Mach 5 IXL 18.2.2 Box opinions

13817 Views 112 Replies 12 Participants Last post by Mike P., Jun 11, 2009

sub_junkie

Discussion Starter · May 25, 2009 (Edited)

I am probably going to get the IXL 18.2.2 when they are back in stock...
But until then, I wanted to see what you guys thought about my planned box dimmensions.
It will be 7 cu.ft tuned to 17.99hz so the port lengths can be a quarter multilple like .75 or .25.

The box needs to be the same depth and width to fit in the corner of my room to clear the furniture.
Just to make sure, the 19 inch depth and width are external dimmensions and not internal, correct?

Here is the port lengths and volume:

You need to multiply the port volume 524.6459731494955 (yes, that is the actual number it has) by three due to the three 4 inch ports at 41.75 inches long to keep the tune the same.

And, here is the bracing:

You will need to multiply 54 cubic inches by 2 becuase I was thinking that 2 of those braces would be sufficient? Do you think that I will need more braces or just different dimmensions for them?

Would you guys recommend anything else for me to change? I am not sure how much bracing I would need for this box, so I am hoping someone could help me out there.
Would I need to secure the ports to the bracing? If so, should I just change the bracing number of cutouts to 2 and then just drill a hole big enough for the three 4 inch ports to fit through? Also, I would have the ports exiting through the top of the box...if I changed the cutouts to 2, I would have to change the heighth of the box to compensate for the extra volume taken up. The driver will be down firing. (I'm assuming that the driver will fit with a base plate?) The box will have 1 inch square legs with a <probably> one inch thick baseplate screwed into the legs.

I am open to any suggestions you guys have.

Thank you

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salvasol

· #61 · Jun 2, 2009

sub_junkie said:
I have changed my decisions for ports. I think I will go for one 6 inch pipe 33.50 inches long. It will have two free ends, unless Home Depot or Lowes has something that will function like a flanged end. What kind of roundover bit should I use for one six inch pipe? Or could I use something else that wouldn't be so expensive?

If you're not using an elbow (straight port), check the price for 6" or 8" sonotube; then you can make a donut out of wood and use the a roundover :yes: (here is a picture of what a member did)

Tire Automotive tire Bicycle tire Automotive wheel system Auto part

Pottery earthenware Cylinder

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sub_junkie

Discussion Starter · #62 · Jun 2, 2009 (Edited)

Hmm, that kinda looks confusing to me. I don't know. Maybe I will just roundover the top of the box where the port will exit like robbo266317 did in his Shiva-X Extended Bass Shelf build. Here are his pictures from his thread:

Hope he won't mind that I used his pictures...

raying:
What roundover bit should I use for a 6 inch port?

Thanks for the help

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robbo266317

· #63 · Jun 2, 2009

Actually the small disc is for the port end inside the box. and I put a half inch roundover around the outside edge later.
That is a 1" roundover and I used a circle of mdf bolted to the router so it would sit flat as I did the roundover with top mounted on the 6" pipe as the template.

sub_junkie

Discussion Starter · #64 · Jun 2, 2009 (Edited)

OK.
Does Home Depot or Lowes sell PVC fittings that can work like a flanged port end? I checked their websites, but couldn't find anything, so I figured I would check here and see if one of you guys would already know.

Thanks

collo

· #65 · Jun 2, 2009 (Edited)

I see you live in the States. The 6inch PSP flared ports are very affordable if you don't want to go the router / rollover route. Their flares are nearly as good (1 inch flare radius) as anything you can do with a router - you might need an extra tube to get the length.

A 6inch port without flares is not real good....

sub_junkie

Discussion Starter · #66 · Jun 2, 2009 (Edited)

Thanks for that link. I need the port to be 33.5 inches long, so could I buy the port you linked, and just use 6 inch PVC that is 33.5 inches long? Or would I just have to buy three of these ports? ( http://www.thrilleraudio.com/detail.aspx?ID=533 )

Thanks for the help everyone. I would be nowhere if you guys didn't help me out...

collo

· #67 · Jun 2, 2009

To get 33 inches, you would need:

One 6-inch flare kit (2 flares, 2 rings, 1 tube)
Two extra tubes
Two extra connectors

I'm in Oz, so can't say if you can use normal PVC instead of theirs, although I suspect the dimensions might be different.

