Sonotube - Got my stuff but need a hand getting started

[Eric_C]

I picked up all my stuff yesterday for my sonotube sub but is doing some searching to get started I found a lot of the little things were not mentioned.

I apparently screwed up a bit on my calcs too because I forgot to take into account the endcaps going into the tube.

Here is what I bought and what I will work with. If I'm not happy with it I'll just build another. I suppose if I got the dimensions wrong that all I'll need is a new sonotube and a new port, I can reuse everything else.

I have a 44x24 sonotube, which now I realize for sonosub is actually 41", not 44" because I'll have 1.5 inch of endcap on each end.

So that leaves me with a port that will be 6" wide 34 1/4" long using PVC as the port to get to 15.1hz.

From what Thomas said the size of the tube is more aesthetics than sound as long as the tube is big enough to support the driver.

Based on that I'm going to stick with what I have. I just need to adjust the port length and if those numbers look correct then I'll go for that.

Today I just want to get the hardware side of it done.

So my list of questions:

1. If the ID is 24" and I want to use a press fit how much bigger do I let the end caps be? 1/16, 1/8, 1/4? If it sounds good and everything is to my liking I'll glue them in but I'd like to do a press first. Then I chamfer the leading edge that goes into the tube correct?

2. I've done very little woodworking so these questions are super basic. I know I can cut the circles PE delivered the larger Jasper rig yesterday. I picked up a Rigid Router 2 1/4 hp with dust collection. I went back and forth between it and the Hitachi but the Rigid had dust collection and got rave reviews plus I own a few of their other products like their miter saw that is a great piece. When cutting the port do I glue all 3 pieces together, the 2 at 24.xx inch to go into the tube and then the top cap at 26", then cut the port a little at a time? If you do them separate what is the easiest way to make sure they all line up and are the same? Do you recess the floor plate for the dowels or just screw them in from the top and bottom which I guess would facilitate the longer dowel.

3. Space between the bottom place and the floor plate. Does it matter, 3" enough, too much, too little? Can I use 5 or 6 dowels or is 4 enough? How do you ensure they are spaced equidistant?

4. Do I need speaker caulk on the sub itself or does it just affix itself to the MDF. Also how big do I cut? From the website these are the specs for the TC2000 15":

15TC-3000 14.10" 15.65" 0.65" 8.75"

14.10 is the cutout diameter, 15.65 is the basket and .65 is the gasket height. So do I cut 14.1 or cut smaller, then make a second cut that equals 14.1 but is only .65" deep?

5. What size wire should I use to run from the terminal to the sub? I bought the Dayton extra long inputs and at least know how to do that part Can I use hotglue to affix the wire to the baseplate inside so it doesn't rattle?

6. Where can I get polybatting? Is this the same stuff Joann fabrics sells that you can use for the acoustic panels? How thick should it go on? I know Thomas said fiberglass works as well and is cheaper but I don't want to work in a spacesuit I prefer something that is easy to handle. We have pets and my wife will helping me so the easier the material is to handle the better.

7. I bought Gorilla glue, best stuff right?


Am I forgetting anything or is there anything else I should be especially careful of?

Thanks a lot for all the help and explanations I'm hoping this will turn out pretty well and I can move onto my next more difficult project with a much better understanding.

[parboy]

I'll try to answer what I can. First, I wouldn't suggest pvc for the port. It's heavy, try to find 6" sonotube. The pvc will work if you already have it though. Second, it doesn't sound like that port length will work. Rule of thumb is to have open space around the bottom end of the port equal to the diameter. So you want 6" of space between the bottom of the port and the bottom of the driver. I can't remember off the top of my head, but im sure that driver is 7-8" deep. If your tube is 41", driver is 8", that leaves ~33" between the bottom of the driver and the top of your tube. That means your port should be no longer than 27".

Your questions:
1)Be sure to measure the ID of the tube before you cut. Some of the tubes are a touch smaller than the listed diameter and some are a bit larger. They ship the tubes one inside the other, so the diamter can change depending on which tube you have. When I cut my circles I had one piece of scrap that I used to get the size just right. Mine ended up being just a bit larger than the ID of the tube, then I sanded it down to get the good fit. I did round over the leading inside edge to help it go in a bit easier.

2) I cut the holes for the driver and the port on each piece individually, prior to gluing them together. Just make sure to cut all the holes that need the same setting on the jig at the same time. In other words, you will have 3 plates to cut for the port, so make sure to set the jig and cut all 3 plates with that setting before going to cut the holes for the driver. After cutting them all, then glue the pieces together. I just lined up my center holes (like for the port) and then clamped. Glue 2 pieces at a time, let them set, then glue the 3rd to the other 2 already set. If you try to glue and clamp all 3 at once, the middle piece could float on you a little. You can recess for the dowels if you want. I think most just run a long screw through all 3 layers of the cap, then run a shorter one through the floorplate.

