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Discussion Starter · #1 ·
Anyone know who makes the best Baltic Birch and Marine Grade plywood... Anyone have a list of manufacturers with wood products and their modulus of elasticity? I'm primarily looking to order some stuff in 1.5" thickness which is special order, so if anyone can recommend which wood product manufacturers offer some really thick Baltic Birch, Marine Ply, or similar, whould be appreciated if you could post some info. I forget the nmaufacturer I used last time...


Thanks,


Chris
 

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We have a Midwest chain called Menards(like Lowes and Home Depot) that carries 1/4" to 3/4" Baltic Birch in 4x8 sheets. I was looking for thicker at one point, and tracked Menard's ultimate supplier to the place I linked above. I ended up using the Menard's 3/4" and I still go back there every time I need some. You can call North American Ply and see what they can do for you. The sales guys were great to deal with. I think if you need bigger sizes that you have to buy quite a bit, but it's worth asking.
 

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Discussion Starter · #5 ·
When I built the Black Holes subs, I layed out all my cuts on graph paper to see the least amount of 4' x 8' sheets I would need... I still needed 13 sheets of 1.25" thick 4' x 8' from what I remember.


Thank-you... the Finnish stuff look great.


I'll check on the prices of Quartz while I am at it...


Thanks again for posting the link!


If I can afford to cover my subs in Quartz, I'll just use 3/4"


I wonder what is more expensive, Granite or Quartz? What is some exotic 'countertop' stuff people have used to make (or cover) enclosures with? I'll have to think about granite also... I just can;t get over how small of an enclosure the LMS 5400 speaker requires for sealed... amazing.
 

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Quote:
Originally Posted by Health Nut /forum/post/17011484


I just can;t get over how small of an enclosure the LMS 5400 speaker requires for sealed... amazing.

be advised that box volume also affects something you don't see in the models - distortion.


this has to do with voice coil current, suspension linearity and air spring linearity.


unfortunately i have no idea what box volume would result in lowest distortion for LMS.


but i don't recall any very small subs such as Sunfire described as good sounding.


in other words you may consider using more than the bare minimum of 3.5 cubic foot per driver.
 

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Discussion Starter · #7 ·
I agree... but at the same time I can't go much lower than 0.5 Qtc simplly because I will lose power handling, and/or maybe it sounds overdamped... I think it is hilarious that even if I use 1.5" thick Baltic Birch, I can still stick (2) LMS 5400 in a 23" x 30" x 34" box (external dimensions) and have a Qtc of 0.497 without any stuffing... I'm just used to building big boxes and I find these boxes rediculously small for two of those drivers in a sealed enclosure, but hey, that is starting to be part of the appeal... I'm sold on the plan, but looks like I probably shouldn't build the boxes until I know for sure that Kyle and Thilo are 110% moving forward... I'd like to get 8....
 

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Quote:
Originally Posted by Health Nut /forum/post/17011982


I agree... but at the same time I can't go much lower than 0.5 Qtc simplly because I will lose power handling, and/or maybe it sounds overdamped... I think it is hilarious that even if I use 1.5" thick Baltic Birch, I can still stick (2) LMS 5400 in a 23" x 30" x 34" box (external dimensions) and have a Qtc of 0.497 without any stuffing... I'm just used to building big boxes and I find these boxes rediculously small for two of those drivers in a sealed enclosure, but hey, that is starting to be part of the appeal... I'm sold on the plan, but looks like I probably shouldn't build the boxes until I know for sure that Kyle and Thilo are 110% moving forward... I'd like to get 8....


And as mentioned before. Yes, it is possible but it will create air spring distorsion and planety of thermal compression due to the silly huge amounts of air compression (and power needed to do it which will result in very hot voice coils).
 

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Apple Ply is worthy of consideration, as well.


I don't have a link, but it should pop up in a search.


The story on this product is, an American company wanted to compete with the quality of Baltic Birch, which comes from the Baltics.

And, to make it more appealing to Americans, they used the phrase, "It's as American as Apple Ply (Pie)."

That's the story I heard, anyway.

I understand that Baltic Birch, while still good, is not quite as good as it once was.

But, that Apple Ply is still on par with the original Baltic Birch.

I'm not a cabinet maker, so I am not speaking from experience.
 

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Discussion Starter · #10 ·

Quote:
Originally Posted by Steveo1234 /forum/post/17012254


And as mentioned before. Yes, it is possible but it will create air spring distorsion and planety of thermal compression due to the silly huge amounts of air compression (and power needed to do it which will result in very hot voice coils).

What is your suggestion then? Not use LMS 5400 18" drivers in a sealed configuration? I would be putting them in the largest box possible... So basically you are saying the LMS 5400 is not suitable for sealed configuration? Or are you saying to stuff moderatley with fiberglass anyway, even if it makes the Qtc 0.42'ish? Or just build a slighty biger box to 12 cubic feet/2 drivers (Q = 0.44) with no stuffing? What exactly are you recommending?
 

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Discussion Starter · #11 ·

Quote:
Originally Posted by Fatawan /forum/post/17011420


You can call North American Ply and see what they can do for you. The sales guys were great to deal with. I think if you need bigger sizes that you have to buy quite a bit, but it's worth asking.

They are great to deal with... Talked with them this morning... Thank-you.
 

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Quote:
Originally Posted by Health Nut /forum/post/17013742


What is your suggestion then? Not use LMS 5400 18" drivers in a sealed configuration? I would be putting them in the largest box possible... So basically you are saying the LMS 5400 is not suitable for sealed configuration? Or are you saying to stuff moderatley with fiberglass anyway, even if it makes the Qtc 0.42'ish? Or just build a slighty biger box to 12 cubic feet/2 drivers (Q = 0.44) with no stuffing? What exactly are you recommending?

Have you seen Illka's sub testing at the Home Theater Shack? He tested it in a small 100l sealed box and it's distortion performance was very, very good even on a 3600w amp. Almost to the point of being in a different league from most of the other subs. To avoid ASD try to limit the total swept volume that the driver would possibly displace to less than 5% of the air volume of the enclosure. However this would likely place you well below 0.45q thus severely limiting your amplifier input power to avoid bottoming below 16hz. Tradeoffs. They are everywhere.
In general I believe that it is safe to say that a larger box will result in better distortion performance, whether it is enough of a difference for you to hear it is something else. The LMS does not appreciably distort until pushed stupid hard.
 

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Discussion Starter · #13 ·
In the case of reducing air spring distortion, is it better to slightly increase the box size fuurther or stuff with fiberglass? In this case with two drivers in a small box, maybe it is better to have more air in a slightly larger box than to use fiberglass... ??
 
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