Stewart Pinkerton wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

Nobody seem to worry about air distortion in spite of using 4:1 or
higher (guesstimated) compression in loading the room, including
distortion due to the asymmetric airload experienced by the drivers (box
with 5 (?) ceiling mounted drivers and small room entry seen on some
site linked to).

Stewart Pinkerton | Music is Art - Audio is Engineering

Seasons greetings, but not to the spammers celebrating with 50% extra
spam to my mailbox :-(


Kind regards, spammers excluded

Peter Larsen

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Stewart Pinkerton wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

Nobody seem to worry about air distortion in spite of using 4:1 or
higher (guesstimated) compression in loading the room, including
distortion due to the asymmetric airload experienced by the drivers (box
with 5 (?) ceiling mounted drivers and small room entry seen on some
site linked to).

Stewart Pinkerton | Music is Art - Audio is Engineering

Seasons greetings, but not to the spammers celebrating with 50% extra
spam to my mailbox :-(


Kind regards, spammers excluded

Peter Larsen

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Stewart Pinkerton wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

Nobody seem to worry about air distortion in spite of using 4:1 or
higher (guesstimated) compression in loading the room, including
distortion due to the asymmetric airload experienced by the drivers (box
with 5 (?) ceiling mounted drivers and small room entry seen on some
site linked to).

Stewart Pinkerton | Music is Art - Audio is Engineering

Seasons greetings, but not to the spammers celebrating with 50% extra
spam to my mailbox :-(


Kind regards, spammers excluded

Peter Larsen

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

"Stewart Pinkerton" wrote in message


On Wed, 24 Dec 2003 17:28:39 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due to
mechanical coupling. IME, ceilings are not so strongly built as
floors!

Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.

That's certainly the logical way to minimise box rattle.

IME it's a working plan. You may see both Nousaine and I referring to a
pair of subwoofers engineered and built by our friend Dave Clark. He went
this route and it just works.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast.

Yup - that was my point. You can certainly do this with an IB, and I
doubt that it does the components much good! :-)

Stewart, I've always thought your comments were dead on but I
think you're blowing this way out of proportion. With a typical
IB setup you'll never hit Xsus. Even if you do it won't damage
the driver.

OK, I'll take your word on that, but voice coils slamming into
backplates (as you yourself describe) doesn't sound like a recipe for
longevity!

Agreed.

For example, I can play Telarc's DVD-A version of Tchaikovsky's
1812 Overture at such volume that I seriously worry my double
sash windows are going to come out the their frames. I'm talking
about pegging the radio shack SPL meter at 126dB before getting
scared and backing off the volume (even with earplugs). Not once
have those 7Hz digital cannons hit Xsus. Now I can hook up a
tone generator and hit Xsus with a 3Hz tone but how realistic is
that? The sub will play several times louder than my mains so
it's a moot point anyway. To get to the SPL numbers above I have
to turn off the main amplifers to keep from toasting the
speakers. Because of the IB's large headroom I can EQ the sub
for flat response from 10Hz up and hit reference levels without
running out of bass.

OK, so long as you're happy with it. Since I need 500 watts into 4
ohms to drive a Tempest fully for my target 115dB at 30-100Hz, I see
no harm in cushioning the driver by using a box sized so that max
power just drops below Xmax from 20Hz down. I'm not wasting any power
'cos it's there anyway, and I protect the drivers from any wayward
infrabass accidents.

The approach that Clark used was along similar lines. The boxes are minimal,
but large enough for the maximum rated driver motor force to stimulate
enough cone motion to meet design goals for low bass.

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".

Yup, I'm familiar with his weapon of house destruction!

Last time I was there the house was still standing and seemed to be
suffering minimal damage. It seems to be a fairly ordinary modern box with
normal to-code wood frame structure and drywall. A tad flimsy compared to
mine, but if I had my druthers...

drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.

Agreed.

Or you can just use the correct size of sealed box and avoid the
problem altogether........

Why? What problem?

Agreed. I've suffered with a subwoofer box the size of a nice freezer chest
in my living room for something like 25 years. In the days when it was
built, 400 wpc was a BIIIIIG amp. Good equalizers were not the everyday
items they are today. Thiel-Small was still fairly new. When I do it all
over again it's gonna be a minimal-sized box. The basement solution is a
non-starter the reinforced-concrete and steel box I live in.

The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.

You can still have the box in the loft space, and a Linkwitz transform
equaliser will give you any alignment you want. A small box doesn't
have to mean a high Qts in 2003/4. I guess I'm just hedging my bets.
Besides, SWMBO doesn't want a hole in the ceiling!

Slits work and are pretty inconspicious. It's all a matter of hydraulics.

You do raise an interesting point, however, as I'm having trouble
running the numbers as to how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

I see several approaches:

Crib details from a working design.

Forget the port and equalize

Build a scale model and then multiply by a suitable integer

"Stewart Pinkerton" wrote in message


On Wed, 24 Dec 2003 17:28:39 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due to
mechanical coupling. IME, ceilings are not so strongly built as
floors!

Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.

That's certainly the logical way to minimise box rattle.

IME it's a working plan. You may see both Nousaine and I referring to a
pair of subwoofers engineered and built by our friend Dave Clark. He went
this route and it just works.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast.

Yup - that was my point. You can certainly do this with an IB, and I
doubt that it does the components much good! :-)

Stewart, I've always thought your comments were dead on but I
think you're blowing this way out of proportion. With a typical
IB setup you'll never hit Xsus. Even if you do it won't damage
the driver.

OK, I'll take your word on that, but voice coils slamming into
backplates (as you yourself describe) doesn't sound like a recipe for
longevity!

Agreed.

For example, I can play Telarc's DVD-A version of Tchaikovsky's
1812 Overture at such volume that I seriously worry my double
sash windows are going to come out the their frames. I'm talking
about pegging the radio shack SPL meter at 126dB before getting
scared and backing off the volume (even with earplugs). Not once
have those 7Hz digital cannons hit Xsus. Now I can hook up a
tone generator and hit Xsus with a 3Hz tone but how realistic is
that? The sub will play several times louder than my mains so
it's a moot point anyway. To get to the SPL numbers above I have
to turn off the main amplifers to keep from toasting the
speakers. Because of the IB's large headroom I can EQ the sub
for flat response from 10Hz up and hit reference levels without
running out of bass.

OK, so long as you're happy with it. Since I need 500 watts into 4
ohms to drive a Tempest fully for my target 115dB at 30-100Hz, I see
no harm in cushioning the driver by using a box sized so that max
power just drops below Xmax from 20Hz down. I'm not wasting any power
'cos it's there anyway, and I protect the drivers from any wayward
infrabass accidents.

The approach that Clark used was along similar lines. The boxes are minimal,
but large enough for the maximum rated driver motor force to stimulate
enough cone motion to meet design goals for low bass.

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".

Yup, I'm familiar with his weapon of house destruction!

Last time I was there the house was still standing and seemed to be
suffering minimal damage. It seems to be a fairly ordinary modern box with
normal to-code wood frame structure and drywall. A tad flimsy compared to
mine, but if I had my druthers...

drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.

Agreed.

Or you can just use the correct size of sealed box and avoid the
problem altogether........

Why? What problem?

Agreed. I've suffered with a subwoofer box the size of a nice freezer chest
in my living room for something like 25 years. In the days when it was
built, 400 wpc was a BIIIIIG amp. Good equalizers were not the everyday
items they are today. Thiel-Small was still fairly new. When I do it all
over again it's gonna be a minimal-sized box. The basement solution is a
non-starter the reinforced-concrete and steel box I live in.

The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.

You can still have the box in the loft space, and a Linkwitz transform
equaliser will give you any alignment you want. A small box doesn't
have to mean a high Qts in 2003/4. I guess I'm just hedging my bets.
Besides, SWMBO doesn't want a hole in the ceiling!

Slits work and are pretty inconspicious. It's all a matter of hydraulics.

You do raise an interesting point, however, as I'm having trouble
running the numbers as to how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

I see several approaches:

Crib details from a working design.

Forget the port and equalize

Build a scale model and then multiply by a suitable integer

"Stewart Pinkerton" wrote in message


On Wed, 24 Dec 2003 17:28:39 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due to
mechanical coupling. IME, ceilings are not so strongly built as
floors!

Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.

That's certainly the logical way to minimise box rattle.

IME it's a working plan. You may see both Nousaine and I referring to a
pair of subwoofers engineered and built by our friend Dave Clark. He went
this route and it just works.

Ultra-long throw 15" drivers such as the Stryke AV15 handle
overdrive quite well. Xmax is 23mm but Xsus is over 30mm. The
suspension is designed to handle overdrive without damage up to
the power rating of the coil. That said, once you hit Xsus
you'll never want to do it again...the aluminum voice coil former
hitting the backplate sounds like a shotgun blast.

Yup - that was my point. You can certainly do this with an IB, and I
doubt that it does the components much good! :-)

Stewart, I've always thought your comments were dead on but I
think you're blowing this way out of proportion. With a typical
IB setup you'll never hit Xsus. Even if you do it won't damage
the driver.

OK, I'll take your word on that, but voice coils slamming into
backplates (as you yourself describe) doesn't sound like a recipe for
longevity!

Agreed.

For example, I can play Telarc's DVD-A version of Tchaikovsky's
1812 Overture at such volume that I seriously worry my double
sash windows are going to come out the their frames. I'm talking
about pegging the radio shack SPL meter at 126dB before getting
scared and backing off the volume (even with earplugs). Not once
have those 7Hz digital cannons hit Xsus. Now I can hook up a
tone generator and hit Xsus with a 3Hz tone but how realistic is
that? The sub will play several times louder than my mains so
it's a moot point anyway. To get to the SPL numbers above I have
to turn off the main amplifers to keep from toasting the
speakers. Because of the IB's large headroom I can EQ the sub
for flat response from 10Hz up and hit reference levels without
running out of bass.

OK, so long as you're happy with it. Since I need 500 watts into 4
ohms to drive a Tempest fully for my target 115dB at 30-100Hz, I see
no harm in cushioning the driver by using a box sized so that max
power just drops below Xmax from 20Hz down. I'm not wasting any power
'cos it's there anyway, and I protect the drivers from any wayward
infrabass accidents.

The approach that Clark used was along similar lines. The boxes are minimal,
but large enough for the maximum rated driver motor force to stimulate
enough cone motion to meet design goals for low bass.

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".

Yup, I'm familiar with his weapon of house destruction!

Last time I was there the house was still standing and seemed to be
suffering minimal damage. It seems to be a fairly ordinary modern box with
normal to-code wood frame structure and drywall. A tad flimsy compared to
mine, but if I had my druthers...

drivers we're talking over 20 liters of displacement at Xsus.
For another $700 you can make it 40 liters. An amp with an 8 Hz
double integrated 3rd-order Butterworth high-pass filter will
essentially eliminate hitting Xsus.

Agreed.

Or you can just use the correct size of sealed box and avoid the
problem altogether........

Why? What problem?

Agreed. I've suffered with a subwoofer box the size of a nice freezer chest
in my living room for something like 25 years. In the days when it was
built, 400 wpc was a BIIIIIG amp. Good equalizers were not the everyday
items they are today. Thiel-Small was still fairly new. When I do it all
over again it's gonna be a minimal-sized box. The basement solution is a
non-starter the reinforced-concrete and steel box I live in.

The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.

You can still have the box in the loft space, and a Linkwitz transform
equaliser will give you any alignment you want. A small box doesn't
have to mean a high Qts in 2003/4. I guess I'm just hedging my bets.
Besides, SWMBO doesn't want a hole in the ceiling!

Slits work and are pretty inconspicious. It's all a matter of hydraulics.

You do raise an interesting point, however, as I'm having trouble
running the numbers as to how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

I see several approaches:

Crib details from a working design.

Forget the port and equalize

Build a scale model and then multiply by a suitable integer

Arny Krueger wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as to how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

I see several approaches:

Crib details from a working design.

