I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy

"Andy" wrote in message
...

I have 4 speakers in my apartment.
I would like to minimize the vibration transmitted to the floor.
Right now, they are sitting on towels.

This transmitted vibration suggests the speaker cones are
causing the speaker case to vibrate. This suggests poor
design of the speaker case (wasting energy that ought to
have been output through the speakers) but you may not wish
to rehouse the speakers -- just to reduce contact between
the cases and the floor. The cheapest way to do this is
to hang them on wires from the ceiling.

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

On Dec 11, 8:54*am, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy

You could try some foam squares. It would help if you raise the
speakers on stands. Part of the sound transfer will be to the floor
in front of the speaker and raising it will reduce that. Don't expect
much improvement though. Is the room carpeted? The biggest
improvement will be from turning down the volume.

You actually want the speaker to be as rigid as possible for good
sound quality. If the speaker is free to vibrate it muddies the bass.

Andy wrote:

I have 4 speakers in my apartment.
I would like to minimize the vibration transmitted to the floor.

You either have to mount the speakers to heavy base (that you would have
to make yourself, likely out of concrete or stone) or suspend the
speakers from the ceiling so they have no contact with the floor at all.

I've seen custom-made speakers integrated into 100 pound blocks used as
the mounting base. The blocks were made from cement mixed with lead
beads.

I've never seen speakers suspended from the ceiling (so that they're
almost touching the floor) but if you want to isolate the speakers from
the floor - that's what you'd have to do. Use stainless-steel aircraft
cable for that modern look.

On Sat, 11 Dec 2010 05:54:33 -0800 (PST), Andy
wrote:

I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy
Buy those interlocking foam floor tile kits - usually can get 4 2x2
foot for about 10 bux.
Cut to speaker size - stack 2 or 3 deep.

On Sat, 11 Dec 2010 09:25:10 -0500, Home Guy wrote:

Andy wrote:

I have 4 speakers in my apartment.
I would like to minimize the vibration transmitted to the floor.

You either have to mount the speakers to heavy base (that you would have
to make yourself, likely out of concrete or stone) or suspend the
speakers from the ceiling so they have no contact with the floor at all.

I've seen custom-made speakers integrated into 100 pound blocks used as
the mounting base. The blocks were made from cement mixed with lead
beads.

I've never seen speakers suspended from the ceiling (so that they're
almost touching the floor) but if you want to isolate the speakers from
the floor - that's what you'd have to do. Use stainless-steel aircraft
cable for that modern look.
I was going to recommend, somewhat tongue in cheek, that he build a
bigger box and pour concrete in the space between the speeker and the
box.

On 12/11/2010 8:54 AM, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Not a bad start.

You could suspend them.

Or continue with your idea. A sandwich: Low density, high density,
low density, high density, low density...

The low density is what is stopping conductance of the bass. The high
density is what is holding it together. Lost of ways to go about that.
Low density could be air (use spacers or threaded rod/nuts), foam,
corrugated cardboard. High density could be plyood.

Jeff

Look for those "on the cheap" ideas. :-)

Andy

On 12/11/2010 9:46 AM, Jeff Thies wrote:
On 12/11/2010 8:54 AM, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Not a bad start.

You could suspend them.

Or continue with your idea. A sandwich: Low density, high density, low
density, high density, low density...

The low density is what is stopping conductance of the bass. The high
density is what is holding it together. Lost of ways to go about that.
Low density could be air (use spacers or threaded rod/nuts), foam,
corrugated cardboard. High density could be plyood.

Jeff

Look for those "on the cheap" ideas. :-)

Try 4 rolls of TP, one under each speaker corner.

Note to others, We are trying to stop conductance of lows, dense
materials will stop highs, but that is *not* the problem here.

Jeff


Andy

On 12/11/2010 8:54 AM, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy

Set them on heavy duty bubble wrap.

Jeff Thies wrote:

Note to others, We are trying to stop conductance of lows, dense
materials will stop highs, but that is *not* the problem here.