Make the physical length 1inch longer than the acoustic length to compensate for part of the air in the flares belonging to outside the port

Mike P.

· #68 · Jun 2, 2009

Most places that sell the port will also sell you a center extension piece and connecting rings.

So when is the box building going to start?

sub_junkie

Discussion Starter · #69 · Jun 2, 2009

OK, thanks for the links, collo. That's a great help. I didn't even know about that website...

The box building will start as soon as I get a chance to go to Home Depot or Lowes.

Thanks for the help everyone. It's greatly appreciated, and I look forward to building the box!!

sub_junkie

Discussion Starter · #70 · Jun 3, 2009

My Uncle saw what I was planning for the box, and I decided to go with a slot port so I wouldn't have to use bracing and spend the extra money on the 6 inch port and extensions. The slot port will be 18.5 inches long, with a 90 degree turn in it, and then 26" from there, so the port will be 44.5 inches overall length. The box plans have also changed. It will be 20 inches wide and deep, and 43 inches tall. The slot port will be secured by being screwed to the sides of the box, and will be 2 inches from the bottom of the box.
Should I change anything else? I will post a picture of the slot port plans, hopefully to clear up any misunderstandings

Sorry for yet another question. It will be one of my last ones for a while.
Thanks for all of the help

Mike P.

· #71 · Jun 3, 2009

You're still going to need bracing. Post a pic of what you have planned.

sub_junkie

Discussion Starter · #72 · Jun 3, 2009

The pic I took doesn't show what I had planned so I will draw something in Paint. I will be back!!

Thanks

sub_junkie

Discussion Starter · #73 · Jun 3, 2009

OK, here it is drawn up. If you need me to clarify something, I will either try to explain it, or just draw up something new

How should I do the bracing?

Thanks for the help

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sub_junkie

Discussion Starter · #74 · Jun 3, 2009 (Edited)

Should I just put a brace from the top of the port and put it above the driver?

Thanks

Oops double post...

robbo266317

· #75 · Jun 3, 2009

Have a look through this thread. fairly basic bracing.
http://www.hometheatershack.com/forums/exodus-audio/14208-shiva-x-sub-build.html

also check through the rest of the members dabase for more ideas.
And remember it doesn't have to be pretty on the inside, just sturdy.

sub_junkie

Discussion Starter · #76 · Jun 3, 2009 (Edited)

I don't care how the insides look, just the outside and the performance. :T
Here is the type of bracing I was thinking of:

I would probably need more than that huh? I was thinking about another bracing above where it says "The brace pictured would go here"
I am downloading Google Sketchup to hopefully give you guys a clearer picture of what I am thinking of...

Thanks for the help

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dgilme

· #77 · Jun 3, 2009

So you are going for roughly a 8.4 cf box with a 18.5" x 2" x 46" port. That turns out to be a 14.46 hz tune. The F6 is around 15.2 hz, F3 is 21hz and are at -1db around 40 hz. Where as if you went with a 19hz tune you get an f6 at 18.8, f3 at 17.5 hz and aren't -1db until 21.5hz. Are you doing that for port air speed?

sub_junkie

Discussion Starter · #78 · Jun 3, 2009 (Edited)

No, I had planned on the box being around 7-7.2cu.ft according to the enclosure volume calculator here. The tune should be 16.92hz according to WinISD, and the port will be 18.50 inches wide by 2.00", and 44.50 inches long. The box is 8 cu.ft without the port volume subtracted. I was going for a lower tune so it could be closer to a LLT, and so it would have better low end extension.

I will put a window pane brace above the driver and secure it to the top of the port, and then another brace around 6 inches above that one also, and secure it to the back of the box.

Thanks for the help

Mike P.

· #79 · Jun 3, 2009

Move your sub up and put a brace above and below it. A couple of pieces from side to side would help also. Port length is measured through the center of the port, just so you know.

Diagram Line Text Parallel

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sub_junkie

Discussion Starter · #80 · Jun 3, 2009

So, the port will be seperated into two 1 inch sections, one above the red line, and one below? I'm not fulling understanding that...

Thanks for the diagram, Mike

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