Forget the port and equalize

Build a scale model and then multiply by a suitable integer

Horn it.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Arny Krueger wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as to how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

I see several approaches:

Crib details from a working design.

Forget the port and equalize

Build a scale model and then multiply by a suitable integer

Horn it.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Arny Krueger wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as to how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

I see several approaches:

Crib details from a working design.

Forget the port and equalize

Build a scale model and then multiply by a suitable integer

Horn it.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

"Stewart Pinkerton" wrote in message
...
Besides, SWMBO doesn't want a hole in the ceiling!

You do raise an interesting point, however, as I'm having
trouble
running the numbers as tpo how small the hole in the ceiling
can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from
your
own experience?

There are two things to consider. Manifold cross sectional area
and opening size.

In a nutshell, if the manifold's cross sectional area and opening
is less than the driver's summed Sd, then it becomes a bandpass
design with a fairly low tuned low pass filter. Once the Sd/area
rises above about 3:1 you can start getting harmonic distortion.
The opening L:W ratio should be less than about 1.3:1 to keep
slit diffraction from nonlinear loading of the drivers and to
average out internal standing waves.

However, my opening is 16"x16" or only 1/2 the total Sd. It's a
huge hole but my ceiling is 12 feet up and painted black (front
projection theater) so the hole is essentially invisible even
with the lights on. Even at obscene levels I hear no port noise
and it doesn't seem to affect the frequency response or add
harmonics (ECM8000 measurement mic).

One IB forum member is using two 4"x10" HVAC floor vents with two
Dayton 15" drivers due to wife factors. Even without considering
the grill obstruction this is less than 1/3 Sd so would seem bad.
However, he won't stop gushing about how great it is. He has
some pictures of his manifold/vents he
http://users.rcn.com/mjrjunk/

Do you have Thiele Small numbers for the AV15? I might take you
up on
that if I can't source them any other way. As you say,
displacement is
everything at LF.

The AV15s were going for $165 USD during preorder but that's over
and they're now $205. Still a great bargain for IB but a little
more pricey.

http://www.stryke.com/AVseries.html
Fs: 22.39 Hz
Qms: 5.293
Qes: .517
Qts: .471
Vas: 140.1L
2.95 ohm
Z: 4 ohm
(dual 2ohm)
BL: 16.84 Tm
Cms: .143 mm/N
Mms: 353g
Rms: 9.391kg/s
Le: 3.5mH
Pe: 500W cont.
2.83V: 91.15dB
Xmax: 23 mm
Xsus: 30 mm
Sd: 830 sq cm
Vd: 3.8 L

"Stewart Pinkerton" wrote in message
...
Besides, SWMBO doesn't want a hole in the ceiling!

You do raise an interesting point, however, as I'm having
trouble
running the numbers as tpo how small the hole in the ceiling
can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from
your
own experience?

There are two things to consider. Manifold cross sectional area
and opening size.

In a nutshell, if the manifold's cross sectional area and opening
is less than the driver's summed Sd, then it becomes a bandpass
design with a fairly low tuned low pass filter. Once the Sd/area
rises above about 3:1 you can start getting harmonic distortion.
The opening L:W ratio should be less than about 1.3:1 to keep
slit diffraction from nonlinear loading of the drivers and to
average out internal standing waves.

However, my opening is 16"x16" or only 1/2 the total Sd. It's a
huge hole but my ceiling is 12 feet up and painted black (front
projection theater) so the hole is essentially invisible even
with the lights on. Even at obscene levels I hear no port noise
and it doesn't seem to affect the frequency response or add
harmonics (ECM8000 measurement mic).

One IB forum member is using two 4"x10" HVAC floor vents with two
Dayton 15" drivers due to wife factors. Even without considering
the grill obstruction this is less than 1/3 Sd so would seem bad.
However, he won't stop gushing about how great it is. He has
some pictures of his manifold/vents he
http://users.rcn.com/mjrjunk/

Do you have Thiele Small numbers for the AV15? I might take you
up on
that if I can't source them any other way. As you say,
displacement is
everything at LF.

The AV15s were going for $165 USD during preorder but that's over
and they're now $205. Still a great bargain for IB but a little
more pricey.

http://www.stryke.com/AVseries.html
Fs: 22.39 Hz
Qms: 5.293
Qes: .517
Qts: .471
Vas: 140.1L
2.95 ohm
Z: 4 ohm
(dual 2ohm)
BL: 16.84 Tm
Cms: .143 mm/N
Mms: 353g
Rms: 9.391kg/s
Le: 3.5mH
Pe: 500W cont.
2.83V: 91.15dB
Xmax: 23 mm
Xsus: 30 mm
Sd: 830 sq cm
Vd: 3.8 L

"Stewart Pinkerton" wrote in message
...
Besides, SWMBO doesn't want a hole in the ceiling!

You do raise an interesting point, however, as I'm having
trouble
running the numbers as tpo how small the hole in the ceiling
can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from
your
own experience?

There are two things to consider. Manifold cross sectional area
and opening size.

In a nutshell, if the manifold's cross sectional area and opening
is less than the driver's summed Sd, then it becomes a bandpass
design with a fairly low tuned low pass filter. Once the Sd/area
rises above about 3:1 you can start getting harmonic distortion.
The opening L:W ratio should be less than about 1.3:1 to keep
slit diffraction from nonlinear loading of the drivers and to
average out internal standing waves.

However, my opening is 16"x16" or only 1/2 the total Sd. It's a
huge hole but my ceiling is 12 feet up and painted black (front
projection theater) so the hole is essentially invisible even
with the lights on. Even at obscene levels I hear no port noise
and it doesn't seem to affect the frequency response or add
harmonics (ECM8000 measurement mic).

One IB forum member is using two 4"x10" HVAC floor vents with two
Dayton 15" drivers due to wife factors. Even without considering
the grill obstruction this is less than 1/3 Sd so would seem bad.
However, he won't stop gushing about how great it is. He has
some pictures of his manifold/vents he
http://users.rcn.com/mjrjunk/

Do you have Thiele Small numbers for the AV15? I might take you
up on
that if I can't source them any other way. As you say,
displacement is
everything at LF.

The AV15s were going for $165 USD during preorder but that's over
and they're now $205. Still a great bargain for IB but a little
more pricey.

http://www.stryke.com/AVseries.html
Fs: 22.39 Hz
Qms: 5.293
Qes: .517
Qts: .471
Vas: 140.1L
2.95 ohm
Z: 4 ohm
(dual 2ohm)
BL: 16.84 Tm
Cms: .143 mm/N
Mms: 353g
Rms: 9.391kg/s
Le: 3.5mH
Pe: 500W cont.
2.83V: 91.15dB
Xmax: 23 mm
Xsus: 30 mm
Sd: 830 sq cm
Vd: 3.8 L

Arny Krueger wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as to how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

I see several approaches:

Crib details from a working design.

I'd like to, but I don't know where to look!

Forget the port and equalize

That's the most likely scenario - sealed box built into a room corner
and disguised. Mind you, if I can source Stryke AV15s in the UK, I'm
tempted to leave the alloy cones on show!

Build a scale model and then multiply by a suitable integer

Doesn't work - different Reynold's number.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Arny Krueger wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as to how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

I see several approaches:

Crib details from a working design.

I'd like to, but I don't know where to look!

Forget the port and equalize

That's the most likely scenario - sealed box built into a room corner
and disguised. Mind you, if I can source Stryke AV15s in the UK, I'm
tempted to leave the alloy cones on show!

Build a scale model and then multiply by a suitable integer

Doesn't work - different Reynold's number.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Arny Krueger wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as to how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

I see several approaches:

Crib details from a working design.

I'd like to, but I don't know where to look!

Forget the port and equalize

That's the most likely scenario - sealed box built into a room corner
and disguised. Mind you, if I can source Stryke AV15s in the UK, I'm
tempted to leave the alloy cones on show!

Build a scale model and then multiply by a suitable integer

Doesn't work - different Reynold's number.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Thu, 25 Dec 2003 13:32:47 +0100, Peter Larsen
wrote:

Stewart Pinkerton wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

Nobody seem to worry about air distortion in spite of using 4:1 or
higher (guesstimated) compression in loading the room, including
distortion due to the asymmetric airload experienced by the drivers (box
with 5 (?) ceiling mounted drivers and small room entry seen on some
site linked to).

Could you give me a pointer to such a site? It's the idea of a *big*
hole in the ceiling that is caused WAF problems.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Thu, 25 Dec 2003 13:32:47 +0100, Peter Larsen
wrote:

Stewart Pinkerton wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

Nobody seem to worry about air distortion in spite of using 4:1 or
higher (guesstimated) compression in loading the room, including
distortion due to the asymmetric airload experienced by the drivers (box
with 5 (?) ceiling mounted drivers and small room entry seen on some
site linked to).

Could you give me a pointer to such a site? It's the idea of a *big*
hole in the ceiling that is caused WAF problems.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Thu, 25 Dec 2003 13:32:47 +0100, Peter Larsen
wrote:

Stewart Pinkerton wrote:

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

Nobody seem to worry about air distortion in spite of using 4:1 or
higher (guesstimated) compression in loading the room, including
distortion due to the asymmetric airload experienced by the drivers (box
with 5 (?) ceiling mounted drivers and small room entry seen on some
site linked to).

Could you give me a pointer to such a site? It's the idea of a *big*
hole in the ceiling that is caused WAF problems.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Thu, 25 Dec 2003 09:31:58 -0500, "Arny Krueger"
wrote:

"Stewart Pinkerton" wrote in message


On Wed, 24 Dec 2003 17:28:39 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due to
mechanical coupling. IME, ceilings are not so strongly built as
floors!

Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.

That's certainly the logical way to minimise box rattle.

IME it's a working plan. You may see both Nousaine and I referring to a
pair of subwoofers engineered and built by our friend Dave Clark. He went
this route and it just works.

It certainly should work, if you carefully align the driver
centrelines and have the drivers perfectly parallel. I canna' change
the laws o' physics (Newton's 2nd in this case), cap'n! :-)

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".

Yup, I'm familiar with his weapon of house destruction!

Last time I was there the house was still standing and seemed to be
suffering minimal damage. It seems to be a fairly ordinary modern box with
normal to-code wood frame structure and drywall. A tad flimsy compared to
mine, but if I had my druthers...

Yes, I'm expecting very good bass drive, as my room has a concrete
slab floor and 13" brick and block walls. Even the ceiling is heavily
joisted, so it shouldn't absorb *too* much bass, according to LspCAD.

The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.

You can still have the box in the loft space, and a Linkwitz transform
equaliser will give you any alignment you want. A small box doesn't
have to mean a high Qts in 2003/4. I guess I'm just hedging my bets.
Besides, SWMBO doesn't want a hole in the ceiling!

Slits work and are pretty inconspicious. It's all a matter of hydraulics.

Well, pneumatics and aerodynamics, but I know what you mean! :-)

My main concern is to keep the hole close to the room corner, to
maximise 1/8 space gain. OTOH, I can see how a long slit might be
useful in smoothing the response across the room. Decisions,
decisions........................
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Thu, 25 Dec 2003 09:31:58 -0500, "Arny Krueger"
wrote:

"Stewart Pinkerton" wrote in message


On Wed, 24 Dec 2003 17:28:39 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due to
mechanical coupling. IME, ceilings are not so strongly built as
floors!

Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.

That's certainly the logical way to minimise box rattle.

IME it's a working plan. You may see both Nousaine and I referring to a
pair of subwoofers engineered and built by our friend Dave Clark. He went
this route and it just works.

It certainly should work, if you carefully align the driver
centrelines and have the drivers perfectly parallel. I canna' change
the laws o' physics (Newton's 2nd in this case), cap'n! :-)

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".

Yup, I'm familiar with his weapon of house destruction!

Last time I was there the house was still standing and seemed to be
suffering minimal damage. It seems to be a fairly ordinary modern box with
normal to-code wood frame structure and drywall. A tad flimsy compared to
mine, but if I had my druthers...

Yes, I'm expecting very good bass drive, as my room has a concrete
slab floor and 13" brick and block walls. Even the ceiling is heavily
joisted, so it shouldn't absorb *too* much bass, according to LspCAD.

The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.

You can still have the box in the loft space, and a Linkwitz transform
equaliser will give you any alignment you want. A small box doesn't
have to mean a high Qts in 2003/4. I guess I'm just hedging my bets.
Besides, SWMBO doesn't want a hole in the ceiling!

Slits work and are pretty inconspicious. It's all a matter of hydraulics.

Well, pneumatics and aerodynamics, but I know what you mean! :-)

My main concern is to keep the hole close to the room corner, to
maximise 1/8 space gain. OTOH, I can see how a long slit might be
useful in smoothing the response across the room. Decisions,
decisions........................
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Thu, 25 Dec 2003 09:31:58 -0500, "Arny Krueger"
wrote:

"Stewart Pinkerton" wrote in message


On Wed, 24 Dec 2003 17:28:39 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Well, unless you have the box on springs, it will also be due to
mechanical coupling. IME, ceilings are not so strongly built as
floors!

Not so. With identical opposing drivers the mechanical forces
cancel. It's not like a box sub trying to walk it's way across
the floor.

That's certainly the logical way to minimise box rattle.

IME it's a working plan. You may see both Nousaine and I referring to a
pair of subwoofers engineered and built by our friend Dave Clark. He went
this route and it just works.

It certainly should work, if you carefully align the driver
centrelines and have the drivers perfectly parallel. I canna' change
the laws o' physics (Newton's 2nd in this case), cap'n! :-)

Tom Nousaine's IB has eight TC Sounds 15s (23.4mm Xmax) and he
has been unable to test maximum SPL at 10 Hz with a 5000 watt amp
due to his windows not being up to the task. To quote Tom,
"vinyl double windows twist in frame severely".

Yup, I'm familiar with his weapon of house destruction!

Last time I was there the house was still standing and seemed to be
suffering minimal damage. It seems to be a fairly ordinary modern box with
normal to-code wood frame structure and drywall. A tad flimsy compared to
mine, but if I had my druthers...

Yes, I'm expecting very good bass drive, as my room has a concrete
slab floor and 13" brick and block walls. Even the ceiling is heavily
joisted, so it shouldn't absorb *too* much bass, according to LspCAD.

The poor sealed box has the problem due to
lack of displacement. If you're hitting Xsus with an IB then a
typical sealed box would have long since hit it's limit . A
sealed box of Tempests with equivalent displacement requires over
1000 liters for a Butterworth alignment. I'd rather have a small
discrete hole in my ceiling than a massive expensive box in the
room.

You can still have the box in the loft space, and a Linkwitz transform
equaliser will give you any alignment you want. A small box doesn't
have to mean a high Qts in 2003/4. I guess I'm just hedging my bets.
Besides, SWMBO doesn't want a hole in the ceiling!

Slits work and are pretty inconspicious. It's all a matter of hydraulics.

Well, pneumatics and aerodynamics, but I know what you mean! :-)

My main concern is to keep the hole close to the room corner, to
maximise 1/8 space gain. OTOH, I can see how a long slit might be
useful in smoothing the response across the room. Decisions,
decisions........................
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Fri, 26 Dec 2003 02:47:23 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Besides, SWMBO doesn't want a hole in the ceiling!

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

There are two things to consider. Manifold cross sectional area
and opening size.

In a nutshell, if the manifold's cross sectional area and opening
is less than the driver's summed Sd, then it becomes a bandpass
design with a fairly low tuned low pass filter.

Aah! Of course. I'd completely forgotten bandpass principles! Doh!

Once the Sd/area
rises above about 3:1 you can start getting harmonic distortion.
The opening L:W ratio should be less than about 1.3:1 to keep
slit diffraction from nonlinear loading of the drivers and to
average out internal standing waves.

Hmmmm. Not so sure about this one, as there won't be any standing
waves in the 150Hz passband, but I take your point about possible
distortion from pressure loading - that was my main concern.

However, my opening is 16"x16" or only 1/2 the total Sd. It's a
huge hole but my ceiling is 12 feet up and painted black (front
projection theater) so the hole is essentially invisible even
with the lights on. Even at obscene levels I hear no port noise
and it doesn't seem to affect the frequency response or add
harmonics (ECM8000 measurement mic).

Ah, OK. I'd be using a an 11" x 11" hole for that ratio, but it's a
white ceiling 9 feet up, so rather more visible!

One IB forum member is using two 4"x10" HVAC floor vents with two
Dayton 15" drivers due to wife factors. Even without considering
the grill obstruction this is less than 1/3 Sd so would seem bad.
However, he won't stop gushing about how great it is. He has
some pictures of his manifold/vents he
http://users.rcn.com/mjrjunk/

Thanks, that's exactly the kind of thing I was looking for. I'll start
running the numbers again for a 'semi-bandpass' design, but like you
say, that looks like an effective ratio of around 4:1 with the grilles
on. I probably could get away with a couple of large ventilation
grilles, Anne could claim that we've installed air-con! :-)

It does strike me that I'd need to be careful about turbulence noise,
but that's a problem for another day......

Do you have Thiele Small numbers for the AV15? I might take you up on
that if I can't source them any other way. As you say, displacement is
everything at LF.

The AV15s were going for $165 USD during preorder but that's over
and they're now $205. Still a great bargain for IB but a little
more pricey.

http://www.stryke.com/AVseries.html
Fs: 22.39 Hz
Qms: 5.293
Qes: .517
Qts: .471
Vas: 140.1L
2.95 ohm
Z: 4 ohm
(dual 2ohm)
BL: 16.84 Tm
Cms: .143 mm/N
Mms: 353g
Rms: 9.391kg/s
Le: 3.5mH
Pe: 500W cont.
2.83V: 91.15dB
Xmax: 23 mm
Xsus: 30 mm
Sd: 830 sq cm
Vd: 3.8 L

Thanks Rusty, I did find them after trawling the Stryke site. I've
e-mailed them for a quote, as their on-line store implies world-wide
shipping, so we'll see what transpires. I must say that they are the
coolest *looking* drivers around, with those big alloy cones!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Fri, 26 Dec 2003 02:47:23 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Besides, SWMBO doesn't want a hole in the ceiling!

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

There are two things to consider. Manifold cross sectional area
and opening size.

In a nutshell, if the manifold's cross sectional area and opening
is less than the driver's summed Sd, then it becomes a bandpass
design with a fairly low tuned low pass filter.

Aah! Of course. I'd completely forgotten bandpass principles! Doh!

Once the Sd/area
rises above about 3:1 you can start getting harmonic distortion.
The opening L:W ratio should be less than about 1.3:1 to keep
slit diffraction from nonlinear loading of the drivers and to
average out internal standing waves.

Hmmmm. Not so sure about this one, as there won't be any standing
waves in the 150Hz passband, but I take your point about possible
distortion from pressure loading - that was my main concern.

However, my opening is 16"x16" or only 1/2 the total Sd. It's a
huge hole but my ceiling is 12 feet up and painted black (front
projection theater) so the hole is essentially invisible even
with the lights on. Even at obscene levels I hear no port noise
and it doesn't seem to affect the frequency response or add
harmonics (ECM8000 measurement mic).

Ah, OK. I'd be using a an 11" x 11" hole for that ratio, but it's a
white ceiling 9 feet up, so rather more visible!

One IB forum member is using two 4"x10" HVAC floor vents with two
Dayton 15" drivers due to wife factors. Even without considering
the grill obstruction this is less than 1/3 Sd so would seem bad.
However, he won't stop gushing about how great it is. He has
some pictures of his manifold/vents he
http://users.rcn.com/mjrjunk/

Thanks, that's exactly the kind of thing I was looking for. I'll start
running the numbers again for a 'semi-bandpass' design, but like you
say, that looks like an effective ratio of around 4:1 with the grilles
on. I probably could get away with a couple of large ventilation
grilles, Anne could claim that we've installed air-con! :-)

It does strike me that I'd need to be careful about turbulence noise,
but that's a problem for another day......

Do you have Thiele Small numbers for the AV15? I might take you up on
that if I can't source them any other way. As you say, displacement is
everything at LF.

The AV15s were going for $165 USD during preorder but that's over
and they're now $205. Still a great bargain for IB but a little
more pricey.

http://www.stryke.com/AVseries.html
Fs: 22.39 Hz
Qms: 5.293
Qes: .517
Qts: .471
Vas: 140.1L
2.95 ohm
Z: 4 ohm
(dual 2ohm)
BL: 16.84 Tm
Cms: .143 mm/N
Mms: 353g
Rms: 9.391kg/s
Le: 3.5mH
Pe: 500W cont.
2.83V: 91.15dB
Xmax: 23 mm
Xsus: 30 mm
Sd: 830 sq cm
Vd: 3.8 L

Thanks Rusty, I did find them after trawling the Stryke site. I've
e-mailed them for a quote, as their on-line store implies world-wide
shipping, so we'll see what transpires. I must say that they are the
coolest *looking* drivers around, with those big alloy cones!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Fri, 26 Dec 2003 02:47:23 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Besides, SWMBO doesn't want a hole in the ceiling!

You do raise an interesting point, however, as I'm having trouble
running the numbers as tpo how small the hole in the ceiling can be
before it causes problems with either port noise or turning the
manifold into a reflex cabinet. Any advice on that mattter from your
own experience?

There are two things to consider. Manifold cross sectional area
and opening size.

In a nutshell, if the manifold's cross sectional area and opening
is less than the driver's summed Sd, then it becomes a bandpass
design with a fairly low tuned low pass filter.

Aah! Of course. I'd completely forgotten bandpass principles! Doh!

Once the Sd/area
rises above about 3:1 you can start getting harmonic distortion.
The opening L:W ratio should be less than about 1.3:1 to keep
slit diffraction from nonlinear loading of the drivers and to
average out internal standing waves.

Hmmmm. Not so sure about this one, as there won't be any standing
waves in the 150Hz passband, but I take your point about possible
distortion from pressure loading - that was my main concern.

However, my opening is 16"x16" or only 1/2 the total Sd. It's a
huge hole but my ceiling is 12 feet up and painted black (front
projection theater) so the hole is essentially invisible even
with the lights on. Even at obscene levels I hear no port noise
and it doesn't seem to affect the frequency response or add
harmonics (ECM8000 measurement mic).

Ah, OK. I'd be using a an 11" x 11" hole for that ratio, but it's a
white ceiling 9 feet up, so rather more visible!

One IB forum member is using two 4"x10" HVAC floor vents with two
Dayton 15" drivers due to wife factors. Even without considering
the grill obstruction this is less than 1/3 Sd so would seem bad.
However, he won't stop gushing about how great it is. He has
some pictures of his manifold/vents he
http://users.rcn.com/mjrjunk/

Thanks, that's exactly the kind of thing I was looking for. I'll start
running the numbers again for a 'semi-bandpass' design, but like you
say, that looks like an effective ratio of around 4:1 with the grilles
on. I probably could get away with a couple of large ventilation
grilles, Anne could claim that we've installed air-con! :-)

It does strike me that I'd need to be careful about turbulence noise,
but that's a problem for another day......

Do you have Thiele Small numbers for the AV15? I might take you up on
that if I can't source them any other way. As you say, displacement is
everything at LF.

The AV15s were going for $165 USD during preorder but that's over
and they're now $205. Still a great bargain for IB but a little
more pricey.

http://www.stryke.com/AVseries.html
Fs: 22.39 Hz
Qms: 5.293
Qes: .517
Qts: .471
Vas: 140.1L
2.95 ohm
Z: 4 ohm
(dual 2ohm)
BL: 16.84 Tm
Cms: .143 mm/N
Mms: 353g
Rms: 9.391kg/s
Le: 3.5mH
Pe: 500W cont.
2.83V: 91.15dB
Xmax: 23 mm
Xsus: 30 mm
Sd: 830 sq cm
Vd: 3.8 L

Thanks Rusty, I did find them after trawling the Stryke site. I've
e-mailed them for a quote, as their on-line store implies world-wide
shipping, so we'll see what transpires. I must say that they are the
coolest *looking* drivers around, with those big alloy cones!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Stewart Pinkerton wrote:

Nobody seem to worry about air distortion ...

