Compression driver frequency response? - 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 10th May 2009, 12:58 PM   #1
diyAudio Member
 
Join Date: Apr 2009
Default Compression driver frequency response?

Compression frequency response is given with specific horn.
I want to test horn with two different compression driver.
I want to see which compression driver is having better frequency response with available horn.
I have got LMS with me. But no anechoic chamber.
Guide me in the matter.
  Reply With Quote
Old 10th May 2009, 01:58 PM   #2
diyAudio Member
 
Robh3606's Avatar
 
Join Date: Nov 2002
Location: Destiny
Testing them should be no big deal. I am assuming you have done measurements before as you have LMS. Do an inroom measurement and gate using MLS. I would also run a limited range sine sweep. They should both be the same. Don't know how large the horn is but above 800-1K you sould be fine depending on how large the room is. Do the measurements outside if you can.

Compression drivers roll off above their mass break point at about 6db per octave. Depending on the horn type you may need to do a compensation circuit to smooth the response and flatten things out.

On a CD type horn using passive components you would need to pad down the midrange response to give you a flat curve. Simple example would be a circuit that gives you the reverse of the 6db roll-off. Typically a series capacitor is used to do this.

With an exponential horn they self equalize so normally no compensation circuit is needed. They use the change in directivity to smooth the on axis response.

What you need to do is measure the impedance curves and on on axis response for each driver on the horn and then go from there. You could also do off axis measurements as well.

When you measure the compression drivers as a safety net you can use a large value capacitor in series to protect the driver from excessive excursion and fumbly hands. If you are not sure of the value use the manual from an active crossover and look up protection caps. You don't have to use them but it's an option if you don't feel comfortable without one.

http://www.jblproservice.com/pdf/Vin...5%20manual.pdf

Depending on what you get you can decide if you need to build up a compensation circuit of not. If you have Crossover Shop you would load the FR and Imp into the Guide Curve library and then into the driver. Then you just go from there.

That should get you started have fun

Rob
  Reply With Quote
Old 10th May 2009, 04:26 PM   #3
diyAudio Member
 
Join Date: Apr 2009
Robh3606,
Thanks u very much.

I got the info to start with.
  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
FS: Silver Iris Coaxial 15" driver pair (sans XO and compression driver) theAnonymous1 Swap Meet 0 24th April 2007 12:09 AM
frequency response pmarcouxx Digital Source 2 20th July 2005 07:43 PM
This amplifier is distorting high frequency, some audio compression too. Know why? destroyer X Solid State 97 8th November 2004 02:46 PM
Is my frequency response bad? SimontY Multi-Way 21 2nd July 2004 08:44 AM
Doubts on Phase Response and Frequency Response dumrum Multi-Way 11 5th April 2004 10:39 AM


New To Site? Need Help?

All times are GMT. The time now is 04:14 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