How should I measure this speaker? (for crossover creation) - Page 3 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

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 5th February 2014, 07:01 PM   #21
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by Defo View Post
Should the placement of the mic be on axis with the tweeter?

I reckon the latter will be more correct for the midrange area, which is the area of interest here (1600 hz XO).
If matching dispersion at the crossover point is part of your design criteria, you will need to measure the drivers individually off axis (in as narrow increments as you have time for, 5 degrees is generally sufficient) as well as on axis.

Since the horn height is fairly small, it will loose vertical control at a higher frequency than it's horizontal dispersion.

I'd guess that at 1600 Hz the horn has wider horizontal dispersion (and much wider vertical dispersion) than the woofer.
  Reply With Quote
Old 5th February 2014, 08:33 PM   #22
diyAudio Member
 
Greebster's Avatar
 
Join Date: Aug 2010
Location: South of the Skyway
Quote:
Originally Posted by weltersys View Post
If matching dispersion at the crossover point is part of your design criteria, you will need to measure the drivers individually off axis (in as narrow increments as you have time for, 5 degrees is generally sufficient) as well as on axis.

Since the horn height is fairly small, it will loose vertical control at a higher frequency than it's horizontal dispersion.

I'd guess that at 1600 Hz the horn has wider horizontal dispersion (and much wider vertical dispersion) than the woofer.
Places another twist on one octave above radius crossover minima
  Reply With Quote
Old 5th February 2014, 09:35 PM   #23
diyAudio Member
 
TMHutson's Avatar
 
Join Date: Dec 2010
Location: SoCal
Are you using both gating and smoothing?
Holmimpulse only lets you choose between raw, smoothed or gated.
Can't combine. The smoothed gets a little too smooth, and as you change the octave scale to get more detail, the reflections creep farther up in frequency.
I prefer the gated on holm impulse.
With nearfield (for bass response), you don't need smoothing or gating.
I guess outdoors is best route. Have not tried it. My measuring setup is not portable, yet.

Your first measurement looks rather similar to my seos12, but with the obvious deeper frequency response.
My off axis measurements are the same as all the other seos12 testers. Falling control at @1.5k.
I measured my woofer as having similar response, so not too bad.

I just looked up the woofer you have. The factory FR looks to have a 2.5db increase starting at 1.5k. Having the larger waveguide might help to cross below that peak. You will need a steep crossover point if you want to crossover higher than 1k. I am having a problem with my woofer's resonance at 1.7k.

I am curious how your woofer measures compared to the factory specs.

Why did you go with such a large waveguide, and smaller woofer?
Have you considered going with a 12" or 15" woofer?
  Reply With Quote
Old 5th February 2014, 11:07 PM   #24
Defo is offline Defo  Norway
diyAudio Member
 
Join Date: Nov 2008
Quote:
Originally Posted by TMHutson View Post
Are you using both gating and smoothing?
Holmimpulse only lets you choose between raw, smoothed or gated.
Can't combine. The smoothed gets a little too smooth, and as you change the octave scale to get more detail, the reflections creep farther up in frequency.
I prefer the gated on holm impulse.
With nearfield (for bass response), you don't need smoothing or gating.
I guess outdoors is best route. Have not tried it. My measuring setup is not portable, yet.

Your first measurement looks rather similar to my seos12, but with the obvious deeper frequency response.
My off axis measurements are the same as all the other seos12 testers. Falling control at @1.5k.
I measured my woofer as having similar response, so not too bad.

I just looked up the woofer you have. The factory FR looks to have a 2.5db increase starting at 1.5k. Having the larger waveguide might help to cross below that peak. You will need a steep crossover point if you want to crossover higher than 1k. I am having a problem with my woofer's resonance at 1.7k.

I am curious how your woofer measures compared to the factory specs.

Why did you go with such a large waveguide, and smaller woofer?
Have you considered going with a 12" or 15" woofer?
I use a little smoothing on the gated response as well as the non-gated. The resolution is too high (rugged) without it. I went with the SEOS 15, as it was the only one the distributor had in stock at the time I went with a 10 inch for the smaller form factor. With a 1500-1600hz crossover point it would match directivity of the SEOS-15 (around 100 degrees).

I've done measurements and experimented the whole day, only to become more confused... The measurements, and impulse response are extremely sensitive to the slightest changes. Just me changing posture, will drasticly change the response.

I ended up making a XO and EQ configuration by ear, which sounded 10x better then all previous attemts with careful measuring, gating and so on...

I will try to take the speaker outdoors for measurements when summer arrives, and make another attemt the "right way"...

Last edited by Defo; 5th February 2014 at 11:20 PM.
  Reply With Quote
Old 5th February 2014, 11:17 PM   #25
ScottG is offline ScottG  United States
diyAudio Member
 
Join Date: Feb 2003
Location: US
Quote:
Originally Posted by Defo View Post

I've done measurements and experimented the whole day, only to become more confused...

Try it with ARTA and the technique that Charlie mentions in his tutorial:

http://audio.claub.net/tutorials/FR%...ing%20ARTA.pdf

-shouldn't cost you anything but some more time.
__________________
perspective is everything
  Reply With Quote
Old 5th February 2014, 11:20 PM   #26
Defo is offline Defo  Norway
diyAudio Member
 
Join Date: Nov 2008
Quote:
Originally Posted by ScottG View Post
Try it with ARTA and the technique that Charlie mentions in his tutorial:

http://audio.claub.net/tutorials/FR%...ing%20ARTA.pdf

-shouldn't cost you anything but some more time.
Thanks, I will look into it
  Reply With Quote
Old 6th February 2014, 02:37 AM   #27
diyAudio Member
 
R-Carpenter's Avatar
 
Join Date: Oct 2007
Location: Brooklyn Navy Yard
"Testing Loudspeakers" by D'Appolito is a good read. Explains gating, systems, merging, how and why.
__________________
http://www.diy-ny.com/
  Reply With Quote
Old 6th February 2014, 06:08 AM   #28
diyAudio Member
 
TMHutson's Avatar
 
Join Date: Dec 2010
Location: SoCal
Just purely luck that I went with holmimpulse instead of REW first. I don't have computing power to do both. I am only using the LIMP portion of ARTA right now. Wish I could help you with REW. I have good luck with holmimpulse. When I can upgrade my computer, I would like to have as many programs as possible to compare.

My measurements have been somewhat consistent even when changing rooms. I now know the basic signature of the various speakers and drivers I have. I am sure you will get it all sorted soon.

Have you looked at FR results of other seos15's to compare your results to? I looked at seos12 results to make sure my results were ok. Heck, I even measured in a different room and on a different baffle and got pretty much the same results.


Nothing wrong with doing it by ear. Especially if it sounds better. Many people fine tune passive crossovers by ear.
I would still work with measurements to see what changes you made.

Last edited by TMHutson; 6th February 2014 at 06:17 AM.
  Reply With Quote
Old 6th February 2014, 06:43 AM   #29
diyAudio Member
 
TMHutson's Avatar
 
Join Date: Dec 2010
Location: SoCal
Just downloaded and read the PDF. Thanks for the info, ScottG!
  Reply With Quote
Old 6th February 2014, 06:45 AM   #30
ScottG is offline ScottG  United States
diyAudio Member
 
Join Date: Feb 2003
Location: US
Quote:
Originally Posted by TMHutson View Post
Just downloaded and read the PDF. Thanks for the info, ScottG!
Thank Charlie!

..he's somewhere on this forum, sometimes.
__________________
perspective is everything
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Loudspeaker measure and crossover design 05cordie Software Tools 22 29th June 2013 06:32 PM
Using praxis to measure transfer function of active crossover pjwd Full Range 0 2nd May 2010 08:23 AM
Easiest and fastest way to measure a crossover's transfer function? 454Casull Analog Line Level 3 26th August 2009 08:52 AM
crossover question Measure at 2500? ben62670 Multi-Way 6 1st January 2007 04:18 PM
Speaker Workshop - using "Measure -> Passive Components" to measure ESR ? percy Multi-Way 0 12th March 2006 10:18 PM


New To Site? Need Help?

All times are GMT. The time now is 02:33 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