In-floor subwoofers - 8x8" drivers each, highest WAF factor - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #1 of 13 Old 02-04-19, 07:46 PM Thread Starter
Shackster
 
Will P's Avatar
 
Join Date: Jan 2019
Location: GoldenHorseshoe,Canada
Posts: 17
In-floor subwoofers - 8x8" drivers each, highest WAF factor

I built in-floor sealed subwoofers consisting of 8 x 8" drivers each (Dayton Audio DCS 205-4). Those were the only 8" drivers which I found to fit in the subfloor cavity with a box built around them. Each sub has the cone surface area of 2 x 15" subs and 1 x 15" sub displacement. The drivers were not the reference type but I had to compromise since they were the only ones which would fit. The whole build was designed around the subfloor cavity restriction.
The purpose of the subs was to use them below 40Hz. The box size gives each driver Qtc=0.9, Vb=5 Ltr, , Fb=82Hz .
When the house was still renovated and did not have the drywall installed yet I tested them both with 120Hz x-over at full displacement and they played really loud - I would say around 120dB at 120Hz. The garage floor concrete slab was shaking .
Each subwoofer has 2 boxes - the first one is the "drivers head", the second box is the "cavity box". Assembled total length is 10.5ft, height 9.25", width 14".
The subwoofer boxes are bolted together and have a removable cover for bolts access. They were installed in the basement ceiling - between the floor joists. The boxes are separated from the floor structure and don't transfer vibrations to the house. The drivers are mounted opposed to each other to cancel any vibrations too. The boxes are suspended by multiple metal straps (like a swing cradle). For safety there are aircraft cables spun across the bottom too (not tensioned, slightly loose and taped to the boxes to prevent rattling).
The subwoofer ports are covered with the same covers used for the heating ducts in the house and you can't tell that they are there.
When there was no furniture in the house yet you could feel the floor bending from the air pressure whenever the subs played.
Now when I have them set up below 40Hz they are enough for movie playing. For this open floor plan and the music levels I enjoy occasionally though I would need 4x that displacement. That's why there is another project on the go for few years already - but that's another topic altogether .
Attached Thumbnails
In-floor subwoofers - 8x8" drivers each, highest WAF factor-001.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-002.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-003.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-004.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-005.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-006.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-007.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-008.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-009.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-011.jpg  

Will P is offline  
Sponsored Links
Advertisement
 
post #2 of 13 Old 02-04-19, 07:50 PM Thread Starter
Shackster
 
Will P's Avatar
 
Join Date: Jan 2019
Location: GoldenHorseshoe,Canada
Posts: 17
Re: In-floor subwoofers - 8x8" drivers each, highest WAF factor

More pictures of the build..
Attached Thumbnails
In-floor subwoofers - 8x8" drivers each, highest WAF factor-012.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-014.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-015.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-016.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-017.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-018.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-019.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-020.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-021.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-022.jpg  

Will P is offline  
post #3 of 13 Old 02-04-19, 07:52 PM Thread Starter
Shackster
 
Will P's Avatar
 
Join Date: Jan 2019
Location: GoldenHorseshoe,Canada
Posts: 17
Re: In-floor subwoofers - 8x8" drivers each, highest WAF factor

.. and some more pictures..
Attached Thumbnails
In-floor subwoofers - 8x8" drivers each, highest WAF factor-023.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-024.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-025.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-026.jpg  

In-floor subwoofers - 8x8" drivers each, highest WAF factor-027.jpg  

Will P is offline  
 
post #4 of 13 Old 02-05-19, 07:53 AM
HTS Moderator
Reviewer
 
theJman's Avatar
Jim
 
Join Date: Mar 2012
Location: New Joisey
Posts: 3,260
My System
Re: In-floor subwoofers - 8x8" drivers each, highest WAF factor

That was a very innovative and remarkably well executed solution you created. Impressive work!

-Jim

If you take yourself too seriously, expect me to do the exact opposite
theJman is offline  
post #5 of 13 Old 02-06-19, 07:06 PM
New Member
 
Join Date: Apr 2011
Location: Seattle, WA.
Posts: 2
Re: In-floor subwoofers - 8x8" drivers each, highest WAF factor

Very cool!

Couple of questions:
1. Do you have more detail on the business end of the box? Specifically the port that feeds into the room.
2. What are using to power these?
3. Do you have any drawings of this?

I have seen some other applications of under floor band-pass subs, but yours is pretty elaborate and well made.
jkline is offline  
post #6 of 13 Old 02-06-19, 08:46 PM Thread Starter
Shackster
 
Will P's Avatar
 
Join Date: Jan 2019
Location: GoldenHorseshoe,Canada
Posts: 17
Re: In-floor subwoofers - 8x8" drivers each, highest WAF factor

Here are the in-floor subwoofer design drawings..
I'm using Crown XLS 2500 to power both subs. You can use Crown XLS 1500 too. Plenty of power to drive them both to Xmax.
The combined cone surface per sub equals 21" sub. The excursion is 8mm only though. Displacement equals 15" sub each subwoofer box.
Attached Thumbnails
In-floor subwoofers - 8x8" drivers each, highest WAF factor-subwoofer-floor-subwoofer-box-dimensions-model.jpg  

Attached Files SubwooferBox.pdf (25.4 KB) 
Will P is offline  
post #7 of 13 Old 02-06-19, 08:48 PM Thread Starter
Shackster
 
Will P's Avatar
 
Join Date: Jan 2019
Location: GoldenHorseshoe,Canada
Posts: 17
Re: In-floor subwoofers - 8x8" drivers each, highest WAF factor

The subwoofer port is 10" cavity at the end of the subwoofer with grill mounted on top

Last edited by Will P; 02-06-19 at 08:58 PM.
Will P is offline  
post #8 of 13 Old 02-07-19, 10:50 AM
New Member
 
Join Date: Apr 2011
Location: Seattle, WA.
Posts: 2
Re: In-floor subwoofers - 8x8" drivers each, highest WAF factor

Thanks for sharing!

Last question, how are the 8 drivers wired? Series/parallel or some combination?
jkline is offline  
post #9 of 13 Old 02-07-19, 11:09 AM Thread Starter
Shackster
 
Will P's Avatar
 
Join Date: Jan 2019
Location: GoldenHorseshoe,Canada
Posts: 17
Re: In-floor subwoofers - 8x8" drivers each, highest WAF factor

You can wire them based on you amp power and amp speaker Zmin.
I wired them for 8ohm : (2) parallel groups, each group consist of (4) in series.
Will P is offline  
post #10 of 13 Old 02-09-19, 01:10 AM
New Member
 
Join Date: Feb 2011
Location: Tucson, AZ
Posts: 3
Brilliant concept and fantastic execution! I’m a big proponent of putting tactile transducers in seating risers, so when I saw the title, I had to know the whole story. I’m curious- you seem to have gone to a lot of trouble to decouple these from the floor; did you consider letting them do some “bass shaking”? Or is that a natural side effect even with all the decoupling?

Kudos on a VERY cool idea!
Donny Bahama is offline  
Reply

Bookmarks

Tags
drivers , factor , highest , infloor subwoofers 8x8 , waf

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