[fishdude]

I am looking ot build a new sub and have settled on the Shiva for my driver.  I am trying to decide on ported or sealed.  I have read the two threads on here about ported and sealed designs and now I have some questions.  I watch a lot of movies.  Everything from action and sci-fi to drama and thrillers.  Here is the tricky part, I watch quite a bit of live concerts on DVD.  Pink Floyd, Clapton, The Stones to say the least.  Primarily classic rock. 

What is my best direction to go here?  I started off wanting to use a Sonotube design, but liked the ease of build on the boxes shown here.  Any help would be greatly appreciated.

[Kevin Haskins]

How big is your room and is the room closed, or open to the rest of the house?   

[fishdude]

16' x 22.5' x 8' ceiling.  Opens at one end to the kitchen/dinette.  Two doorways on back wall by tv.

[Kevin Haskins]

I'd build the larger dual ported design if you have the space.    This larger version uses a pair of 4" Precision Sound Ports tuned low.   You need an extra center section because the ports are long, 24" long in this case.    You may be concerned about the proximity to the rear wall but don't be, I've done this intentionally.     This tunes the enclosure down around 17-18Hz with 75% fill and you get great in-room output and with a standard subsonic filter around 17-18Hz you get killer driver protection.   You won't get port noise or chuffing except at very extreme output levels and this should be a musical alignment also.   

For the amp give me a call.   I'm putting some 1000W amps into inventory with subsonic filters designed for my enclosure designs.   That takes some of the guess-work about such things out of the equation.   The 1000W amp is $425 plus shipping.   The Shiva, two ports and the amp runs $610 plus shipping.

For some idea of how this would perform, look at the following.    This is very close to the same driver as the Sadhara used.   The difference is that the Sadhara was tuned higher.   You wouldn't see the broad 40Hz peak in this design and the 20Hz distortion number would be low like the rest of the measurements.   The Sadhara didn't have a subsonic filter on it in that test and the driver was overloading under port tuning hence the reason for the high distortion levels in the 20Hz measurement.     This lower tuned version would have wider bandwidth too, you get good output into the teens.

http://www.ultimateavmag.com/features/704way/index1.html

[Carl V]

Ok I'm a little slow on the uptake....is this Larger dual ported desing on the website?
I looked over your Shiva X applications pdf. & did not see this.

Thanks

[fishdude]

I think this is what I am going to do.  Will I have any problems with the larger amp and this driver?  When you say 75% fill, where is it best to leave the gaps?  How much poly are we talking about?  The internal ports look to be about 10", is this correct?  Sorry for all of the questions, this is my first DIY.

btw:  I am a CAD designer by trade.  I am going to model out this box in Inventor so I can get my cut info.  I will send you an exploded view of the complete box design.

[Kevin Haskins]

Ok I'm a little slow on the uptake....is this Larger dual ported desing on the website?
I looked over your Shiva X applications pdf. & did not see this.

Thanks

Not yet.... I'll be making some more application notes that will include some enclosure designs in the future.     The Shiva ones are coming first.

[Kevin Haskins]

I think this is what I am going to do.  Will I have any problems with the larger amp and this driver?  When you say 75% fill, where is it best to leave the gaps?  How much poly are we talking about?  The internal ports look to be about 10", is this correct?  Sorry for all of the questions, this is my first DIY.

btw:  I am a CAD designer by trade.  I am going to model out this box in Inventor so I can get my cut info.  I will send you an exploded view of the complete box design.

The amp is no problem.   For this enclosure I'd say 72 oz. of polyfill.   You don't leave gaps, just shove it in the box.   You only have to keep it clear of the port opening.   The ports are 4", and the internal holes in the braces are about 10".   

I'd love to see your box design.   I use Alibre but I have this file in Google Sketchup.   Its a free download so just let me know if you want the file.   

[fishdude]

Cool.  I modeled the box today and will update the drawing witht the new info tomorrow.  I will have to update it again when I get the amp in. 

Thanks for all of you help.  I will try and give you a ring to place the order in the next couple of days.

[Kevin Haskins]

Cool.  I modeled the box today and will update the drawing witht the new info tomorrow.  I will have to update it again when I get the amp in. 

Thanks for all of you help.  I will try and give you a ring to place the order in the next couple of days.

No problem.... don't be afraid to call if you have any questions.