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calculating my sealed volume? help! (Read 1864 times)
backfixer
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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
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musgofasa
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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
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backfixer
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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
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ST33M
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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.
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Adrian
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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.
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