Could you give me a pointer to such a site? It's the idea of a *big*
hole in the ceiling that is caused WAF problems.

http://t-3.cc/users/audioworx/page13-12Shiva1.html

- a subpage of http://www.klone-audio.com/ - 12 large bass units firing
into a box with an estimated 12 by 12 inch opening into the listening
room.

For a more practical implementation of using multiple loudspeakers one
should in my opinion think differently. I would arrange a row of
loudspeakers on the loft in each side of the room and let the sound
enter the room via a long slit near the ceiling/wall junction. It would
still be possible to mount the loudspeakers vertically for longevity
(playing "downwards-sideways" into the slit) and it could be implemented
very discreetly. It will also provide a superiour coupling to the room.

|\
\
speaker(s) here \
playing - \
\
______________| \
- notice the consequence
ceiling ^ w | of too loud music ...
a | the roof must be securely
l | fastened to the building
l | to prevent this .... O;-)


Stewart Pinkerton | Music is Art - Audio is Engineering

Peerless has a 10" sub-bass that looks about right if used in multiples.


Kind regards

Peter Larsen

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Stewart Pinkerton wrote:

Nobody seem to worry about air distortion ...

Could you give me a pointer to such a site? It's the idea of a *big*
hole in the ceiling that is caused WAF problems.

http://t-3.cc/users/audioworx/page13-12Shiva1.html

- a subpage of http://www.klone-audio.com/ - 12 large bass units firing
into a box with an estimated 12 by 12 inch opening into the listening
room.

For a more practical implementation of using multiple loudspeakers one
should in my opinion think differently. I would arrange a row of
loudspeakers on the loft in each side of the room and let the sound
enter the room via a long slit near the ceiling/wall junction. It would
still be possible to mount the loudspeakers vertically for longevity
(playing "downwards-sideways" into the slit) and it could be implemented
very discreetly. It will also provide a superiour coupling to the room.

|\
\
speaker(s) here \
playing - \
\
______________| \
- notice the consequence
ceiling ^ w | of too loud music ...
a | the roof must be securely
l | fastened to the building
l | to prevent this .... O;-)


Stewart Pinkerton | Music is Art - Audio is Engineering

Peerless has a 10" sub-bass that looks about right if used in multiples.


Kind regards

Peter Larsen

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Stewart Pinkerton wrote:

Nobody seem to worry about air distortion ...

Could you give me a pointer to such a site? It's the idea of a *big*
hole in the ceiling that is caused WAF problems.

http://t-3.cc/users/audioworx/page13-12Shiva1.html

- a subpage of http://www.klone-audio.com/ - 12 large bass units firing
into a box with an estimated 12 by 12 inch opening into the listening
room.

For a more practical implementation of using multiple loudspeakers one
should in my opinion think differently. I would arrange a row of
loudspeakers on the loft in each side of the room and let the sound
enter the room via a long slit near the ceiling/wall junction. It would
still be possible to mount the loudspeakers vertically for longevity
(playing "downwards-sideways" into the slit) and it could be implemented
very discreetly. It will also provide a superiour coupling to the room.

|\
\
speaker(s) here \
playing - \
\
______________| \
- notice the consequence
ceiling ^ w | of too loud music ...
a | the roof must be securely
l | fastened to the building
l | to prevent this .... O;-)


Stewart Pinkerton | Music is Art - Audio is Engineering

Peerless has a 10" sub-bass that looks about right if used in multiples.


Kind regards

Peter Larsen

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

"Stewart Pinkerton" wrote in message
...
Thanks Rusty, I did find them after trawling the Stryke site.
I've
e-mailed them for a quote, as their on-line store implies
world-wide
shipping, so we'll see what transpires. I must say that they
are the
coolest *looking* drivers around, with those big alloy cones!

I think the Tumults are more impressive but the AV15s are
certainly awe inspiring! During the first preorder (over a year
ago) the drivers came with a logo on the cone by default. You
may have to specify no logo. Stryke is essentially a one man
shop (John E. Janowitz). I think his wife just had a baby so he
may be somewhat tied up. His phone is 920-469-9198 if all else
fails. There's also a Stryke web forum.
http://forum.stryke.com/

"Stewart Pinkerton" wrote in message
...
Thanks Rusty, I did find them after trawling the Stryke site.
I've
e-mailed them for a quote, as their on-line store implies
world-wide
shipping, so we'll see what transpires. I must say that they
are the
coolest *looking* drivers around, with those big alloy cones!

I think the Tumults are more impressive but the AV15s are
certainly awe inspiring! During the first preorder (over a year
ago) the drivers came with a logo on the cone by default. You
may have to specify no logo. Stryke is essentially a one man
shop (John E. Janowitz). I think his wife just had a baby so he
may be somewhat tied up. His phone is 920-469-9198 if all else
fails. There's also a Stryke web forum.
http://forum.stryke.com/

"Stewart Pinkerton" wrote in message
...
Thanks Rusty, I did find them after trawling the Stryke site.
I've
e-mailed them for a quote, as their on-line store implies
world-wide
shipping, so we'll see what transpires. I must say that they
are the
coolest *looking* drivers around, with those big alloy cones!

I think the Tumults are more impressive but the AV15s are
certainly awe inspiring! During the first preorder (over a year
ago) the drivers came with a logo on the cone by default. You
may have to specify no logo. Stryke is essentially a one man
shop (John E. Janowitz). I think his wife just had a baby so he
may be somewhat tied up. His phone is 920-469-9198 if all else
fails. There's also a Stryke web forum.
http://forum.stryke.com/

"Stewart Pinkerton" wrote in message
...
I'd like to, but I don't know where to look!

Two pages of gallery pictures here with links for construction
info, frequency response measurements, etc.
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

IB faq
https://home.comcast.net/~ttriff/

IB forum with ~22 pages of archives
http://f20.parsimony.net/forum36475/

"Stewart Pinkerton" wrote in message
...
I'd like to, but I don't know where to look!

