PDA

View Full Version : How much wood?



Sweetride01
12-16-2005, 07:21 PM
OK, well I'm going to start making an enclosure for a 10" RL-i soon.
I plan on using birch ply to save weight.
2 Questions: which type of sealed enclosure should I build (Butterworth or Quasi-Bessel)? http://www.soundsplinter.com/rli_series/rli_10_inch_DIY_car_and_home_subwoofer_driver_info rmation.html
How much wood do I need - 1 sheet or two? I presume only one, unless the box will be double-thickness.

JimJ
12-16-2005, 07:23 PM
The Bessel alignment is going to reduce power handling, improve low end response and decrease group delay. Although, the .707 Qtc Butterworth alignment is a good place to start. Try it in the middle, and see if you think it needs improvement.

Also..."saving weight" and good subwoofers enclosures don't really go together. You want the wood to be acoustically dead, and that takes mass and bracing :)

squeak9798
12-16-2005, 07:29 PM
Unless you are a pure SQ guy, chances are you will like the Butterworth more than the Bessel. Most people prefer slightly higher Qtc alignments for the slightly increased output over the lower Qtc alignments. Generally only the pure SQ type guys get into the .577 and .5 Qtc alignments for their damping qualities and better group delay....at the expense of overall output. That's just a generalization though......

And for as small as those boxes are you should be able to get it built out of 1 sheet.

Sweetride01
12-16-2005, 07:33 PM
The Bessel alignment is going to reduce power handling, improve low end response and decrease group delay. Although, the .707 Qtc Butterworth alignment is a good place to start. Try it in the middle, and see if you think it needs improvement.

Also..."saving weight" and good subwoofers enclosures don't really go together. You want the wood to be acoustically dead, and that takes mass and bracing :)

So you're saying go with a Butterworth that is in-between those two volumes?
Also, I know that the best setups are going to be pretty heavy, but I like to autoX my car you know... ;)
I did a search for lightweight and someone mentioned the birch ply, so I presume it is just as good as MDF?
Also, to save me searching some more, is there any other stuff I can buy at Home Depot at the same time that I will need for the enclosure? Thanks.

Squeak, I am going more for SQ, but only "right of middle" so to speak - I wouldn't mind a decent output either.

squeak9798
12-16-2005, 07:34 PM
Glue/adhesive, silicone and screws or nails.

JimJ
12-16-2005, 07:34 PM
Liquid Nails, carpenter's wood glue, some drywall screws to assemble the box and mount the driver...

squeak9798
12-16-2005, 07:35 PM
I win

JimJ
12-16-2005, 07:36 PM
:)

All in good fun ;)

squeak9798
12-16-2005, 07:37 PM
I Pwnt J00 Back ;)

InhumanAcura
12-16-2005, 07:43 PM
...could a wood chuck, chuck...if a wood chuck, could chuck wood?

ftw?

Sweetride01
12-16-2005, 07:48 PM
:laugh:

Subz
12-16-2005, 08:01 PM
May want to get some weather stripping as well to seal up that sub real nice. Get the dense kind that still flattens nice... perfectly air tight in my case. (I think)

Sweetride01
12-17-2005, 01:30 PM
May want to get some weather stripping as well to seal up that sub real nice. Get the dense kind that still flattens nice... perfectly air tight in my case. (I think)

Isn't that what the silicone caulking is for?

Here's what I got yesterday:
A 4x8ft (I think) sheet of birch ply, $45 from Home Depot. It barely fit in the Odyssey.
http://i8.photobucket.com/albums/a24/sweetride01/Pic1513.jpg

It's quite thick:
http://i8.photobucket.com/albums/a24/sweetride01/Pic1514.jpg

And some supplies - I hope I got the right screws. The Silicone is called "Silicone II".
http://i8.photobucket.com/albums/a24/sweetride01/Pic1515.jpg

Sweetride01
12-17-2005, 01:51 PM
The Bessel alignment is going to reduce power handling, improve low end response and decrease group delay. Although, the .707 Qtc Butterworth alignment is a good place to start. Try it in the middle, and see if you think it needs improvement.

.707 Qtc would make it a .284 cu ft. enclosure.
Supposedly this is a "maximally flat" alignment. What does that mean?

To make a .21 cu ft. enclosure like Soundsplinter recommend, that would mean a .805 Qtc value.

PV Audio
12-17-2005, 02:19 PM
i would have gotten drywall screws, they're cheaper and have the same purpose. also, i recommend against using cheap plywood like that as the wood isn't solid (not pressed well at all) and will resonate.

Sweetride01
12-17-2005, 02:30 PM
i would have gotten drywall screws, they're cheaper and have the same purpose. also, i recommend against using cheap plywood like that as the wood isn't solid (not pressed well at all) and will resonate.

Read Moe Lester's comments: http://forums.caraudio.com/vb/showthread.php?t=92730
Or was I supposed to get Baltic Birch Ply?
I got 5-ply "beech-birch-hickory", grade b-2, 3/4" thick.

Why did no one contradict him before?
Also, once I have this materials problem sorted out, I'd like you to design me an enclosure please LeMans23.

Pyro_By_Nature
12-17-2005, 03:02 PM
Read Moe Lester's comments: http://forums.caraudio.com/vb/showthread.php?t=92730
Or was I supposed to get Baltic Birch Ply?

Why did no one contradict him before?
Also, once I have this materials problem sorted out, I'd like you to design me an enclosure please LeMans23.


He's stupid, esp. saying that stuff is low quality.

It's used in higher end home audio because of it's "acoustic properties" as it doesn't resonate at higher freq. like MDF.It'll work perfect for your application where saving weight is the main concern.IIRC a sheet of that stuff weighs about half the amount of a sheet of MDF.

http://img384.imageshack.us/img384/655/mockinglemans2327zg.jpg
Look at lemans work and you'll see how much experience he has :thumbsdo: :uhoh: :hilariou: :hilariou:

Sweetride01
12-17-2005, 03:12 PM
I hate not knowing who to believe. Perhaps I shouldn't be tricked by post count. :)

OK mountaineer man, maybe you can design me an enclosure.
So I can go with the plywood I got? I could probably exchange it for MDF if need be.
Also, should I go with that .707Qtc value?

Oh and BTW, I found out that 4x8 sheet I got weighs 63.5 lbs. Not sure how that compares to MDF.

Pyro_By_Nature
12-17-2005, 03:12 PM
BTW: Maximally flat means it won't be peaky or "boomy" once you put it in the car.AKA It'll sound nice :)

Yes you'll be fine with that.