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Subwoofer for high end theater.
I have a _fairly_ high end theater room consisting of Thiel CS3.6
fronts, and paradigm surround. I intend to build a subwoofer for the
room that must match up well with the existing speakers. Note that
this is for critical listening also, so the subwoofer will be
completely concealed (and perhaps not used for this purpose). It will
be used mostly for theater purposes.
The room has an elevated floor in the back (7" rise). This part of the
floor is wood frame construction, and I intend to build a the
subwoofer into the floor (vented). The room dimensions are 21 (l) 15
(w) 9.5 (h). The raised floor takes up the back seven feet.
I am looking for just the driver, with perhaps some ready-made
enclosure parameters I can go with. Ideally, I would go with a long,
vented enclosure in the raised area, and vent it where the step comes
up. I can angle the driver to fit it into the 7" floor, and probably
fit up around a 10" or 12" speaker.
Looking briefly on the web, I see Dayton and Peerless and prevalent,
but there must be something a bit better? Anyone with some good ideas.
Thanks,
Todd
fronts, and paradigm surround. I intend to build a subwoofer for the
room that must match up well with the existing speakers. Note that
this is for critical listening also, so the subwoofer will be
completely concealed (and perhaps not used for this purpose). It will
be used mostly for theater purposes.
The room has an elevated floor in the back (7" rise). This part of the
floor is wood frame construction, and I intend to build a the
subwoofer into the floor (vented). The room dimensions are 21 (l) 15
(w) 9.5 (h). The raised floor takes up the back seven feet.
I am looking for just the driver, with perhaps some ready-made
enclosure parameters I can go with. Ideally, I would go with a long,
vented enclosure in the raised area, and vent it where the step comes
up. I can angle the driver to fit it into the 7" floor, and probably
fit up around a 10" or 12" speaker.
Looking briefly on the web, I see Dayton and Peerless and prevalent,
but there must be something a bit better? Anyone with some good ideas.
Thanks,
Todd
Subwoofers are extremely location dependent. Building a driver in will
not be the best idea. Better to buy a complete unit that can me moved
around for the best results.
---MIKE---
>>In the White Mountains of New Hampshire
>> (44° 15' N - Elevation 1580')
not be the best idea. Better to buy a complete unit that can me moved
around for the best results.
---MIKE---
>>In the White Mountains of New Hampshire
>> (44° 15' N - Elevation 1580')
"---MIKE---" <twinmountain@webtv . net > wrote in message
news:fnecqf01hf1@news1.newsguy . com ...
> Subwoofers are extremely location dependent. Building a driver in will
> not be the best idea. Better to buy a complete unit that can me moved
> around for the best results.
But they're only "extremely location dependent" because they're premade. If
you can custom make the speaker/enclosure, then you don't have that concern.
news:fnecqf01hf1@news1.newsguy . com ...
> Subwoofers are extremely location dependent. Building a driver in will
> not be the best idea. Better to buy a complete unit that can me moved
> around for the best results.
But they're only "extremely location dependent" because they're premade. If
you can custom make the speaker/enclosure, then you don't have that concern.
On Sat, 26 Jan 2008 07:30:07 -0800, jeffc wrote
(in article <fnfjlv02nqu@news1.newsguy . com >):
> "---MIKE---" <twinmountain@webtv . net > wrote in message
> news:fnecqf01hf1@news1.newsguy . com ...
>> Subwoofers are extremely location dependent. Building a driver in will
>> not be the best idea. Better to buy a complete unit that can me moved
>> around for the best results.
>
> But they're only "extremely location dependent" because they're premade. If
> you can custom make the speaker/enclosure, then you don't have that concern.
>
I'm sorry, but this is not true (unless I'm misunderstanding you). A home
made sub, without the benefit of some pretty sophisticated measurements (low
frequency spectrum analysis) is much more of a turkey-shoot for a DIYer than
buying a commercial servo'd unit. A proper enclosure is a proper enclosure
and where that enclosure is located in the room is of primary importance if
you are to avoid standing waves at low frequencies. Also, a self-powered,
servo sub (like the SunFire series) is going to have less distortion than a
passive unit where the driver is not part of the low-frequency amp's feedback
circuit.
(in article <fnfjlv02nqu@news1.newsguy . com >):
> "---MIKE---" <twinmountain@webtv . net > wrote in message
> news:fnecqf01hf1@news1.newsguy . com ...
>> Subwoofers are extremely location dependent. Building a driver in will
>> not be the best idea. Better to buy a complete unit that can me moved
>> around for the best results.
>
> But they're only "extremely location dependent" because they're premade. If
> you can custom make the speaker/enclosure, then you don't have that concern.
>
I'm sorry, but this is not true (unless I'm misunderstanding you). A home
made sub, without the benefit of some pretty sophisticated measurements (low
frequency spectrum analysis) is much more of a turkey-shoot for a DIYer than
buying a commercial servo'd unit. A proper enclosure is a proper enclosure
and where that enclosure is located in the room is of primary importance if
you are to avoid standing waves at low frequencies. Also, a self-powered,
servo sub (like the SunFire series) is going to have less distortion than a
passive unit where the driver is not part of the low-frequency amp's feedback
circuit.
"Sonnova" <sonnova@audiosanatorium . com > wrote in message
news:fnh25k0ts2@news4.newsguy . com
> A home made sub, without the
> benefit of some pretty sophisticated measurements (low
> frequency spectrum analysis) is much more of a
> turkey-shoot for a DIYer than buying a commercial servo'd
> unit.
