Discussion on what materials to build speakers out of

planet10 · 23rd March 2007, 02:19 AM

Quote:

Originally posted by ruerose
Finally, I don't have access to decent (for my taste) no-void ply, just MDF and laminated 1x2 Project pine boards in 16" widths.

Where in BC are you that you can't get BB?

I'd use the pine before i used the MDF.

dave

Edit: 02-dec-09 (some of this is easier to wade thru if you read this post 1st)

ruerose · 23rd March 2007, 03:25 AM

Okanagan, I have a someone looking for some decent no-void for me, but in the end the price will dictate what I can end up using.

When I worked in building supplies a short while back, the decent stuff was a more than I cared to pay, especially since it would be just a single sheet. Seems everyone up here just stocks what is needed to build houses and make kitchen cabinets.

I really hate the voids (black spots, gaps) that will happen when I roundover the side baffles (cosmetic). I'd rather not use edge veneer as that would be a new experience for me and I do want a roundover (full roundover inside the throats).

Thinking...

I suppose I could waste a bit of wood getting a cut that has no voids along the whole line, but the dark spots will probably still bother me. Mabye my expectations of no-void are too high. But hey, this is cosmetics, no point being disapointed in the look before I even start. Hence the MDF and gloss white, at least it would have high WAF and hide then.

planet10 · 23rd March 2007, 04:03 AM

The point of void free isn't cosmetics but sonics. Even shop grade BB has potential cosmetic issues. Even spending 3x as much on architectural grade doesn't guarantee the cosmetics (althou it goes a long wayd)

Can't someone order you in some (it is going to take more than 1 sheet to fo Calhoun). Given driver cost & your time to do the boxes, it seems a shame to compromise by using MDF,

Pine would be interesting thou -- and you said it was laminated, so that should help as far as the usual problems with solid go.

As to doing a round-over on anything but the external edges, i'd be hesitant. Part of the design is the discontinuities.

dave

MJL21193 · 23rd March 2007, 04:17 AM

There's another problem with voids that all speaker builders should be aware of: there might be loose material in the void that will vibrate and buzz along with your music.
Use the MDF already.
NEVER in a million years would I ever use solid wood to build a speaker. Probably the worst choice ever.

ruerose · 23rd March 2007, 04:36 AM

I used Project pine for some cabinets, it is more than MDF ($20 for a 16"x4' piece vs $30 for a 4x8 3/4") but there is a large batch to pick some interesting grain patterns out of and minimize the knots.

Because of the lamination though, cutting with the grain is more of a chore than ply.

If a roundover on the inside edge isnt recommended, is a small bevel a good compromise?

planet10 · 23rd March 2007, 04:38 AM

Quote:

Originally posted by MJL21193
solid wood to build a speaker. Probably the worst choice ever.

Not so. Scott has built some fantastic speakers of solid fir, GM has used pine boards (as have a number of others on the FR Forum). At least a few hi-end commercial speakers are made of solid.

It is true that solid wood requires the most care & attention when building. In this case he is talking laminated pine boards not solid.

MDF just seems to suck the life out od a speaker. If you have to at least use medite (HDF)

dave

planet10 · 23rd March 2007, 04:44 AM

Quote:

Originally posted by ruerose
If a roundover on the inside edge isnt recommended, is a small bevel a good compromise?

One of the intentional design features of this kind of cabinet are the sharp corners. The deflector could be made of a single piece, bur the only place wher you might be able to put a bevel is the edge at the transition from the straight section of the port to the bell.

dave

ruerose · 23rd March 2007, 04:44 AM

Solid fir...mmmmm that sounds seductive.

You coasters get all the good stuff. Up here in this dry clime fir likes to do the magic bending spoon trick.

ruerose · 23rd March 2007, 05:13 AM

http://www.hardwoods-inc.com/Products/dragonply.cfm

Project pine might be as expensive in the end as a decent ply. I'm going to get some pricing and decide which way I want to go.

planet10 · 23rd March 2007, 05:36 AM

Quote:

Originally posted by ruerose
Solid fir...mmmmm that sounds seductive.

You coasters get all the good stuff. Up here in this dry clime fir likes to do the magic bending spoon trick.

The particular fir Scott uses came out of a railroad trestle built in 190-something, so it is old growth and has had a 100 years to age.

dave

23rd March 2007, 04:03 AM	#3
planet10 frugal-phile(tm) diyAudio Moderator Join Date: Oct 2001 Location: Victoria, BC, NA, Sol III Blog Entries: 5	The point of void free isn't cosmetics but sonics. Even shop grade BB has potential cosmetic issues. Even spending 3x as much on architectural grade doesn't guarantee the cosmetics (althou it goes a long wayd) Can't someone order you in some (it is going to take more than 1 sheet to fo Calhoun). Given driver cost & your time to do the boxes, it seems a shame to compromise by using MDF, Pine would be interesting thou -- and you said it was laminated, so that should help as far as the usual problems with solid go. As to doing a round-over on anything but the external edges, i'd be hesitant. Part of the design is the discontinuities. dave __________________ community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi p10-hifi forum here at diyA

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23rd March 2007, 03:25 AM	#2
ruerose diyAudio Member Join Date: Aug 2005	Okanagan, I have a someone looking for some decent no-void for me, but in the end the price will dictate what I can end up using. When I worked in building supplies a short while back, the decent stuff was a more than I cared to pay, especially since it would be just a single sheet. Seems everyone up here just stocks what is needed to build houses and make kitchen cabinets. I really hate the voids (black spots, gaps) that will happen when I roundover the side baffles (cosmetic). I'd rather not use edge veneer as that would be a new experience for me and I do want a roundover (full roundover inside the throats). Thinking... I suppose I could waste a bit of wood getting a cut that has no voids along the whole line, but the dark spots will probably still bother me. Mabye my expectations of no-void are too high. But hey, this is cosmetics, no point being disapointed in the look before I even start. Hence the MDF and gloss white, at least it would have high WAF and hide then.

23rd March 2007, 04:17 AM	#4
MJL21193 Account disabled at member's request Join Date: Mar 2007	There's another problem with voids that all speaker builders should be aware of: there might be loose material in the void that will vibrate and buzz along with your music. Use the MDF already. NEVER in a million years would I ever use solid wood to build a speaker. Probably the worst choice ever.

23rd March 2007, 04:36 AM	#5
ruerose diyAudio Member Join Date: Aug 2005	I used Project pine for some cabinets, it is more than MDF ($20 for a 16"x4' piece vs $30 for a 4x8 3/4") but there is a large batch to pick some interesting grain patterns out of and minimize the knots. Because of the lamination though, cutting with the grain is more of a chore than ply. If a roundover on the inside edge isnt recommended, is a small bevel a good compromise?

23rd March 2007, 04:44 AM	#8
ruerose diyAudio Member Join Date: Aug 2005	Solid fir...mmmmm that sounds seductive. You coasters get all the good stuff. Up here in this dry clime fir likes to do the magic bending spoon trick.

23rd March 2007, 05:13 AM	#9
ruerose diyAudio Member Join Date: Aug 2005	http://www.hardwoods-inc.com/Products/dragonply.cfm Project pine might be as expensive in the end as a decent ply. I'm going to get some pricing and decide which way I want to go.