"Quick and dirty" sealed subwoofer - HELP! - Page 2 - 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 3rd October 2011, 08:50 PM   #11
diyAudio Member
 
revboden's Avatar
 
Join Date: Feb 2011
6ft^3 is the approximate volume of air in a 1st floor ceiling gap between the 2x6s in a average 12x12ft room.
  Reply With Quote
Old 3rd October 2011, 10:32 PM   #12
Lenin21 is offline Lenin21  United Kingdom
diyAudio Member
 
Join Date: Mar 2011
Revboden, that doesn't help, I'm afraid.

I'm just trying to get a rough and ready estimate of the approximate volume required for an 8 and 10 inch drivers in sealed enclosures, that's all. With no available T/S parameters (as predicted, the manufacturers have none) I realise that suggestions will all be very much 'ballpark', but that's better than nothing!

I've supplied my guesstimates (0.7 cu ft for the 8 inch driver, 1.2 cu ft for the 10 inch) I'd be truly grateful if some of you could provide some too - it would (hopefully) reassure me that I'm in the right ballpark. As I say, I'm after a taught and articulte sound rather than a loose, Ill-defined 'boom'.
  Reply With Quote
Old 4th October 2011, 12:20 AM   #13
Djim is offline Djim  Netherlands
diyAudio Member
 
Join Date: Dec 2009
Location: 'Ollanda
Logical thinking;

If it looks like a ceiling speaker, if it is marketed like a ceiling speaker and if the brandís main activity is ceiling speakers and conference systems, how big are the chances that:

  • You are dealing with a ceiling speaker?
  • You are dealing with T/S parameters tuned for ceiling purposes?
  Reply With Quote
Old 4th October 2011, 01:26 AM   #14
tb46 is offline tb46  United States
diyAudio Member
 
Join Date: Jan 2006
Location: Texas
Hi Bart West-VL.,

Post #10: There are just too many to list them here, another good one is on Brian Steele's Subwoofer DIY Page: The Subwoofer DIY Page - Measurements

Hi Lenin21,

It obviously is a ceiling speaker, so when in doubt it might be best to mount them without an enclosure. Alternatively, if you don't have the T/S parameters for your driver, and if you don't want to take the time to measure them, just build the largest sealed box that will fit the available space, stuff it loosely with polyfill. That would be my enclosure estimate.

Regards,
__________________
Oliver
  Reply With Quote
Old 4th October 2011, 05:34 AM   #15
diyAudio Member
 
Ŗart West-VL.'s Avatar
 
Join Date: Jun 2005
Location: West Vlaanderen
@tb46 Thank you, I'll have a look at Brian's page and hopefully find some time to continue my measurements.

As for the speakers, I'm with tb46:
big box, full of loose stuffing. And bracing of course.
__________________
Break in your loudspeakers at 35% RMS power Right-click'save as...'
Brown noise mono 192kbps(hit "repeat")
  Reply With Quote
Old 4th October 2011, 06:27 AM   #16
diyAudio Member
 
Moondog55's Avatar
 
Join Date: Jun 2007
Location: Norlane; Geelong: Victoria: Australia
Sorry to say I'm with the other guys. better to get an old set of boxes or buy better drivers. most ceiling speakers are pretty bad, if you are lucky you get a set designed for the gap between floors; some need cubic meters to work in IE the whole roof space.
6 cubic feet (180/200 liters ) is a fairly small box as far as my speakers go but SWMBO is starting to put her foot down where my sub woofers (9 of them ) are concerned
__________________
QUOTE" The more I know, the more I know, I know (insert maniacal laugh >here<) NOTHING"
  Reply With Quote
Old 4th October 2011, 12:47 PM   #17
Lenin21 is offline Lenin21  United Kingdom
diyAudio Member
 
Join Date: Mar 2011
Default If it looks like a duck and quacks like a duck - it aint necessarily a duck...

Djim, I wish things were that simple.

