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Building sub box..........

post #1 of 25
6/20/09 at 11:19am
Thread Starter 
I figured I would start a new thread for this since the other one was titled plate amp, and this is more of a question about the box construction.

I have put together most of the box except the front (which I am still deciding about, mostly just cosmetic) , and the dowels I plan on using as support.

Any opinions on the layout of them? I originaly had planned on using 5 of them, but once I had the box together 5 is way overkill. So I was thinking 3, but that even seems to be more than needed. If you were doing it like this how many would you use? and any particular layout?
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post #2 of 25
6/20/09 at 11:21am
Thread Starter 

Re: Building sub box..........

I guess a picture might help eh?

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post #3 of 25
6/20/09 at 11:56am

Re: Building sub box..........

Since you aren't finished with the box, remove the dowels and use window braces like this and this. Use the dowels to connect the braces together if you want. Make sure the baffle is double thick.

-Robert
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post #4 of 25
6/20/09 at 12:20pm
Thread Starter 

Re: Building sub box..........

Appreciate the response, but what is the significance of using that type of braceing vs other type? I checked out the two links and neither explain the reason for that type bracing. I thought the bracing was to stiffen the box over large spans.
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post #5 of 25
6/20/09 at 2:32pm
Thread Starter 

Re: Building sub box..........

Seeing the dimensions of my box, that type bracing seems like alot of wasted work. The dimensions are 2' by 2' by 12.5"

If there is some reasoning behind making a windowed piece vs just actually supporting the box, then I would understand........but I would think with the dowels as I had in mind would definatly stiffin it up, and use less space. The only thing I found doing a search for why the other way would be better was a quote that it was efficient.....not why it was just that it was, and didn't offer any other solutions.
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post #6 of 25
6/20/09 at 2:51pm

Re: Building sub box..........

Nice box! My homebuilt sub is an infinite baffle so all the bracing is external and easy to install. Can't really help, but I like the look of that!
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post #7 of 25
6/20/09 at 3:14pm
Thread Starter 

Re: Building sub box..........

Quote:
Originally Posted by Philip Hamm
Nice box! My homebuilt sub is an infinite baffle so all the bracing is external and easy to install. Can't really help, but I like the look of that!
Thanks dude. I have got the other side on and the 2 front pieces on now. And I have primed it and skimed all the screw holes too, also got the inside joints caulked. I have yet to decide on the dowels. I believe I am going to lay out for 4 of them and see what that looks like. Once the primer dries I will stand it up and take another picture so it's sitting like I plan on using it. Gonna finish all the sides, so that if I want to I can lay it flat like it sits now too.
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post #8 of 25
6/20/09 at 4:54pm
Thread Starter 

Re: Building sub box..........

Got 3.1 cf after subtracting for the dowels and the sub, now for the ports. My plan now is to put 2 ports on the front. Have to do alittle more research to make sure about the placement.....I am thinking one above and one below centered. Using 2" ports.





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post #9 of 25
6/21/09 at 11:37am
Thread Starter 

Re: Building sub box..........

Well I have it looking smooth and a good final coat of primer. And I guess I am going to order that amp from PE. Should time it just right to finish the baffle and port (or ports) as the amp gets here.

Still yet to decide on finishing it. As for now I am thinking high gloss black, with satin black baffle.....or the other way around.

It sure is a big box, but almost perfect as an end table with maybe a wood top on it. I have a few options for it.


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post #10 of 25
6/21/09 at 1:32pm

Re: Building sub box..........

Marvin - The window type bracing gives you rigidity and support from four sides instead of just the two sides the dowels will give you. It also stiffens the inside jointed edges along the long axis of the box. Same reason you use trusses when you build a tunnel and not just poles to keep the roof from falling in.

It's a moot point now since you have the box assembled. It does look good so far. Let us know how it performs when it's finished and make sure to post some completed pics.
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post #11 of 25
6/21/09 at 1:47pm
Thread Starter 

Re: Building sub box..........

Thanks

I see your point. I didn't figure I needed much support the other way seeing as how it's just 11" across inside. I was think of using some small blocks or something in the corners for strengthening up the box.

I appreciate any opinions, you know this is my 1st real attempt at building a sub box for home, and I know I will make mistakes. But to me that's the fun of it.....learning by trial and error to some extent, and a somewhat educated quess.

I think as it is now the box is pretty solid, and ridged. And as bad as the box I have the sub in now I build for my truck.....this will be a vast improvement. I reentered all the specs from the box in my truck and it is horrible! lol
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post #12 of 25
6/24/09 at 6:44pm
Thread Starter 

Re: Building sub box..........

Any opinions on port size? I had thought I was gonna use this pvc pipe I had but it is 2" dia hole......seems rather small.

3".........4"?

Still have to make the front baffle, but have till friday when the amp gets in. Considering going sealed (it specs out pretty good sealed that size) until I research more on the port, just so I have 1st hand knowledge of the difference once I decide on the port or ports.
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post #13 of 25
6/24/09 at 7:09pm

Re: Building sub box..........

What driver and amp combo? What is your Fb? Have you modeled the air speed in the port at full power to determine if you will have chuffing? Flared port?