Even if you suspend the speakers from the ceiling, the low frequencies
coming from the speakers will still couple with the room acoustics and
your floor and walls will still probably vibrate almost as much as if
the speakers were in contact with the floor.

Does your speaker setup include a dedicated sub-woofer, or do you have
large, full-range speakers such that you don't need a sub-woofer?

I personally feel that any sound system with a sub-woofer is
sub-standard compared to having 2 or 4 large, full-range speakers. The
use of sub-woofers will almost certainly not accurately reproduce the
sonic content in recorded material - you will get an over-emphasis (to
the point of distortion) of the low frequency content.

Your goal may not be to obtain accurate sound reproduction, but instead
to impress your friends by having a sound system that rattles their
internal organs. I don't know.

Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Well they do sell isolation cones (spikes) for just this purpose, but like
many things audio they are a lot more expensive than they are worth
(especially if you buy the ones with oxygen free metal).

For on the cheap, though, maybe make your own with some bolts and nuts?

Jon

On 12/11/2010 10:22 AM, Home Guy wrote:
Jeff Thies wrote:

Note to others, We are trying to stop conductance of lows, dense
materials will stop highs, but that is *not* the problem here.

Even if you suspend the speakers from the ceiling, the low frequencies
coming from the speakers will still couple with the room acoustics and
your floor and walls will still probably vibrate almost as much as if
the speakers were in contact with the floor.

You are a bright guy, but I don't know how much experience you have with
designing speakers and rooms.

The problem at hand is keeping bass from coupling into the concrete of
the apartment structure.

A speaker is a resonant box, whether it is sealed or ported. That
resonance is designed in to extend the bottom end. This is all
calculated. You make the box as stiff as possible, but there are
reasonable limits (there are sand filled double wall boxes, which is
really off the chart). As a result the box will vibrate, and you don't
want to conduct that into the floor or everyone in the apartment
building will hear that low end rumbling.

The sound coming from the speaker itself will be best contained by
having dense room walls, there is little that can be done for that now.
Some bass will couple into the floor regardless, but this is much weaker
transmission path.



Does your speaker setup include a dedicated sub-woofer, or do you have
large, full-range speakers such that you don't need a sub-woofer?

I personally feel that any sound system with a sub-woofer is
sub-standard compared to having 2 or 4 large, full-range speakers.


Bass has limited directionality, the more so the lower you go. It's a
factor of the wavelength. That is why you can do dedicated sub woofers.
The sound origin does not have to be close as it does for higher
frequencies. Whether people crank up the sub too much is a different
matter. They do.

As far as speaker size, larger diameter speakers develop the sound
much further out. That is why large speakers in cars can be heard from
so far away, but are not that overbearing in the car. Somewhat related
to why bands can never get the bass player to turn down!


Jeff

I've run live sound, built monster touring sound systems, worked as an
engineer in radio, designed high end car audio. Not the most
experienced, but I have a background... currently just a programmer and
out of the biz.

On 12/11/2010 7:54 AM, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy

Don't know the cost of their stuff but you might call them for
expert advice:

http://www.polycrystal.com/pc-mainframe.htm

TDD

On 12/11/2010 8:46 AM, Jeff Thies wrote:
On 12/11/2010 8:54 AM, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Not a bad start.

You could suspend them.

Or continue with your idea. A sandwich: Low density, high density, low
density, high density, low density...

The low density is what is stopping conductance of the bass. The high
density is what is holding it together. Lost of ways to go about that.
Low density could be air (use spacers or threaded rod/nuts), foam,
corrugated cardboard. High density could be plyood.

Jeff

Look for those "on the cheap" ideas. :-)

Andy


Invite friends over, let them lay on the floor put the speakers on their
backs and tell them it's a free massage. :-)

TDD

On 12/11/2010 1:41 PM, Home Guy wrote:
Jeff Thies wrote:

You are a bright guy, but I don't know how much experience you
have with designing speakers and rooms.

Are we talking about having the luxury of designing and building a room
specificially for A/V use,

No.

or are we talking about making do with
what-ever room we have?

Correct me if I'm wrong, but this thread did not seem to be about
"designing speakers and rooms", so I did not say anything on that topic.