Seems unlikely, provided the home made unit is well-designed. The available
software that you feed Thiel-Small parameters to, and spits out a box
design, gets you about as good of a system as a commercial product, if not
better.
I know a number of professional speaker designers, who have each designed
subwoofers that have been produced and sold by the 100,000's. Their basic
designs are often pretty close to what driver Thiel-small parameters
suggest. The common exception is when space is an important parameter and
they design systems that need appreciable amounts of equalization. They
also often use equalization to get better matching of a specific box/driver
combination to a specific room. But the above is within the realm of things
that diligent amateurs can do for themselves.
Often, the home-made systems results are a far better value because
woodwork, marketing, and shipping costs intrude, while the home-made system
takes advantage of the fact that good-enough woodwork is not rocket science.
As far as servo subwoofers or woofers with loop feedback goes, the fact is
that a good feed-forward design without any feedback loop, can easily
perform on a par with them. This is one of those areas where good practice
for electronics such as loop feedback, does not necessarily give better
results with speakers.
Both well-designed home-made and commercial systems are about equally
difficult to emplace.
> A proper enclosure is a proper enclosure and where
> that enclosure is located in the room is of primary
> importance if you are to avoid standing waves at low
> frequencies.
Actually, the enclosure design is pretty much irrelevant to the problem of
standing waves. This is particularly true for subwoofers, because low
frequency sounds are pretty much non-directional within rooms sized like
common residential listening rooms.
Furthermore, if you have any hopes of avoiding standing waves with a speaker
in a room, don't even bother trying - all is lost before you start. When you
place a speaker the goal is not to avoid standing waves, but rather to get
the best possible combination of standing waves.
Standing waves with speakers in a room are like death and taxes - completely
unavoidable unless your room is an large anechoic chamber. If you had a
listening room that was an anechoic chamber, you'd have other serious
problems.
> Also, a self-powered, servo sub (like the
> SunFire series) is going to have less distortion than a
> passive unit where the driver is not part of the
> low-frequency amp's feedback circuit.
Actually, the Sunfire speakers aren't servod in the conventional sense.
There is no direct sensing of the position, or velocity, or acceleration of
the cone. I've had Sunfire speakers in my hand and they have a voice coil
and that is about that. There's no feedback element on or in the speaker
driver.
The so-called servoing that the Sunfire woofers use is implemented with a
power amp whose response and source impedance is tailored to the
driver/enclosure. That's pretty standard stuff.
news:fnh25k0ts2@news4.newsguy . com
> A home made sub, without the
> benefit of some pretty sophisticated measurements (low
> frequency spectrum analysis) is much more of a
> turkey-shoot for a DIYer than buying a commercial servo'd
> unit.
Seems unlikely, provided the home made unit is well-designed. The available
software that you feed Thiel-Small parameters to, and spits out a box
design, gets you about as good of a system as a commercial product, if not
better.
I know a number of professional speaker designers, who have each designed
subwoofers that have been produced and sold by the 100,000's. Their basic
designs are often pretty close to what driver Thiel-small parameters
suggest. The common exception is when space is an important parameter and
they design systems that need appreciable amounts of equalization. They
also often use equalization to get better matching of a specific box/driver
combination to a specific room. But the above is within the realm of things
that diligent amateurs can do for themselves.
Often, the home-made systems results are a far better value because
woodwork, marketing, and shipping costs intrude, while the home-made system
takes advantage of the fact that good-enough woodwork is not rocket science.
As far as servo subwoofers or woofers with loop feedback goes, the fact is
that a good feed-forward design without any feedback loop, can easily
perform on a par with them. This is one of those areas where good practice
for electronics such as loop feedback, does not necessarily give better
results with speakers.
Both well-designed home-made and commercial systems are about equally
difficult to emplace.
> A proper enclosure is a proper enclosure and where
> that enclosure is located in the room is of primary
> importance if you are to avoid standing waves at low
> frequencies.
Actually, the enclosure design is pretty much irrelevant to the problem of
standing waves. This is particularly true for subwoofers, because low
frequency sounds are pretty much non-directional within rooms sized like
common residential listening rooms.
Furthermore, if you have any hopes of avoiding standing waves with a speaker
in a room, don't even bother trying - all is lost before you start. When you
place a speaker the goal is not to avoid standing waves, but rather to get
the best possible combination of standing waves.
Standing waves with speakers in a room are like death and taxes - completely
unavoidable unless your room is an large anechoic chamber. If you had a
listening room that was an anechoic chamber, you'd have other serious
problems.
> Also, a self-powered, servo sub (like the
> SunFire series) is going to have less distortion than a
> passive unit where the driver is not part of the
> low-frequency amp's feedback circuit.
Actually, the Sunfire speakers aren't servod in the conventional sense.
There is no direct sensing of the position, or velocity, or acceleration of
the cone. I've had Sunfire speakers in my hand and they have a voice coil
and that is about that. There's no feedback element on or in the speaker
driver.
The so-called servoing that the Sunfire woofers use is implemented with a
power amp whose response and source impedance is tailored to the
driver/enclosure. That's pretty standard stuff.
<google@toddandjoanna . com > wrote in message
news:fnds1g02b1q@news3.newsguy . com
> I have a _fairly_ high end theater room consisting of
> Thiel CS3.6 fronts, and paradigm surround. I intend to
> build a subwoofer for the room that must match up well
> with the existing speakers. Note that this is for
> critical listening also, so the subwoofer will be
> completely concealed (and perhaps not used for this
> purpose). It will be used mostly for theater purposes.
