Speakerplans.com Homepage
Forum Home Forum Home > General > General Forum
  New Posts New Posts RSS Feed - spruce plywood
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

spruce plywood

 Post Reply Post Reply
Author
Message
snowflake View Drop Down
Old Croc
Old Croc


Joined: 29 December 2004
Location: Bristol
Status: Offline
Points: 3118
Post Options Post Options   Thanks (0) Thanks(0)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Topic: spruce plywood
    Posted: 09 October 2017 at 8:10pm
Does anyone use spruce plywood?

It isn't as stiff (apparently about 20% less) but is about 2/3 the density of birch ply. so if you use 21mm spruce instead of 18mm ply you have panels that are 30% stiffer but 25% lighter. I expect it doesn't wear tools as quickly either. Any downside I am missing?

Phil
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: 09 October 2017 at 9:06pm
There is a thing called Wisa Twin. Softwood inner 9 plys or so hardwood good faced outer. Used it on a pair of MS18, was good but not much cheaper than Birch which I could not get in time. They were biscuit joined though, not routed. But jointed cabs built in far east with Spruce all over You Tube

 It has been pointed out by on here that saving 15 quid a sheet is probably a tiny amount when you figure in grills and paint, that said, 150quid will buy the paint and grills for 4 scoops and that's a good ten sheets.....


Edited by nickyburnell - 09 October 2017 at 9:06pm
It's everything, not everythink!
Back to Top
ceharden View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 05 June 2005
Location: Southampton
Status: Offline
Points: 11776
Post Options Post Options   Thanks (0) Thanks(0)   Quote ceharden Quote  Post ReplyReply Direct Link To This Post Posted: 09 October 2017 at 9:08pm
You probably won't get as good a finish, especially on end-grain and I expect it would dent and take corner damage more easily.

Lower density and stiffness will also probably mean higher panel vibration and energy dissipation in the cabinet.

However if you can live with or work around those then there's no big reason not to use it.
Back to Top
snowflake View Drop Down
Old Croc
Old Croc


Joined: 29 December 2004
Location: Bristol
Status: Offline
Points: 3118
Post Options Post Options   Thanks (1) Thanks(1)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Posted: 12 October 2017 at 12:02am
Originally posted by ceharden ceharden wrote:


Lower density and stiffness will also probably mean higher panel vibration and energy dissipation in the cabinet.


surely you would move any vibrations higher in frequency, further away from the operational band, and therefore reduce panel vibration.
Back to Top
ceharden View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 05 June 2005
Location: Southampton
Status: Offline
Points: 11776
Post Options Post Options   Thanks (0) Thanks(0)   Quote ceharden Quote  Post ReplyReply Direct Link To This Post Posted: 12 October 2017 at 12:19am
Lower stiffness will reduce the resonant frequency.

Also, you don't need a resonance for the panel to flex.


Edited by ceharden - 12 October 2017 at 12:20am
Back to Top
snowflake View Drop Down
Old Croc
Old Croc


Joined: 29 December 2004
Location: Bristol
Status: Offline
Points: 3118
Post Options Post Options   Thanks (0) Thanks(0)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Posted: 12 October 2017 at 1:32pm
Originally posted by ceharden ceharden wrote:

Lower stiffness will reduce the resonant frequency.


Also, you don't need a resonance for the panel to flex.


but it's only the stiffness per unit thickness that is lower. the stiffness per unit weight is approximately doubled. (as stiffness is a function of thickness to the power three.)
Back to Top
snowflake View Drop Down
Old Croc
Old Croc


Joined: 29 December 2004
Location: Bristol
Status: Offline
Points: 3118
Post Options Post Options   Thanks (0) Thanks(0)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Posted: 12 October 2017 at 1:36pm
Originally posted by ceharden ceharden wrote:




Also, you don't need a resonance for the panel to flex.


quite right. resonance is a function of stiffness, mass, and damping. energy loss due to flex is just down to stiffness.
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

This page was generated in 0.156 seconds.