30 HZ from a 10 X 7 box - Page 3 - 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 7th July 2013, 02:35 AM   #21
diyAudio Member
 
fwbutler's Avatar
 
Join Date: Sep 2012
Location: Hillsboro, Oregon
Ok you guys convinced me! did a re-design now a 13" X 8" box using the Tang Band W5-1138, 40, Watt RMS/60 Watt max, 85.6 dB 1W/1m, Vas 0.17 ft^3
here is the results.

They will exceed the PP point with these!
These will give over 100 db SPL with about 30 watts.
33 Hz is only about -1 db, the F3 point is about 30 HZ depending on the software.
I think these are better, Thanks
Now for the crossover
Attached Images
File Type: jpg w5-1138-1.jpg (61.3 KB, 148 views)
File Type: jpg w5-1138-2.jpg (58.4 KB, 141 views)
File Type: jpg w5-1138-3.jpg (87.6 KB, 137 views)
  Reply With Quote
Old 7th July 2013, 02:57 AM   #22
diyAudio Member
 
Join Date: May 2010
Location: MN
That is an impressive little driver, bass-wise, but you may have some trouble using in a 2-way. Looks like it's best below 100Hz, okay to 500Hz, bad above 1k.
  Reply With Quote
Old 7th July 2013, 03:47 AM   #23
diyAudio Member
 
fwbutler's Avatar
 
Join Date: Sep 2012
Location: Hillsboro, Oregon
I will be crossing it over to the Vifa D27TG35-06 1" Silk Dome Tweeter at 1k to 1500. could start cutting the 1138 earlier to compensation for it's peaking between 1 & 2k. Do you have experience with either of these? All I know is what I read.

A mod to improve the tweeter
http://www.raylectronics.nl/pdfs/Mod...fa_tweeter.pdf

Last edited by fwbutler; 7th July 2013 at 04:15 AM.
  Reply With Quote
Old 7th July 2013, 07:55 PM   #24
diyAudio Member
 
fwbutler's Avatar
 
Join Date: Sep 2012
Location: Hillsboro, Oregon
I just wanted to thank the folks that posted this crossover tutorial. amazing amount of knowledge. If anyone has not read this already they should.

Introduction to designing crossovers without measurement
  Reply With Quote
Old 7th July 2013, 08:30 PM   #25
Wizard of Kelts
diyAudio Moderator
 
Join Date: Sep 2001
Location: Connecticut, The Nutmeg State
FWButler:

I would tune the speaker a little higher-about 45 Hz, which is its Fs. The Qts of 0.45 is only a little higher than the ideal Qts of 0.38 for a maximally flat system.

Even more important is the excursion. The following is a chart by Richard Small for the amount of air required to be moved to produce a given low frequency at a given SPL. I converted his metric numbers to inches.For a reflex box, you can divide this number by four.

Your TangBand speaker has a cone area of 3.6 in²-I converted from metric. The excursion is listed at 9.5mm-I assume that is one way, (P-P). The chart applies to midpoint-to-peak excursion, so we divide that by half. That is about 5mm-about 0.2in. Still a very good excursion for that size speaker.

So the total amount of air this speaker can move, in square inches, is 0.72in. Again, if you use it in a reflex, it only has to move ¼ the air listed.
Attached Images
File Type: gif displacement chart regular.gif (34.4 KB, 130 views)
__________________
"A friend will help you move. A really good friend will help you move a body."
-Anonymous
  Reply With Quote
Old 7th July 2013, 08:39 PM   #26
Wizard of Kelts
diyAudio Moderator
 
Join Date: Sep 2001
Location: Connecticut, The Nutmeg State
If you put your speaker in a reflex box you can multiply your displacement by 4, since a reflex reduces the excursion at the tuning point by that amount. 0.72in² times 4 = 2.9. Close enough to 3.2in².

If you extrapolate the chart between 40 Hz and 50 Hz, you can see that 3.2 in² gets you about 92 dB at 45 Hz before your excursion limit is reached.

To put this into perspective, the lowest tuning on a bass guitar, (normal tuning), is 42 Hz. That's usually the lower limit for most popular music, and you are just about at that point. Also consider that most professional DJ's use speakers that go down to 60 Hz or so. That's good enough for dances, etc. You'll be going down lower, though of course not as loud, as those pro speakers.

That is what I would suggest for getting the best, cleanest bass without running the risk of damaging your speakers by driving them into overexcursion. I would also suggest that you make the cubic volume of your speaker the same as the Vas, 0.21 ft.³ . You'll get a very, very small hump in the response, but nothing to worry about.
__________________
"A friend will help you move. A really good friend will help you move a body."
-Anonymous
  Reply With Quote
Old 7th July 2013, 11:10 PM   #27
diyAudio Member
 
fwbutler's Avatar
 
Join Date: Sep 2012
Location: Hillsboro, Oregon
Thanks kelticwizard. I was just reading Small Vented-box Loudspeaker...part 2, trying to make since of equation (41) Par(Vb) = 3.0 f3^4 Vd^2 trying to make sure that 90 db, after what the others have said, would not bottom out the speakers. Your evaluative comments are of great help. you have sent me back to figuring.
  Reply With Quote
Old 7th July 2013, 11:37 PM   #28
diyAudio Member
 
fwbutler's Avatar
 
Join Date: Sep 2012
Location: Hillsboro, Oregon
So your advice is to go from the red circle to one of the blue ones
Attached Images
File Type: jpg TB 1138 SPL.jpg (80.0 KB, 127 views)
  Reply With Quote
Old 7th July 2013, 11:43 PM   #29
diyAudio Member
 
fwbutler's Avatar
 
Join Date: Sep 2012
Location: Hillsboro, Oregon
I do not understand your comments about the Qts? the TB1138 has a Qts of 0.43. do you mean a desired Qtc? and should that not be Sqrt 2 = 0.707 vs an allignment like chebychev => Qtc =1+
  Reply With Quote
Old 7th July 2013, 11:59 PM   #30
diyAudio Member
 
fwbutler's Avatar
 
Join Date: Sep 2012
Location: Hillsboro, Oregon
yes you were talking about alignment vs displacment
Attached Images
File Type: jpg Displacment vs allignment.jpg (51.2 KB, 29 views)
  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
Which woofer does 30-1000 Hz / JBL 2235A Equivalent audiothings Multi-Way 25 5th November 2010 01:38 PM
Sanity check request for 30 Hz Tapped Horn pk Subwoofers 17 13th April 2010 05:44 AM
10-25 hz, is it necessary for HT or Music? Daveis Subwoofers 236 26th October 2008 02:31 AM
Boosting 25-30 hz qguy Subwoofers 2 13th January 2007 02:10 AM


New To Site? Need Help?

All times are GMT. The time now is 02:18 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