s_carter

I just like to set the bar really high for my designs, and it seems to be paying off, yet another enclosure I designed was featured on CAE again as an install of the week.... I'm loving it! The design looks great, and it should get wicked low. Have you thought about how you are going to finish it, yet?

No, it will be fine, the group delay is just a bit higher than what I like to see in the builds I do... It is still probably lower than many similar commercial designs (what similar designs?) though, if that gives you any idea.

Whats the point of tuning the box for subsonics, just to use it at 40 or 60 hertz? I think it should sound its best, right around its tuning frequency, and introducing group delay doesn't help that. Maybe I'm just too dam picky!

It looks good to me, the overall volume came out to 9.674 after displacements, and the port tuning is 21.9 hertz. The group delay is rather high for what I like to run @47, but the specs are according to the latest at fi's site. The parameters I have on my computer must be older models, they are showing a completely different tune.

Take a gander at this discussion on pro amps. there is a ton of good info there about them. I am looking over your design now, give me a few more minutes to check the math.

It uses the same connections as the Behringer, and its build quality looks great. I have talked to a few people on AVS asking about these amps as well, so I'm trying to find out if it would be a good buy or not. It looks like a steal at that price, though.

WinISD always assumes that the volume you enter is AFTER port and driver displacements, so make sure to factor this into your design measurements. Sure- go ahead and email me the sketchup file, an I can take a look at it for you and double check the numbers. I'm super excited, my SSD18's have been featured on Car Audio And Electronics home page, and also in the featured picture gallery! Check it out at CAE Featured Picture. I also got news today that a number of shops in the area will soon be contracting me to design and build "stock boxes," as I like to call them, since SubZero is going out of business (no surprise there, such garbage engineering, if you ask me!!!) and they will be looking for a new enclosure supplier.

just build it up in sketchup, and then you can measure your panels from there. Its a bit hard to get a hang of sketchup, but i have found the tutorials in the help center to be very useful. Always start with your bottom panel, then push/pull it to the thickness of your wood, and start drawing your edge panel dimensions onto it and use the CTRL modifier with push/pull+ to bring your walls and ports up from there. You will be designing boxes with ease in no time! It usually only takes me a few minutes to sketch it once I get the design finalized. Sometimes I will design them on the fly while I am drawing them up too.

There is over 3 inches of mechanical excursion (xmech) on these subs, and winisd is a bit misleading, did you enter 28mm under xmax, or 56mm? It should be 56, as winisd is peak to peak, and the specs for the sub under the site are one way limits. I don't think you will be able to bottom them out whatsoever, I have never once been able to do that with mine, and I am running over twice what they are rated for! If I remember correctly, the Q18's are suspension limited as well, so the spiders will give out before the coil starts clanking.

Well, three 4 inch aeros gives you 38 inches of port area, but I haven't used any aero ports in my boxes, so I couldn't tell you if that's enough or not. I would see if anybody with more experience with flared ports can help you out there. Other than that, it looks good. With a 22 hertz tune, you should be OK without an SSF. Here is the program I use to calculate my volumes, and I love using it! Enclosure Volume Calculator

Amp headroom never hurts, it will actually help with your sound quality.

You will want at least two of them, as you will want a lot of port area for the box size and amount of power you will be running, but your port length will be really long to keep that low of a tune using those. Ideally, you would want 12-16 inches of port area per cubic foot of air space in the box. With the same box dimensions as the plan I sent you, minus the slot port, is 8.836 cubes. Two of those ports will bring the volume to 7.690 with each port being 35 inches long for the 22 hertz tune, and that only gives you 55 inches of port area. You will need to buy some 90 degree bends to make it fit in the box though, since each port will be 35 inches long, and your depth is only 23.75" to the back wall with the ports mounted to the front of the baffle... Good luck!

Its not any more difficult at all, when it comes to the port walls, just attach the second port wall to the first, then attach the first port wall to the front panel of the box. Here is a few pictures of my last enclosure, which had two ports, each with three port walls, and since the design I gave you only has one port and two walls, its super easy to do. It does help to mark an outline of the port walls on the top and bottom panels before assembling it so you have a reference of where they need to go. I hope these pictures can help give you a reference on how to assemble it...

Allright sounds good, thanks for all the help. i was looking over your diagram and its probably just me making a mistake but using slot port calculators online i am getting 5-6 inches shorter then your port length for a 22 Hz tune, again probably just me but wanna make sure. I believe its because they dont calculate for end correction, that's why the tune seems off according to them. 22 hertz isn't the exact tune, but it was 21.81 hertz by my math. close enough for government work, right?

And the screw nazi strikes me down. Not to get on your case, bud, I have nothing against you or the way you like to do things. But I have done my homework, and do know what I am doing, I come from a large family of woodworkers. "Though widely used by woodworkers, PVA's (such as Elmer's and Titebond Wood glue) are not really suitable as a primary adhesive or for edge gluing... They are "plastic", so without other supporting fasteners such as screws or nails, metal reinforcements or dowels, the glued joints will eventually break apart." Quoted from: Wood Glue Information Ease up buddy, its not the end of the world. I'm out....

can you spend the extra 30-60 minutes of time it takes to screw it all together? and can you spare the 5 bucks that a box of screws cost? if you answer those you will answer your own question. It wont hurt anything if you answered yes to both of those.

Just go with the dual 2 so you can either bridge it at 4 ohms to the outputs to the EP, or run it at 2 ohm stereo. I would also go with the cooling option and the extra spider pack, to keep up with that amp, and you should be OK, unless you need the Samson box.

as long as your gains are set properly, they shouldn't have an issue running 1000 RMS, since they are dual 4's your options are 1 or 4 ohms. =) I run twice what my SSD's are rated for without a problem.

passive radiators, basically a speaker with no motor, just the cone and suspension. you can use them to tune an enclosure just like you would a port, by adding weight to them.

my guess is that it will probably be enough to double baffle the driver panel, and then have two cross braces inside as well, or you could go with some 2x4 bracing too. 2x4's will be better, since they have a higher resonance frequency than the MDF will. PR's are a much better design than a ported, no port noise and less group delay, but the only downside to that idea is that the PR's will most likely cost almost as much as the subs do, and you would need two of them for one speaker.

The design is all yours, I hope you enjoy it! I didn't include the cut list, but I'm sure you can figure it out from the model I emailed to you.

Yep, I use it for every enclosure I design, and then transfer the data over to a program called Cutmaster 2D so I can use the most efficient cuts for each panel. Good stuff right there. Let me draw up a model for you, and I am going to improve it for more port area, since that was one thing that wasn't up to my standards. Do you care if its a slot ported design? PM me with an email I can send the sketchup file to.

I don't have any cut sheets for it saved on my computer, but I could probably make one up for you, and it will take two full sheets of MDF to build an 8 cube box. They are about $35 a sheet at Lowes, but I have found that a lot of the smaller local lumber yards sell it here for about $25 a panel. Call around and find out what your options are. The design I used was 32" wide, and 24" deep and 24" high with a 2" by 22.5" port.

well if you have the space, 8 cubes @23 will work fine. I had one of my 18s in an 8@20 and it performed very nicely.

I always glue and screw my enclosures that I build. The glue will hold it together for a while, but it will lose its bond after so long. The vibrations don't help either. As I have said, its entirely up to you. I would rather over build it. Why spend the time to build an enclosure, just to have it blow apart at the joints after a few years? I have a lot of prefab boxes in my garage that did just that, because they were only glued at the joints.