World's smallest subwoofer? - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

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 13th November 2011, 10:58 PM   #1
diyAudio Member
 
ByronInPortland's Avatar
 
Join Date: Nov 2010
Location: Portland, Oregon
Default World's smallest subwoofer?

I found someone was having a special on a pair of Peerless 830855s (don't remember who). It's the smallest driver I've ever seen described, by the manufacturer, as a subwoofer - 4"!
http://www.tymphany.com/files/SDS-P830855%20Rev1_0.pdf
The idea of a 4" subwoofer intrigued me and I figured I could use them for my computer.

I measured impedance with Dayton's WT3, and modeled them with Audua's Speaker Workshop (I never trust manufacturer's specs). Even though Tympani's data sheet said they're ideal for sealed boxes, SW modeled a much better response for a pair in a 14.3 liter ported enclosure tuned to 53Hz. As you can see in the photo, I put them on opposite ends of the same 14.3 liter cube with a single port, even though they will be driven by separate amplifier channels. After building it I was disappointed with the very loud chuffing, and a loud resonance when playing a 45Hz test tone.

Next day, I did some nearfield measurements of both drivers, and of the port with Holm Impulse. The two drivers were driven by separate channels being fed the same signal. I had to take time-aligned measurements of the two drivers separately, sum them, then sum that response with the time-aligned port response, all in Impulse. I then taped an extra 1cm, 2cm and 3cm on the end of port and repeated the measurements. I got a much nicer response with an additional 2cm on the port. I was a bit surprised because usually SW's calculations are spot-on.

All-in-all I'm impressed with what Peerless can get a 4" woofer to do. Some people may be wondering whether or not they can be used as a full range driver. I would not recommend it. I listened to some music, and thought the mids were pretty muffled.

This project got me wondering just what a subwoofer is. That is: how does a driver described as a "subwoofer" differ from the same size driver described as just a "woofer". Is it their inability to play mid bass, and a need for a low X-over point? Just wondering if anyone has any ideas.
Attached Images
File Type: jpg comp subwoof_SW data&simulation.jpg (200.7 KB, 491 views)
File Type: jpg comp subwoof_photo.jpg (196.7 KB, 492 views)
File Type: jpg comp subwoof_spliced F-R curves.jpg (264.5 KB, 479 views)

Last edited by ByronInPortland; 13th November 2011 at 11:01 PM.
  Reply With Quote
Old 13th November 2011, 11:04 PM   #2
GloBug is offline GloBug  Canada
Banned
 
Join Date: Jun 2011
Yes, thicker cone, heavier, generally more excursion etc, things that rob it of accuracy help bolster it's performance at a lower frequency.
  Reply With Quote
Old 13th November 2011, 11:29 PM   #3
NEO Dan is offline NEO Dan  United States
diyAudio Member
 
NEO Dan's Avatar
 
Join Date: Jun 2008
Location: N.E. Ohio
Hey Byron,
Is the (Volume of Sealed Box) 35.311' used in the VAS calculation?
__________________
Regards,
Dan
  Reply With Quote
Old 13th November 2011, 11:46 PM   #4
diyAudio Member
 
ByronInPortland's Avatar
 
Join Date: Nov 2010
Location: Portland, Oregon
Neo Dan,

That's a curious glitch that Speaker Workshop has. I didn't use the sealed box method for calculations. I used the added weight method. But SW puts that value in the driver description anyway. I didn't build a 35^3 speaker cabinet.

-Byron
  Reply With Quote
Old 13th November 2011, 11:57 PM   #5
NEO Dan is offline NEO Dan  United States
diyAudio Member
 
NEO Dan's Avatar
 
Join Date: Jun 2008
Location: N.E. Ohio
you interested in ~35hz?
__________________
Regards,
Dan
  Reply With Quote
Old 14th November 2011, 12:22 AM   #6
diyAudio Member
 
revboden's Avatar
 
Join Date: Feb 2011
Quote:
Originally Posted by ByronInLawrence View Post

This project got me wondering just what a subwoofer is. That is: how does a driver described as a "subwoofer" differ from the same size driver described as just a "woofer". Is it their inability to play mid bass, and a need for a low X-over point? Just wondering if anyone has any ideas.
I think it depends on what the marketing department needs to sell more of.

I always thought of sub-woofers as just that, a driver with a Fs 20-30Hz that filled in below the woofers (~60Hz). But I'm just an old IATSE sound engineer, most of my career I only used Subwoofers for "effects" so what would i know.

later,
rev.
  Reply With Quote
Old 14th November 2011, 01:55 AM   #7
NEO Dan is offline NEO Dan  United States
diyAudio Member
 
NEO Dan's Avatar
 
Join Date: Jun 2008
Location: N.E. Ohio
No to 35hz eh? How about 40hz, it's smaller and a bit more efficient.

This is 1/2" sheet stock.
~17-5/16" x 6" x ~29-7/16" hwd
Attached Images
File Type: png 1w.png (27.8 KB, 406 views)
File Type: png SDS_830855_1.png (42.1 KB, 405 views)
__________________
Regards,
Dan

Last edited by NEO Dan; 14th November 2011 at 02:00 AM.
  Reply With Quote
Old 14th November 2011, 05:08 AM   #8
diyAudio Member
 
ByronInPortland's Avatar
 
Join Date: Nov 2010
Location: Portland, Oregon
Hi NEO Dan,

I don't understand the question. I'm not planning on building any more subwoofers for a long time.

-Byron
  Reply With Quote
Old 14th November 2011, 05:52 AM   #9
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
Hey Byron, I remembered seeing these Tang Band subs in a PE flyer and thought you might be interested. Maybe it's the upper freq response that is used to categorize subwoofers? I'm also intrigued by little subs that can provide usable output <50Hz. Looks like a neat PC multimedia box you've put together. Where did you set the LPF?
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 14th November 2011, 02:48 PM   #10
bjorno is offline bjorno  Sweden
diyAudio Member
 
Join Date: Mar 2005
Location: Jacobsmountain
Send a message via MSN to bjorno
Quote:
Originally Posted by sofaspud View Post
.. a neat PC multimedia box ..
Hi,

FYI, A less than 1 liter box suggestion using two TB-W2-1625SA:

b
Attached Images
File Type: gif TB-W2-1625SA_OD-TL.GIF (173.5 KB, 177 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
Smallest possible subwoofer enclosure Peezlepop Subwoofers 2 17th April 2011 03:10 AM
World's Largest Subwoofer orangeshasta Everything Else 9 27th July 2008 03:06 PM
Oki Electric Industry intros "world's smallest MP3 chip" Nordic Parts 1 16th September 2006 10:21 AM
The world's sexiest finish? The Dudster Multi-Way 8 8th November 2004 12:41 PM
World's Ultimate Subwoofer? dantwomey Subwoofers 10 21st April 2004 12:21 PM


New To Site? Need Help?

All times are GMT. The time now is 11:32 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