Hi X,
that's funny. So big difference.
But now I am about to finish the speakers, so the driver are not in the boxes, and I can play with the stuffing.
Will see.
Yes, I think too, the eggcrate foam can make the difference when stuffing, mine differs from yours based on the pictures.
Sorry X, a couple more questions regarding the TL design (or maybe someone else can answer) :-
1. Wading through the 178 pages of this thread, it appears that the eggcrate foam is NOT the special acoustic convoluted foam that costs an arm and a leg. You have just used whatever cheap convoluted foam you could buy - mattress topper, etc. Is that correct?
2. Given that during TL tuning, you have to remove the RS225 each time you alter the stuffing, what fixings do you recommend for the driver to the baffle?
I will probably use MDF, even for the baffle? In the past, I have used T-nuts, but there might be something better these days?🙄
1. Wading through the 178 pages of this thread, it appears that the eggcrate foam is NOT the special acoustic convoluted foam that costs an arm and a leg. You have just used whatever cheap convoluted foam you could buy - mattress topper, etc. Is that correct?
2. Given that during TL tuning, you have to remove the RS225 each time you alter the stuffing, what fixings do you recommend for the driver to the baffle?
I will probably use MDF, even for the baffle? In the past, I have used T-nuts, but there might be something better these days?🙄
Yes, any open cell eggcrate foam. You can get acoustic eggcrate panels from Amazon etc it’s not that expensive. But mattress topper works too. If you want to, use melamine magic eraser sponges. That is the the best as it’s the same as BASF Basotect. 100 6cm x10cm x 2cm thick sponges for $7 from China. Thick felt works also or carpet padding denim felt.
for example:
https://www.amazon.com/dp/B076JNCQ39/ref=cm_sw_r_cp_api_glt_i_A5DDWK3C3W8ZGMBCS20A
I typically use #8 x 3/4in pan head Philips wood screws to hold the woofer to the baffle (BB ply). I get these from Parts a express. I think maybe use Spax drywall screws on MDF. T nuts work well too. I don’t think you will be removing it more than 2-3 times.
https://www.parts-express.com/8-x-3-4-Deep-Thread-Pan-Head-Screws-Black-100-Pcs.-081-422
for example:
https://www.amazon.com/dp/B076JNCQ39/ref=cm_sw_r_cp_api_glt_i_A5DDWK3C3W8ZGMBCS20A
I typically use #8 x 3/4in pan head Philips wood screws to hold the woofer to the baffle (BB ply). I get these from Parts a express. I think maybe use Spax drywall screws on MDF. T nuts work well too. I don’t think you will be removing it more than 2-3 times.
https://www.parts-express.com/8-x-3-4-Deep-Thread-Pan-Head-Screws-Black-100-Pcs.-081-422
Thanks X.
Exactly what I was hoping to hear.
I don't know if you have it in the States, but under most carpet that is laid here, they first lay 5"underlay", which is 6-8mm of reconstituted rubber foam. Not sure if there is a self adhesive version or not. However it has a smooth face and may not produce the required acoustic effect.
Those pan heads from PE have a nice deep thread and should be OK in MDF if I'm careful each time I screw them back in.
As you said, if I'm testing each time I add/remove filling, 2 or 3 trials hopefully should be enough.
BTW, why I'm using MDF throughout, is because BB ply, or veneered ply, is expensive compared to MDF, and also I quite like the white TLs you put up on page 1. They should have the required WAF (which is critical in my case, as SWMBO thought my speaker building days were well and truly over).
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I see it is being sold this way. Strange, because convoluted is not the right term. It is 'reticulated' foam. Hope that helps you finding it.
I don't think either is strictly correct. Had a quick look in a thesaurus, but couldn't find anything that technically describes "eggcrate" shape. Maybe "dimpled"?
I used this one https://www.soundimports.eu/en/monacor-mdm-40.html
It doesn't cost the earth and I think the quality of this speaker requires good materials.
It doesn't cost the earth and I think the quality of this speaker requires good materials.
The egg-crate shape is not very important. 'Reticulated' refers to the way the air bubbles are not sealed. They are 'popped' during the manufacturing process.
I only mentioed it for general info.
I'm defnitely planning to use mattress topper egg crate foam.
A question for the Aussies.
I've been trying to source eggcrate foam in Australia.
It's easy to find "convoluted mattress toppers", and also so-called "acoustic" squares.
My worry is that living in Queensland, I know that most non-rubber foam only last 10 years or so, then slowly disintergrates, turning into foam dust.
This is the main reason I only buy speaker drivers with genuine rubber surrounds.
I'm wondering if anyone has had experience with the longevity of the various available foams?
Maybe the grey or blue foam does better than say the yellow foam, which I know is rubbish?
I've been trying to source eggcrate foam in Australia.
It's easy to find "convoluted mattress toppers", and also so-called "acoustic" squares.
My worry is that living in Queensland, I know that most non-rubber foam only last 10 years or so, then slowly disintergrates, turning into foam dust.
This is the main reason I only buy speaker drivers with genuine rubber surrounds.
I'm wondering if anyone has had experience with the longevity of the various available foams?
Maybe the grey or blue foam does better than say the yellow foam, which I know is rubbish?
Use melamine sponges then. They last forever. Polyurethane foam rots in 15-20yrs. But it only falls apart if physically touched. It has a funky smell though. Anyone who has an old polyurethane coated nylon tent knows this. Even the handles on my Craftsman screwdrivers get this funky smell when the handles turn brown after 20 years.
The reticulated foam is good for adding some resistance to the vent and keeping critters out of the TL.