>
> The room has an elevated floor in the back (7" rise).
> This part of the floor is wood frame construction, and I
> intend to build a the subwoofer into the floor (vented).
> The room dimensions are 21 (l) 15 (w) 9.5 (h). The raised
> floor takes up the back seven feet.
I have a number of friends who have built subwoofers into the floor of their
listening room.
The general approach is to build a plenum or duct that vents into the room's
floor, preferably near a corner near the rest of the speakers. The woofers
are attached to the plenum. Their rear wave vents into the basement.
> I am looking for just the driver, with perhaps some
> ready-made enclosure parameters I can go with. Ideally, I
> would go with a long, vented enclosure in the raised
> area, and vent it where the step comes up. I can angle
> the driver to fit it into the 7" floor, and probably fit
> up around a 10" or 12" speaker.
> Looking briefly on the web, I see Dayton and Peerless and
> prevalent, but there must be something a bit better?
> Anyone with some good ideas.
This may be the best value quality subwoofer driver around:
w w w .ficaraudio . com
Q18 subwoofer driver.
news:fnds1g02b1q@news3.newsguy . com
> I have a _fairly_ high end theater room consisting of
> Thiel CS3.6 fronts, and paradigm surround. I intend to
> build a subwoofer for the room that must match up well
> with the existing speakers. Note that this is for
> critical listening also, so the subwoofer will be
> completely concealed (and perhaps not used for this
> purpose). It will be used mostly for theater purposes.
>
> The room has an elevated floor in the back (7" rise).
> This part of the floor is wood frame construction, and I
> intend to build a the subwoofer into the floor (vented).
> The room dimensions are 21 (l) 15 (w) 9.5 (h). The raised
> floor takes up the back seven feet.
I have a number of friends who have built subwoofers into the floor of their
listening room.
The general approach is to build a plenum or duct that vents into the room's
floor, preferably near a corner near the rest of the speakers. The woofers
are attached to the plenum. Their rear wave vents into the basement.
> I am looking for just the driver, with perhaps some
> ready-made enclosure parameters I can go with. Ideally, I
> would go with a long, vented enclosure in the raised
> area, and vent it where the step comes up. I can angle
> the driver to fit it into the 7" floor, and probably fit
> up around a 10" or 12" speaker.
> Looking briefly on the web, I see Dayton and Peerless and
> prevalent, but there must be something a bit better?
> Anyone with some good ideas.
This may be the best value quality subwoofer driver around:
w w w .ficaraudio . com
Q18 subwoofer driver.
google@toddandjoanna . com wrote:
> I have a _fairly_ high end theater room consisting of Thiel CS3.6
> fronts, and paradigm surround. I intend to build a subwoofer for the
> room that must match up well with the existing speakers. Note that
> this is for critical listening also, so the subwoofer will be
> completely concealed (and perhaps not used for this purpose). It will
> be used mostly for theater purposes.
>
> The room has an elevated floor in the back (7" rise). This part of the
> floor is wood frame construction, and I intend to build a the
> subwoofer into the floor (vented). The room dimensions are 21 (l) 15
> (w) 9.5 (h). The raised floor takes up the back seven feet.
>
> I am looking for just the driver, with perhaps some ready-made
> enclosure parameters I can go with. Ideally, I would go with a long,
> vented enclosure in the raised area, and vent it where the step comes
> up. I can angle the driver to fit it into the 7" floor, and probably
> fit up around a 10" or 12" speaker.
>
> Looking briefly on the web, I see Dayton and Peerless and prevalent,
> but there must be something a bit better? Anyone with some good ideas.
1st, i suggest you not spend your time
building a subwoofer
i mean, modifying is one thing, but
building it from scratch (even as a kit)
doesn't add up, at least not for me
2nd, run *two* subwoofers coz it gives
fewer problems with standing waves; see:
w w w .harman . com /wp/pdf/multsubs.pdf
i myself have two Martin Logan Dynamos placed
front center and back center, which are
surprisingly small (and therefore manageable
in just about any room), yet put out a decent
amount of sound in the 10-to-100 cycle range.
they have 5 different subs, of which the Dynamos
are both the least expensive subs ($600 each)
*and* smallest. see: w w w .martinlogan . com
fwiw, my Dynamos do not have a remote. but to
tell the truth i've discovered that it's really
not needed. it was easy enough to place a
conveniently located on/off (surge protector)
for the rear sub's on/off
if you're concerned about volume ability,
given your room size, go with either M.L.
top end unit (but it's heavy), or the 2nd
one down (which is more reasonable on weight)
bill
> I have a _fairly_ high end theater room consisting of Thiel CS3.6
> fronts, and paradigm surround. I intend to build a subwoofer for the
> room that must match up well with the existing speakers. Note that
> this is for critical listening also, so the subwoofer will be
> completely concealed (and perhaps not used for this purpose). It will
> be used mostly for theater purposes.
>
> The room has an elevated floor in the back (7" rise). This part of the
> floor is wood frame construction, and I intend to build a the
> subwoofer into the floor (vented). The room dimensions are 21 (l) 15
> (w) 9.5 (h). The raised floor takes up the back seven feet.
>
> I am looking for just the driver, with perhaps some ready-made
> enclosure parameters I can go with. Ideally, I would go with a long,
> vented enclosure in the raised area, and vent it where the step comes
> up. I can angle the driver to fit it into the 7" floor, and probably
> fit up around a 10" or 12" speaker.
>
> Looking briefly on the web, I see Dayton and Peerless and prevalent,
> but there must be something a bit better? Anyone with some good ideas.
1st, i suggest you not spend your time
building a subwoofer
i mean, modifying is one thing, but
building it from scratch (even as a kit)
doesn't add up, at least not for me
2nd, run *two* subwoofers coz it gives
fewer problems with standing waves; see:
w w w .harman . com /wp/pdf/multsubs.pdf
i myself have two Martin Logan Dynamos placed
front center and back center, which are
surprisingly small (and therefore manageable
in just about any room), yet put out a decent
amount of sound in the 10-to-100 cycle range.
they have 5 different subs, of which the Dynamos
are both the least expensive subs ($600 each)
*and* smallest. see: w w w .martinlogan . com
fwiw, my Dynamos do not have a remote. but to
tell the truth i've discovered that it's really
not needed. it was easy enough to place a
conveniently located on/off (surge protector)
for the rear sub's on/off
if you're concerned about volume ability,
given your room size, go with either M.L.
top end unit (but it's heavy), or the 2nd
one down (which is more reasonable on weight)
bill
On Sat, 26 Jan 2008 07:43:58 -0800, willbill wrote
(in article <fnfkfu02ojr@news1.newsguy . com >):
> google@toddandjoanna . com wrote:
>
>> I have a _fairly_ high end theater room consisting of Thiel CS3.6
>> fronts, and paradigm surround. I intend to build a subwoofer for the
>> room that must match up well with the existing speakers. Note that
>> this is for critical listening also, so the subwoofer will be
>> completely concealed (and perhaps not used for this purpose). It will
>> be used mostly for theater purposes.
>>
>> The room has an elevated floor in the back (7" rise). This part of the
>> floor is wood frame construction, and I intend to build a the
>> subwoofer into the floor (vented). The room dimensions are 21 (l) 15
>> (w) 9.5 (h). The raised floor takes up the back seven feet.
>>
>> I am looking for just the driver, with perhaps some ready-made
>> enclosure parameters I can go with. Ideally, I would go with a long,
>> vented enclosure in the raised area, and vent it where the step comes
>> up. I can angle the driver to fit it into the 7" floor, and probably
>> fit up around a 10" or 12" speaker.
>>
>> Looking briefly on the web, I see Dayton and Peerless and prevalent,
>> but there must be something a bit better? Anyone with some good ideas.
>
> 1st, i suggest you not spend your time
> building a subwoofer
>
> i mean, modifying is one thing, but
> building it from scratch (even as a kit)
> doesn't add up, at least not for me
>
> 2nd, run *two* subwoofers coz it gives
> fewer problems with standing waves; see:
> w w w .harman . com /wp/pdf/multsubs.pdf
>
> i myself have two Martin Logan Dynamos placed
> front center and back center, which are
> surprisingly small (and therefore manageable
> in just about any room), yet put out a decent
> amount of sound in the 10-to-100 cycle range.
> they have 5 different subs, of which the Dynamos
> are both the least expensive subs ($600 each)
> *and* smallest. see: w w w .martinlogan . com
>
> fwiw, my Dynamos do not have a remote. but to
> tell the truth i've discovered that it's really
> not needed. it was easy enough to place a
> conveniently located on/off (surge protector)
> for the rear sub's on/off
>
> if you're concerned about volume ability,
> given your room size, go with either M.L.
> top end unit (but it's heavy), or the 2nd
> one down (which is more reasonable on weight)
>
> bill
Also. most commercial, powered subs are "servo'd" (the speaker cone itself is
part of the feedback loop of the driving amp). This gives bass with less
distortion. Also unless one is equipped to make some pretty fancy
measurements, It's difficult to know where the proper place in the floor is
to cut-out for a subwoofer in order to minimize standing-waves.
(in article <fnfkfu02ojr@news1.newsguy . com >):
> google@toddandjoanna . com wrote:
>
>> I have a _fairly_ high end theater room consisting of Thiel CS3.6
>> fronts, and paradigm surround. I intend to build a subwoofer for the
>> room that must match up well with the existing speakers. Note that
>> this is for critical listening also, so the subwoofer will be
>> completely concealed (and perhaps not used for this purpose). It will
>> be used mostly for theater purposes.
>>
>> The room has an elevated floor in the back (7" rise). This part of the
>> floor is wood frame construction, and I intend to build a the
>> subwoofer into the floor (vented). The room dimensions are 21 (l) 15
>> (w) 9.5 (h). The raised floor takes up the back seven feet.
>>
>> I am looking for just the driver, with perhaps some ready-made
>> enclosure parameters I can go with. Ideally, I would go with a long,
>> vented enclosure in the raised area, and vent it where the step comes
>> up. I can angle the driver to fit it into the 7" floor, and probably
>> fit up around a 10" or 12" speaker.
>>
>> Looking briefly on the web, I see Dayton and Peerless and prevalent,
>> but there must be something a bit better? Anyone with some good ideas.
>
> 1st, i suggest you not spend your time
> building a subwoofer
>
> i mean, modifying is one thing, but
> building it from scratch (even as a kit)
> doesn't add up, at least not for me
>
> 2nd, run *two* subwoofers coz it gives
> fewer problems with standing waves; see:
> w w w .harman . com /wp/pdf/multsubs.pdf
>
> i myself have two Martin Logan Dynamos placed
> front center and back center, which are
> surprisingly small (and therefore manageable
> in just about any room), yet put out a decent
> amount of sound in the 10-to-100 cycle range.
> they have 5 different subs, of which the Dynamos
> are both the least expensive subs ($600 each)
> *and* smallest. see: w w w .martinlogan . com
>
> fwiw, my Dynamos do not have a remote. but to
> tell the truth i've discovered that it's really
> not needed. it was easy enough to place a
> conveniently located on/off (surge protector)
> for the rear sub's on/off
>
> if you're concerned about volume ability,
> given your room size, go with either M.L.
> top end unit (but it's heavy), or the 2nd
> one down (which is more reasonable on weight)
>
> bill
Also. most commercial, powered subs are "servo'd" (the speaker cone itself is
part of the feedback loop of the driving amp). This gives bass with less
distortion. Also unless one is equipped to make some pretty fancy
measurements, It's difficult to know where the proper place in the floor is
to cut-out for a subwoofer in order to minimize standing-waves.
"Sonnova" <sonnova@audiosanatorium . com > wrote in message
news:fnh2320tov@news4.newsguy . com
> Also. most commercial, powered subs are "servo'd" (the
> speaker cone itself is part of the feedback loop of the
> driving amp).
Actually, there's no way to keep the speaker cone from being closely related
to the feedback circuitry in the power amp, except maybe have a voice coil
with an impractically large DC resistance that swamps out the impedance
variations of the driver due to cone motion.
> This gives bass with less distortion.
The strongest determiner of distortion in a subwoofer driver is Xmax. If the
driver lacks sufficient Xmax that in combination with cone area pumps the
necessary volumes of air, there's no amount of anything else, particularly
feedback, that will help you avoid audible distortion.
> Also unless one is equipped to make some pretty fancy
> measurements, It's difficult to know where the proper
> place in the floor is to cut-out for a subwoofer in order
> to minimize standing-waves.
Actually the place to put the cutout is pretty easy to figure. You need to
put it near the regular speakers, and either in a corner, or along the wall.
news:fnh2320tov@news4.newsguy . com
> Also. most commercial, powered subs are "servo'd" (the
> speaker cone itself is part of the feedback loop of the
> driving amp).
Actually, there's no way to keep the speaker cone from being closely related
to the feedback circuitry in the power amp, except maybe have a voice coil
with an impractically large DC resistance that swamps out the impedance
variations of the driver due to cone motion.
> This gives bass with less distortion.
The strongest determiner of distortion in a subwoofer driver is Xmax. If the
driver lacks sufficient Xmax that in combination with cone area pumps the
necessary volumes of air, there's no amount of anything else, particularly
feedback, that will help you avoid audible distortion.
> Also unless one is equipped to make some pretty fancy
> measurements, It's difficult to know where the proper
> place in the floor is to cut-out for a subwoofer in order
> to minimize standing-waves.
Actually the place to put the cutout is pretty easy to figure. You need to
put it near the regular speakers, and either in a corner, or along the wall.
On Sun, 27 Jan 2008 07:31:30 -0800, Arny Krueger wrote
(in article <fni84i010c0@news1.newsguy . com >):
> "Sonnova" <sonnova@audiosanatorium . com > wrote in message
> news:fnh2320tov@news4.newsguy . com
>
>> Also. most commercial, powered subs are "servo'd" (the
>> speaker cone itself is part of the feedback loop of the
>> driving amp).
>
> Actually, there's no way to keep the speaker cone from being closely related
> to the feedback circuitry in the power amp, except maybe have a voice coil
> with an impractically large DC resistance that swamps out the impedance
> variations of the driver due to cone motion.
>
>> This gives bass with less distortion.
>
> The strongest determiner of distortion in a subwoofer driver is Xmax. If the
> driver lacks sufficient Xmax that in combination with cone area pumps the
> necessary volumes of air, there's no amount of anything else, particularly
> feedback, that will help you avoid audible distortion.
>
>> Also unless one is equipped to make some pretty fancy
>> measurements, It's difficult to know where the proper
>> place in the floor is to cut-out for a subwoofer in order
>> to minimize standing-waves.
>
> Actually the place to put the cutout is pretty easy to figure. You need to
> put it near the regular speakers, and either in a corner, or along the wall.
>
Every one I've ever heard was tubby or wooly and totally disconnected
(sound-wise) from the main speakers. I've put that down to improper
placement. I know that standing waves cannot be eliminated in most rooms, but
with careful placement (arrived at empirically by moving said sub(s) around.
Obviously, this only works with subs in enclosures - unless, of course, one
wants to cut 11" holes all over one's floor! :->) one can certainly minimize
their impact on the sound of the system somewhat.
(in article <fni84i010c0@news1.newsguy . com >):
> "Sonnova" <sonnova@audiosanatorium . com > wrote in message
> news:fnh2320tov@news4.newsguy . com
>
>> Also. most commercial, powered subs are "servo'd" (the
>> speaker cone itself is part of the feedback loop of the
>> driving amp).
>
> Actually, there's no way to keep the speaker cone from being closely related
> to the feedback circuitry in the power amp, except maybe have a voice coil
> with an impractically large DC resistance that swamps out the impedance
> variations of the driver due to cone motion.
>
>> This gives bass with less distortion.
