Fireplace IB Build - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #1 of 11 Old 11-24-15, 01:09 PM Thread Starter
Shackster
 
Join Date: Apr 2011
Location: Western Slope, Colorado
Posts: 5
Fireplace IB Build

Why did I build this? For the exact same reason George Mallory climbed Mt. Everest, "Because it's there." That and maybe because of all the internet know-it-alls who told me it wouldn't work.

"it's" in this case being a nice big old brick fireplace smack dab between in the middle between my two main speakers, hidden and made unusable by my new 60" flatscreen. This build couldn't be easier or cheaper. I used a single JBL 2245h, a sheet of MDF, a 16' roll of metal roof sealant and eight masonry bolts. The flue was left open.

How does it sound? Magnificent! Power is from a bridged BGW 620b, crossover is 24 dB/8ve at 40 Hz. Mains are JBL SVA 1800's. I use it occasionally for movies at fairly low levels, but I mainly I use it for music, most of which is 24 bit downloads.

The chimney is about 30 ft long, so I calculate a fundamental open pipe/closed pipe resonance of around 9 or 10 Hz. which doesn't seem to be a problem as it it's outside the range of most material. There is room for another 18 on the baffle, so if I get upgradeitis, that will be my next move. I screwed the bolts into the mortar between the bricks so it will be easy to remove when I upgrade or sell the house. In the mean time I'm getting the cleanest most satisfying glorious bass I've ever heard in my system or any other, but this is after all, the first and only IB I've ever heard. I can't imagine ever going back to conventional box bass.
Attached Thumbnails
Fireplace IB Build-sub-rotated.jpg  

Fireplace IB Build-20150928_154811.jpg  

Fireplace IB Build-20150923_092656.jpg  

Fireplace IB Build-20150923_182939.jpg  


Last edited by audiomagnate; 11-24-15 at 01:31 PM.
audiomagnate is offline  
Sponsored Links
Advertisement
 
post #2 of 11 Old 11-24-15, 01:31 PM
HTS Moderator
Reviewer
 
theJman's Avatar
Jim
 
Join Date: Mar 2012
Location: New Joisey
Posts: 2,934
My System
Re: Fireplace IB Build

The picture where the TV is showing a burning fire is a classic! Very nicely done.

-Jim

If you take yourself too seriously, expect me to do the exact opposite
theJman is offline  
post #3 of 11 Old 11-24-15, 01:37 PM
Elite Shackster
Quenten
 
Join Date: Jun 2007
Location: Tallahassee, Florida
Posts: 2,434
My System
Re: Fireplace IB Build

+1, very nicely done! The only thing I might add is...you might consider painting the bottom of the MDF black to make it blend with the surroundings. Just a thought.

Last edited by Tonto; 11-25-15 at 05:38 PM.
Tonto is offline  
post #4 of 11 Old 11-24-15, 02:16 PM Thread Starter
Shackster
 
Join Date: Apr 2011
Location: Western Slope, Colorado
Posts: 5
Re: Fireplace IB Build

Quote:
Tonto wrote: View Post
+1, very nicely done! The only thing I might add it you might consider painting the bottom of the MDF black to make it blend with the surroundings. Just a thought.
The had to move the cable box up to get better remote response so it's pretty stealthy back there now, but I need to get around to doing that.

I'm playing Reference Recordings Organ Polychrome 24 bit/176 right now, and it does seem to be working that solo 18 a little close to its Xmax, but boy are we going deep! The room is well damped, fully carpeted and 63 feet long in one dimension, with lots of alcoves, hallway entrances and other irregularities.
Attached Thumbnails
Fireplace IB Build-20151124_140307-1-.jpg  


Last edited by audiomagnate; 11-24-15 at 02:21 PM.
audiomagnate is offline  
post #5 of 11 Old 11-25-15, 12:18 PM
HTS Reviewer
 
Peter Loeser's Avatar
 
Join Date: Aug 2012
Location: Texas
Posts: 1,756
Re: Fireplace IB Build

Quote:
theJman wrote: View Post
The picture where the TV is showing a burning fire is a classic! Very nicely done.
Agreed! Love it!


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.
Peter Loeser is offline  
post #6 of 11 Old 11-25-15, 02:49 PM
Senior Shackster
 
Join Date: Sep 2015
Location: Las Vegas
Posts: 378
My System
Re: Fireplace IB Build

I'd argue that it's technically an Transmission Line and not an IB... but that doesn't mean the idea and its execution don't bring a smile to my face. I love it. I build a partition wall IB (it's a high aspect ratio enclosure at 10x Vas of the 4 drivers, so mine also fails to meet the strictest definition of IB), andI couldn't agree with you more. I'm never boxing a subwoofer again.

I gotta ask though... how does it sound outside your house? Do you have any angry neighbors yet?
DqMcClain is offline  
post #7 of 11 Old 11-25-15, 03:41 PM Thread Starter
Shackster
 
Join Date: Apr 2011
Location: Western Slope, Colorado
Posts: 5
Re: Fireplace IB Build

Quote:
DqMcClain wrote: View Post
I'd argue that it's technically an Transmission Line and not an IB... but that doesn't mean the idea and its execution don't bring a smile to my face. I love it. I build a partition wall IB (it's a high aspect ratio enclosure at 10x Vas of the 4 drivers, so mine also fails to meet the strictest definition of IB), andI couldn't agree with you more. I'm never boxing a subwoofer again.

I gotta ask though... how does it sound outside your house? Do you have any angry neighbors yet?
And I would argue that it behaves nothing like a real transmission line, nor like the speakers that are commonly marketed as transmission line speakers, such as vintage IMF's. A real transmission line, be it acoustic or otherwise, "fools" a wave into not reflecting at the intersection of two dissimilar transmission media, like the wedges in an anechoic chamber fool the sound into the solid wall at the fat end of the wedge. "Transmission line" speakers are really just 1/4 wave resonators that dump the resonance back into the listening room.They do absorb upper frequency information along the way, but that's incidental to their real design function, which is to augment the low end of a speaker. What I have is a 1/4 wave resonator that dumps the resonance and rearward information into the sky. So on the roof it's acting like the bottom half of a misnamed transmission line speaker, but in the room, since there is insignificant back pressure on the driver and virtually all rearward radiation is ducted away, just like in a manifold IB, it's acting like an IB. The 1/4 wave resonance, 8 or 9 Hz, is below even the lowest pipe organ notes, so that's not an issue with music, I know there might be some junk down there in Blu-ray movies, but that's not what I use this for. I've done some sweeps all the way down to 1 Hz, and nothing crazy happens at F1, but it is putting out some serious energy down there as evidenced by some structural creaking down the hall and up the stairs.

I suppose if I went up on the roof with the music playing I would hear something, but it is completely inaudible from the ground, even at very high levels in the house, so that's not an issue. It's doesn't act like the sealed trunk of a competition Civic rolling past your house or in the lane next to you at a stop light, it's a different beast entirely, acoustically speaking. There really are no downsides to this setup, except that I won't be burning any yule logs next month.

Last edited by audiomagnate; 11-26-15 at 12:17 PM.
audiomagnate is offline  
post #8 of 11 Old 12-10-15, 10:32 AM
Shackster
Ronnie
 
Join Date: Feb 2015
Location: Atascocita, TX
Posts: 23
Re: Fireplace IB Build

I have always wanted to build a subwoofer in the space underneath my stairs. It is closed in and wasted space, someday maybe....
ronno1973 is offline  
post #9 of 11 Old 12-10-15, 01:12 PM Thread Starter
Shackster
 
Join Date: Apr 2011
Location: Western Slope, Colorado
Posts: 5
Re: Fireplace IB Build

Quote:
ronno1973 wrote: View Post
I have always wanted to build a subwoofer in the space underneath my stairs. It is closed in and wasted space, someday maybe....
It sounds like you're a few minutes work with a jigsaw away from audio nirvana; go for it!
audiomagnate is offline  
post #10 of 11 Old 12-10-15, 03:02 PM
Senior Shackster
 
Join Date: Sep 2015
Location: Las Vegas
Posts: 378
My System
Re: Fireplace IB Build

Quote:
ronno1973 wrote: View Post
I have always wanted to build a subwoofer in the space underneath my stairs. It is closed in and wasted space, someday maybe....
dooooo iiiiitttt!!!
DqMcClain is offline  
Reply

Bookmarks

Tags
build , fireplace , ib

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









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



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