Time to try a 3-way. - 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 20th June 2011, 07:06 PM   #1
DrDyna is offline DrDyna  United States
diyAudio Member
 
DrDyna's Avatar
 
Join Date: May 2007
Blog Entries: 3
Default Time to try a 3-way.

Ok, so lately I've been mulling over the idea of making a floor standing 3 way speaker. I've played with too many 2 ways and I'm getting bored. Time to try something bigger!

I've still got a couple of Peerless 831759's available, and a couple of Vifa SC14SG-49 midbass and a couple of Vifa AC25TG05-04 soft domes.

I've considered crossover points perhaps 700/4000.

I'd like to make a fairly large cabinet with enough space (guessing 150L perhaps?) to use a 3"x 11" or so port for the peerless 10 to get it down somewhere in the neighborhood of 25-28 cycles.

Does anyone have any input on those crossover frequencies? I haven't tried to set out designing one yet (I'm usually pretty bad at it and would end up having to ask for help anyway!) but I'd really like to try my hand at a large, classic speaker, you know, the kind with terrible WAF.

Any comments, suggestions or fun-pokes are welcome!
  Reply With Quote
Old 20th June 2011, 07:40 PM   #2
Loren42 is offline Loren42  United States
diyAudio Member
 
Join Date: Sep 2008
Location: "Space Coast" Florida, USA
Passive Crossover Network Design
  Reply With Quote
Old 20th June 2011, 08:01 PM   #3
DrDyna is offline DrDyna  United States
diyAudio Member
 
DrDyna's Avatar
 
Join Date: May 2007
Blog Entries: 3
Quote:
Originally Posted by Loren42 View Post
Thank you Loren

I do have several such sites bookmarked that I use from time to time. They are a good starting point, but usually the finished crossover design ends up being quite a bit different
  Reply With Quote
Old 20th June 2011, 08:54 PM   #4
Loren42 is offline Loren42  United States
diyAudio Member
 
Join Date: Sep 2008
Location: "Space Coast" Florida, USA
Quote:
Originally Posted by DrDyna View Post
Thank you Loren

I do have several such sites bookmarked that I use from time to time. They are a good starting point, but usually the finished crossover design ends up being quite a bit different
Here are my observations/questions:

1. What is your selection criteria for 700 and 4,000 Hz as your crossover and how did you arrive at those numbers? Can yo

2. Why the shelf port versus a round port?

3. Why the large port area?

4. Have you calculated the shelf port length?

5. Why did you select 5.3 cubic feet for the box size? At 100 Watts you reach xmax at 45 Hz.
  Reply With Quote
Old 20th June 2011, 08:57 PM   #5
a.wayne is offline a.wayne  United States
Sin Bin
 
Join Date: May 2008
Location: Front Row Center
Good choice , a good 3way can be very rewarding ...
  Reply With Quote
Old 20th June 2011, 09:01 PM   #6
DrDyna is offline DrDyna  United States
diyAudio Member
 
DrDyna's Avatar
 
Join Date: May 2007
Blog Entries: 3
Quote:
Originally Posted by Loren42 View Post
Here are my observations/questions:

1. What is your selection criteria for 700 and 4,000 Hz as your crossover and how did you arrive at those numbers? Can yo

2. Why the shelf port versus a round port?

3. Why the large port area?

4. Have you calculated the shelf port length?

5. Why did you select 5.3 cubic feet for the box size? At 100 Watts you reach xmax at 45 Hz.
1.) Just from observation on frequency responses and what looks like good places to cross the drivers over before they start to get messy.

2+3+4.) It's a round port of PVC pipe, 3" in diameter and 11" long. I'm using it as a starting point because it's the same size and shape of a port used in a small cube subwoofer that was designed with this woofer that was tuned to 26 cycles. (well small, it's about 26"...let me go measure it....more like 22" square.)

5.) I'm not entirely sure what the size is going to end up being, I just had the looks of the box in my head and threw out that number, chances are it's going to be pretty different.

edit: 6.) You'll have to excuse my napkin scribblings, quite often I'll have a few beers and come up with something that I have to share, lol.

Last edited by DrDyna; 20th June 2011 at 09:10 PM.
  Reply With Quote
Old 20th June 2011, 09:14 PM   #7
Loren42 is offline Loren42  United States
diyAudio Member
 
Join Date: Sep 2008
Location: "Space Coast" Florida, USA
Quote:
Originally Posted by DrDyna View Post
1.) Just from observation on frequency responses and what looks like good places to cross the drivers over before they start to get messy.

2+3+4.) It's a round port of PVC pipe, 3" in diameter and 11" long. I'm using it as a starting point because it's the same size and shape of a port used in a small cube subwoofer that was designed with this woofer that was tuned to 26 cycles. (well small, it's about 26" square.

5.) I'm not entirely sure what the size is going to end up being, I just had the looks of the box in my head and threw out that number, chances are it's going to be pretty different.
I don't have your specific woofer on file, but I bet if I ran it in LEAP I would see some pipe organ effect on the port. It may not be big, but having such a high crossover for the woofer invites the possibility of port noises and issues with the woofer cone break up (wherever that really is for that driver).

What works well for a sub does not necessarily lend itself to a multiway speaker. Generally the sub uses larger port area to reduce port noise, but cut the woofer off early before pipe organ effects take place (i.e., below 200 Hz). For a multiway you have to balance port noise with the pipe organ effect (if present), so the design is a compromise either way.

One of the virtues of a 3-way is getting a lower crossover for the woofer than you would for a 2-way and letting a mid carry some of that load. 700 Hz may not work well in this case, but without going through a lot of testing and modeling I just don't know.

All of these things are just things you need to consider and are not necessarily gospel.
  Reply With Quote
Old 20th June 2011, 09:22 PM   #8
DrDyna is offline DrDyna  United States
diyAudio Member
 
DrDyna's Avatar
 
Join Date: May 2007
Blog Entries: 3
Quote:
Originally Posted by Loren42 View Post
Generally the sub uses larger port area to reduce port noise, but cut the woofer off early before pipe organ effects take place (i.e., below 200 Hz). For a multiway you have to balance port noise with the pipe organ effect (if present), so the design is a compromise either way.
Right. I had not really considered this. Perhaps it would be better off sealed, or ported if I drop the crossover frequency down a bit.

Sealed might be the way to go, part of the reason I was looking to build a 3 way like this was to have great power handling by letting the large driver cover as much of the band as it could.
  Reply With Quote
Old 20th June 2011, 09:33 PM   #9
a.wayne is offline a.wayne  United States
Sin Bin
 
Join Date: May 2008
Location: Front Row Center
Depends on driver QTS value ....
  Reply With Quote
Old 20th June 2011, 09:38 PM   #10
DrDyna is offline DrDyna  United States
diyAudio Member
 
DrDyna's Avatar
 
Join Date: May 2007
Blog Entries: 3
Quote:
Originally Posted by a.wayne View Post
Depends on driver QTS value ....
Our qts, she be .2713.
  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
My first time...... tonynorie Solid State 5 4th January 2009 09:12 AM
First time caller, long time listener... smallangryboy Introductions 15 19th March 2005 08:10 PM
is doing time alignment now a waste of time? Beggar Multi-Way 9 28th July 2003 05:45 AM
Well, it's time for me... Spherion Introductions 3 23rd December 2002 05:34 PM
What time is it? halojoy Everything Else 48 21st November 2002 03:16 AM


New To Site? Need Help?

All times are GMT. The time now is 05:55 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