My first measurements Justmls - Page 2 - 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 27th June 2009, 09:15 AM   #11
Shaun is offline Shaun  South Africa
diyAudio Member
 
Shaun's Avatar
 
Join Date: Aug 2001
Location: Cape Town, South Africa
Quote:
Originally posted by djarchow
As long as you place your reference probe after the capacitor, the measurement will be the same as without it.
Right. The problem I have seen, however, is further degradation of S/N towards the lower end due to the roll-off introduced by the cap. This may not be of that much significance. For instance, here widi has captured the most significant part of the tweeter's FR, and the low end can be tailed off. Agreed that with or without the cap nothing will change above 500Hz. The point of my addressing the low end data is that this is his first measurement, and that strange curve is bound to confuse any first-timer.
__________________
Shaun Onverwacht
|||||||||| DON'T PANIC ||||||||||
  Reply With Quote
Old 27th June 2009, 12:59 PM   #12
widi is offline widi  Spain
diyAudio Member
 
widi's Avatar
 
Join Date: Sep 2006
Well friends, I used another amp, and again I made the measurements, the capacitor is placed on the negative tweeter.
Think that these new measurements.
Here: http://img.villagephotos.com/p/2009-6/1342104/2095188
  Reply With Quote
Old 27th June 2009, 01:22 PM   #13
Shaun is offline Shaun  South Africa
diyAudio Member
 
Shaun's Avatar
 
Join Date: Aug 2001
Location: Cape Town, South Africa
It is a bit better; you'll still have to do the tailing off, though. It will be better for your low frequency measurements.

Did you use this setup?

Click the image to open in full size.
__________________
Shaun Onverwacht
|||||||||| DON'T PANIC ||||||||||
  Reply With Quote
Old 27th June 2009, 02:57 PM   #14
widi is offline widi  Spain
diyAudio Member
 
widi's Avatar
 
Join Date: Sep 2006
No, but I will put the capacitor, the output sound card, as you indicated in your schedule, and I will try.
This is what I post.
Attached Images
File Type: gif dibujo.gif (3.1 KB, 232 views)
  Reply With Quote
Old 27th June 2009, 04:10 PM   #15
Shaun is offline Shaun  South Africa
diyAudio Member
 
Shaun's Avatar
 
Join Date: Aug 2001
Location: Cape Town, South Africa
If you want to use the series capacitor you must ensure that the reference point is on the tweeter side of the cap, as I have drawn. I have put the capacitor inside my jig with a bypass switch connected across it.
__________________
Shaun Onverwacht
|||||||||| DON'T PANIC ||||||||||
  Reply With Quote
Old 27th June 2009, 07:31 PM   #16
widi is offline widi  Spain
diyAudio Member
 
widi's Avatar
 
Join Date: Sep 2006
I put the capacitor, the output of the sound card.
As the measurements were good, I have adjusted the latency of the sound card in 2048, and the mic preamp to 256.
Here's the results:
http://img.villagephotos.com/p/2009-6/1342104/2095227
  Reply With Quote
Old 27th June 2009, 07:47 PM   #17
Shaun is offline Shaun  South Africa
diyAudio Member
 
Shaun's Avatar
 
Join Date: Aug 2001
Location: Cape Town, South Africa
The first photo looks much better. What is the difference between this and the second photo?
__________________
Shaun Onverwacht
|||||||||| DON'T PANIC ||||||||||
  Reply With Quote
Old 27th June 2009, 08:00 PM   #18
widi is offline widi  Spain
diyAudio Member
 
widi's Avatar
 
Join Date: Sep 2006
The first picture, the measurement distance is 70 centimeters, and the second at 8 centimeters from the tweeter.
Now you are good measurements?.
  Reply With Quote
Old 27th June 2009, 08:04 PM   #19
widi is offline widi  Spain
diyAudio Member
 
widi's Avatar
 
Join Date: Sep 2006
Almost I forget, the sample rate is 48,000 instead of 44,100
  Reply With Quote
Old 29th June 2009, 08:10 PM   #20
widi is offline widi  Spain
diyAudio Member
 
widi's Avatar
 
Join Date: Sep 2006
Shaun,Now you are good measurements?
  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
Wallin II jig with JustMLS? Mos Fetish Multi-Way 2 9th December 2008 06:53 AM
Radio Shack SPL Meter and justMLS - I'm getting odd measurements... fjhuerta Multi-Way 19 2nd January 2008 03:39 AM
Looking for some help with JustMLS JonW Multi-Way 7 16th April 2007 10:03 PM
JustMLS impedance anomaly Mos Fetish Multi-Way 0 6th March 2007 02:00 AM
JustMLS problem a007udio Multi-Way 4 18th July 2005 09:49 PM


New To Site? Need Help?

All times are GMT. The time now is 02:39 AM.


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