Speakerplans.com Homepage
Forum Home Forum Home > General > Advanced Discussion
  New Posts New Posts RSS Feed - Poplar ply - any good?
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Poplar ply - any good?
 Post Reply Post Reply Page  123>
Author
Message Reverse Sort Order
  Topic Search Topic Search  Topic Options Topic Options
infrasound View Drop Down
Old Croc
Old Croc


Joined: 13 May 2011
Location: Brizzle
Status: Offline
Points: 2261 		Post Options Post Options   Thanks (0) Thanks(0)   Quote infrasound Quote  Post ReplyReply Direct Link To This Post Topic: Poplar ply - any good?
    Posted: 05 March 2021 at 3:04pm
Nope, only for personal toys

IMO it would be hard to commercialise, specifically due to the cost, assembly complexity, tolerance, wear and definitely overall strength.

I'm happy to manage these personally, but wouldn't scale well upwards from there
Back to Top
stevie View Drop Down
Registered User
Registered User


Joined: 16 March 2008
Location: Dorchester
Status: Offline
Points: 425 		Post Options Post Options   Thanks (0) Thanks(0)   Quote stevie Quote  Post ReplyReply Direct Link To This Post Posted: 05 March 2021 at 2:27pm
And did all this FEA and physical validation result in a commercial product?
Back to Top
infrasound View Drop Down
Old Croc
Old Croc


Joined: 13 May 2011
Location: Brizzle
Status: Offline
Points: 2261 		Post Options Post Options   Thanks (0) Thanks(0)   Quote infrasound Quote  Post ReplyReply Direct Link To This Post Posted: 05 March 2021 at 1:48pm
Originally posted by stevie stevie wrote:

Originally posted by infrasound infrasound wrote:


Stiffness is determined by the bracing primarily, thickness second.

With proper bracing, "just" 9mm of poplar ply can exceed the stiffness of 24mm birch plywood in cabinet.


How exactly did you reach that conclusion?
]

FEA and some physical validation Smile
Back to Top
snowflake View Drop Down
Old Croc
Old Croc


Joined: 29 December 2004
Location: Bristol
Status: Online
Points: 3000 		Post Options Post Options   Thanks (0) Thanks(0)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Posted: 05 March 2021 at 12:16pm
Originally posted by stevie stevie wrote:

Originally posted by infrasound infrasound wrote:


Stiffness is determined by the bracing primarily, thickness second.

With proper bracing, "just" 9mm of poplar ply can exceed the stiffness of 24mm birch plywood in cabinet.


How exactly did you reach that conclusion?

deflection of a panel is proportional to the width^3 and inversely proportional to the thickness^3.
Back to Top
stevie View Drop Down
Registered User
Registered User


Joined: 16 March 2008
Location: Dorchester
Status: Offline
Points: 425 		Post Options Post Options   Thanks (0) Thanks(0)   Quote stevie Quote  Post ReplyReply Direct Link To This Post Posted: 04 March 2021 at 1:08pm
Originally posted by infrasound infrasound wrote:


Stiffness is determined by the bracing primarily, thickness second.

With proper bracing, "just" 9mm of poplar ply can exceed the stiffness of 24mm birch plywood in cabinet.


How exactly did you reach that conclusion?
Back to Top
VECTORDJ View Drop Down
Registered User
Registered User
Avatar

Joined: 11 June 2006
Location: United States
Status: Offline
Points: 481 		Post Options Post Options   Thanks (0) Thanks(0)   Quote VECTORDJ Quote  Post ReplyReply Direct Link To This Post Posted: 18 February 2021 at 8:02pm
I am basing My choice of Finland 4 x 8 sheets as to what is stocked in Maine USA. The Poplar cored ply here has very thin Birch outer layers and is not water proof. Sort of soft too.  Go Finland. Like a Rock.
Back to Top
snowflake View Drop Down
Old Croc
Old Croc


Joined: 29 December 2004
Location: Bristol
Status: Online
Points: 3000 		Post Options Post Options   Thanks (0) Thanks(0)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Posted: 17 February 2021 at 9:19pm
Originally posted by VECTORDJ VECTORDJ wrote:

