Welcome, Guest. Please Login or Register
Decware Audio Forums
04/19/24 at 02:56:46 




Pages: 1
Send Topic Print
calculating my sealed volume? help! (Read 6012 times)
backfixer
Verified Member
**




Posts: 18
calculating my sealed volume? help!
06/25/07 at 07:18:25
 
alright,

this is my 1st WO, Ive made a DB12 and 2 HW15s.  okay, my problem is I have laid out the design for a WO36x36" for my 2 12" cerwin vegas, with the modified 2" increase in height per Steve's rec.  When I calculate the sealed volume, its almost about 1.6cuft for each sub. (is that right? or have I forgotten how to calculate volume?)  that seems a bit big right? I mean, when I use the 4th order band pass calculators online, it shows I need to use about .75cuft given the specs of the cerwins...soooooo, are these numbers right? if anyone would be willing to double check my speaker specs, using a sealed Q of .7, or whatever optimum # it should be for an in house theater WO and anyother suggestions, I would much appreciate it!

CV Vmax 12svc:
woofer Diam: 283mm
4 ohms
300 RMS watts
Fs: 20
Qts: .31
Qms: 9.92
Qes: .32
Vas: 93 liters
Xmax: 20.3mm
Sensitivity (2.8V@1m) 92dB

should I use the 36x24" model to decrease the sealed volume...or is that what I really need to do? someone please verify for me what my perfect sealed volume in 4th order should be for the specs above Cool
Back to top
 
 
  IP Logged
musgofasa
Seasoned Member
****


Where is that
monkey? I want to
shoot something!

Posts: 556
Re: calculating my sealed volume? help!
Reply #1 - 06/25/07 at 12:46:54
 
If you are using it for an HT system, the larger sealed volume will give you a more robust and lower tuned sound. Of course, the CV's might have a bit of an excursion issue at real low freqs. My suggestion would be to build it and listen to it first. Then, if you need to lower the internal volume a bit add wood a little at a time and test it to see how it sounds. It is a bit tedious, but guaranteed to get what you are after.

I would listen at full size first, then make a pretty drastic change (IE: cut the volume in half) and see what difference it makes. If it is better, you have a starting point, if it is worse, then you know to try something in between first.

Personally, for HT, I think the larger space will be better. For music, it might be a little boomy so a listening test is the only way to find out.

Take care,
Robert
Back to top
 
 

The graveyard is full of important men
musgofasa   IP Logged
backfixer
Verified Member
**




Posts: 18
Re: calculating my sealed volume? help!
Reply #2 - 06/28/07 at 01:48:14
 
As fate would have it...The Cerwins ended up not fitting into the WO, I even made the 36x36 version with the side peices fitting flush outside of the base of the WO....still not enough room...so never mind, I just bought a pair of Infinity PERFECT 10.1....not the new infinity VQ's, which I feel dont come close to the 10.1's of last years model...the sensitivity on these puppies are 94dbs and Fs is 18! tastey  :D!  Now I just need a nice amp, any suggestions?  

What is the difference between using a home audio amp (like the Yamaha MX-1000) as opposed to a DJ type amp like a Crown XLS series?  thanks
Back to top
 
 
  IP Logged
ST33M
Ex Member



Re: calculating my sealed volume? help!
Reply #3 - 06/30/07 at 08:30:38
 
Is there a drastic difference in the fullsize compared to the 36x24 version ? I only have room for the smaller version in my trunk and was curious.
Back to top
 
 
  IP Logged
Adrian
Ex Member



Re: calculating my sealed volume? help!
Reply #4 - 06/30/07 at 09:13:28
 
the perfect 10.1 is nowhere close to 94dB sensitivity. wish i would see a high excursion 10 so efficient. iirc, that number is in-car sensitivity.
Back to top
 
 
  IP Logged
Pages: 1
Send Topic Print