Originally Posted by DankNuggz
Hello AVS. I have recently been getting into Home Theater, and wanted to build
a powered subwoofer to replace (or add to) my current sub. I have an old car
subwoofer that I would like to use, and I purchased a Dayton SA240 plate amp.
I posted this on another site, but haven't got much response.
Just ordered a Dayton SA240 240w plate amplifier http://www.parts-express.com/pe/show...number=300-804
I plan on building an enclosure for an Infinity Kappa Perfect 12.1 http://www.crutchfield.com/S-iYEj8X7...ml#details-tab
My current subwoofer is an old Cerwin-Vega! that I can't find any info on, but
its a 10" sub and probably 100 watts. It sounds like **** on music, and does ok on movies.
My goal on the new sub is a flat response from 20hz-80hz
I found plans for a 12" Infinity Kappa VQ MidQ build http://forums.audioholics.com/forums...idq-plans.html
here are the specs for the Kappa VQ MidQ http://www.crutchfield.com/S-dAWz3Fl...fo#details-tab
First question is will the plans for the VQ MidQ work for the perfect 12.1 ?
The box is 4 cubes tuned to 20hz----and they power it with an EP2500 amp
Also do I need a crossover or does the plate amp do it all?
I know it has a low pass on it, but do I need to protect it from frequencies below 20hz?-----I was looking for terminal plates and seen some with built in crossovers, and it made me wonder.
Any help or suggestions would be appreciated.
Will be posting pics during and after build.
TV: Dynex 42" 1080i LCD
Reciever: pioneer VSX-920 7.1
Fronts: Energy Veritas 2.3i
Center: Mirage OM-C2HB-1
Rears: Sony SS-MB300H
Surrounds: Sony SS-MB100H
Subwoofers: Cerwin Vega ARPHS-2004-5
HTPC-Intel corei7 ,bluray ,Nvidia 260gtx, windows7, 4gb DDR3 , solid-state HD
A few comments first, I have an Infinity Kappa Perfect VQ in 4.3 ft^3 tuned at 19 hz that sounds awesome off half an EP2500. I saw avaserfi's build thread after I bought my 12s and considered that design before I went with my end-table design. I would imagine the sound is quite similar.
My cabinet is 18"W X 22"T X28"D with a 7" X 3" slot port that runs along the bottom and half way up the back. I built the port as a separate "L" out of MDF and nailed it in as one piece. Then used a cut off bit to open each face plate with a final round-over for the outer edge.
I used an Oak plywood for mine, but did not spend near enough time sanding before I applied a stain. This cabinet was more of a "test" box anyways, so I didn't worry too much at the time, but 18 months later, it is still in the corner by the loveseat and I am wishing I had spent more time finishing it out. I have another VQ12 in my truck that needs to move to the living room soon, so maybe when I build the matching cabinet, I can do two and finish them both off properly and donate my current cabinet to my son.
Things I would do differently, I would use an 11-ply Birch instead of the Oak I spent more money on. I would spend much more time sanding, because the stain shows every minor scratch, or at least the one I used does. I would use the same cabinet design, but do a 3rd face so I can inset the woofer and maintain double face integrity. I would also do the port out of the same wood as the cabinet, because staining the MDF port is butt ugly!
As for your specific questions, those woofers are close enough that you can use the same cabinet design. If anything, the 12.1 prefers a slightly smaller cabinet than the VQ design, so you could shrink it if needed. The great thing about DIY is you should not feel restricted by a specific design. If you have a space in your home to dedicate to a sub, adjust the cabinet accordingly. My end-table cabinet is the size it is because that is the area between my loveseat and the window. I adjusted the dimensions a bit, but it fills that functional space.
The Dayton SA240 has an adjustable low-pass cross-over built in as well as a 20hz high-pass filter to protect vented cabinets. I would not tune the cabinet below 20.
Best of luck with your build.