Most subwoofer manufacturers recommend corner placement. Seems to me that a 3
sided enclosure would be ideal, yet that's not the norm. Why is that? It's
probably cheaper to make a regular box but with so many high priced subs
available, I doubt that's the reason-

On 30 Sep 2004 00:25:57 GMT, (CCSman) wrote:

Most subwoofer manufacturers recommend corner placement. Seems to me that a 3
sided enclosure would be ideal, yet that's not the norm. Why is that? It's
probably cheaper to make a regular box but with so many high priced subs
available, I doubt that's the reason-

I take it that you actually mean a tetrahedron. Bear in mind however
that with an upperv limit of say 100Hz, one wavelength is about 11
feet, and you'll see that, so long as the driver is within a couple of
feet of the room corner, it doesn't really matter. Hence, a Cube,
which gives you the maximum volume of any recangular enclosure, is an
ideal shape for getting a big driver tucked well into the room corner.
A sphere would be stronger and more voluminous for the same maximum
dimension, but significantly more expensive to build. Note that B&W
have just released a very compact spherical subwoofer, with balanced
drivers.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

(CCSman) wrote:




Most subwoofer manufacturers recommend corner placement. Seems to me that a 3
sided enclosure would be ideal, yet that's not the norm. Why is that? It's
probably cheaper to make a regular box but with so many high priced subs
available, I doubt that's the reason-

Well at subwoofer frequencies the wavelengths are so long that small dimension
changes are not important. Besides square or rectangular enclosures fit into a
corner as tightly as a triangle.

(CCSman) wrote in message ...
Most subwoofer manufacturers recommend corner placement. Seems to me that a 3
sided enclosure would be ideal, yet that's not the norm. Why is that? It's
probably cheaper to make a regular box but with so many high priced subs
available, I doubt that's the reason-

1) By far the easiest and therefore cheapest cabinet to manufacture.
2) Still the most widely seen and there accepted form of cabinet.

So what's the all encompassing reason?
People who make subwoofers for a living want to stay in business and
be able to feed their kids.

From: (CCSman)
Date: 9/29/2004 5:25 PM Pacific Standard Time
Message-id:

Most subwoofer manufacturers recommend corner placement. Seems to me that a 3
sided enclosure would be ideal, yet that's not the norm. Why is that? It's
probably cheaper to make a regular box but with so many high priced subs
available, I doubt that's the reason-







Martin Logan subs are three sided. Ironically, I don't think they recomend
corner placement though.

Cheaper and EASIER!
Takes more cabinetry skill and expense to make triangular enclosures. The
Marti-Logan subs are nice; though not triangular, the design is said (by
them) to decrease distortion.

"CCSman" wrote in message
...
Most subwoofer manufacturers recommend corner placement. Seems to me that
a 3
sided enclosure would be ideal, yet that's not the norm. Why is that?
It's
probably cheaper to make a regular box but with so many high priced subs
available, I doubt that's the reason-

That's the reason. Why would you want to pay more for the same options
unless it is just to save space? Most makers like to keep a range of
product looking similar as well. I never recommend corner placement as
a rule, but it can work in some situations where space is limited or
the xover frequency is very low.
Tannoy actually makes a corner sub and it is triangular. It is also
more expensive than their square options. In a rather neat placement
option, it can be hung at any height on the walls corner, so ceiling
placement is an option if you want the floor space badly. Companies
that shape them in other styles do so to try to appeal to people who
just want something different or feel that it may be superior for some
reason. The best boom for your buck is square man, like L7. It also
has space saving appeal as most rooms are square and so most furniture
follows suit.
-Bill
www.uptownaudio.com
Roanoke VA
(540) 343-1250

"CCSman" wrote in message
...
Most subwoofer manufacturers recommend corner placement. Seems to me
that a 3
sided enclosure would be ideal, yet that's not the norm. Why is
that? It's
probably cheaper to make a regular box but with so many high priced
subs
available, I doubt that's the reason-

Seems to me that a 3
sided enclosure would be ideal...

I am so literal minded that it is a handicap. I can't imagine a three sided
three-dimensional object. I need some help visualizing this, as everything
I visualize has four sides, though I suppose a sphere could be said to have
one side, half a sphere two sides, and so on.

Wylie Williams

Stewart Pinkerton wrote:



On 30 Sep 2004 00:25:57 GMT, (CCSman) wrote:

Most subwoofer manufacturers recommend corner placement. Seems to me that a
3
sided enclosure would be ideal, yet that's not the norm. Why is that? It's
probably cheaper to make a regular box but with so many high priced subs
available, I doubt that's the reason-

I take it that you actually mean a tetrahedron. Bear in mind however
that with an upperv limit of say 100Hz, one wavelength is about 11
feet, and you'll see that, so long as the driver is within a couple of
feet of the room corner, it doesn't really matter. Hence, a Cube,
which gives you the maximum volume of any recangular enclosure, is an
ideal shape for getting a big driver tucked well into the room corner.
A sphere would be stronger and more voluminous for the same maximum
dimension, but significantly more expensive to build. Note that B&W
have just released a very compact spherical subwoofer, with balanced
drivers.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

The "easiest" subwoofer I ever built was a cylinder made of Sonotube (the
cardboard concrete former used on those bridges.) I went to a construction
supply house and had then cut-off a 6.5-foot of 28-inch i.d. Sonotube and
hauled it home strapped atop a '74 Volvo 164.

The actual subwoofer was built in an afternoon and consisted of cutting a pair
of circular end-pieces of which the top-piece had a cut-out for the 18-inch
driver and a pair of 6-inch holes for the vents. The unit was 'finished' with
birled walnut vinyl wrap.

The subwoofer had an internal volume of 25-ft3 was tuned to 12.5 Hz and
produced an honest sub-16 Hz in room and consumed a relatively . Facing up and
shoved as far as possible into a corner the enclosure was within 1.5 feet of
the ceiling and consumed less than 5 ft2 of floor space. While the unit
resisted balloning very well there was quite a bit of bending force along the
length of the tower which could be felt if you wrapped your arms around it
while it was playing.

Lengthwise or circumferential bracing is a fix but one could consider a
2-walled cylinder with a smaller Sonotube placed inside a larger one with
bracing or damping material poured between the two.

Anyway it was a great project; inexpensive, easy to build and better performing
commerical subwoofer product available at that time (1979 I think.)

Uptown Audio wrote:

That's the reason. Why would you want to pay more for the same options
unless it is just to save space? Most makers like to keep a range of
product looking similar as well. I never recommend corner placement as
a rule, but it can work in some situations where space is limited or
the xover frequency is very low.

I've response mapped over a dozen rooms for single subwoofer placement and in
every case with one exception corner placement provided the best response at
the main and up to 2 other listening psoitions what weere actially used in
those rooms.

I was initially surprised but there's a good reason for this. The biggest
in-room subwoofer problem is adequate SPL at low frequencies; but the 2nd
biggest problem is the presence of nulls (or sometimes peaks) in reponse caused
by modal interaction relative to the wavelength of the sound. (20 Hz has a
wvavelength over 50 feet long.)

In a typical room there will only be 5 modes active below 100 Hz and any
location that fails to excite any one of them will leave a hole in response.
The ONLY location that will excite all low frequency modes is a closed-corner
(one with at least 5-6 feet of wall to both sides) meaning that the best
listening position response will be most likely attained with a corner locus.
Response won't be perfect but in most cases it will as smooth as you can get.

Another option is to place the subwoofer close (in the direct field) to the
listener. This is complicated because listening positions tend to be in nulls
and things like suspension and port noises will draw attention of the
subwoofer.


Tannoy actually makes a corner sub and it is triangular. It is also
more expensive than their square options. In a rather neat placement
option, it can be hung at any height on the walls corner, so ceiling
placement is an option if you want the floor space badly.

I've tested the Tannoy tri-angle. It's a nice touch but the subwoofer itself
lacks sufficient displacement to deliver adequate SPL at low frequencies.

Companies
that shape them in other styles do so to try to appeal to people who
just want something different or feel that it may be superior for some
reason. The best boom for your buck is square man, like L7. It also
has space saving appeal as most rooms are square and so most furniture
follows suit.
-Bill
www.uptownaudio.com
Roanoke VA
(540) 343-1250

IMO a tall rectangle is the best floor space saver and an optimal enclosure
shape. I'm surprised that there aren't' more floor standing coat-closet-like or
crystal closet shapes that are made to resemble furniture. Or more subwoofers
made to look like structure such as a corner "column' painted or wallpapered to
match the walls.


"CCSman" wrote in message
...
Most subwoofer manufacturers recommend corner placement. Seems to me
that a 3
sided enclosure would be ideal, yet that's not the norm. Why is
that? It's
probably cheaper to make a regular box but with so many high priced
subs
available, I doubt that's the reason-

(Nousaine) wrote in message ...
Stewart Pinkerton wrote:



On 30 Sep 2004 00:25:57 GMT, (CCSman) wrote:

Most subwoofer manufacturers recommend corner placement. Seems to me that a
3
sided enclosure would be ideal, yet that's not the norm. Why is that? It's
probably cheaper to make a regular box but with so many high priced subs
available, I doubt that's the reason-

I take it that you actually mean a tetrahedron. Bear in mind however
that with an upperv limit of say 100Hz, one wavelength is about 11
feet, and you'll see that, so long as the driver is within a couple of
feet of the room corner, it doesn't really matter. Hence, a Cube,
which gives you the maximum volume of any recangular enclosure, is an
ideal shape for getting a big driver tucked well into the room corner.
A sphere would be stronger and more voluminous for the same maximum
dimension, but significantly more expensive to build. Note that B&W
have just released a very compact spherical subwoofer, with balanced
drivers.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

The "easiest" subwoofer I ever built was a cylinder made of Sonotube (the
cardboard concrete former used on those bridges.) I went to a construction
supply house and had then cut-off a 6.5-foot of 28-inch i.d. Sonotube and
hauled it home strapped atop a '74 Volvo 164.

The actual subwoofer was built in an afternoon and consisted of cutting a pair
of circular end-pieces of which the top-piece had a cut-out for the 18-inch
driver and a pair of 6-inch holes for the vents. The unit was 'finished' with
birled walnut vinyl wrap.

The subwoofer had an internal volume of 25-ft3 was tuned to 12.5 Hz and
produced an honest sub-16 Hz in room and consumed a relatively . Facing up and
shoved as far as possible into a corner the enclosure was within 1.5 feet of
the ceiling and consumed less than 5 ft2 of floor space. While the unit
resisted balloning very well there was quite a bit of bending force along the
length of the tower which could be felt if you wrapped your arms around it
while it was playing.

Lengthwise or circumferential bracing is a fix but one could consider a
2-walled cylinder with a smaller Sonotube placed inside a larger one with
bracing or damping material poured between the two.

Anyway it was a great project; inexpensive, easy to build and better performing
commerical subwoofer product available at that time (1979 I think.)


Now that's what I call a cool project! I guess it would be also
theoretically possible to mount a driver on each end in a similar
project which would cancel some stray mechanical energy.