>
> The strongest determiner of distortion in a subwoofer driver is Xmax. If the
> driver lacks sufficient Xmax that in combination with cone area pumps the
> necessary volumes of air, there's no amount of anything else, particularly
> feedback, that will help you avoid audible distortion.
>
>> Also unless one is equipped to make some pretty fancy
>> measurements, It's difficult to know where the proper
>> place in the floor is to cut-out for a subwoofer in order
>> to minimize standing-waves.
>
> Actually the place to put the cutout is pretty easy to figure. You need to
> put it near the regular speakers, and either in a corner, or along the wall.
>
Every one I've ever heard was tubby or wooly and totally disconnected
(sound-wise) from the main speakers. I've put that down to improper
placement. I know that standing waves cannot be eliminated in most rooms, but
with careful placement (arrived at empirically by moving said sub(s) around.
Obviously, this only works with subs in enclosures - unless, of course, one
wants to cut 11" holes all over one's floor! :->) one can certainly minimize
their impact on the sound of the system somewhat.
"Sonnova" <sonnova@audiosanatorium . com > wrote in message
news:fnlojv010h3@news2.newsguy . com
> On Sun, 27 Jan 2008 07:31:30 -0800, Arny Krueger wrote
> (in article <fni84i010c0@news1.newsguy . com >):
>
>> "Sonnova" <sonnova@audiosanatorium . com > wrote in message
>> news:fnh2320tov@news4.newsguy . com
>>
>>> Also. most commercial, powered subs are "servo'd" (the
>>> speaker cone itself is part of the feedback loop of the
>>> driving amp).
>>
>> Actually, there's no way to keep the speaker cone from
>> being closely related to the feedback circuitry in the
>> power amp, except maybe have a voice coil with an
>> impractically large DC resistance that swamps out the
>> impedance variations of the driver due to cone motion.
>>
>>> This gives bass with less distortion.
>>
>> The strongest determiner of distortion in a subwoofer
>> driver is Xmax. If the driver lacks sufficient Xmax that
>> in combination with cone area pumps the necessary
>> volumes of air, there's no amount of anything else,
>> particularly feedback, that will help you avoid audible
>> distortion.
>>
>>> Also unless one is equipped to make some pretty fancy
>>> measurements, It's difficult to know where the proper
>>> place in the floor is to cut-out for a subwoofer in
>>> order to minimize standing-waves.
>>
>> Actually the place to put the cutout is pretty easy to
>> figure. You need to put it near the regular speakers,
>> and either in a corner, or along the wall.
>>
>
> Every one I've ever heard was tubby or wooly and totally
> disconnected (sound-wise) from the main speakers.
The systems I heard were all set up by pros. They all knew how to spell
*equalizer*, None were tubby or wooly. Some used measurement mics, some just
used their ears. But, they were well-educated ears.
> I've put that down to improper placement.
One valid strategy for positioning subs is to put them where the deep bass
is strongest, and then equalize to taste. It is far easier to tame peaks
with an equalizer, than it is to fill in nulls.
news:fnlojv010h3@news2.newsguy . com
> On Sun, 27 Jan 2008 07:31:30 -0800, Arny Krueger wrote
> (in article <fni84i010c0@news1.newsguy . com >):
>
>> "Sonnova" <sonnova@audiosanatorium . com > wrote in message
>> news:fnh2320tov@news4.newsguy . com
>>
>>> Also. most commercial, powered subs are "servo'd" (the
>>> speaker cone itself is part of the feedback loop of the
>>> driving amp).
>>
>> Actually, there's no way to keep the speaker cone from
>> being closely related to the feedback circuitry in the
>> power amp, except maybe have a voice coil with an
>> impractically large DC resistance that swamps out the
>> impedance variations of the driver due to cone motion.
>>
>>> This gives bass with less distortion.
>>
>> The strongest determiner of distortion in a subwoofer
>> driver is Xmax. If the driver lacks sufficient Xmax that
>> in combination with cone area pumps the necessary
>> volumes of air, there's no amount of anything else,
>> particularly feedback, that will help you avoid audible
>> distortion.
>>
>>> Also unless one is equipped to make some pretty fancy
>>> measurements, It's difficult to know where the proper
>>> place in the floor is to cut-out for a subwoofer in
>>> order to minimize standing-waves.
>>
>> Actually the place to put the cutout is pretty easy to
>> figure. You need to put it near the regular speakers,
>> and either in a corner, or along the wall.
>>
>
> Every one I've ever heard was tubby or wooly and totally
> disconnected (sound-wise) from the main speakers.
The systems I heard were all set up by pros. They all knew how to spell
*equalizer*, None were tubby or wooly. Some used measurement mics, some just
used their ears. But, they were well-educated ears.
> I've put that down to improper placement.
One valid strategy for positioning subs is to put them where the deep bass
is strongest, and then equalize to taste. It is far easier to tame peaks
with an equalizer, than it is to fill in nulls.
On Jan 28, 3:31 pm, Sonnova <sonn...@audiosanatorium . com > wrote:
> On Sun, 27 Jan 2008 07:31:30 -0800, Arny Krueger wrote
> (in article <fni84i01...@news1.newsguy . com >):
>
>
>
> > "Sonnova" <sonn...@audiosanatorium . com > wrote in message
> >news:fnh2320tov@news4.newsguy . com
>
> >> Also. most commercial, powered subs are "servo'd" (the
> >> speaker cone itself is part of the feedback loop of the
> >> driving amp).