The problem at hand is keeping bass from coupling into the concrete
of the apartment structure.

Um, where exactly did the OP (Andy) say that? As far as I can see, he's
made only one post in this thread, and did not give details about the
room's construction.

I'm operating under the assumtion of a single-family dwelling, with
wood-stud / drywall construction.


Right in the first line of the OPs post. Apartment. My assumption is
concrete, because this is a common apartment construction and is a
common problem with that.

My girlfriend has lived in more than one of those, and I've beat on the
door (usually several apartments away) and dealt with this. Having a big
white guy pounding on your door at 1 AM leaves an impression, no matter
who you are!


As a result the box will vibrate, and you don't want to conduct
that into the floor or everyone in the apartment building will
hear that low end rumbling.

Did I say anything to the contrary?

No.

I said that attaching the speakers to a heavy, massive base would reduce
the speaker's ability to transfer low-frequencies into the floor,

There is probably not enough dampening there, isolation is preferable,
and practical. I still think 4 rolls of TP is the best and cheapest
solution.


and I
said that suspending the speakers from the ceiling would do it as well.

Jeff

On Dec 11, 8:54*am, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy


Headphones...

All of the vibrations will be directly transmitted to your head,
bypassing
the floor...

Your neighbors will be grateful...

If you have to ask how to reduce vibrations from speakers within an
apartment you have too much speaker for too little apartment...

~~ Evan

"Home Guy" wrote in message ...

Even if you suspend the speakers from the ceiling, the low frequencies
coming from the speakers will still couple with the room acoustics and
your floor and walls will still probably vibrate almost as much as if
the speakers were in contact with the floor.

This suggests a non-standard physics. The basic complaint is that
the floor vibrates, and we know the speaker cases are in direct contact
with the floor. HG now suggests that if the cases were separated from
the floor by a foot or two of (compressible) air the "floor and walls will
still
probably vibrate almost as much." We should be interested to learn
how this could possibly occur.

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

On 12/11/2010 9:30 AM, wrote:
On Sat, 11 Dec 2010 05:54:33 -0800 (PST), Andy
wrote:

I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy
Buy those interlocking foam floor tile kits - usually can get 4 2x2
foot for about 10 bux.
Cut to speaker size - stack 2 or 3 deep.

Or hit the dumpster behind the appliance store- those 2-inch slabs of
closed-cell foam (NOT the molded styro things) used to pack high-end
heavy electronics, make great vibration dampers. They are designed to
protect expensive stuff in the box, as the semi bounces over chuckholes.
Stack up a bunch of squares cut from those. I'm currently accumulating a
stack at work from an ongoing project, but haven't figured out how to
painlessly get them home yet. Great for carving equipment case liners
out of, and they don't rot away into black crud like the fancy foam kits do.
--
aem sends...

Evan wrote:
On Dec 11, 8:54 am, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy


Headphones...

All of the vibrations will be directly transmitted to your head,
bypassing
the floor...

Your neighbors will be grateful...

If you have to ask how to reduce vibrations from speakers within an
apartment you have too much speaker for too little apartment...

~~ Evan


If a tree falls in the forest and no one is around to hear it, does it
make a sound?
What I'm thinking is some kind of active anti-vibration unit,
http://www.halcyonics.de/active-vibr...tion_products/

On Dec 11, 8:49*am, Jeff Thies wrote:
On 12/11/2010 9:46 AM, Jeff Thies wrote:



On 12/11/2010 8:54 AM, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Not a bad start.

You could suspend them.

Or continue with your idea. A sandwich: Low density, high density, low
density, high density, low density...

The low density is what is stopping conductance of the bass. The high
density is what is holding it together. Lost of ways to go about that.
Low density could be air (use spacers or threaded rod/nuts), foam,
corrugated cardboard. High density could be plyood.

Jeff

Look for those "on the cheap" ideas. :-)

Try 4 rolls of TP, one under each speaker corner.

Note to others, We are trying to stop conductance of lows, dense
materials will stop highs, but that is *not* the problem here.