Cigarettes used to be marketed as good for you, by companies who insisted that they were good for you, supported by glossy ads, featuring glowing, healthy-looking people making it clear that they were good for you. What are the chances that cigarettes are good for you? The reality of course, was (both for cigarettes and budget speakers) making large bucks, as cheaply as possible, using the thinest, most scientifically baseless marketing imaginable.

The idea that these speakers have been specifically designed to exploit the likely volume of air to be found in floor/ceiling cavities in an average room is as baseless as the idea that cigarettes are good for you. I'm fairly sure that we are talking about a manufacturing company keen to exploit a market opportunity by having 'ceiling speakers' in its range. its clear to me that hey have simply taken advantage of the economies of scale that being a large manufacturer brings and cobbled together a full-range driver, using cheap and cheerful components, mounted it in ceiling mounting hardware and then marketed it as a 'ceiling speaker'! If I'm right, the manufacturer wouldnt have the foggiest idea what the T/S parameters are, of course. Guess what? They have absolutely no idea what the T/S parameters are. They do for all their other (more expensive) models, but clearly, the design of these units as ceiling speakers doesnt extend beyond fitting the driver in some ceiling mounting hardware.

Look, I realise I'm being a bit strident here - but this is becoming slightly frustrating. I'm asking for some ballpark recomendations for 8 and 10 inch drivers with compliant surrounds, mounted in sealed boxes, thats all. I realise that no T/S parameters means it's kinda ballpark, but please, go on - just take a punt! Give me a loose range! Tell me that I should stick to the lower or upper range of the volumes I gave in my first post!

Please, lets not postulate any longer on whether the drivers were specifically designed for IB use - let's just pretend that they are suitable for sealed box use and contribute 'safe zone' guestimates.
  Reply With Quote
Old 4th October 2011, 01:40 PM   #18
tb46 is offline tb46  United States
diyAudio Member
 
Join Date: Jan 2006
Location: Texas
Hi Lenin21,

Just some quick examples of 8" and 10" in sealed boxes:

Regards,
Attached Images
File Type: jpg 8_10_sealed.jpg (138.8 KB, 38 views)
__________________
Oliver
  Reply With Quote
Old 4th October 2011, 03:17 PM   #19
Djim is offline Djim  Netherlands
diyAudio Member
 
Join Date: Dec 2009
Location: 'Ollanda
In case the Adastraís use the same driver as enclosed ceiling (cheap Chinese) speakers the volume would be something like 15 to max 22litres. In those cases the usable frequency is often marketed as 50Hz but in my experience itís more like 60/65Hz.
  Reply With Quote
Old 4th October 2011, 09:29 PM   #20
diyAudio Member
 
Moondog55's Avatar
 
Join Date: Jun 2007
Location: Norlane; Geelong: Victoria: Australia
OK For a quick and dirty solution it really doesn't matter if the box is big or even really big.Volume for Qtc=1 may be 30 litres but making the box 200 litres may only give you a Qtc of 0.7. When in doubt make the box bigger, it really doesn't matter that much with cheap drivers for which there is no data
__________________
QUOTE" The more I know, the more I know, I know (insert maniacal laugh >here<) NOTHING"
  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
So now I have to worry about "dirty electricity"?? amt Everything Else 47 11th March 2011 06:57 PM
Fender Frontman 212R-Clean channel sounds "dirty" EronSilva Instruments and Amps 5 24th January 2011 05:50 PM
Advice on a 15&quot;+ sealed subwoofer design gwgjr31 Subwoofers 25 27th April 2006 04:18 PM
Subwoofer guide posted, Sealed Dayton 15" DVC wigginjs Subwoofers 2 4th November 2004 05:39 AM
Early Punk Fans: "Talk Dirty" Lyrics? kelticwizard Music 0 30th October 2004 05:49 AM


New To Site? Need Help?

All times are GMT. The time now is 08:01 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