Dampen inside of speaker with some stuff - How important?

[lineup]

How important is it to dampen inside of the box?
What happens if we not?
Will it impact the sound?

 

[JonSnell Electronic]

Do you want them to sound like a cardboard box being kicked around or a bass drum.
That is the difference.

Baffle the box with fibreglass wadding and it will sound like it should.

 

[tansand]

For a fullrange driver, I would add, the amount of stuffing you put in will affect the sound. You might prefer more or less.

 

[Scottmoose]

How important is it to dampen inside of the box?

Generally important.

What happens if we not?

Depends on the speaker design. Increased internal reflections / standing waves modulating the driver, potentially passing through the diaphragm etc., and changes in the alignment if it was designed assuming a given amount & type of damping material was present (and most quality designs do).

Will it impact the sound?

Yes.

 

[Arthur Jackson]

Wool felt and fiberglass are your friends. Upholstery foam and pillow stuffing not so much.

 

[UniQ]

IMO no damping VS damping material inside loudspeaker enclosure makes a huge difference, and running open baffle makes yet another huge incremental difference in removing "boxy" sound.
I have tried it, see here:

Post in thread 'What makes a speaker sound boxy? the box?'

2024-12-26 11:10 am

I am sure that speakers that absolutely don't sound boxy exist
I would only like to know what makes them sounding not boxy
That boxy feeling is just not acceptable
I think I have found in the baffle design and build the key factor
From what I have read learned and watched the best baffle could be very rigid with some kind of damping
Like a turntable plinth for instance
staying on speaker a very interesting solution imho for baffle is the one of the epos es11

View attachment 1395767

it should be very rigid Plastic is not the very best material Something similar but in metal with the spaces...

• UniQ

• 
• 

ps, the whole post in above quotation is not visible, go to the post to see the full content.
:)

 

[DrBoar]

No damping will sound bad as the soundwaves bounce around inside the box and then with delay is transmitted through the cone. At minimum cover the walls on the inside with Ljudisoleringsfilt (10mm thick felt)from Biltema. Then on top of that you can experiment with fiber materials like pillow stuffing.

 

[picowallspeaker]

That Biltema is making swimming pools and everything involved. Not that a compressed recycled fibers sheet is not of no usage (?!) but...

 

[lineup]

No damping will sound bad as the soundwaves bounce around inside the box and then with delay is transmitted through the cone. At minimum cover the walls on the inside with Ljudisoleringsfilt (10mm thick felt)from Biltema. Then on top of that you can experiment with fiber materials like pillow stuffing.

Would this be a proper damping?
https://www.biltema.se/bil---mc/bil...dampningsplatta-1000-x-500-x-20-mm-2000058345

I see most recommend 15-20mm thickness

 

[UniQ]

No, that rubber foam have an aluminized polyester foil covering the surface, and foam in general is not good for lower frequencies.
I think Boar had this one in mind:
https://www.biltema.se/bil---mc/bil.../ljudisoleringsfilt-1000-x-2000-mm-2000021215
Glass and rockwool is effective and affordable alternative.

 

[Vix]

I just bought some damping material to play with. Bought it in a big hardware/construction store. They sell it in big quantities, though they were willing to sell me just one sheet, for about 5 euro.
Looks like some recycled wool, sort of. Doesn't look pretty, but it may be good enough.
Btw, for no apparent reason, I am playing with some old/recycled boxes, and their cutout happened to match Alpair 10.3. So...why not. Though they are a bit small, around 10 L...
(if vented doesn't work, I can always drill many small holes on the back of the box, and make it aperiodic 😀 )