Sealed Enclosure with a 'Twist' - Any Problems?

[qObsession]

It is just 2 enclosures glued together. So the only compliction is orienting the 2 boxes so that you satisfy the basik premise of the drawing you did (correct, but i do usually like having something between the 2 magnets, and with woofers with polepiece vents you do not want to cover them up.

So if you have a 2ft³ for one driver then you need 4ft³ for the pair.

What woofer?

dave

Well, Dave... I think this whole thing is starting to make sense to me now. It's funny you say that about the pole piece. In my head, when I thought about that brace between the magnets, I thought about it right in the middle of the magnets (just not thinking about the vent). I wonder if I would have built the whole dang box, put the subwoofer in, and thought, "NOOOOO!!!" lol

 

[planet10]

OH! So... let's say for simplicity and sake of discussion that you took two cubical boxes and attached their backs with the subs firing in opposite directions... that would give you the 'cancellation effect'??

If tight coupling of the drivers can be maintained. One would have to design the single boxes so that a good mechanical connection between the woofers mechanical movement is maintained.

dave

 

[qObsession]

What woofer?

dave

Oh, yeah... these are Soundstream Reference 12s (SS-12Rs) from 'back in the day' (ca. 1995). 😉

 

[qObsession]

If tight coupling of the drivers can be maintained. One would have to design the single boxes so that a good mechanical connection between the woofers mechanical movement is maintained.

dave

Awesome... it FINALLY makes sense to me, and I'm probably going to go back to the drawing board and do this.

Thanks for taking me to school (in a good way)!

 

[planet10]

Do you have the T/S? Current one does not want to be in a box at all.

dave

 

[qObsession]

Yeah, I have all the T/S parameters. Can I ask you what you mean by 'current one doesn't want to be in a box'?

 

[planet10]

https://soundstream.com/product/r3-12/

One only needs to see 1 number Q_ts = 0.9878

Ideallly one wants the end Q of the box to be 0.5 to 0.707.

If you put a driver in a box the Q almost always goes up, it is very hard to reduce it (you can a bit), so something like the current one would be used OB where the OB roll-off can help kill some of the excess bass.

dave

 

[qObsession]

Huh... I have the driver's Qts listed as 0.462

 

[planet10]

That makes them much more useful. F_s and V_as?

dave

 

[qObsession]

Here's the whole package:

 

[planet10]

What is the application again?

For home use looks good in vented 100-150 litre, in a car, 80 litres sealed looks good but it could be as big as 700 litres.

dave

 

[planet10]

Sealed

Suggested set

dave

 

[qObsession]

You're the man, Dave!

It's going in the back of a hatchback, but space isn't an issue (at all!). I gutted it, so there's nothing but a huge cabin behind the front seats. 🙂

Thanks for the help!

 

[planet10]

Keep in mind that with room gain almost any sealed box becomes flat. Vented produce too much.

dave

 

[PRR]

Wouldn't it have to look something like this

Or:

 

[planet10]

Harder to build, better protection, a bit trickier to get as tight a coupling, but it will work. If the noise off the back of the driver is low enuff you can mount them like this for easier coupling.

dave

 

[phase]

https://soundstream.com/product/r3-12/

One only needs to see 1 number Q_ts = 0.9878

Ideallly one wants the end Q of the box to be 0.5 to 0.707.

If you put a driver in a box the Q almost always goes up, it is very hard to reduce it (you can a bit), so something like the current one would be used OB where the OB roll-off can help kill some of the excess bass.

dave

That link looks like a current offering from the Soundstream brand, the drivers the op has are from 1995.

I’ve had decent results using smaller sealed cabinets in the corners of vehicles.

 

[planet10]

I was looking for an ON design i did, ran across this, updated it to cover more stuff. Thot it might fit in here:

dave