OR.. it's a matter that the RTA and/or my microphones are just THAT inaccurate.  or i'm a caveman.. which is also possible (!)  .

A horn is 3-4 octaves devise. The 20-20k is not a myth but to get  it properly is difficult and not only at speaker level...

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=755

stuck.wilson wrote:

any light to shed on this phenomenon?  i realize that there could be an incredibly complex bevy of factors at work here..  but i wonder if anyone else has had a civilized experience with listening this way.

Dan, I do not know where you have seen a lot of food for thought, all posts above were about nothing, as I said I really do not know what this thread is all about. If your interest is the relationship between measurable and auditable and extreme frequencies then it is a noble subject but I don't think it is what you are talking about. You were talking about general applications of RTA, but I generally have difficulties is to talk with audio people about RTA.

Generally a RTA’s are very accurate and the microphones are the one which create discrepancies.  Getting at good-quality an instrumental calibrated microphone is mandatory.  An alternative way would be to build a correction chain in mic-preamps and to calibrate against reference microphone… however a properly calibrated microphone and RTA are just very beginning of the entire RTA saga.

Audio people attribute to RTA some kind of supernatural meaning, without spending efforts toward interpreting the RTA measurements. RTA measurements themselves are completely bogus and irrelevant unless they are viewed in intelligent format. Where to measure? How to measure it? What kind signals to use? How to correlate all conditionals parameters with what RTA outputs? And of course the most important is how to or correlate the result of RTA measurements we is listening experiences of the given playback installation. I do not know how for others but it took for me approximately 5 years to measure and to listen until I begin to understand what is really important in the RTA interpretation.

Also one very-very important moment that unfortunately many audio people do not “get”. RTA shows just amplitude but does not show the reasons for that amplitude.  We, as humans of course register amplitude but we also are capable to recognize and to be influenced by them means by which the amplitude was reached. That is very imperative concept because the correct understanding of amplitude is possible ONLY in context of the methods which created that amplitude. So, answering the questions that you did not ask: the linearity of frequency response is very positive and very important thing but only if the linearity was achieved by only “proper ways”.

Fundamentally, you must examine the RTA with a system with a known frequency response to know if it is accurate, or you must obtain a second RTA from a friend which is known to be accurate, to compare against your own RTA.

However it is always a matter of interpreting the RTA results.  One goal is to have a flat frequncy response, and we are inclined toward this by the RTA.  But this has only a little to do with sound since frequency response is only one of many factors going into accurate musical reproduction. 

Just don't fall into the trap that there must always be some correlation.  You can have a flat frequency response and still have bad sound, therefore bad sound doesn't necessarily correlate to frequency response abnormalities.

Likewise, improving frequency response will not necessarily improve the sound, since it may simultaneously make something else worse.

Adrian