OmniTop 12 and Tuba 30

[bzb]

I tried the picture again and it seems ok - AVG weirdness maybe?? Anyway that plywood looks fine. BB is the grade - not an abbreviation for baltic birch. A lot of big companies are using poplar now because it's light.(Dynacord for one)

I don't know about that, I think we use BB for Baltic Birch. If you're at a hardwood/specialty lumberyard, the grade should be CC or C1, as almost all Baltic Birch has the little footballs on both faces.

B grade, when it comes to hardwoods, is useful for faces but will have slight defects or are rotary cut. A grade is almost flawless. The best grade you can get at a specialty wood store would be AA-AA... and there would be a HEFTY price tag associated with it.

Hardwood plywood can also have a G1S grade, which means one side is nicer than the other (similar to AC or BC grading for construction panels). These aren't signified by letters, but rather, numbers. C1 is basically the same grade on both sides.

Construction-grade softwood materials use two letter codes, such as AC for the Arauco, and usually come with an exposure rating.

[digi128pci]

Thank you for all the reply's. I will continue the build and evaluate the performance dat the end of the build. Then i will decide if i would use the wood for the build of the next OT 12 and the two tuba 30's.

My lumberyard also sells brich they told me that it has 9 layers, but i don't have a picture from it.

Ow yes before i forget, i have looked for some damping materials in local shops. I started in shops that sell mattress but couldn't find any good damping material, so i went to my local hardware shop and found sound damping foam.

I wonder if i could use it?

Here is a picture:


Greetings from Belgium

[Harley]

....good damping material, so i went to my local hardware shop and found sound damping foam.I wonder if i could use it?

Yes

[digi128pci]

Another quick question: How do i mount the back panel to the 1" mounting flanges so i get no air leaks?

I was planning to drill a lager hole in the back panel and a smaller hole in the mounting flanges and use screws to attach the panel.
Is this the correct way to do it? I also got a weatherstrip to put between the panel and mounting flange to make an air tight seal. Is this oké?

Can someone give me a bit more info, i don't seem to get the plans

Thx

[cliffhanger]

Another quick question: How do i mount the back panel to the 1" mounting flanges so i get no air leaks?

I was planning to drill a lager hole in the back panel and a smaller hole in the mounting flanges and use screws to attach the panel.
Is this the correct way to do it? I also got a weatherstrip to put between the panel and mounting flange to make an air tight seal. Is this oké?

This sounds good. If you have a router you can do this http://www.bgavinsound.com/reference/mu ... ver-36.jpg to your flange for your weatherstripping to sit in but not all the way down in it. I don't have a router so I just used a dremel sanding disc and lowered it enough so the back panel would sit flush with the frame around it. This is optional though...

[digi128pci]

Another quick question: How do i mount the back panel to the 1" mounting flanges so i get no air leaks?

I was planning to drill a lager hole in the back panel and a smaller hole in the mounting flanges and use screws to attach the panel.
Is this the correct way to do it? I also got a weatherstrip to put between the panel and mounting flange to make an air tight seal. Is this oké?

This sounds good. If you have a router you can do this http://www.bgavinsound.com/reference/mu ... ver-36.jpg to your flange for your weatherstripping to sit in but not all the way down in it. I don't have a router so I just used a dremel sanding disc and lowered it enough so the back panel would sit flush with the frame around it. This is optional though...

Thx for the advice i will consider this!
Great picture btw it explains alot !

[cliffhanger]

Thx for the advice i will consider this!
Great picture btw it explains alot !

Gotta give the credit where it is due that is taken from forum member bgavin!

I find pictures to be immensely usefull.

[digi128pci]

Oh yes, i was wondering how many screws i should use in the back panel ?

[cliffhanger]

WB has some great pics that follow his builds, but don't put your screws as deep as he did as he has strips of ply attached to his back as well as the flange not sure if that was per the plans or choice:

http://web.me.com/wb12/iWeb/WB%20/OT12% ... G_0552.jpg

http://web.mac.com/wb12/iWeb/WB%20/OT12 ... 02008.html

This is an older version of the OTop. But you get the idea with the screws. I think I used 4 or 5 across and 3 or 4 up and down. I think the easiest way to do it is after you have your weatherstripping good to go lay the front down so the back is the top. Next lay your back panel in place drill small pilot holes thru your back into the flanges then countersink or use a larger drill bit for where your screws will meet the back.

