DIY Waveguide loudspeaker kit - Page 203 - diyAudio
Go Back   Home > Forums > Commercial Sector > Manufacturers > GedLee

GedLee Home of the renown Geddes Loudspeakers

Reply
 
Thread Tools Search this Thread
Old 23rd August 2011, 05:11 AM   #2021
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
to me its very clear that this is what makes a lot of music sound like poorly produced

I wonder how to measure it
I know you can measure phase
but will it also show like distortion
  Reply With Quote
Old 23rd August 2011, 06:25 AM   #2022
soongsc is offline soongsc  Taiwan
diyAudio Member
 
soongsc's Avatar
 
Join Date: Mar 2005
Location: Taiwan
Reading data and finding problematic areas is an art itself. Reading distortion data is not so straightforward either because the cause of distortion is more critical than a single point measured value.
__________________
Hear the real thing!
  Reply With Quote
Old 23rd August 2011, 03:24 PM   #2023
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
Quote:
Originally Posted by tinitus View Post
well, there's no doubt in my mind that the worst distortion comes from crossover malfunction
I'm not sure what you mean here? Do you mean crossover distortion in a split supply amplifier? If so then yes, this is the most insidious type of distortion. I am rather surprised that you are not familiar with our work in this area. You should read it as it will answer your questions about measureing it etc.

But amplifier distortion is beyond the scope of this thread since we are talking about loudspeakers. In loudspeakers there are no types of distortion that are significant - unless the speaker is broken. Amps can have highly audible forms of distortion, but thats a topic for an amplifier thread.
  Reply With Quote
Old 23rd August 2011, 03:25 PM   #2024
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
I have a funny analogy describing how we may have to look at it

when looking for planets in orbit around a star/sun they can't see the planet because it radiated no energy or light, or too little to make it visible on such distances

but they fund that the gravity relation between a planet and its sun causes a small imballance
this imballance makes the light fluctuate
and when they see fluctuating light from a star, they know there is planet in orbit around it

what we want to find may be invisible
but its effect on other parts of the system may well be more visible
that is, if we know what we are looking fore
  Reply With Quote
Old 23rd August 2011, 03:28 PM   #2025
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by gedlee View Post
I Do you mean crossover distortion in a split supply amplifier?
I'm sure that is not what it is

we are definately talking about phase induced distortion, caused by crossover
  Reply With Quote
Old 23rd August 2011, 03:41 PM   #2026
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
let me show you my xo, to illustrate what I found

changing a resistor from 12ohm to 15ohm made a huge impact on the whole system, and the sound
almost like night and day
Attached Images
File Type: jpg Micoc 4way filter.JPG (61.6 KB, 440 views)
  Reply With Quote
Old 23rd August 2011, 04:23 PM   #2027
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
That is a completely linear situation, its not nonlinear distortion and not at all what I was talking about. You changed the frequency response of the crossover, of course you will hear that. Generally when people use the term "distortion" they mean "nonlinear distortion". Thats what everyone is going to assume you meant, thats what I mean. You can say "linear distortion" and it would be clear, but just "distortion" is going to be assumed to mean "nonlinear".
  Reply With Quote
Old 23rd August 2011, 05:43 PM   #2028
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by gedlee View Post

You changed the frequency response of the crossover, of course you will hear that.
well, how much do think the change from 12ohm to 15ohm in series with a 4mH paralel inductor would alter frequency response
you think it's just that

but I can't show measurements, so I will keep it and leave at that
and just enjoy it myself
  Reply With Quote
Old 23rd August 2011, 06:47 PM   #2029
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
I do resistance values in inductor legs to tenths of an ohm and include the actual inductors resistance, again in tenths of an ohm. So would three ohms make a difference? Heck yes. I suspect that it changed the Q of the highpass on that section by as much as several dB, maybe more. And yes these kinds of subtle things can make a lot of difference in just the frequency response. Certainly until you can rule out that explaination you can't offer up anything else since that is the most likely.
  Reply With Quote
Old 24th August 2011, 05:16 AM   #2030
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by gedlee View Post
And yes these kinds of subtle things can make a lot of difference in just the frequency response. Certainly until you can rule out that explaination you can't offer up anything else since that is the most likely.
I surely can
FR response changes are there, ofcourse
but its just a minor sideeffect
ofcourse it has to be considered too, in overall balance
but the phase variations have much more impact
I believe thats a fact

but why it can cause distortion I still don't know
or how to measure that kind of distortion
as said, it can be severe with xo malfunction
or less with better xo function
but you can trust me on this, it is there
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 06:05 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2