Two pages of gallery pictures here with links for construction
info, frequency response measurements, etc.
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

IB faq
https://home.comcast.net/~ttriff/

IB forum with ~22 pages of archives
http://f20.parsimony.net/forum36475/

"Stewart Pinkerton" wrote in message
...
I'd like to, but I don't know where to look!

Two pages of gallery pictures here with links for construction
info, frequency response measurements, etc.
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

IB faq
https://home.comcast.net/~ttriff/

IB forum with ~22 pages of archives
http://f20.parsimony.net/forum36475/

On Fri, 26 Dec 2003 16:37:33 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
I'd like to, but I don't know where to look!

Two pages of gallery pictures here with links for construction
info, frequency response measurements, etc.
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

IB faq
https://home.comcast.net/~ttriff/

IB forum with ~22 pages of archives
http://f20.parsimony.net/forum36475/

Thanks for the links Rusty, they have given me lots to think about!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Fri, 26 Dec 2003 16:37:33 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
I'd like to, but I don't know where to look!

Two pages of gallery pictures here with links for construction
info, frequency response measurements, etc.
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

IB faq
https://home.comcast.net/~ttriff/

IB forum with ~22 pages of archives
http://f20.parsimony.net/forum36475/

Thanks for the links Rusty, they have given me lots to think about!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Fri, 26 Dec 2003 16:37:33 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
I'd like to, but I don't know where to look!

Two pages of gallery pictures here with links for construction
info, frequency response measurements, etc.
https://home.comcast.net/~ttriff//page2IB-Gallery.html
https://home.comcast.net/~ttriff//page3IB-Gallery2.html

IB faq
https://home.comcast.net/~ttriff/

IB forum with ~22 pages of archives
http://f20.parsimony.net/forum36475/

Thanks for the links Rusty, they have given me lots to think about!
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Fri, 26 Dec 2003 16:35:18 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Thanks Rusty, I did find them after trawling the Stryke site.
I've
e-mailed them for a quote, as their on-line store implies
world-wide
shipping, so we'll see what transpires. I must say that they
are the
coolest *looking* drivers around, with those big alloy cones!

I think the Tumults are more impressive but the AV15s are
certainly awe inspiring! During the first preorder (over a year
ago) the drivers came with a logo on the cone by default. You
may have to specify no logo. Stryke is essentially a one man
shop (John E. Janowitz). I think his wife just had a baby so he
may be somewhat tied up. His phone is 920-469-9198 if all else
fails. There's also a Stryke web forum.
http://forum.stryke.com/

Thanks for that, Rusty. I must say, the recent discussions on the
Stryke forum are *not* encouraging to a potential purchaser!

I appreciate the problems if he's a 'one man band' and a new dad, but
at the end of the day I'll need products, not promises............
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Fri, 26 Dec 2003 16:35:18 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Thanks Rusty, I did find them after trawling the Stryke site.
I've
e-mailed them for a quote, as their on-line store implies
world-wide
shipping, so we'll see what transpires. I must say that they
are the
coolest *looking* drivers around, with those big alloy cones!

I think the Tumults are more impressive but the AV15s are
certainly awe inspiring! During the first preorder (over a year
ago) the drivers came with a logo on the cone by default. You
may have to specify no logo. Stryke is essentially a one man
shop (John E. Janowitz). I think his wife just had a baby so he
may be somewhat tied up. His phone is 920-469-9198 if all else
fails. There's also a Stryke web forum.
http://forum.stryke.com/

Thanks for that, Rusty. I must say, the recent discussions on the
Stryke forum are *not* encouraging to a potential purchaser!

I appreciate the problems if he's a 'one man band' and a new dad, but
at the end of the day I'll need products, not promises............
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Fri, 26 Dec 2003 16:35:18 -0600, "Rusty Boudreaux"
wrote:

"Stewart Pinkerton" wrote in message
...
Thanks Rusty, I did find them after trawling the Stryke site.
I've
e-mailed them for a quote, as their on-line store implies
world-wide
shipping, so we'll see what transpires. I must say that they
are the
coolest *looking* drivers around, with those big alloy cones!

I think the Tumults are more impressive but the AV15s are
certainly awe inspiring! During the first preorder (over a year
ago) the drivers came with a logo on the cone by default. You
may have to specify no logo. Stryke is essentially a one man
shop (John E. Janowitz). I think his wife just had a baby so he
may be somewhat tied up. His phone is 920-469-9198 if all else
fails. There's also a Stryke web forum.
http://forum.stryke.com/

Thanks for that, Rusty. I must say, the recent discussions on the
Stryke forum are *not* encouraging to a potential purchaser!

I appreciate the problems if he's a 'one man band' and a new dad, but
at the end of the day I'll need products, not promises............
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Fri, 26 Dec 2003 15:17:13 +0100, Peter Larsen
wrote:

Stewart Pinkerton wrote:

Nobody seem to worry about air distortion ...

Could you give me a pointer to such a site? It's the idea of a *big*
hole in the ceiling that is caused WAF problems.

http://t-3.cc/users/audioworx/page13-12Shiva1.html

- a subpage of http://www.klone-audio.com/ - 12 large bass units firing
into a box with an estimated 12 by 12 inch opening into the listening
room.

Very impressive! Especially considering the ratio of driver area to
throat area.

For a more practical implementation of using multiple loudspeakers one
should in my opinion think differently. I would arrange a row of
loudspeakers on the loft in each side of the room and let the sound
enter the room via a long slit near the ceiling/wall junction. It would
still be possible to mount the loudspeakers vertically for longevity
(playing "downwards-sideways" into the slit) and it could be implemented
very discreetly. It will also provide a superiour coupling to the room.

A slit is certainly an option in my room, although I might have to
write my own modelling program! :-(

Peerless has a 10" sub-bass that looks about right if used in multiples.

At the moment, a pair of Adire Tempests looks to be the most likely
solution.
--

Stewart Pinkerton | Music is Art - Audio is Engineering