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

Crossover design problems/suggestions
Crossover design problems/suggestions
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 12th March 2018, 07:44 PM   #1
sese317j is offline sese317j  Germany
diyAudio Member
 
Join Date: Apr 2017
Post Crossover design problems/suggestions

Hey,

i once again need your help/suggestion for the design of a crossover. The frequency response curves of the drivers i want to use are not that flat, and i m not really sure how to solve these issues. The woofer i m using is the Monacor Sp-6/108Pro and for the high frequencies, i chose the Eminence Apt80. The frd measurements i did myself with my Umik-1 in REW, both the drivers were meassured with exactly the same gain/volume settings, but the microphone is not spl calibrated. The Apt80 has a horn, so the source of the sound is about 2 inches behind the woofer. Eminence recommends 3.5khz with a second or third order highpass as the lowest crossover point. My goal is to keep the efficiency as high as possible, as the speaker will be used for a small sort of Pa Setup with one or two 12" Subs. Form my point of view the frequency response of the Atp80 is extremely difficult to flatten out and that's where i need your help.

Thanks in advance.
Attached Images
File Type: jpg 4mDUkpY.jpg (475.1 KB, 352 views)
Attached Files
File Type: zip Files_Speaker.zip (926.8 KB, 17 views)

Last edited by sese317j; 12th March 2018 at 07:54 PM.
  Reply With Quote
Old 12th March 2018, 11:36 PM   #2
bwaslo is offline bwaslo  United States
Old guy with soldering iron
diyAudio Member
 
bwaslo's Avatar
 
Join Date: May 2006
Location: Portland, Oregon!
Crossover design problems/suggestions
Well, you can try this quickly tossed-together one (XSim design file is here: http://www.diyaudio.com/forums/attac...1&d=1520897421).

Crossover design problems/suggestions-quick-ckt-png
Crossover design problems/suggestions-quick-ckt-resp-png

But I gotta tell you, you really should get your phase response files accurately aligned (about "2 inches" really isn't very accurate, and the placement of the driver magnets doesn't really give the whole information needed). Particularly with such a high crossover frequency (3500Hz has a wavelength of less than 4 inches, so to be within 1/8 wavelength you need to be right to closer than 0.5 inch).

Maybe see Jeff Bagby's how-to on getting measurements for this at http://techtalk.parts-express.com/fi...tch?id=1149302
Attached Images
File Type: png quick ckt.png (10.7 KB, 694 views)
File Type: png quick ckt resp.png (16.5 KB, 681 views)
Attached Files
File Type: zip quick ckt try.zip (945.7 KB, 15 views)
__________________
[W9MJE] Horn spreadsheet SynergyCalc/; SmallSyns SmallSyns;
Crossover design Xsim; Depot diffusor super-easy diffusors
  Reply With Quote
Old 13th March 2018, 08:48 AM   #3
sese317j is offline sese317j  Germany
diyAudio Member
 
Join Date: Apr 2017
Quote:
Originally Posted by bwaslo View Post

Maybe see Jeff Bagby's how-to on getting measurements for this at http://techtalk.parts-express.com/fi...tch?id=1149302
Thanks for the link, im going to take the new measurements as soon as possible.
  Reply With Quote
Old 13th March 2018, 11:58 AM   #4
EarlK is offline EarlK  Canada
diyAudio Member
 
Join Date: Mar 2006
Location: Toronto (GTA), Ontario
Hi,

Here's another kick at the can.

Crossover design problems/suggestions-6in-pa-speaker_schematic_-pngCrossover design problems/suggestions-6in-pa-speaker_trace_-png

The tweeter distance is set to "0".
- If the offset of the tweeter is truly 2" behind the woofer then you would need to flip the polarity of either the woofer or the tweeter.

This design tries to maintain maximum efficiency ( at the expense of the low-end ).

Download the "zipped" dxo file that I have included ( place it in the same folder as your current zma & frd files ) and then play with it.
- Do the same with the one Bill posted.
- Use the best ideas from each & see what you can create on your own.

There are a couple of notch filters in mine ( one in each the top & bottom sections ).
- See if you can eliminate them in your actual implementation .

Attached Images
File Type: png 6in PA Speaker_Schematic_.png (9.6 KB, 337 views)
File Type: png 6in PA Speaker_Trace_.png (21.9 KB, 324 views)
Attached Files
File Type: zip 6inch PA Speaker_modE.zip (945.4 KB, 0 views)

Last edited by EarlK; 13th March 2018 at 12:25 PM.
  Reply With Quote
Old 13th March 2018, 12:38 PM   #5
sese317j is offline sese317j  Germany
diyAudio Member
 
Join Date: Apr 2017
In the text from Jeff Bagby's it is mentioned to connect the drivers in parallel while remaining the polarity, but the problem ist my amp is not 2ohm stable, so is it possible to connect a 4ohm Resistor in series to the two drivers connected in parallel to keep the overall impedance of two 4 Ohm drivers above 2 Ohm ?
  Reply With Quote
Old 13th March 2018, 01:05 PM   #6
EarlK is offline EarlK  Canada
diyAudio Member
 
