Not clear on box size, Help please! - diyAudio
Go Back   Home > Forums > General Interest > Car Audio

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 24th December 2007, 04:04 AM   #1
skooter is offline skooter  United States
diyAudio Member
 
Join Date: Oct 2007
Default Not clear on box size, Help please!

went to down load and it ask for Qtc. Manual dosen't list it. just Qts.

Fs-32Hz
Qts-0.72
Qes-0.83
Qms-5.397
Vas (Cu.Ft.)-2.26
Vas (Liters)-63.99
Re-1.5ohms
Le-0.43mH
Mmd-126.5 grams
Xmax- +/-8mm
RMS-400 watts
Sd-480 sqcm
Freq. Resp.-20Hz-500Hz
Efficiency (2.8V)-92.7
EBP-39
Displacement- 0.23Cu.Ft.

can someone please run this and let me know what size box I need to build for these subs. Thanks, I hate to be so stupid.
  Reply With Quote
Old 24th December 2007, 05:00 AM   #2
Clipped is offline Clipped  Thailand
diyAudio Member
 
Join Date: Mar 2005
Location: home
Send a message via MSN to Clipped
what size, brand sub is it?
  Reply With Quote
Old 24th December 2007, 05:19 AM   #3
skooter is offline skooter  United States
diyAudio Member
 
Join Date: Oct 2007
It is a Dub200 12" dual 4ohm. Yes I know it is a cheap sub. but I ain't got much money. Thanks.
  Reply With Quote
Old 24th December 2007, 06:17 AM   #4
jol50 is offline jol50  United States
diyAudio Member
 
Join Date: Nov 2007
What Hz you want to tune it to? Ported, slot or tube? A pair right, in one box?

I have a digital audio 12, its pretty cool with that huge surround but SQ people scoff at them. No matter, your enclosure makes much more difference.
  Reply With Quote
Old 24th December 2007, 06:39 AM   #5
Clipped is offline Clipped  Thailand
diyAudio Member
 
Join Date: Mar 2005
Location: home
Send a message via MSN to Clipped
how many subs and what kind of car?

ported:

just make the box between 2.25-2.75 cuft
with 14"-16" of port area per cubic foot.
start the port length at around 22" and keep cutting off 1 " at a time until its loudest. 16"-18" port length is just about right for most subs.


this is the way competitors do it.
  Reply With Quote
Old 24th December 2007, 06:43 AM   #6
skooter is offline skooter  United States
diyAudio Member
 
Join Date: Oct 2007
2 12" subs
1 sealed box
back of 97 cherokee, subs pointed to back hatch.
Hz? listen to rock, metal, some bass stuff
running them with a PPI PCX2200 mono 4 ohm load

The manual recomends .75-1.50 Cu.Ft. (per sub)
  Reply With Quote
Old 29th December 2007, 12:39 AM   #7
skooter is offline skooter  United States
diyAudio Member
 
Join Date: Oct 2007
Ok, I am building tonight my new sub box. I have decided to stick my 2 12" in a 2.70 Cu.Ft. sealed box. wish me luck!
  Reply With Quote
Old 29th December 2007, 06:03 AM   #8
diyAudio Member
 
tsmith1315's Avatar
 
Join Date: Jul 2003
Location: Doerun, GA
Skooter asked:

Quote:
went to down load and it ask for Qtc. Manual dosen't list it
Qtc is the resulting system Q of speaker+box combined.

Therefore, you have to specify what Qtc you want before box size can be determined.

Smaller box = higher Qtc

And Skooter said:

Quote:
Ok, I am building tonight my new sub box. I have decided to stick my 2 12" in a 2.70 Cu.Ft. sealed box. wish me luck!
Obviously my post is moot at this point. But just for reference, from the parameters you posted:

Subtracting 0.23 cu ft per speaker from the 2.7 leaves 1.12 ft per speaker.

In that size box, your Qtc (theoretically) will be 1.25. This is a little high for some folks, but works well for rock and metal IME. What it means is that you will have a couple of dB rise in frequency response around the system resonant frequency. In this case that will be about 55Hz.

Your -3dB cutoff (in free space) would be about 40 Hz.

The confined space of the car will add quite a bit of low end boost, and you should be happy with the results.

Good luck and have fun building!

Tim
  Reply With Quote
Old 29th December 2007, 06:38 AM   #9
skooter is offline skooter  United States
diyAudio Member
 
Join Date: Oct 2007
Good to hear a positive reply! My music normally consists of rock and roll, steve miller, motley crue, don henley, corn, metalica, cure, billy squire, 75% of the time. then I have some of the newer r&b stuff that is out. and I like to listen to instimental stuff like kraftwerk and some pink floyd too! but thanks for the input!!
  Reply With Quote
Old 29th December 2007, 06:46 AM   #10
jol50 is offline jol50  United States
diyAudio Member
 
Join Date: Nov 2007
Oh great, now I have to dig out my billy squire and cure CDs....
  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
Is Thier Away To Clear Up Distortion??? prorms Tubes / Valves 12 30th October 2007 07:34 PM
Can somebody clear me up? DolbyR Instruments and Amps 2 29th December 2005 08:44 PM
1 channel not clear hipyo Car Audio 13 25th August 2005 05:12 AM
Clear PA Enclosures Limpingshrew Multi-Way 13 18th August 2004 07:01 AM
Please clear this up 805 or pcl805 georgehifi Tubes / Valves 3 24th November 2003 05:16 PM


New To Site? Need Help?

All times are GMT. The time now is 06:18 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