"Tired2way" speaker building.

[_henry_]

have u tried to put some bitumen? it may helps alot.

 

[Starre]

No henry, since I have stuffing at the back. I have to remove that first then. But since I have to do that anyway if I put in some ribs, I could try that instead. I do not know what is best. Perhaps I should do both.

 

[Salas]

Other wood material flexes too just has a different resonance, can be stiffer & lighter or not etc. MDF is not that bad neither excellent. Bracing, constrained layer damping, thin wall & loss via contact mass BBC, rigid school resin and/or metal based etc etc. are methods.

 

[Starre]

Yes, not the easiest thing to get controll over. I will try a few ribs at the back glued in place, not too big to destroy air flow but big enough to increase stability. Maybe it even might dissolve some of that backwave with its non-flat surface.

 

[Starre]

It seem ART from Scotland is using the same unit.Price 12500 GBP

One interesting aspect of that speaker is its weight: 40 kg!
It tells me something about that cabinet, probably very solid. I think the 8 inch woofer with its powerful magnet needs a very stable cabinet to shine.
I will add an extra bracing from front to back just below the woofer, I could hear some resonance there with music, and even feel it vibrate with me fingers. So 2 mods to do, one extra bracing and a few ribs at the back. I hope this will be good since after that I have no ambition to go on, and I don´t want to get smaller volume than that, might affect bass.

 

[Salas]

If you ever chance at an Avalon speaker, try lift it when they are not watching. That's MDF again. But a mass layered and heavily ribbed sandwich.

 

[Starre]

I will if possible. News to come when my work on the cabinet is done.

 

[Starre]

Salas, what do you think of using this foam I have on this panel? It is 2cm thick and I am considering using it at the back-panel between a few supporting ribs to dampen the back bounce, then use some of the usual white stuffing over it.
Same foam is on this panel:

 

[Salas]

Are you hopping to feel less back panel resonance after that?

 

[Starre]

Want I am after is less sound from the back-panel, yes.

 

[Salas]

Won't do anything, its a matter of structural mass or support against the direct high energy LF wave blows. Such absorption like foam is for the box modes echo control higher in frequency.

 

[Starre]

OK, but a few ribs that will strengthen the back-panel should make it less prone to make sound itself, even if slight?

 

[Salas]

Surely any reinforcement there works towards that goal by stiffening. How much of a difference, you can't say if not simulating flex in some special software.

 

[Starre]

So what do you think is the way to go? I am a little confused. Not much to do, you mean?

 

[Salas]

I would trust a front to back rod better.

 

[Starre]

OK, just hard to get in place there. I will see what is possible. I could use one of the bracing side-to-side as support, I guess.

 

[Salas]

Telescopic something so it can go in easily and you can extend it and tension it after. A bit tensioned and not only connected is surely better.

 

[Starre]

If i use a rod and support it on the higher of the 2 bracings and angle it upwards it can easiy be squeezed into place with some pressure on it. I have already removed the back stuffing, easy to put back again afterwards.

 

[Starre]

What do you think of using the magnet of the woofer and connect a rod from it to the back? Takes some fine tuning to get in place, but if I do it might be good?

 

[Salas]

Its better. Use a pad on the magnet's back. Don't remember if it has a ventilation hole though. If it has, you should not block it.