Hi,

I am getting towards the final stages of building my first subwoofer - a 60 litre, dual-ported, 150W, 12 inch beast....

I have bought some "polyfill" polyester wool to stuff the box with - as recommended by hundreds of DIY subwoofer sites. Just on a whim last night I put a match to a small amount of the wool to see how well it burns - it caught light immediately and burned away happily when I droppped it into the toilet bowl!

Do I need to be worried about stuffing my box with this? The amp I am using ( a 150W model manufactured by Acoustic Energy and sold here in Australia through Jaycar, similar store to Maplins) is not fully enclosed - the electronics are all bare at the rear of the plate.

I am thinking, even if it did catch light...

A. it would only happen whilst I was using the sub, as the amp powers down automatically when not in use - so hopefully I would notice!?
B. the box, although vented, would probably not allow a fire to take hold.
C. I should really get myself an electrical-fire extinguisher for the house anyway!

Any thoughts? What do commerical subs get filled / lined with? Should I consider standard fibreglass roof insulation or similar lining, and forget about stuffing?

Cheers,

lhalha

...who is wondering how much it would cost to get an SVS into Australia, and whether I am saving any money at all in building this bloody thing myself....!

[Nimby]

I would be very wary of using roof insulation materials.

A ported sub is rather well ventilated when working and will fill the room with small particles pumped out of the ports.
Both glass or rockwool micro-slivers are unpleasant and a potential health risk.

I used thick car-damping felt on the walls of my DIY subs and polyester on top of that. But being passive, no internal amp was involved. I certainly wouldn't insulate over the amp. You want it kept cool apart from your supposed potential fire risk.

Remember that the sub amp is in quite a closed box (in a fairly uninflammable material) so if there was a fire it should be contained in the box and the oxygen would be quickly consumed. You could always build your amp into a seperate well ventilated box if you think the risk is too great.

As to SVS: Even if you are curious rather than serious: Standard procedure is to e-mail the address on their website. Tell them where you live and which model interests you and they will e-mail you back with a delivery price. If you need advice first on which SVS model tell them the size of your room and any large openings and how loud you like your bass.

Usually you have two delivery options: "Door to door" or the nearest airport. For the (usually) quite small savings I'd go for 'door to door'. But your kilometreage may vary.

Good luck whatever you decide to do.

Nimby

[stevegreen]

This was contained in an email that I received from Erik from SVS regarding non door to door deliveries.

If you opt for door to airport you are responsible for finding out about any
required procedures in advance. We had one recipient that had to become a
registered importer in his country in order to be able to pick up at the
airport (a lengthy and expensive process) and because he didn't find out
about this requirement in advance, he was not only forced to go through it,
but he also had to pay storage fees on the box while waiting for his forms
to process.

[avanzato]

If you want fireproof then it's mineral wool all the way, Glass fibre/Rockwool are both classed a non toxic but are a minor irritant.

BTW What's inside the SVS Nimby?

lhalha: As you're in Australia you could get Autex insulation which is polyester and does pass the relevant construction fire codes.

[Nimby]

Originally Posted by avanzato

BTW What's inside the SVS Nimby?

Laughing gas!

Nimby

Originally Posted by avanzato

?

lhalha: As you're in Australia you could get Autex insulation which is polyester and does pass the relevant construction fire codes.

Thanks for the tip - that stuff looks great for my freezing cold floor as well!

Cheers!

[Nimby]

Originally Posted by avanzato

BTW What's inside the SVS Nimby?

Sorry about that. I had to go to work and caught the question about wadding just as I was about to go offline.

I have no idea other than it looks like a typical white sound absorbtion blanket. I haven't opened up my SVS to find out. But saw an image on a US website illustrating a driver upgrade to PCi from the earlier standard PC driver.The cylinder was lined with about an inch (25mm) of the stuff.

BTW: Who killed the rotfl smiley? Perhaps he didn't like my joke?

Too much laughing gas?

Nimby a dead smiley? still dead? deceased RIP

[Ian J]

Originally Posted by Nimby

BTW: Who killed the rotfl smiley? Perhaps he didn't like my joke?

According to the note on the deleted post - you did

[Nimby]

Is there no chance of a miraculous recovery?

It won't be the same without him.

Bwah!



Nimby

[Ian J]

Your wish is my command

[avanzato]

Originally Posted by Nimby

I have no idea other than it looks like a typical white sound absorbtion blanket. I haven't opened up my SVS to find out.

It must be the gas getting to me as I thought you'd opened up the Sub for some reason or other. I wonder who it was? I'll have to get a torch and look in mine tonight.

[Nimby]

Originally Posted by avanzato

I I'll have to get a torch and look in mine tonight.

You'll have a struggle.

The only way into you sub is either to remove the drive unit, take the top off or remove the amp plate. I really wouldn't bother.

Your only view of the interior is through the port(s) and there is no clear line of sight to the inside wall of the cylinder. You might get a distant view of the back of the driver but that's about all.
Mine's chrome plated.

Nimby