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Discussion Starter #1
Sometimes to do a clean install it would be nice to get big bass in a smaller space! I have never heard of any of this being done so I wanted to pose a few strange ideas and see what people think, or know about it!

1) Remote volume
Build a box just large enough to house the speaker, then use a fairly rigid tube to connect the air space to a remote resivior that has the volume needed to allow the sub to have the correct compressability to make the sub work as designed. I imaging that the surface area of the extension tube would be pretty important here.

2) Mimicking the air volume with a smaller flexible enclosure
Build a box just large enough to house the speaker, then mount a diaphragm of some sort that could be tuned via spring tension to flex/compress like the appropriate air volume would do. On the outside of this moving part, it would be shaped to be an extremely inefficient radiator so that it doesn't produce sound waves that interfere with the speaker.

Probably both totally nuts with a lot more problems than I considered. But hey, you guys here probably have tons more experience with the theory of operation for subwoofer enclosures than I do!

James
 

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Using a tube to a remote location is fine. It just has to be big enough that it doesn't act like a port inside the box.

The other idea just sounds like a passive radiator.
 

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Using a tube to a remote location is fine. It just has to be big enough that it doesn't act like a port inside the box.

The other idea just sounds like a passive radiator.
I would think if you modelled the connecting tube as a port for the small enclosure volume and made sure it tuned to higher than the usable range you wanted the sub to play the ‘port’ would just unload and not act as a port
 

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I would think if you modelled the connecting tube as a port for the small enclosure volume and made sure it tuned to higher than the usable range you wanted the sub to play the ‘port’ would just unload and not act as a port
Good thinking there, a nice way to determine minimum pipe diameter.
 

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Good thinking there, a nice way to determine minimum pipe diameter.
The only caveat I can think of is the extra chamber a conventional port plays into normally is huge like a cars cabin, so a smaller volume of air may have a negative effect on the ‘tuning’ of the ‘not a port’ if you see what I mean, kind of like when doing spl walls the cabins tuning effects results and tuning more so than a street 2cu ft box if you see what I mean...

Ideally I’d want to use the sd of the driver, but appreciate it may not be so ideal and may not fit so well... for example a ten would ideally need an eight inch tube I’d guess...
 

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The only caveat I can think of is the extra chamber a conventional port plays into normally is huge like a cars cabin, so a smaller volume of air may have a negative effect on the ‘tuning’ of the ‘not a port’ if you see what I mean, kind of like when doing spl walls the cabins tuning effects results and tuning more so than a street 2cu ft box if you see what I mean...



Ideally I’d want to use the sd of the driver, but appreciate it may not be so ideal and may not fit so well... for example a ten would ideally need an eight inch tube I’d guess...
Yep, gonna have to be a big pipe. But I don't see much of a problem with the idea itself.
 

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The only caveat I can think of is the extra chamber a conventional port plays into normally is huge like a cars cabin, so a smaller volume of air may have a negative effect on the ‘tuning’ of the ‘not a port’ if you see what I mean, kind of like when doing spl walls the cabins tuning effects results and tuning more so than a street 2cu ft box if you see what I mean...

Ideally I’d want to use the sd of the driver, but appreciate it may not be so ideal and may not fit so well... for example a ten would ideally need an eight inch tube I’d guess...
You don't have to guess, you can actually model this sort of thing in Hornresp.
 

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I think Zardnok really hit it with aperiodic membranes.

Pretty much this, but if you have enough EQ, a lot of excursion and a lot of power you can seriously undersize a sealed box. People will debate if you can hear the difference between a high Q box and a "nomal" box, but pretty easy to try out since you can just add scrap wood to a regular sealed box to try it quickly.

Winisd will let you know how much excursion and power you need for your desired listening level.
 

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Discussion Starter #12
Thanks for the info guys! That aperiodic membrane sounds really cool. It's like having the tube to another box, but without the second box!
 
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