Easy enclosure for tiny alnico speakers

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Just had these tiny (4") vintage speakers for near to nothing (2 euros). They have an alnico magnet but no mounting holes. Maybe they come from an old compact radiorecorder? Anyway, I gave them a chance with a simple cardboard open baffle (40cm x 40cm). I know you can't believe it but they sound amazingly well.
So I would like to build a little, supersimple (sealed?) bookshelf and I wonder if someone could suggest me an easy enclosure project.
Thank you in advance for any help.
 

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GM

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Joined 2003
You're welcome!

?? Folding up the baffle makes a pretty small box already and the fact that it sounds so good on a simple open baffle (OB) tells us that its T/S specs requires a relatively huge box if sealed or ported and why I recommended leaving the back open. If your nephew is at an age where he's likely to handle/play with the speaker, then of course the driver and back will need a durable grill to protect both the driver and him from damage. If you make the box smaller, then consider making the sides and back of the box out of pegboard or similar with the baffle, bottom and top being solid pieces.

Rather than stuffing the box with loose polyfil or similar, line (cover) the inside of all panels except the baffle with felt, open cell foam or similar. What type and how thick has to be found by experimentation to find what sounds best to you, though due to a female's generally more acute hearing I recommend you let his mother decide what sounds acceptable. Remember, if mom isn't happy, nobody is happy.

GM
 
if mom isn't happy, nobody is happy

How RIGHT you are! And she's my sister so we lived in the same house for a very long time!
Anyway, I thank you so much for your very clear and educational explanation (I'm not kidding at all). As speakers sounds really good on a square 40cm OB, I could just leave them this way. But as space is a premium I'll try a smaller baffle (cm 20x30) with back and sides made out of pegboard as you suggest. In this case I think that I haven't to line perforated parts.
 
To mount to a baffle make a steel - (any stiff and strong material) plate and sandwich the driver between these with the plate to the back of the magnet. If you place a good piece of slate - same size as the magnet in the sandwich it will give a little mass.

Try and make the plate a little bigger than the front of the driver so that you can use long bolts through the baffle to tighten the whole thing together. With such small drivers 3 mounting points should be enough, so you can use triangular plates.

This is - I have found - is a good way to mount any driver in any situation.

I would certainly try these as open baffles....if the test sounded good they will sound better in proper o/bs; why bother to restrict them in boxes?
 
This morning I tried a little open box. Hmmm...
Then I made some holes on sides. Hmmm...
Then I filled the box with some fabric. Hmmm...

Then I tried some smaller baffles and... I feel imbarassed but the little speakers sound stunningly EVEN on these. Highs are so clean. I also hear very nice basses.

So I'll definitely go for OBs, maybe 40cm x30.

I don't know, I can't accept they sound so good :scratch:
 

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Calamaro said:

Anyway, I thank you so much for your very clear and educational explanation (I'm not kidding at all).

.........I'll try a smaller baffle (cm 20x30) with back and sides made out of pegboard as you suggest. In this case I think that I haven't to line perforated parts.

You're welcome!

Yes, you need to damp them even if perforated.

GM
 
brianco said:
To mount to a baffle make a steel..........This is - I have found - is a good way to mount any driver in any situation.

As a general rule, I agree since mass loading the driver to the cab as well as mass loading the cab to whatever surface it sets on improves the driver's acoustical-mechanical efficiency.

GM
 
Calamaro said:

Then I filled the box with some fabric. Hmmm...

So I'll definitely go for OBs, maybe 40cm x30.

'Fabric'? This doesn't indicate a suitable damping material and with rare exception, whatever is used shouldn't fill the box when ~'FR' drivers are going to be used for most/all of its BW.

For sure, all drivers sound their best on OBs since both sides of the driver is 'feeling' a near identical acoustic load.

GM
 
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