[Ryan Anderson]

this warehouse has an 18" Maelstrom-X mounted in the center divider. 12000 square feet on either side. super-insulated, as there are chemicals and elements inside that need protection from the outside. why do they have a subwoofer in such a place? I don't know!

The weird thing is, this 30 foot wall has the driver on 1 side, and a 14" port on the other side.... so this wall divides a total of 24,000 cubic feet.... and there is a sub and port mounted in the middle.

Is this a ported alignment? series tuned 6th order?

 

[vann_d]

Your description is not very clear. Does the port travel through the entire wall? How thick is the wall? It must be pretty thick for the sub to not stick through to the other side. Or does it? What does 30 ft. wall mean? Must be a really narrow room if the wall is 30 ft. wide. Or does it mean 30 ft. tall?

Pics or diagrams would help

 

[Ryan Anderson]

the port is 12" long, traveling through the wall 30foot long, 20 ft high at the center crest, 15 foot tall at the ends (front and rear of the building). 12,000 cubic feet on either side of the wall.

 

[vann_d]

Ahh, 12,000 cubic feet on either side. That's not such a big warehouse. It's only 30 ft. x 22 ft. on either side. I think the conference room in my small office building is bigger than that. Anyway, sounds like a leaky infinite baffle to me.

 

[Ryan Anderson]

so there are no interactions with "the port"?

 

[Mike P.]

this warehouse has an 18" Maelstrom-X mounted in the center divider. 12000 square feet on either side. super-insulated, as there are chemicals and elements inside that need protection from the outside. why do they have a subwoofer in such a place? I don't know!

Where did you see this?

​

 

[Ryan Anderson]

Where did you see this?

​

OK, I lied... I haven't been reprimanded in a while, so I pushed the envelope...again

I'm sorry. BUT.. the point is, at what point does a chamber for a given alignment become too big? no longer function? If you have an IB, you can't just stick a port in it and now its a giant LLT...can you?

I'm just wondering. I'd like some good feedback with real answers that make sense. Credible.

 

[SteveCallas]

There is no valid reason a really large enclosure won't behave according to plan as long as it is air tight.

 

[Ryan Anderson]

There is no valid reason a really large enclosure won't behave according to plan as long as it is air tight.

seriousely? come on... just for the sake of argument... 24,000 cubic feet 6' port 1" long 2.9Hz tune

ok, shows next to no effect on excursion... a touch... maybe I do believe this thing!

ok, a touch of vent velocity, next to none... I believe that too

showing quite a gain in spl at tuning...seriousely?? IDK... I guess in a huge warehouse the air from the sub should be felt throughout, and, if the rear wave were aligned with the front... maybe I am a believer now HOWEVER this is only because I can see the driver stimulating the entire warehouse, and the rear room vibrating could easily pass through the 6' (72") hole in the wall.... but a normal 8" port? no.

look at that massive port gain! OK, i guess.... so just because an enclosure is big does not mean the port doesnt do anything... but, it does show it will not help excursion much in that ridiculous scenario...


with my 21 cubic foot box, I show I should still have had much less excursion at tuning than at 25Hz-35Hz...which was not the case.

If I can't blame the outragious airspace.... ugh...back where I started...

 

[Lonely Raven]

I knew something was fishy about this thread.

 

[vann_d]

I think the most interesting issue with the question (although I knew it was fake anyway) was that both sides of the baffle were supposedly the same volume. I think you could model this problem if there was only one room and the other room was open to the outside. Then the one room would act like an enclosure with a port.

Because both rooms in the original (ill posed) question were the same volume, there would not be much air flow though the port at all. Both chamber would be pressurized equally with a small transient due to phase difference.

I think the driver would act pretty much like an IB or, if the vent was big enough, an open baffle

 

[Ryan Anderson]

it is 6th order BP anti-external radiation

 

[SteveCallas]

Not much sense in a 3hz tune in my opinion, the port will never get used. Also, since the gain from a port covers a certain multiple of an ocatve, when you tune really, really low, like 3hz, the gain from the port covers an extremely small FR range.

The lowest I would ever practically tune would be ~10hz. Less than that and I just don't see the port getting much use at all. If you want to chase single digits and your sealed subs run out of excursion at 7hz, then you may want to look at a 7hz tune, but the topic of chasing single digits is a whole other can of worms.

 

[Lonely Raven]

Not much sense in a 3hz tune in my opinion, the port will never get used. Also, since the gain from a port covers a certain multiple of an ocatve, when you tune really, really low, like 3hz, the gain from the port covers an extremely small FR range.

The lowest I would ever practically tune would be ~10hz. Less than that and I just don't see the port getting much use at all. If you want to chase single digits and your sealed subs run out of excursion at 7hz, then you may want to look at a 7hz tune, but the topic of chasing single digits is a whole other can of worms.

I'd love to hear some thoughts on chasing single digits...just for the fun of it.

Some of the electronic music I listen to goes to the single digits, and I dream of a day when my sub will cover 6hz as well as it covers 20Hz...but that's very few and far between.