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 26th July 2013, 08:54 PM   #11
diyAudio Member
 
Join Date: May 2009
Location: Seattle, WA
Quote:
Originally Posted by jlaakso View Post
You could mount the Peerless sideways so that the truncated frame would face the tweeter.
I know that would be the more appropriate thing to do from an engineering standpoint, but I just don't like the look of the woofer mounted that way.
__________________
Then again, what do I know?
  Reply With Quote
Old 26th July 2013, 09:45 PM   #12
IG81 is offline IG81  Canada
diyAudio Member
 
IG81's Avatar
 
Join Date: Feb 2008
Quote:
Originally Posted by chazdrumzalot View Post
I know that would be the more appropriate thing to do from an engineering standpoint, but I just don't like the look of the woofer mounted that way.
I mounted the truncated sides up and down on mine, but it worked well with my square waveguide. Might indeed look better the other way with your round waveguide and the CTC spacing gain is very minimal anyway.

Good luck with the build, looking forward to see what comes out of it.

IG
Attached Images
File Type: jpg peerless.jpg (61.2 KB, 247 views)
  Reply With Quote
Old 27th July 2013, 09:46 AM   #13
system7 is offline system7  United Kingdom
diyAudio Member
 
system7's Avatar
 
Join Date: Aug 2008
Just to get you heading in the right direction, chazdrumzalot...

You'll never get anything good with a 1.8mH coil and a 10uF capacitor on the 8" bass. 8" bass peaks badly in the midrange if you overdo the shunt capacitor, it's just how they are.

These drivers need a Zobel type capacitor shunt to get some serious rolloff. Say 7.5R and 6uF along with a suitable bafflestep coil around 2mH. I'd add a tank around 6-7kHz across the coil to dip the breakup too. In fact Troels does exactly that here:

TQWT-

Hope it helps.
__________________
Well, there it is! Best regards from Steve in Portsmouth, UK.
  Reply With Quote
Old 27th July 2013, 10:10 AM   #14
jlaakso is offline jlaakso  Finland
diyAudio Member
 
Join Date: Mar 2010
^is it due to above average voice coil inductance?
  Reply With Quote
Old 27th July 2013, 11:22 AM   #15
ODougbo is offline ODougbo  United States
diyAudio Member
 
Join Date: Aug 2011
Location: Maryland USA
^^ that fellow build that with a skill saw? Good post.
  Reply With Quote
Old 27th July 2013, 11:34 AM   #16
system7 is offline system7  United Kingdom
diyAudio Member
 
system7's Avatar
 
Join Date: Aug 2008
Quote:
Originally Posted by jlaakso View Post
^is it due to above average voice coil inductance?
Partly, I suppose, but the difficulties are mainly to do with the major cone resonance around 3.5kHz with an 8" driver which is uncomfortably close to crossover point.

Most 8" drivers also have a natural steep frequency response rolloff around 24dB per octave which doesn't give you much scope with filtering or time alignment.

Using a recessed horn tweeter might help a lot here. I'd trust Troels' design as a start.
TQWT-
__________________
Well, there it is! Best regards from Steve in Portsmouth, UK.
  Reply With Quote
Old 27th July 2013, 01:00 PM   #17
jlaakso is offline jlaakso  Finland
diyAudio Member
 
Join Date: Mar 2010
That's more or less what I had in my mind for CA22RNY and 27TDC + waveguide. Targetting xo 2kHz region or below, depending on tweeters power handling on such low xo. Afaik 27TDC is fairly robust and should handle 2kHz pretty well.
  Reply With Quote
Old 27th July 2013, 01:07 PM   #18
IG81 is offline IG81  Canada
diyAudio Member
 
IG81's Avatar
 
Join Date: Feb 2008
AFA using a Zobel, 7.5ohm + 11uF did the trick on my 830869. I felt it was pretty much needed to get good behavior.

IG
  Reply With Quote
Old 27th July 2013, 02:26 PM   #19
diyAudio Member
 
Michael Chua's Avatar
 
Join Date: Jul 2006
Location: Calais, ME
I tested the 830869 with a Selenium D220 coupled with a Pyle PH715 asymmetric horn. I'm quite happy with the results. A sample of my crossover can be found at Nightingale-V.

I'll be running more test, this time with a DNA350 compression driver and a selection of horns from DIY Sound Group. I think it'll be even better.
__________________
AmpsLab.com
  Reply With Quote
Old 27th July 2013, 04:37 PM   #20
diyAudio Member
 
Join Date: May 2009
Location: Seattle, WA
Quote:
Originally Posted by system7 View Post
Just to get you heading in the right direction, chazdrumzalot...

You'll never get anything good with a 1.8mH coil and a 10uF capacitor on the 8" bass. 8" bass peaks badly in the midrange if you overdo the shunt capacitor, it's just how they are.

These drivers need a Zobel type capacitor shunt to get some serious rolloff. Say 7.5R and 6uF along with a suitable bafflestep coil around 2mH. I'd add a tank around 6-7kHz across the coil to dip the breakup too. In fact Troels does exactly that here:

TQWT-

Hope it helps.
Hi System7, thanks for your informative reply. A few questions/comments:

In the second simulation I posted, I used a 2.2mH coil and a 15uF cap to get the woofer breakup ~14-15db below the total output. Assuming this is not enough, what minimum suppression should I be aiming for?

...Which leads to my next question:by "overdoing" the shunt capacitor are you saying that 10uF is TOO large? If that's the case, I think I already know how you'll feel about the 2.2mH/15uF option.

I initially started my crossover simulations with a zobel (the same as IG81 recommended, or by using PCD's suggested values) and baffle step and everything, and this morning I went back to that. But I have not yet found a way to incorporate the zobel such that I get a good FR, good phase, AND any additional breakup control compared to 2.2mH/15uF. To get anything that looks good I have to resort to a single series coil in conjunction with the zobel (and then phase is bad anyway). This may all be due to the fact that I'm not yet using my own in-box measurements, and perhaps once I get started with those I'll see (or hear) what you're describing.

If serious rolloff is the goal, maybe I should put more attention toward the 24db crossover, despite the higher complexity and cost.
__________________
Then again, what do I know?
  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
3-way Crossover (Beyama 8BR40, Seas MCA15RCY, Seas 27TFFC) jojino Multi-Way 10 31st January 2012 02:19 PM
FS: Peerless HDS Nomex 8" woofers (830869) cs Swap Meet 3 21st July 2011 08:10 PM
Seas 27TDFC H1189 vs Seas 27TFFC H881 ermes Multi-Way 4 19th April 2011 01:20 PM
Seas 27tdfc + waveguide and Peerless 830870 project pajazo Multi-Way 24 11th April 2008 08:10 AM
FS: Focal 7K4411 - Seas 27TFFC - MCM 55-1855 - Free PE 5.25" DOTD woofer PaulHilgeman Swap Meet 1 23rd July 2003 09:36 PM


New To Site? Need Help?

All times are GMT. The time now is 03:28 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