Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Midrange distortion on 15" PA driver
Midrange distortion on 15" PA driver
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 11th October 2018, 07:47 AM   #11
TBTL is offline TBTL  Germany
diyAudio Member
 
Join Date: Oct 2013
Quote:
Originally Posted by LightBit View Post
I measured speaker with much lower distortion with same mic, but different sound card and amplifier.
Also check the sound pressure level at the microphone, it strongly affects microphone distortion.
  Reply With Quote
Old 11th October 2018, 08:02 PM   #12
LightBit is offline LightBit  Slovenia
diyAudio Member
 
LightBit's Avatar
 
Join Date: Aug 2016
Thank you all for all suggestions.

I measured with different sound card and using REW 5.19 with computer in different room.

Midrange distortion on 15" PA driver-distortion_faital-jpg

At even lower volume it seems much better. Because I wasn't sure, if mic is distorting, I used my ears. Indeed I could hear a lot of distortion at high volume.
I found that some distortion seems to be caused by amplifier top panel vibrating (around 470Hz), chair legs, and probably other stuff.
After removing chair I set amplifier a bit louder and listened just sine waves and there was some obvious clipping.

I suspect amplifier (it's Technics from 90s, supposed to be 40W) is causing most of distortion. So I will try different amplifier (not sure, if it is any better) this weekend. Maybe outside.

Here is REW file of all measurements.
Attached Images
File Type: jpg distortion_faital.jpg (230.4 KB, 404 views)
__________________
SpeakerSim - speaker simulation software
  Reply With Quote
Old 12th October 2018, 06:42 AM   #13
phase_accurate is offline phase_accurate
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
Well - that's not so bad, is it ? I quess it gets even a bit better as soon as the driver is built in a box because the rising response is affecting the output spectrum towards lowering the fundamental relative to the overtones.

Regards

Charles
  Reply With Quote
Old 12th October 2018, 07:42 AM   #14
LightBit is offline LightBit  Slovenia
diyAudio Member
 
LightBit's Avatar
 
Join Date: Aug 2016
Yes, it is good, but it is low volume.
__________________
SpeakerSim - speaker simulation software
  Reply With Quote
Old 12th October 2018, 08:24 AM   #15
phase_accurate is offline phase_accurate
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
And how low is "low volume" ? Keep in mind that things change dramatically as soon as they are in boxes and run as a pair. That low power may suddenly sound quite loud !

Regards

Charles
  Reply With Quote
Old 12th October 2018, 11:26 AM   #16
ErnieM is offline ErnieM  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Fresno, CA
Again, driver measures fine. Proper implementation into the rest of the system and room is much more important.

What do you plan on running above 1khz?
  Reply With Quote
Old 12th October 2018, 06:35 PM   #17
LightBit is offline LightBit  Slovenia
diyAudio Member
 
LightBit's Avatar
 
Join Date: Aug 2016
Quote:
Originally Posted by phase_accurate View Post
And how low is "low volume" ?
I didn't measure volume or voltage, but low enough mic (Behringer ECM8000) didn't distort at ~10 cm distance.

Quote:
Originally Posted by phase_accurate View Post
Keep in mind that things change dramatically as soon as they are in boxes and run as a pair. That low power may suddenly sound quite loud !
My current speakers play well at low volume. So I want new ones to be able to play nice very loud. I'm sure it will be better when they will be in box.

Quote:
Originally Posted by ErnieM View Post
What do you plan on running above 1khz?
Beyma TPL-150H.


I did another measurement with newer amplifier:
Midrange distortion on 15" PA driver-kenwood_faital-jpg

It seems good, but I kinda expected it to be better, because all that surface area.
Attached Images
File Type: jpg kenwood_faital.jpg (168.8 KB, 238 views)
__________________
SpeakerSim - speaker simulation software
  Reply With Quote
Old 12th October 2018, 08:46 PM   #18
puppet is offline puppet  United States
diyAudio Member
 
Join Date: Dec 2011
Location: The Dells, WI
LightBit, is that test still at 10cm (4") ? Why not 1/2 meter with that large of a driver?
  Reply With Quote
Old 12th October 2018, 09:30 PM   #19
mark100 is offline mark100  United States
diyAudio Member
 
Join Date: Dec 2010
I think you have a catch22 trying to measure distortion on a strong sub/lower mid indoors.
If you're at a SPL low enough not to excite room/object resonances, noise floor bums up the measurement.
If you climb above the noise floor significantly, you excite all kinds of resonances in all kinds of room objects.

I'd take it outside if you can, and test at about 110-120dB/ 1meter.
  Reply With Quote
Old 12th October 2018, 09:58 PM   #20
LightBit is offline LightBit  Slovenia
diyAudio Member
 
LightBit's Avatar
 
Join Date: Aug 2016
Quote:
Originally Posted by puppet View Post
LightBit, is that test still at 10cm (4") ? Why not 1/2 meter with that large of a driver?
No, that test was about 5m, to prevent mic distortion. However, this probably excited many resonances.

Quote:
Originally Posted by mark100 View Post
I'd take it outside if you can, and test at about 110-120dB/ 1meter.
That would be better way, but I would first need amplifier capable of doing that and hope neighbors won't kill me.
Maybe, when they are finished.
__________________
SpeakerSim - speaker simulation software
  Reply With Quote

Reply


Midrange distortion on 15" PA driverHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Midrange 1" driver Fredenando Multi-Way 5 4th November 2015 12:30 AM
Infinity Kappa 90 speakers - distortion with midrange driver samoloko Multi-Way 2 29th August 2012 06:24 AM
INCREDIBLE 12" woofer-midrange SE friendly, lowest distortion-2khz...MUST READ!!!! Spiritzly Multi-Way 17 29th August 2010 01:05 AM
ScanSpeak 4" midrange (12M_4631G00) Distortion Tests Tenson Multi-Way 12 22nd April 2007 02:09 AM


New To Site? Need Help?

All times are GMT. The time now is 05:13 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki