New speakers have no WAF - looking for a new design - but what about sound?

[chrisb]

Originally Posted by Kindhornman

There is more than just stiffness at work here. There is also mass involved. I won't argue that plywood isn't stiffer per thickness but there is also the ratio of stiffness to thickness involved. I rarely would see plywood in 1" thickness though you could glue multiple sheets together. So to say that plywood is superior just doesn't really answer the question, that is an incomplete answer.

If I read the above correctly, you're suggesting that high(er) mass is a desirable goal itself in enclosure design. The practicality of building and moving larger boxes around aside, there are many here among us who feel differently.

We use 1" plywood frequently in our commercial work - I'd consider it overkill for enclosures for small fullrange speakers - among other things it would certainly mean extra work for relieving of rear side of driver cutout for something like the FE126En contemplated for this particular build (FH3)

[planet10]

Originally Posted by Kindhornman

There is more than just stiffness at work here. There is also mass involved.

Indeeed. Less mass is a desirable trait.

but there is also the ratio of stiffness to thickness involved

The generalized metric is that it takes >1.25" of MDF to match the stiffness of 18mm of good plywood.

dave

[Kindhornman]

Chrisb,
You would be correct that I think that higher mass does have an advantage. But if you are going to compare apples to apples it is hard without knowing an entire design. This would include all internal bracing and the resonant tuning of each panel. If you are just looking at weight then I go along with you and if you are making portable enclosures I would never use MDF. But as far as the sound of an enclosure and the emination of sound the physics get more complicated truly. You would have to look at the emmissive qualities of the cabinet walls in each configuration. Neither one of us can make blanket statements about a cabinet just based on the outer dimensions alone.

[planet10]

Originally Posted by Kindhornman

You would have to look at the emmissive qualities of the cabinet walls in each configuration. Neither one of us can make blanket statements about a cabinet just based on the outer dimensions alone.

Well i can certainly speak about the FH3, the enclosure in question. Use (good) plywood.

dave

[Kindhornman]

Planer10,
Won't argue about a cabinet I don't know.

[Tias]

Thanks Kindhornman, Chris and Dave!

Your little discussion actually explained a lot to me that I didn't know about wood. Still a little confused, but getting there.

In short, is quality plywood always better than MDF in regards to sound and stiffness, but it just costs more?

Are there any advantages to using MDF except price and ease of working with (not thinking about the noxious dust )?

I have to say I've never been a fan of MDF in regards to what it looks like.
Had a look at the Appleply site and must say I like the way it looks.
I would want my FH3's to be very light in colour if not high gloss white (overdone?)

I'll contact Ben at Sound with Style and ask what kind of plywood they use.
He already got back to me about price, it would be around $500 to get an FH3 flatpack sent to me. Sounds reasonable to me.

[chrisb]

Originally Posted by planet10

Well i can certainly speak about the FH3, the enclosure in question. Use (good) plywood.

dave

Originally Posted by Kindhornman

Planer10,
Won't argue about a cabinet I don't know.

and as the guy at Planet10 who's built more than a couple of pairs of the enclosure in question (FH3), as well as numerous other horns, MLTLs, BR, various vented, car audio subs etc, including directly comparing identical builds of MDF and BB plywood, I've reached my own conclusions as to the sonic benefits of the latter

[chrisb]

Originally Posted by Tias

Thanks Kindhornman, Chris and Dave!

Your little discussion actually explained a lot to me that I didn't know about wood. Still a little confused, but getting there.

In short, is quality plywood always better than MDF in regards to sound and stiffness, but it just costs more?

our thoughts on that should be pretty clear by now, but just to emphasize; '"yes"

Are there any advantages to using MDF except price and ease of working with (not thinking about the noxious dust )?

it makes for a great substrate for veneering / plastic laminating, and some folks like a painted or even natural lacquer finish (think glossy kraft paper shopping bag)

I have to say I've never been a fan of MDF in regards to what it looks like.
Had a look at the Appleply site and must say I like the way it looks.
I would want my FH3's to be very light in colour if not high gloss white (overdone?0

A natural clear coat on the veneer can look very nice - particularly if a warmer NC lacquer or oil based varnish is used as opposed to water based urethanes

A pro grade high gloss finish of any color is certainly doable, but very time consuming - frankly you might be better served post laminating with plastic (Formica / Arborite / Wilsonart - or whatever brands are locally available)

I'll contact Ben at Sound with Style and ask what kind of plywood they use.
He already got back to me about price, it would be around $500 to get an FH3 flatpack sent to me. Sounds reasonable to me.

His site lists material as hardwood marine ply, and I thought I read somewhere the species of face veneer as Hoop Pine - he can best answer that question, as well as perhaps have some photos of the material with a natural top coat finish. I'm personally fond of NC lacquer in a 15` sheen.

[Tias]

Hey thanks Chris for putting it into newbie words for me, that made it so much clearer.
I will contact Dave today and yes some photos would be great.

I don't mind it being time consuming for the high gloss finish because plastic laminating is out for me, not sure why but feels like a big nono for me,.. Probably because of my dad, he never wanted anything plastic if it could be done better a different way.
I got the music/good sound bug from him as well.
He recently bought some Martin Logans, and it might be in my head but I think my monsters sound better

[Tias]

Not sure if I should start a new thread or not, but here it goes.

When I take the FE126's out of these Mikasa cabinets and put them in the FH3's.
What would be a suitable replacement for the FE126's in the Mikasa?

I wont get rid of the cabinets, I'll put them in my office, but I'm keen to 'experiment' with different drivers in it (after I repainted it)
Would the Alpair-7 be a good choice?