Why send all the time and work to make custom speaker cabs and use cheapie ply??? The best I have found is "Finland" 3/4" 4 x 8 foot 100 % birch exterior...........Like a Rock....


the good poplar isn't cheap - if anything it's more expensive than birch.
Back to Top
VECTORDJ View Drop Down
Registered User
Registered User
Avatar

Joined: 11 June 2006
Location: United States
Status: Offline
Points: 481 		Post Options Post Options   Thanks (0) Thanks(0)   Quote VECTORDJ Quote  Post ReplyReply Direct Link To This Post Posted: 17 February 2021 at 9:05pm
Why send all the time and work to make custom speaker cabs and use cheapie ply??? The best I have found is "Finland" 3/4" 4 x 8 foot 100 % birch exterior...........Like a Rock....
Back to Top
infrasound View Drop Down
Old Croc
Old Croc


Joined: 13 May 2011
Location: Brizzle
Status: Offline
Points: 2261 		Post Options Post Options   Thanks (0) Thanks(0)   Quote infrasound Quote  Post ReplyReply Direct Link To This Post Posted: 17 February 2021 at 6:13pm
Thanks for the link snowflake! Just what I'm after.


Stiffness is determined by the bracing primarily, thickness second.

With proper bracing, "just" 9mm of poplar ply can exceed the stiffness of 24mm birch plywood in cabinet.

Add a CF/GF skin to that and you're fixing that wear resistanceParty


Nb. 'Proper bracing' involves multiple rounds in FEM analysis & isn't a walk in the park. With guessing the bracing, you can go surprisingly far though.





Edited by infrasound - 17 February 2021 at 6:16pm
Back to Top
snowflake View Drop Down
Old Croc
Old Croc


Joined: 29 December 2004
Location: Bristol
Status: Online
Points: 3000 		Post Options Post Options   Thanks (0) Thanks(0)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Posted: 17 February 2021 at 1:15pm
anyone looking for poplar ply I think I have FINALLY found somewhere that will deliver small quantities for a reasonable price. And they have a cutting service.

https://www.atlantictimber.co.uk/efficency_ply_int_18mm.html

commenting on the above thread:

poplar surface is not as hard as birch but is better than spruce or pine. hard surface can be achieved with high quality resin/paint/liner/fibreglass. poplar takes paint very well.

poplar is not quite as stiff as birch but it is 40% lighter. If you want really stiff panels then use 24mm poplar instead of 18mm birch - it will be lighter and twice as stiff. If you want heavy cabs then replace some of the wood weight with bigger drivers!

poplar machines very well and reduces tool wear.
Back to Top
nickyburnell View Drop Down
Old Croc
Old Croc


Joined: 06 February 2005
Status: Offline
Points: 4410 		Post Options Post Options   Thanks (0) Thanks(0)   Quote nickyburnell Quote  Post ReplyReply Direct Link To This Post Posted: 21 November 2014 at 8:45pm
Originally posted by MarjanM MarjanM wrote:

I wonder what kind of cardboard wood is used in the JRX range.


Have some here, made from MDF, screwed together OK, wood screws holding drivers in, although I have seen VERY high end cabs do that in the past.
As I mentioned before, worst I've seen is OSB in EV cabs of old, apart from chipboard of course.
It's everything, not everythink!
Back to Top
KidCreole View Drop Down
Old Croc
Old Croc
Avatar

Joined: 06 November 2013
Location: London (East)
Status: Offline
Points: 3599 		Post Options Post Options   Thanks (0) Thanks(0)   Quote KidCreole Quote  Post ReplyReply Direct Link To This Post Posted: 21 November 2014 at 5:02pm
You can have string and stiff but if its light it will go walkabout
 
I like bass bins to stay where they are
Mykey Wattco
Back to Top
 Post Reply Post Reply Page  123>

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.05
Copyright ©2001-2022 Web Wiz Ltd.

This page was generated in 0.063 seconds.