3) I used 4" long dowels and wouldn't go any shorter than that. 5" or 6" would be fine as well. I only used 4 on mine. To get them equidistant, just be sure to mark off the wood before you cut it into the circle. Just find the center and mark it along both axis.

4) You don't need speaker caulk. The rubber surround on the sub works well IMO. On my sono, I recessed the sub into the bottom layer cap. I cut the inside 2 layers at 14.10 and the outside layer at 15.65. Just make sure to measure, cut, test fit, then adjust as necessary to get a good fit.

5) I'd use at least 12ga wire. Personally I went with 10ga. If you cut your wire the correct length to get from the sub to your terminals, their shouldn't be any rattling. I don't hear anything from mine but sweet sounds

6) You should be fine using the stuff from JoAnn's. Wrap it around to ~2" thick. I used the acoustic dampening panels from PE that are 2.5" thick I believe.

7) Just regular old wood glue is fine. My experience with gorilla glue has not been good. It expands when it dries and I just didn't like it.

Hope that helps. Im sure if I didn't get anything correct, someone will let you know Have fun!

[ThomasW]

Personally I prefer thin wall PVC for ports.

Space between the endcap and the floor plate should be 4"-4.5". Four dowels is enough, use more if you like the looks.

Don't use poly, get R13 fiberglass from a home center store.

Yes bevel/camfer the edge of the cap that enters the tube.

Cut the endcap diameter slightly oversize, you can trim it to fit using you router and the jig.

Let me think a while to see if I can come up with a way to 'fudge' a longer port. So don't cut the hole for the port until I ponder this awhile. We may use a series of 45 degree PVC elbows to snake the port and create more length.

[Eric_C]

Thanks...I had a DUH moment on how to cut the center holes. I forgot I'll have a center point from cutting the original circles.

I have not purchased anything as far as a port at all. I wanted to get the hardware and cutting done today.

The parts won't be here for a bit. I am trying to find a used amp or deciding if I want to build one myself. I ordered a kit for a Gainclone and got it last night. Its 95 percent complete and I just need to wire up the power, test, and see how it sounds.

They have some new units out that will do 300-500 watts per chip so I might build a monoblock for each sub.

I found the EP2500 being sold by the manufactures as blems, customer returns, etc for $239 but now I can't find them so now I'm looking for something in the similar price range.

[Eric_C]

The wife is going to use the Sonotube to make some plaything for the cats.

I'm going to order one in the correct height.

If I try something different and end up with some odd response out of it I'll end up chasing a problem that is the oddball out of the group.

I also might reconsider the width. After seeing it in the house I cannot fit a second one in the location I wanted it unless I put them in the rear of the room which I am supposed to avoid.

So now I'm back to a point...Thomas said the tube diameter did not matter, you pick a target frequency and build to that frequency.

Is that true, if so why build larger diameter tubes?

Is it overall interior volume?

If I went down to a 20" diameter tube then I'd need to go 60" high, 57" interior height with end caps gives me:

247 Liters
15.7hz tune
20" Tube
6" Port
4'9" of tube end cap to endcap
Port of 2'7"

When it says endcap to endcap, it means inside the tube, correct?

[collo]

From your statement "4'9" of tube end cap to endcap" I assume you're using sonosub.exe

If you look at the drawing on the RHS of the screen you'll see a dimension line indicating that the measurement is an "outside measurement" which includes the thickness of the visible portion of the endcaps.

This information is also displayed as "tooltip text" when you "hover" your mouse over the "Height from endcap to endcap" label

[Eric_C]

Ok to cut out any confusion.

Here it is with my original 24"x44" Sonotube.

If it really is measured top to bottom including the endcaps then it looks like I am ok with 44"

With an RPL15

Image not available

With a TC2000

Image not available

[collo]

The actual length of sonotube is shown in the circled area of this screenshot.

Also notice that "Display Warnings" is shown in red.

If you click the label, the Warnings screen will display and you will be informed that the clearance between the driver and the end of the port is less than one port diameter - just as parboy suggested.

[Eric_C]

Ok now I got it.

The RPL will extend too much into the tube where as the TC-2000 will give me enough clearance.

Here is the TC 2000 again

Image not available

And the RL-P15

Image not available

Those are with the correct numbers and a 44" tall tube but total endcap to endcap will be 45.5, assuming .75 for top and bottom.

Now I see where I made my error.

So the only way this tube will work is with the TC2000, not the RLP15.

I'm fine with doing the TC2000, the price of a new tube eats up some of the cost.

Am I causing a problem doing the port that close to the driver even with the TC2000. If it passes with one and fails with the other I must be really close.

[ThomasW]

Eric you can put an elbow in the port. If you place the port opening off center and run the port off to the side of the tube (leave enough room for damping material), you can use a 90 degree elbow to entend the length and keep the opening away from the driver.

Normally we don't recommend this, but the only other choices are use a higher Fb, or get smaller diameter tube that's taller

[Eric_C]

Please see my edited message above.

[ThomasW]

The 3/8" height difference isn't a big enough deal to force you to use one driver over the other. Just pick the driver you want to use and run with it