4 X Fi IB18's infinite baffle, still deciding? - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #1 of 18 Old 09-23-12, 11:52 PM Thread Starter
Shackster
Dave
 
Join Date: Mar 2010
Location: Japan
Posts: 93
4 X Fi IB18's infinite baffle, still deciding?

So as everyone knows, I posted a similar question over at DIY audio, but I am just trying to get as much info from the experts as I can.
http://www.diyaudio.com/forums/subwo...le-sub-me.html

I am trying to decide if I should go the IB route.
This is what I have planned so far.
1. 4 X Fi IB18
2. 250cf of space behind the front wall.
3. The room is 22.3' long 16' wide and 7.9' high all concrete walls, ceiling and floor
4. Looking at having a system to handle the peak 105db's at frequencies as low as 15hz or even 10 hz.

Any thoughts or opinions would be greatly appreciated.

Cheers Dave
JapanDave is offline  
Sponsored Links
Advertisement
 
post #2 of 18 Old 09-24-12, 12:32 AM
HTS Senior Moderator
 
fusseli's Avatar
 
Join Date: May 2007
Location: Colorado, USA
Posts: 1,921
My System
Re: 4 X Fi IB18's infinite baffle, still deciding?

What do you have in mind for your manifold for your subs? I have seen pictures of a lot of creative approaches that people have taken but since yours is in the front wall (hidden behind a screen?) maybe you don't require anything fancy or creative. How do you plan on powering your subs?


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
fusseli is offline  
post #3 of 18 Old 09-24-12, 12:43 AM Thread Starter
Shackster
Dave
 
Join Date: Mar 2010
Location: Japan
Posts: 93
Re: 4 X Fi IB18's infinite baffle, still deciding?

Something like this, only horizontally. Yes it will be hidden behind a 14 ft screen.



I plan to power the subs remotely ,preferable via two separate amps so I can eq all 4 subs individually.
JapanDave is offline  
 
post #4 of 18 Old 09-24-12, 07:28 AM
Ile
Shackster
 
Join Date: Nov 2010
Location: Finland
Posts: 77
Re: 4 X Fi IB18's infinite baffle, still deciding?

Sounds like a plan, just keep in mind you will need good support for that false wall.

Room gain from your concrete room should give much lower -3db point than below simulation. Maybe around 10-15 Hz.
Attached Thumbnails
4 X Fi IB18's infinite baffle, still deciding?-4xib318.jpg  

Ile is offline  
post #5 of 18 Old 09-24-12, 07:55 AM Thread Starter
Shackster
Dave
 
Join Date: Mar 2010
Location: Japan
Posts: 93
Re: 4 X Fi IB18's infinite baffle, still deciding?

Thanks for those graphs, I have been trying to get winISD working all day with no success. The false wall is extremely well braced using 2" X 4"'s at a 6" spacing with 1" of MDF over that. I will have to sort the baffle out though, but that should not be a problem.

Looking at those graphs it would be hard to say no to doing this.
JapanDave is offline  
post #6 of 18 Old 09-24-12, 11:42 PM Thread Starter
Shackster
Dave
 
Join Date: Mar 2010
Location: Japan
Posts: 93
Re: 4 X Fi IB18's infinite baffle, still deciding?

Ile, what software is that you are using?
JapanDave is offline  
post #7 of 18 Old 09-25-12, 01:53 AM
Ile
Shackster
 
Join Date: Nov 2010
Location: Finland
Posts: 77
Re: 4 X Fi IB18's infinite baffle, still deciding?

Used Winisd pro alpha software. Four IB318 driver in 7m3 closed enclosure, pushed to their maximum linear excursion at 5 Hz (400w/driver) gives 127db output to 2pi / 1 meter.

With 2nd order HP filter at 10 Hz you can feed max 550W/driver and you get 2-3 db more output for upper bass, but you lose -11 db at 5Hz.

I have just two of those drivers in my small room, but those seem to be more than enough.


If you tested winisd in Windows 7, that could cause your problems.
http://www.linearteam.org/forum/viewtopic.php?t=2&p=2

Last edited by Ile; 09-25-12 at 02:01 AM.
Ile is offline  
post #8 of 18 Old 09-25-12, 06:02 AM Thread Starter
Shackster
Dave
 
Join Date: Mar 2010
Location: Japan
Posts: 93
Re: 4 X Fi IB18's infinite baffle, still deciding?

Quote:
Ile wrote: View Post
Used Winisd pro alpha software. Four IB318 driver in 7m3 closed enclosure, pushed to their maximum linear excursion at 5 Hz (400w/driver) gives 127db output to 2pi / 1 meter.

With 2nd order HP filter at 10 Hz you can feed max 550W/driver and you get 2-3 db more output for upper bass, but you lose -11 db at 5Hz.

I have just two of those drivers in my small room, but those seem to be more than enough.


If you tested winisd in Windows 7, that could cause your problems.
http://www.linearteam.org/forum/viewtopic.php?t=2&p=2
I don't need upperbase as much, as I will be probably crossing at 55-60 hz depending on how they measure after installation. So I would prefer to have to headroom for the extra low frequencies. I am not a SPL freak, I just want good clean bass down as low as I can get up cinema reference levels (Standard dynamic range of up 115db) But, I don't always watch movies at reference, I can find it too loud at times.

I tried to use the non pro winISD, but I could not get the specs of the drivers right. And I am on Windows 7.

I wanted to see how the 4 X Licars 18"s would stack up against the 4 X AE IB15"s

BTW, nice thread, looks like a nice room!
JapanDave is offline  
post #9 of 18 Old 09-25-12, 07:03 AM
Ile
Shackster
 
Join Date: Nov 2010
Location: Finland
Posts: 77
Re: 4 X Fi IB18's infinite baffle, still deciding?

Quote:
JapanDave wrote: View Post
I tried to use the non pro winISD, but I could not get the specs of the drivers right. And I am on Windows 7.
There is certain order to fill specs to sheet. Qes, Qms, Fs, vas, Mms, BL, xmax and Pe. Software calculate others.

Quote:
JapanDave wrote: View Post
I wanted to see how the 4 X Licars 18"s would stack up against the 4 X AE IB15"s
Two FI IB318 will outperform four AE by 6db, but AE's goes bit lower. (f3=17Hz vs FI 25Hz)
Shouldn't make difference in your concrete bunker, there bottom end could be too rich with f3=17Hz.

AE IB15 might be out of production, least they don't list it in store.
http://aespeakers.com/shop/catalog/index.php?cPath=30

Quote:
JapanDave wrote: View Post
BTW, nice thread, looks like a nice room!
Might be some day, if I find time to finish that room.
Ile is offline  
post #10 of 18 Old 09-25-12, 07:43 PM
HTS Senior Moderator
 
fusseli's Avatar
 
Join Date: May 2007
Location: Colorado, USA
Posts: 1,921
My System
Re: 4 X Fi IB18's infinite baffle, still deciding?

I'm not sure why you would need to EQ your subs individually, since they are all locallized to more or less the same location... then again four 18" subs really do cover some real estate. Was there are particular justification for EQing individually?


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
fusseli is offline  
Reply

Bookmarks

Tags
baffle , deciding , fi , ib18 , infinite

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