Hello all!
I have been searching forums for some information on this subject, but haven't found exactly the information I am looking for yet.
I am custom residential homebuilder, and I am looking at incorporating plasma televisions and audio in all of my future spec homes. In my earlier years, I installed car audio for a living for approximately 5 years, and was a car audio fanatic from 1985 - 1997 or so. I recently got back into car audio somewhat and am looking at expanding my knowledge to the "home side" to where I can have fun with it and make some profit!
The question of the evening for me has to do with subwoofer cabinets underneath the floor of the listening room. In a spec home, there is no furniture. In the house I am currently framing, I plan on having the plasma mounted over the fireplace mantle and running RBH front/rear/center in-wall/ceiling speakers (most likely the MC line). I would also like to install a sub, but make it stealth, not just have a cabinet sitting in the corner of a room (That would look pretty stupid for a consumer to walk into a spec home and see a sub just sitting in the corner). My question regards subwoofer enclosure attachment to floor joists. I do not have a clue as to how much energy would be transferred to the floor if the subwoofer enclosure was directly attached to the floor studs and vented through the floor via a register. My guess is that it would be a lot, and possibly cause a lot of vibrating/rattling. I have an idea and would like to get some opinions on what I am thinking. My idea is this:
I would build the custom enclosure for the subwoofer of my liking. I would pour a concrete slab in the crawlspace (None of my homes are built on slabs) approximately the size of the speaker cabinet. The small concrete slab would be positioned directly under where the subwoofer is desired to be vented into the room (most likely a corner). I would install masonry block on top of the slab with some treated lumber attached to the top of the masonry blocks via anchor bolts. The cabinet could then be attached to the treated lumber with screws, bolts, etc.. The overall height would be adjusted to give my cabinet a 1/4 - 1/8 inch clearance between the face and the subfloor. I would provide some gasket material to couple the cabinet opening to the subfloor. The subwoofer would be mounted inside the cabinet, and access to the driver would be via a removable end on the cabinet. The driver would vent into the room through a register. In this manner, I feel I would provide sufficient support for the speaker cabinet as well as eliminating virtually any transmission of energy to the floor in the house from the cabinet touching the floor.
I would appreciate any/all comments or constructive criticism regarding this.
Thanks!!
Steve
I have been searching forums for some information on this subject, but haven't found exactly the information I am looking for yet.
I am custom residential homebuilder, and I am looking at incorporating plasma televisions and audio in all of my future spec homes. In my earlier years, I installed car audio for a living for approximately 5 years, and was a car audio fanatic from 1985 - 1997 or so. I recently got back into car audio somewhat and am looking at expanding my knowledge to the "home side" to where I can have fun with it and make some profit!
The question of the evening for me has to do with subwoofer cabinets underneath the floor of the listening room. In a spec home, there is no furniture. In the house I am currently framing, I plan on having the plasma mounted over the fireplace mantle and running RBH front/rear/center in-wall/ceiling speakers (most likely the MC line). I would also like to install a sub, but make it stealth, not just have a cabinet sitting in the corner of a room (That would look pretty stupid for a consumer to walk into a spec home and see a sub just sitting in the corner). My question regards subwoofer enclosure attachment to floor joists. I do not have a clue as to how much energy would be transferred to the floor if the subwoofer enclosure was directly attached to the floor studs and vented through the floor via a register. My guess is that it would be a lot, and possibly cause a lot of vibrating/rattling. I have an idea and would like to get some opinions on what I am thinking. My idea is this:
I would build the custom enclosure for the subwoofer of my liking. I would pour a concrete slab in the crawlspace (None of my homes are built on slabs) approximately the size of the speaker cabinet. The small concrete slab would be positioned directly under where the subwoofer is desired to be vented into the room (most likely a corner). I would install masonry block on top of the slab with some treated lumber attached to the top of the masonry blocks via anchor bolts. The cabinet could then be attached to the treated lumber with screws, bolts, etc.. The overall height would be adjusted to give my cabinet a 1/4 - 1/8 inch clearance between the face and the subfloor. I would provide some gasket material to couple the cabinet opening to the subfloor. The subwoofer would be mounted inside the cabinet, and access to the driver would be via a removable end on the cabinet. The driver would vent into the room through a register. In this manner, I feel I would provide sufficient support for the speaker cabinet as well as eliminating virtually any transmission of energy to the floor in the house from the cabinet touching the floor.