-Robert
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post #14 of 25
6/24/09 at 7:41pm
Thread Starter 

Re: Building sub box..........

The sub is just a Kicker Comp 10" and using the Dayton 100w @ 4 ohms Amp. Modeled with winisd, it shows perfect as 3.2 cf tuned to 26 hertz.
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post #15 of 25
6/24/09 at 7:44pm
Thread Starter 

Re: Building sub box..........

Quote:
Originally Posted by Robert_J
Have you modeled the air speed in the port at full power to determine if you will have chuffing? Flared port?

-Robert
Not sure how to do that.....it's says Qes/Pe! in the Vent Mach.
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post #16 of 25
6/25/09 at 5:05am

Re: Building sub box..........

A single 3" port should be fine. I'd use a PSP flared port though. Or use a router with a roundover bit to flare the opening on your box.

-Robert
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post #17 of 25
6/25/09 at 6:53pm
Thread Starter 

Re: Building sub box..........

Trying to utilize the materials I already have......would dual 2" ports work? I have the pvc and a hole cutter that size, so this would be ideal if it would work. According to winisd dual 2' ports measure 6.5".....which as someone said previously, means the length of each port would be that 6.5" in length.
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post #18 of 25
6/25/09 at 7:54pm

Re: Building sub box..........

A pair of 2" ports has a total port area of 6.28"^2. A single 3" port has 7.07"^2 of port area. Since you aren't using a very potent driver you should be OK.

-Robert
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post #19 of 25
6/27/09 at 10:34am
Thread Starter 

Re: Building sub box..........

Got my amp in, pulled my sub from my truck, and got it all together. Gotta charge my camera batteries and I will post a pic. Still gonna finish the front alittle better, but for now it is fine. I wanted to make sure I was happy with the sound before I put much effort in the finishing.

Have to say I am impressed with the results. I know the sub is not the greatest, but I am satisfied. I only paid 60 bucks new for the 10" sub, which makes a total of less than 200 for the whole thing.

Watching Armageddon, and.....well all I can say is YES! I have yet to turn it up past -24 on my Yamaha reciever, and no distortion......and impressive lows.
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post #20 of 25
6/27/09 at 2:36pm
Thread Starter 

Re: Building sub box..........

Question about the gain......
Am I right in that the gain doesn't alter the wattage, it has to do with matching the input signal? correct?
Using the subwoofer out on my reciever, into the left input on the sub amp....any suggestions on setting the gain. As it is now I have it set about 60-70% of wide open. I was always told with car audio, you leave the gain down.....turn your volume up to 75% or so, and ease the gain up till you get distortion. Then back it off alittle. I really don't like the idea of doing it that way. Is there a better way?
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post #21 of 25
6/27/09 at 4:14pm
Thread Starter 

Re: Building sub box..........





Not the pertiest thangs, but the bass in nice. Gonna do something to the front and put a top on, and make it an end table. It is rather large.
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post #22 of 25
6/29/09 at 7:39am

Re: Building sub box..........

Quote:
Originally Posted by MarvinJr
Question about the gain......
Am I right in that the gain doesn't alter the wattage, it has to do with matching the input signal? correct?
Using the subwoofer out on my reciever, into the left input on the sub amp....any suggestions on setting the gain. As it is now I have it set about 60-70% of wide open. I was always told with car audio, you leave the gain down.....turn your volume up to 75% or so, and ease the gain up till you get distortion. Then back it off alittle. I really don't like the idea of doing it that way. Is there a better way?
You need to set the levels using the calibration routine and mic in your receiver (if it has one) or buy an SPL meter and a calibration DVD. Radio Shack SPL meter is the most used and probably the cheapest. You can pick up an older copy of Video Essentials for $10. I try to keep my the LFE setting on my receiver close to zero. I then adjust the gain so that it matches the rest of the speakers using the meter. If that isn't enough to keep the sub turned on, then adjust the LFE up on the receiver and turn down the gain on the amp. Calibrate again so you are 100% correct.

Nice pics of the sub. If you want to stick with 10" subs then the SDX-10 is a great sub.

-Robert
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post #23 of 25
6/30/09 at 6:14pm
Thread Starter 
Thanks dude, appreciate the tip on that other sub. I checked it out....looks like something I might look into more.

I really am impressed with the box and sub. Gonna stop tommorrow at Radio Shack and pick that stuff up. Thanks again dude.
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post #24 of 25
6/30/09 at 7:00pm
If your local Rat Shack can't get the SPL meter, SVS still sells it [URL=http://www.svsound.com/products-parts.cfm]link[/URL].  VE is available from Amazon startingat $10.99.

-Robert
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post #25 of 25
6/30/09 at 8:36pm
Thread Starter 
Kool. Got to thinking, the last time I went to Rat Shack.....the dumas little girl working told me I had to buy a Sirius install kit, when I was just looking for a cable to plug from the docking station to the aux plug on the front of my truck radio. I told her, No...I have all that I just need a cable with the little aux plug on both ends. She said yeah they don't sell those, just comes with the 99.99 kit. I just walked away and went to Best Buy.
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