Join Date: Mar 2006
Location: Toronto (GTA), Ontario
Quote:
Originally Posted by sese317j View Post
In the text from Jeff Bagby's it is mentioned to connect the drivers in parallel while remaining the polarity, but the problem ist my amp is not 2ohm stable, so is it possible to connect a 4ohm Resistor in series to the two drivers connected in parallel to keep the overall impedance of two 4 Ohm drivers above 2 Ohm ?
That's really a question you could get closer to an answer ( on your own ) by running a Xsim of the 2 drivers ( paralleled ) with a 2 ohm resistor put inline between the source and the load.

Anyways, it's not ideal, nor perfect ( due to how the drivers react to losing amp loading/damping ) but yes it's doable.

2 ohms is the best value ( to minimize response changes & still meet the 4 ohm load criteria ).

See for yourself ( in XSim ) how a 10R resistor changes the relative curves of the individual drivers.


Last edited by EarlK; 13th March 2018 at 01:11 PM.
  Reply With Quote
Old 13th March 2018, 06:17 PM   #7
Lojzek is offline Lojzek  Croatia
diyAudio Member
 
Lojzek's Avatar
 
Join Date: Feb 2012
Location: Croatia
Hi sese, you have got the drivers impedance in simulation so put these in parallel and you will find that summed impedance is not a problem, plus if you set the driving voltage to 1Vrms, what's the worse current the amp might send through these, a couple of hundreds of mA's perhaps for as long as it takes the software to measure response which is normally a short period. Yes, no?
__________________
A good dialogue makes you feel like a changed person, not like you have won or lost the competition.
  Reply With Quote
Old 13th March 2018, 07:19 PM   #8
bwaslo is offline bwaslo  United States
Old guy with soldering iron
diyAudio Member
 
bwaslo's Avatar
 
Join Date: May 2006
Location: Portland, Oregon!
Crossover design problems/suggestions
You can actually drive about any amp into very low impedances provided you don't try to drive hard. Amplifiers are damaged by excess power dissipation, and dissipation is minimum when output is minimum (except SE amps, which disippate most at no signal, unrelated to output level). The amp won't be at its best in terms of distortion (which should be low at low level anyway) and some amplifiers can get twitchy with very low impedances, particularly if low at highest frequencies (capacitive load). But with the vast majority of amps you should be fine putting some milliwatts or even a watt into single ohm type loads. Just be careful with the level control, and remember, if it sounds bad turn it down or off!
__________________
[W9MJE] Horn spreadsheet SynergyCalc/; SmallSyns SmallSyns;
Crossover design Xsim; Depot diffusor super-easy diffusors
  Reply With Quote
Old 13th March 2018, 07:24 PM   #9
bwaslo is offline bwaslo  United States
Old guy with soldering iron
diyAudio Member
 
bwaslo's Avatar
 
Join Date: May 2006
Location: Portland, Oregon!
Crossover design problems/suggestions
Quote:
Originally Posted by EarlK View Post
...Download the "zipped" dxo file that I have included ( place it in the same folder as your current zma & frd files ) and then play with it.
EarlK,

-- the FRD files and ZMA files get embedded into the dxo files, so there is no need to find them again when you get an XSim design file. Should be able to just unzip the dxo file and start it up from any folder. I had hoped that diyAudio would allow dxo files to be directly attached (wouldn't it be cool to just double-click on a dxo file in a post and the design simulation pops up on-screen?), but it's not a 'supported file type', so it has to be zipped before attaching.

Bill
__________________
[W9MJE] Horn spreadsheet SynergyCalc/; SmallSyns SmallSyns;
Crossover design Xsim; Depot diffusor super-easy diffusors
  Reply With Quote
Old 13th March 2018, 07:31 PM   #10
EarlK is offline EarlK  Canada
diyAudio Member
 
Join Date: Mar 2006
Location: Toronto (GTA), Ontario
Thanks for the clarification Bill.

I wouldn't have guessed that was the case ( due to XSim creating it's own sub-folder to hold multiple/duplicate copies of those very same zma & frd files.

  Reply With Quote

Reply


Crossover design problems/suggestionsHide 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
XO3: The 1/2/3-way Active Crossover/filter PCB. Design suggestions welcome! s3tup Analog Line Level 52 5th October 2011 03:27 PM
<AUS> B3S active crossover design - Value woofer suggestions? TheSeekerr Multi-Way 0 25th August 2008 12:46 PM
Suggestions on OB problems maoumaou Multi-Way 13 29th February 2008 02:35 AM
Suggestions on my crossover design? JoeyDD Multi-Way 11 11th December 2005 02:05 PM
Amp problems, suggestions needed :( fedx Solid State 3 21st October 2005 03:38 AM


New To Site? Need Help?

All times are GMT. The time now is 04:22 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