[digi128pci]

Allright now im waiting for my tweeters to arrive, i was wondering if i should staple or glue (if so what glue do i use?) the damping material to the inside.
Also the plans state that it may not block the driver magnet so just cut out a hole for the driver magnet?
Does it has to be a tight fit or better to make sure no damping material is touching the driver magnet?
Does the complete inside need to be damped?
Do i have to keep the ports for the reflectors open?

I don't have the components for the filter yet, so i need to keep some space for the filters, where should i put theme and how many space will i need?
The plans say that the filter components may not touch the damping material, why? Do they get hot or does the inductance of the inductors chance? My damping material is fire resistant...

I also found a round wooden bar for the tweeter diffuser. But it is 18mm, the plans say that 5/8" -> 15.9 mm so it is 2mm lager is this bad ?

[Tom Smit]

Allright now im waiting for my tweeters to arrive, i was wondering if i should staple or glue (if so what glue do i use?) the damping material to the inside.
Also the plans state that it may not block the driver magnet so just cut out a hole for the driver magnet?
Does it has to be a tight fit or better to make sure no damping material is touching the driver magnet?
Does the complete inside need to be damped?
Do i have to keep the ports for the reflectors open?

I don't have the components for the filter yet, so i need to keep some space for the filters, where should i put theme and how many space will i need?
The plans say that the filter components may not touch the damping material, why? Do they get hot or does the inductance of the inductors chance? My damping material is fire resistant...

I also found a round wooden bar for the tweeter diffuser. But it is 18mm, the plans say that 5/8" -> 15.9 mm so it is 2mm lager is this bad ?

Put the material as close as you can without touching...about 5mm. here is a quote from the plans that I have Line the back perimeter and braces with foam, avoiding where it will joint the flanges. The driver magnet must not be blocked with foam, so line the area between the braces with carpet or a piece of ¼” thick air-conditioner filter foam.
It also says to staple the foam in place, but if you want you can still use adhesive. Keep the ports open. You could also paint the foam where it is visible through the ports.
A good size for the board for the filter would be approx. 100 x 150mm

[digi128pci]

Allright now im waiting for my tweeters to arrive, i was wondering if i should staple or glue (if so what glue do i use?) the damping material to the inside.
Also the plans state that it may not block the driver magnet so just cut out a hole for the driver magnet?
Does it has to be a tight fit or better to make sure no damping material is touching the driver magnet?
Does the complete inside need to be damped?
Do i have to keep the ports for the reflectors open?

I don't have the components for the filter yet, so i need to keep some space for the filters, where should i put theme and how many space will i need?
The plans say that the filter components may not touch the damping material, why? Do they get hot or does the inductance of the inductors chance? My damping material is fire resistant...

I also found a round wooden bar for the tweeter diffuser. But it is 18mm, the plans say that 5/8" -> 15.9 mm so it is 2mm lager is this bad ?

Put the material as close as you can without touching...about 5mm. here is a quote from the plans that I have Line the back perimeter and braces with foam, avoiding where it will joint the flanges. The driver magnet must not be blocked with foam, so line the area between the braces with carpet or a piece of ¼” thick air-conditioner filter foam.
It also says to staple the foam in place, but if you want you can still use adhesive. Keep the ports open. You could also paint the foam where it is visible through the ports.
A good size for the board for the filter would be approx. 100 x 150mm

You are talking about the ports in the baffle or the one's in the side ?

[RENDOG]

That ply looks fine to me. On another note, after clicking on the ply pic, seems my computer was attacked by something....anybody else get that?

It happened to me....it's nothing bad, imageshack and other sites sometimes do that.

[digi128pci]

The Tweeters arrived today! But the "dowel" i got is 18mm is this bad ?
Here are some more pictures.

[digi128pci]

Is it ok to use a lager dowel ?