>
> > Actually, there's no way to keep the speaker cone from being closely related
> > to the feedback circuitry in the power amp, except maybe have a voice coil
> > with an impractically large DC resistance that swamps out the impedance
> > variations of the driver due to cone motion.
>
> >> This gives bass with less distortion.
>
> > The strongest determiner of distortion in a subwoofer driver is Xmax. If the
> > driver lacks sufficient Xmax that in combination with cone area pumps the
> > necessary volumes of air, there's no amount of anything else, particularly
> > feedback, that will help you avoid audible distortion.
>
> >> Also unless one is equipped to make some pretty fancy
> >> measurements, It's difficult to know where the proper
> >> place in the floor is to cut-out for a subwoofer in order
> >> to minimize standing-waves.
>
> > Actually the place to put the cutout is pretty easy to figure. You need to
> > put it near the regular speakers, and either in a corner, or along the wall.
>
> Every one I've ever heard was tubby or wooly and totally disconnected
> (sound-wise) from the main speakers. I've put that down to improper
> placement. I know that standing waves cannot be eliminated in most rooms, but
> with careful placement (arrived at empirically by moving said sub(s) around.
> Obviously, this only works with subs in enclosures - unless, of course, one
> wants to cut 11" holes all over one's floor! :->) one can certainly minimize
> their impact on the sound of the system somewhat.
As expected this somewhat morphs into the age-old argument on sub
placement. I am not necessarily concerned with that. As was stated
earlier, standing waves are something that will always occur. The only
thing you can do is manage them.
This room is of ideal proportions 21 (l) x 15 (w) 9.5 (h). Contrary to
many arguments on getting a sub and moving it around so it sounds the
best - I elect to design it correctly, and live with the results. If
it doesn't sound perfect, but is technically correct as possible, I
will be more than happy. I am not going to move a sub around my room -
I am going to build it it the floor.
Now, I have looked at the modal frequencies in the room. A sub placed
1/3 the length will not reinforce the 1st or 2nd order axial (length)
modes (~26 and 52 Hz). The 'rogue' modes that are reinforced are axial
(height) and tangential, and oblique modes that have a height
component. Of these, the lone axial (height) mode is the only one that
may be an issue (55 Hz). The reinforced tangential and oblique modes
actually may help to fill a 'hole' in the 55 to 73 Hz range. See
snippet:
l w h Hz Type
----------------------
0 0 1 55.0 Axial
1 0 1 60.9 Tangential
2 1 0 63.9 Tangential
0 1 1 66.1 Tangential
1 1 1 71.1 Oblique
0 2 0 73.3 Axial
Finally, I can elect to put the vents virtually anywhere along the
width of the room to accent (or not) the (w) modes.
Now, those that elect to move a sub around the room (after buying it)
I ask you if you are willing to mount it up on the wall if your two
dimensional placement isn't sufficient (or perhaps suspend it mid-
room). Regardless of what you do, moving it around, and placing it at
a different place on the floor will have little affect on the (h) mode
reinforcement. Only proper design can fix this.
Todd
> On Sun, 27 Jan 2008 07:31:30 -0800, Arny Krueger wrote
> (in article <fni84i01...@news1.newsguy . com >):
>
>
>
> > "Sonnova" <sonn...@audiosanatorium . com > wrote in message
> >news:fnh2320tov@news4.newsguy . com
>
> >> Also. most commercial, powered subs are "servo'd" (the
> >> speaker cone itself is part of the feedback loop of the
> >> driving amp).
>
> > Actually, there's no way to keep the speaker cone from being closely related
> > to the feedback circuitry in the power amp, except maybe have a voice coil
> > with an impractically large DC resistance that swamps out the impedance
> > variations of the driver due to cone motion.
>
> >> This gives bass with less distortion.
>
> > The strongest determiner of distortion in a subwoofer driver is Xmax. If the
> > driver lacks sufficient Xmax that in combination with cone area pumps the
> > necessary volumes of air, there's no amount of anything else, particularly
> > feedback, that will help you avoid audible distortion.
>
> >> Also unless one is equipped to make some pretty fancy
> >> measurements, It's difficult to know where the proper
> >> place in the floor is to cut-out for a subwoofer in order
> >> to minimize standing-waves.
>
> > Actually the place to put the cutout is pretty easy to figure. You need to
> > put it near the regular speakers, and either in a corner, or along the wall.
>
> Every one I've ever heard was tubby or wooly and totally disconnected
> (sound-wise) from the main speakers. I've put that down to improper
> placement. I know that standing waves cannot be eliminated in most rooms, but
> with careful placement (arrived at empirically by moving said sub(s) around.
> Obviously, this only works with subs in enclosures - unless, of course, one
> wants to cut 11" holes all over one's floor! :->) one can certainly minimize
> their impact on the sound of the system somewhat.
As expected this somewhat morphs into the age-old argument on sub
placement. I am not necessarily concerned with that. As was stated
earlier, standing waves are something that will always occur. The only
thing you can do is manage them.
This room is of ideal proportions 21 (l) x 15 (w) 9.5 (h). Contrary to
many arguments on getting a sub and moving it around so it sounds the
best - I elect to design it correctly, and live with the results. If
it doesn't sound perfect, but is technically correct as possible, I
will be more than happy. I am not going to move a sub around my room -
I am going to build it it the floor.
Now, I have looked at the modal frequencies in the room. A sub placed
1/3 the length will not reinforce the 1st or 2nd order axial (length)
modes (~26 and 52 Hz). The 'rogue' modes that are reinforced are axial
(height) and tangential, and oblique modes that have a height
component. Of these, the lone axial (height) mode is the only one that
may be an issue (55 Hz). The reinforced tangential and oblique modes
actually may help to fill a 'hole' in the 55 to 73 Hz range. See
snippet:
l w h Hz Type
----------------------
0 0 1 55.0 Axial
1 0 1 60.9 Tangential
2 1 0 63.9 Tangential
0 1 1 66.1 Tangential
1 1 1 71.1 Oblique
0 2 0 73.3 Axial
Finally, I can elect to put the vents virtually anywhere along the
width of the room to accent (or not) the (w) modes.
Now, those that elect to move a sub around the room (after buying it)
I ask you if you are willing to mount it up on the wall if your two
dimensional placement isn't sufficient (or perhaps suspend it mid-
room). Regardless of what you do, moving it around, and placing it at
a different place on the floor will have little affect on the (h) mode
reinforcement. Only proper design can fix this.
Todd
<google@toddandjoanna . com > wrote in message
news:fnds1g02b1q@news3.newsguy . com ...
>I have a _fairly_ high end theater room consisting of Thiel CS3.6
> fronts, and paradigm surround. I intend to build a subwoofer for the
> room that must match up well with the existing speakers. Note that
> this is for critical listening also, so the subwoofer will be
> completely concealed (and perhaps not used for this purpose). It will
> be used mostly for theater purposes.
>
> The room has an elevated floor in the back (7" rise). This part of the
> floor is wood frame construction, and I intend to build a the
> subwoofer into the floor (vented). The room dimensions are 21 (l) 15
> (w) 9.5 (h). The raised floor takes up the back seven feet.
>
> I am looking for just the driver, with perhaps some ready-made
> enclosure parameters I can go with. Ideally, I would go with a long,
> vented enclosure in the raised area, and vent it where the step comes
> up. I can angle the driver to fit it into the 7" floor, and probably
> fit up around a 10" or 12" speaker.
>
> Looking briefly on the web, I see Dayton and Peerless and prevalent,
> but there must be something a bit better? Anyone with some good ideas.
>
> Thanks,
>
> Todd
My equipment is not necessarily "high end" but I thought I'd share something
I learned.
I have both a Rel sub and a Velodyne (think it's a 15") servo type sub. The
Velodyne is very musical and sounds good to my ear with a set of
Martin-Logan SL3's. I've adjusted the crossovers so the Velodyne only
produces those frequencies that the Martin Logans's cannot (typically 15-40
Hz. I barely have the gain setting on the sub turned up.
A couple of years ago I built a home theater room and, based on the
experience with the older Velodyne, I purchased a bigger (18") Digital
Series Velodyne. It turned out that for watching movies with a lot of LFE
effects, the big Velodyne was great, but musically it sounded terrible. It
just didn't have the nice, tight bass that the smaller Velodyne had. The
original "H" something series Velodyne eventually died and I searched for a
replacement but that series had been discontinued. Then, about a year ago
my son found a couple that were brand new, but never sold at some audio
equipment outlet. We each bought one and I am very satisfied with it.
I don't know where Velodyne ranks in the audiophile world, but I think it
sounds great and much better than the Rel.
RCE
news:fnds1g02b1q@news3.newsguy . com ...
>I have a _fairly_ high end theater room consisting of Thiel CS3.6
> fronts, and paradigm surround. I intend to build a subwoofer for the
> room that must match up well with the existing speakers. Note that
> this is for critical listening also, so the subwoofer will be
> completely concealed (and perhaps not used for this purpose). It will
> be used mostly for theater purposes.
>
> The room has an elevated floor in the back (7" rise). This part of the
> floor is wood frame construction, and I intend to build a the
> subwoofer into the floor (vented). The room dimensions are 21 (l) 15
> (w) 9.5 (h). The raised floor takes up the back seven feet.
>
> I am looking for just the driver, with perhaps some ready-made
> enclosure parameters I can go with. Ideally, I would go with a long,
> vented enclosure in the raised area, and vent it where the step comes
> up. I can angle the driver to fit it into the 7" floor, and probably
> fit up around a 10" or 12" speaker.
>
> Looking briefly on the web, I see Dayton and Peerless and prevalent,
> but there must be something a bit better? Anyone with some good ideas.
>
> Thanks,
>
> Todd
My equipment is not necessarily "high end" but I thought I'd share something
I learned.
I have both a Rel sub and a Velodyne (think it's a 15") servo type sub. The
Velodyne is very musical and sounds good to my ear with a set of
Martin-Logan SL3's. I've adjusted the crossovers so the Velodyne only
produces those frequencies that the Martin Logans's cannot (typically 15-40
Hz. I barely have the gain setting on the sub turned up.
A couple of years ago I built a home theater room and, based on the
experience with the older Velodyne, I purchased a bigger (18") Digital
Series Velodyne. It turned out that for watching movies with a lot of LFE
effects, the big Velodyne was great, but musically it sounded terrible. It
just didn't have the nice, tight bass that the smaller Velodyne had. The
original "H" something series Velodyne eventually died and I searched for a
replacement but that series had been discontinued. Then, about a year ago
my son found a couple that were brand new, but never sold at some audio
equipment outlet. We each bought one and I am very satisfied with it.
I don't know where Velodyne ranks in the audiophile world, but I think it
sounds great and much better than the Rel.
RCE