* *Jeff



Andy

You know, that sounds like a good idea to try.

I could put some fabric around the rolls.
I have some leftover fabric with the U.S. Flag on it.

I may shorten the cardboard tube enuf so it doesn't act as a conduit
for vibration.

Andy

On Dec 11, 9:10*am, Tony Miklos wrote:
On 12/11/2010 8:54 AM, Andy wrote:

I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy

Set them on heavy duty bubble wrap.

Workable, but I have a 7 yr. old grandson who visits. :-)

Andy

On 12/11/2010 6:06 PM, Fat Dumb & Happy wrote:
Evan wrote:
On Dec 11, 8:54 am, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy


Headphones...

All of the vibrations will be directly transmitted to your head,
bypassing
the floor...

Your neighbors will be grateful...

If you have to ask how to reduce vibrations from speakers within an
apartment you have too much speaker for too little apartment...

~~ Evan


If a tree falls in the forest and no one is around to hear it, does it
make a sound?
What I'm thinking is some kind of active anti-vibration unit,
http://www.halcyonics.de/active-vibr...tion_products/

He lives in an apartment, and already said 'cheap'. Doubt high-end
techno-toys are in his budget.

If the neighbors are already hostile, I'd recommend headphones after dark.

--
aem sends...

On Dec 11, 11:34*am, Sjouke Burry
wrote:
Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy

I would do a little experiment first.
Send a friend to the apartment below,with a phone.
Then pick up the speaker(s) off the floor, and check by phone if
that makes any difference.Repeat until sure of the outcome.
If no reduction, isolation from the floor wont do anything.
But if it works well,get a nice 2 inch slab of stiff foamrubber, and put
that under the speaker.

The apartment below me is empty.

Thought of asking the manager to let me test different volume levels
to see what can be heard
on the bottom floor.

Andy

On Dec 11, 12:41*pm, Home Guy wrote:
Jeff Thies wrote:
You are a bright guy, but I don't know how much experience you
have with designing speakers and rooms.

Are we talking about having the luxury of designing and building a room
specificially for A/V use, or are we talking about making do with
what-ever room we have?

Correct me if I'm wrong, but this thread did not seem to be about
"designing speakers and rooms", so I did not say anything on that topic.

The problem at hand is keeping bass from coupling into the concrete
of the apartment structure.

Um, where exactly did the OP (Andy) say that? *As far as I can see, he's
made only one post in this thread, and did not give details about the
room's construction.

I'm operating under the assumtion of a single-family dwelling, with
wood-stud / drywall construction.

As a result the box will vibrate, and you don't want to conduct
that into the floor or everyone in the apartment building will
hear that low end rumbling.

Did I say anything to the contrary?

I said that attaching the speakers to a heavy, massive base would reduce
the speaker's ability to transfer low-frequencies into the floor, and I
said that suspending the speakers from the ceiling would do it as well.

I live in an apartment.

I could try mounting them from the ceiling and have them angled toward
the sweet spot.

I currently have an outdoor antenna mounted 4 inches from the ceiling.

It really doesn't look all that bad. :-)

Andy

On 12/11/2010 6:23 PM, Andy wrote:


I could try mounting them from the ceiling and have them angled toward
the sweet spot.

If they are small enough to do that, do exactly that. It's a more
direct path for the highs and mids, and the corner will boost the bass.

Jeff

On 12/11/2010 6:17 PM, Andy wrote:
On Dec 11, 8:49 am, Jeff wrote:
On 12/11/2010 9:46 AM, Jeff Thies wrote:



On 12/11/2010 8:54 AM, Andy wrote:
I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Not a bad start.

You could suspend them.

Or continue with your idea. A sandwich: Low density, high density, low
density, high density, low density...

The low density is what is stopping conductance of the bass. The high
density is what is holding it together. Lost of ways to go about that.
Low density could be air (use spacers or threaded rod/nuts), foam,
corrugated cardboard. High density could be plyood.

Jeff

Look for those "on the cheap" ideas. :-)

Try 4 rolls of TP, one under each speaker corner.

