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

Equipment & Tools From test equipment to hand tools

Taking measurements without proper gear
Taking measurements without proper gear
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 13th July 2018, 09:58 PM   #1
Jaam is offline Jaam
diyAudio Member
 
Join Date: Apr 2018
Default Taking measurements without proper gear

Hey, so I'm doing my first two-way build using SB Scoustics SB17MFC35-8 and the Vifa XT25SC90-4. I've done a couple sub the past so I'm all good on cab design. I'm also relatively confident in my ability to design a x-over although I'm sure I still have a lot to learn.

So hears the issue, I don't have an Omni mic. Now this is just a project for a mate so he can DJ in his bedroom for fun so it's doesn't have to be perfect. So I had the idea of using my AT2020 to record the frequency response of the drivers when they're in the cab so I can design an x-over and then just try and match the response in xsim to that of the AT2020's response graph. I realise this will hurt a lot of people and everyone is just going to say buy the proper gear, but that's not an option right now, so do you guys think that my idea will allow me to produce an acceptable crossover?

Thanks in advance
  Reply With Quote
Old 13th July 2018, 10:22 PM   #2
Shaun is offline Shaun  South Africa
diyAudio Member
 
Shaun's Avatar
 
Join Date: Aug 2001
Location: Cape Town, South Africa
Taking measurements without proper gear
Have a look at this: Introduction to designing crossovers without measurement
__________________
Shaun Onverwacht
|||||||||| DON'T PANIC ||||||||||
  Reply With Quote
Old 13th July 2018, 10:28 PM   #3
Jaam is offline Jaam
diyAudio Member
 
Join Date: Apr 2018
Thanks Shaun, I'll give it a good read.
  Reply With Quote
Old 14th July 2018, 12:47 AM   #4
nigelwright7557 is offline nigelwright7557  United Kingdom
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
The best crossover is no crossover.
I am very lazy when it comes to crossovers so rarely use them.
I usually stick to full range speakers.
Fane do a great range of 12 and 15 inch full range drivers.
__________________
PCBCAD51 pcb design software. 2018 version out now with lower prices >> http://www.murtonpikesystems.co.uk
  Reply With Quote
Old 14th July 2018, 12:56 AM   #5
Jaam is offline Jaam
diyAudio Member
 
Join Date: Apr 2018
Thank you for the reply but I'm having to work to a budget of £220 so good fullrange drivers are of the table. Also there's the issue of size as this is for his bedroom and he will need to transport them.

Thank you for the pointer though, i love Fane's drivers, Sherman Audio do great systems using them.
  Reply With Quote
Old 14th July 2018, 01:12 AM   #6
wintermute is online now wintermute  Australia
just another
diyAudio Moderator
 
wintermute's Avatar
 
Join Date: Aug 2003
Location: Sydney
Taking measurements without proper gear
Generally speaking an omni mic is suggested for speaker measurements, however if you put the AT-2020 directly on axis and do gated measurements then I think that it should be ok, even though it is a cardioid mic (it would not be appropriate for getting room effects though).

The mic looks to be quite flat from about 500 hz to around 10Khz based on Audio-Technica's specs so again for crossover development even without subtracting the mic response curve from the measurements I think it will give you good results. Certainly better than designing without measurements at all.

Combine with proper impedance measurements taken in cab and I think you will do just fine. The relative levels in your crossover region, and phase matching are what you should concentrate on, and not trying to adjust for any slight differences in upper or lower response.

I do all of my measurements with an uncalibrated home made mic wand using a panasonic WM-60AY capsule and get very good results. It does typically have a very flat freq response as shown in the attachment below...

Tony.
Attached Images
File Type: png wm60ay_typical_response.png (23.0 KB, 58 views)
__________________
Any intelligence I may appear to have is purely artificial!
Some of my photos

Last edited by wintermute; 14th July 2018 at 01:13 AM. Reason: add comment on room effects.
  Reply With Quote
Old 14th July 2018, 10:12 AM   #7
Jaam is offline Jaam
diyAudio Member
 
Join Date: Apr 2018
Hey Tony, thanks for the input, it sounds like a plan to me, thanks
  Reply With Quote
Old 14th July 2018, 11:09 AM   #8
wintermute is online now wintermute  Australia
just another
diyAudio Moderator
 
wintermute's Avatar
 
Join Date: Aug 2003
Location: Sydney
Taking measurements without proper gear
No probs. There are plenty of simulation options once you have the measurements.. pcd, xsim, vituixcad, boxsim.

I've started using vituixcad and really like it.

Tony.
__________________
Any intelligence I may appear to have is purely artificial!
Some of my photos
  Reply With Quote

Reply


Taking measurements without proper gearHide 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
Taking measurements from an Open Baffle juliopr Multi-Way 22 25th November 2016 09:28 PM
What I am taking to LSAF Bob Brines Full Range 69 28th June 2016 06:21 PM
Taking the ****.... mrfeedback Everything Else 9 5th June 2016 01:10 PM
measurements gear. recommendations please mondogenerator Equipment & Tools 5 27th July 2015 05:41 PM
Usefulness of In-Room LF Measurements vs. No Measurements (ref FH) sayrum Full Range 66 19th February 2015 08:44 PM


New To Site? Need Help?

All times are GMT. The time now is 12:12 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki