Shiva-x build for noob's first - Page 6 - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #51 of 105 Old 04-15-09, 11:32 AM Thread Starter
Senior Shackster
rudy
 
Join Date: Jan 2009
Location: Iowa
Posts: 103
Re: Shiva-x build for noob's first

just an update, if you want to call it that, i have the mdf cut and am ready to assemble. however, i went and cut the diameter of the hole for the driver too large. i had to go pick up a new sheet of mdf--(thinking of a smaller sub for another room so will have some mdf for later). after looking at it and doing a pre-assembly before gluing or using screws, i realize where some design flaws have been made. nothing too major, but a cut here and there will make this assembly much easier. will post back hopefully tomorrow with some updates!!
mlkmgr is offline  
Sponsored Links
Advertisement
 
post #52 of 105 Old 04-15-09, 11:47 AM Thread Starter
Senior Shackster
rudy
 
Join Date: Jan 2009
Location: Iowa
Posts: 103
Re: Shiva-x build for noob's first

quick question before assembly begins. i just downloaded winisd "pro" and the slot port required is longer than the other winisd version i was using before. which version should i be modeling after.

the original version, with 6.35cu ft & 18Hz tune stated ~18.92" vent length while winisd pro states 24.22". this would be using a 1" x 21" vent opening.

which should i use? i would like to know now before i begin assembly as i do have the mdf on hand to make the longer vent if necessary. thanks to those that can help!!
mlkmgr is offline  
post #53 of 105 Old 04-15-09, 01:39 PM
Senior Shackster
BigPines
 
Join Date: Jul 2007
Location: Eastern Idaho
Posts: 165
Re: Shiva-x build for noob's first

I don't use WinISD but I have Bass Box Pro and would be willing to do a reality check on the volume and port length for you. Did your outside dimensions end up being 22.5 x 25.5 x 26.5? Using 3/4" MDF? One Shiva Driver? How much bracing did you use? Just what is in the last diagram?

Mike
BigPines is offline  
 
post #54 of 105 Old 04-15-09, 01:50 PM
Senior Shackster
BigPines
 
Join Date: Jul 2007
Location: Eastern Idaho
Posts: 165
Re: Shiva-x build for noob's first

I think this is also going to depend on how much fill you are planning to use. Are you planning to go minimal, typical or heavy fill? Just playing with this factor alone seems to change the necessary port length by about the differences you are looking at there.

Mike
BigPines is offline  
post #55 of 105 Old 04-15-09, 01:53 PM Thread Starter
Senior Shackster
rudy
 
Join Date: Jan 2009
Location: Iowa
Posts: 103
Re: Shiva-x build for noob's first

correct, outside dimensions 22.5 X 25.5 X26.5 and using 3/4" mdf. bracing was used as shown in "cut sheet". using the bracing calculator from this site, i calculated 3.678 L (224.438 cu in) for the bracing. the amp is 10X10X5 mounted to the back.

Thanks for your help Mike!
mlkmgr is offline  
post #56 of 105 Old 04-15-09, 02:14 PM Thread Starter
Senior Shackster
rudy
 
Join Date: Jan 2009
Location: Iowa
Posts: 103
Re: Shiva-x build for noob's first

i based my design off the "6.35 Cu Ft tuned to 18Hz with 50oz polyfill" on the shiva application pdf. http://www.diycable.com/main/pdf/shiva_app.pdf
i just did not want to use the "flared ports" in the design.

so just using the recommendations from the app pdf, i would say using 50 oz poly-fill. i don't know if you classify the fill as min, typ, or heavy? is one type classification better than another?
mlkmgr is offline  
post #57 of 105 Old 04-15-09, 02:20 PM
Senior Shackster
BigPines
 
Join Date: Jul 2007
Location: Eastern Idaho
Posts: 165
Re: Shiva-x build for noob's first

Basically, the more fill you use (up to a point), the larger the enclosure looks to the woofer and the shorter your port has to be to achieve the same tuning frequency. For now, I'm going to call 50oz typical. Kevin may be able to tell us if it is considered typical or heavy fill for a cabinet of this size.

Mike
BigPines is offline  
post #58 of 105 Old 04-15-09, 02:42 PM
Senior Shackster
BigPines
 
Join Date: Jul 2007
Location: Eastern Idaho
Posts: 165
Re: Shiva-x build for noob's first

Well, here is what I come up with...

Using the typical fill option, I get 22.92" as the necessary port length at 1" x 21" to tune to 18Hz.

Even considering the extra wood needed to make the port that length, I come up with a net internal cabinet volume of 6.8 cu.ft.


Using the heavy fill option, I get 20.26" as the necessary port length at 1" x 21" to tune to 18Hz.

Considering the extra wood needed to make the port that length, I come up with a net internal cabinet volume of 6.825 cu.ft.

This thing is going to rock! The attached graph shows FR without room gain. Once you factor in room gain, you should have some very usable output into the teens or lower!

Let me know if you need anything else.

Mike
Attached Thumbnails
Shiva-x build for noob's first-shiva-x.gif  


Last edited by BigPines; 04-15-09 at 02:47 PM.
BigPines is offline  
post #59 of 105 Old 04-15-09, 03:04 PM Thread Starter
Senior Shackster
rudy
 
Join Date: Jan 2009
Location: Iowa
Posts: 103
Re: Shiva-x build for noob's first

so is the 18Hz an ideal tune? would i be better off shooting for a lower tune? should i go lower? as i stated, i simply modeled the internal volume and what not after the shiva pdf.

i noticed in your graph it states 300Watts. i am using a 500Watt amp if that makes a difference?

with my fubarred calculation on box volume (i used the box calculator here on the site, but must have done something wrong!!), should i add some addtional bracing to the box to help stiffen it up? thanks again...
mlkmgr is offline  
post #60 of 105 Old 04-15-09, 03:15 PM
Senior Shackster
BigPines
 
Join Date: Jul 2007
Location: Eastern Idaho
Posts: 165
Re: Shiva-x build for noob's first

Naw, the amount of power will not have an effect on FR, only output. To demonstrate this, I have attached another graph. I also attached a graph showing you will run out of excursion somewhere around 15Hz. You'll want a high pass filter on this baby so you don't trash your brand new woofer.

As Kevin has said many times (and I am paraphrasing) don't sweat the small stuff. Your design is good. The biggest thing I would be worried about is port noise but I think earlier in the thread Kevin said you were good with that so sweet deal!

If you tune this thing to 17Hz or 18Hz or 19Hz I don't think it really matters that much. If you want to go lower you can but the lower you go, the more of a problem port noise may become. Your bracing looks good to me. I really don't see any problems.

Mike
Attached Thumbnails
Shiva-x build for noob's first-shiva-x.gif  

Shiva-x build for noob's first-shiva-x2.gif  

BigPines is offline  
Reply

Bookmarks

Tags
build , noob's , shiva-x

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome