Heat Induced Pressure in Cabinet?

[tnsguy]

I am new to speaker building, so this question may be laughable, but it is stuck in my brain. If I build a sealed enclosure loudspeaker and do a good job of sealing everything, will the temperature rise inside the enclosure during use of the finished speaker give rise to a pressure increase (PV=nRT) that will displace the nominal position of diaphrams of the drivers? If this happened, I would imagine it would cause distortion. Or is it that no speaker is sealed that well?

Thanks for listening.

Tom

[planet10]

Any such change... and it does occur, is likely dwarfed by the day-to-day changes in barometric pressue.

dave

[albin]

hello
Lovely question.Inefficent speakers make heat into the box,the air expands,the diaphragms move out,inescapable.You gots to have a leak,but it only needs to be slow.It's been recognized before.
You think,I think,therefore we are.
regards
Max Albin
ps planet10 ditto

[nigelwright7557]

Originally posted by tnsguy
I am new to speaker building, so this question may be laughable, but it is stuck in my brain. If I build a sealed enclosure loudspeaker and do a good job of sealing everything, will the temperature rise inside the enclosure during use of the finished speaker give rise to a pressure increase (PV=nRT) that will displace the nominal position of diaphrams of the drivers? If this happened, I would imagine it would cause distortion. Or is it that no speaker is sealed that well?

Thanks for listening.

Tom

You shouldnt be making a completely sealed enclosure.
Drill a very small hole in the enclosure to equalise the inside and outside pressure. A small hole wont affect normal running of the speaker. Just an 1/8th of an inch hole would do.

[tnsguy]

Thank you all for the replys. It makes perfect sense. My mind is at ease........

Tom

[DigitalJunkie]

Most speakers have a very small leak through the spider and voice coil gap.(edit-Thinking vented pole-pieces here)Sometimes even the (foam) surround can leak a tiny bit.
I'd seal the box up the best I could,and not worry about it -no drilling small holes or anything.

[nigelwright7557]

Originally posted by DigitalJunkie
Most speakers have a very small leak through the spider and voice coil gap.(edit-Thinking vented pole-pieces here)Sometimes even the (foam) surround can leak a tiny bit.
I'd seal the box up the best I could,and not worry about it -no drilling small holes or anything.

I use jack sockets on my speaker cabinets and they have quite a large hole in them anyway.

[DigitalJunkie]

Exactly. There are enough small,slow leaks (or in your case,larger leaks) in a speaker cabinet to not worry about it.