I would appreciate any/all comments or constructive criticism regarding this.
Thanks!!
Steve
A simpler option would be to use 2 drivers set up so their mechanical movement cancels, think tripple chamber bandpass box, vented center chamber.
That will remove the majority of mechanical energy transfer to the structure and allow for simpler and cheaper construction.
The sub will shake the floor/walls regardless at certain frequencies/volume just from air pressure.
That will remove the majority of mechanical energy transfer to the structure and allow for simpler and cheaper construction.
The sub will shake the floor/walls regardless at certain frequencies/volume just from air pressure.
This would be the perfect application for an infinite baffle install, have a look here:
http://home.comcast.net/~infinitelybaffled/page2IB-Gallery.html
http://home.comcast.net/~infinitelybaffled/
http://home.comcast.net/~infinitelybaffled/page2IB-IBmanifold.html
It needs more woofers and some EQ, but is unparalleled in terms of sound quality and flexibility. All you need is a small hole venting into the listening room, no sign of the woofers or electronics anywhere.
http://home.comcast.net/~infinitelybaffled/page2IB-Gallery.html
http://home.comcast.net/~infinitelybaffled/
http://home.comcast.net/~infinitelybaffled/page2IB-IBmanifold.html
It needs more woofers and some EQ, but is unparalleled in terms of sound quality and flexibility. All you need is a small hole venting into the listening room, no sign of the woofers or electronics anywhere.
I will agree that IB is probably the BEST way to go, but doing a bandpass enclosure which is vented to the room via registers would also be simple enough. I wouldnt say a concrete slab in the crawlspace would be required, or that it be attached to the floor joists structurally. The most important thing is that the sub radiates the full energy of the frontwave into the listening space and not into the crawlspace. What you do with the backwave can depend on your tates, the woofer(s), and application goals
Steve,
With an IB subwwoofer there's no need to pour a concrete pad or use masonery construction. The rear wave will be absorbed by the crawlspace
If you use a manifold design IB the mechanical vibrations of the drivers themselves are canceled.
However ANY sub regardless of the design, will excite the room it's firing into if the SPL is high enough.
With an IB subwwoofer there's no need to pour a concrete pad or use masonery construction. The rear wave will be absorbed by the crawlspace
If you use a manifold design IB the mechanical vibrations of the drivers themselves are canceled.
However ANY sub regardless of the design, will excite the room it's firing into if the SPL is high enough.
There are many, many crawlspace IB subs, and no there aren't problems with them. Believe me I'd hear about it if there were.
Drivers are designed for use in a car. Temperature swings in a crawlspace are nothing compared to those in a car or attic. Humidity isn't an issue.
BTW, insects don't hangout where there are LFE vibrations.
Drivers are designed for use in a car. Temperature swings in a crawlspace are nothing compared to those in a car or attic. Humidity isn't an issue.
BTW, insects don't hangout where there are LFE vibrations.
yeah, dont worry about temps, humidity, or bugs. i kept my 12" philips sub, in a plywood enclosure, on the dirt under my house for 10 years. no problems. when i moved, the sub ended up in the living room. i ended up getting a 15" audiosource driver for the enclosure, and i boxed in an 8 foot section of floor joist under my new living room for the philips driver. the 15" in the room provides air motion, and the 12" in the floor shakes the house. neat combo!
steve, an alternative is to build in some storage space with the driver in the wall of say a closet, or put in a false wall and use it for some other services.
The guys here are very strongly advocating an IB as its an "ultimate" design, the kind that even audio enthusiasts hear and exclaim "that's the best bass I've heard!" Whether it is worthwhile for you from a practical and business point of view is for you to decide, but for enthusiasts it is worth finding a way to make it work rather than just saying "it's not an option!"
If I were you I'd be asking first "is it worthwhile going IB?" If the answer you come up with is yes, I'd then ask "how can I make it work?"
Why go to 90% of the effort of an IB, if the performance is that of a regular box sub?
The guys here are very strongly advocating an IB as its an "ultimate" design, the kind that even audio enthusiasts hear and exclaim "that's the best bass I've heard!" Whether it is worthwhile for you from a practical and business point of view is for you to decide, but for enthusiasts it is worth finding a way to make it work rather than just saying "it's not an option!"
If I were you I'd be asking first "is it worthwhile going IB?" If the answer you come up with is yes, I'd then ask "how can I make it work?"
Why go to 90% of the effort of an IB, if the performance is that of a regular box sub?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.