[nater]

After reading this forum for a few months and acquiring most of the materials I am about to start my first project.

I have demoed a couple of subs in my room and decided to go with two subs.


Using some sonotube that I have on hand the sonosub program shows 237L and a 4" port length of 27". As each tube is 3 feet long this is what I came up with.

I am using a shiva 12" driver, mdf two layers on each end with a third layer as the cap and bottom. The calculator shows a net of 228L and a tuning of 44.8Hz. The warning is for "Driver to box top resonance is 95 hz. With a top that is three inches thick is more damping needed? What sort of damping could be used for this? Is it foam simular to the material used inside the tube?


Does this seem reasonable, is there something I should change?


nater

 

[Willd]

Something is seriously wrong with your calculations so far.


So you have two sonotubes? What diameter?

 

[nater]

The overall length is 3' for each tube. They are 24" in diameter. There are two inches of end cap within each tube and one inch top or bottom total 3" of mdf on each end. I plan to place the vent in the top opposite the driver, driver facing down. The driver will be surface mounted not recessed.


At this stage the only simple adjustment is in port length or changing from 4" to 6" vent size.


thanks for looking at this

Nate

 

[nater]

Wild,

What is looks wrong?

Using WinISD it appears that an 8" length yields what appears to be a better graph.


any suggestions?


thanks

nater

 

[Willd]

Your vent length and tuning frequency are what is "wrong".


We know how long each sonotube is and their diameter.


But what frequency do you want to tune these subs to?

 

[nater]

20 hz seems like a good place to start.


As this is my first attempt I am not sure what the best number to tune for. What will yield a reasonably flat response with as much output at 35hz and below as this combination will produce.


thanks

nater

 

[Kyle Richardson]

Nater, take a look at this link to view 3 different designs using the Shiva. The Shiva typically likes to be in about a 3 cu ft enclosure so pay particular to the "Adire Alignment" which is 85 liters and the "SBB4 Alignment" which is 95 liters. Both of those designs will produce flat frequency response to the low 20Hz region in room with good power handling capabilities as well.

Your original 237 liter design is way, way too big for the Shiva and should not be used. You will have no power handling capabilities and your output will be severely limited as well.

 

[nirvana_av]

Kyle,


I went to the Acoustic Visions website and my Google taskbar application appears to flag your site with a malware warning. I've never seen that before at any website that I've ever visited. What gives?

http://www.google.com/interstitial?u...c-visions.com/

 

[Kyle Richardson]

Yes, I heard they flagged it last week from another user. I have no idea what's up and I've sent in a petition to have it taken off of their black list.

 

[nirvana_av]



Quote:
Originally Posted by Kyle Richardson /forum/post/0


Yes, I heard they flagged it last week from another user. I have no idea what's up and I've sent in a petition to have it taken off of their black list.

I hope they fix it soon. It can't be good for business.

 

[Kyle Richardson]

To all...

I have downloaded the site and checked it against virus' and spyware, etc. Nothing was found and I'm quite confident that it is clean so please don't hesitate to visit the site.


Sorry for the hijack of your thread nater...back on topic now.....