Note to others, We are trying to stop conductance of lows, dense
materials will stop highs, but that is *not* the problem here.

Jeff



Andy

You know, that sounds like a good idea to try.

I could put some fabric around the rolls.
I have some leftover fabric with the U.S. Flag on it.

I may shorten the cardboard tube enuf so it doesn't act as a conduit
for vibration.


Good. Let me know how it turns out, if you try. Hard not to have the
construction materials around.

Wouldn't worry too much about the tube, it's thin, but all low density
would be the ****ter!

Jeff

Andy

Don Phillipson wrote:

Even if you suspend the speakers from the ceiling, the low
frequencies coming from the speakers will still couple with
the room acoustics and your floor and walls will still
probably vibrate almost as much as if the speakers were
in contact with the floor.

This suggests a non-standard physics.

No it doesn't.

The basic complaint is that the floor vibrates,

No - the basic complaint is that low frequency sound is heard either
above or below the room with the speakers. The theory is that this can
be reduced if the speakers are removed from direct contact with the
floor.

and we know the speaker cases are in direct contact with the
floor. HG now suggests that if the cases were separated from
the floor by a foot or two of (compressible) air the "floor
and walls will still probably vibrate almost as much."
We should be interested to learn how this could possibly occur.

Car speakers are not directly connected to the exterior surfaces of a
car, yet low-frequencies are easily transmitted by those surfaces to a
listener dozens or even hundreds of yards away.

If the room's walls, floors and ceiling is made from compliant materials
(ie wood, sheetrock, etc) then it's quite likely that low frequency
sound from a suspended speaker will create standing waves that will
cause the walls, floors to resonate.

In this case, if indeed we are talking about a poured cement structure
(ie - modern multi-story apartment building) then that will be far less
likely.

But I still can't believe that a speaker sitting directly on a concrete
floor that is presumably 3 or more inches thick can possibly experience
enough of a vibration amplitude to be transmitted through the floor.
Presumably there is carpeting on this floor, which would decouple the
speaker to a great extent from the concrete floor.

Andy wrote:

The apartment below me is empty.

Thought of asking the manager to let me test different volume levels
to see what can be heard on the bottom floor.

So - you don't actually know how much sound is actually getting through
to the apartment below. ?

This isin't based on a complaint, or any direct knowledge if your
current setup *needs* to be modified ?

On 12/11/2010 7:56 PM, Home Guy wrote:
Don Phillipson wrote:

Even if you suspend the speakers from the ceiling, the low
frequencies coming from the speakers will still couple with
the room acoustics and your floor and walls will still
probably vibrate almost as much as if the speakers were
in contact with the floor.

This suggests a non-standard physics.

No it doesn't.

The basic complaint is that the floor vibrates,

No - the basic complaint is that low frequency sound is heard either
above or below the room with the speakers. The theory is that this can
be reduced if the speakers are removed from direct contact with the
floor.

and we know the speaker cases are in direct contact with the
floor. HG now suggests that if the cases were separated from
the floor by a foot or two of (compressible) air the "floor
and walls will still probably vibrate almost as much."
We should be interested to learn how this could possibly occur.

Car speakers are not directly connected to the exterior surfaces of a
car, yet low-frequencies are easily transmitted by those surfaces to a
listener dozens or even hundreds of yards away.

A different and rather complex environment. The car is of smaller
dimensions and the bass wavelength are much larger than the car
dimension. In addition, there is little damping from the sheet metal.
And as previously mentioned, a 15" or larger woofer is more like to be
heard at a distance that an 8", this is roughly analogous to power
factor in house current. The "power factor" changes with distance from
the speaker. Just a "trick" to get more sound outside.


If the room's walls, floors and ceiling is made from compliant materials
(ie wood, sheetrock, etc) then it's quite likely that low frequency
sound from a suspended speaker will create standing waves that will
cause the walls, floors to resonate.

Unlikely to be significant. Such resonances that do occur seldom couple
out. Once more it is conductance that is of concern. A diffuse wave
bouncing off or being somewhat absorbed is not even coupling in phase.
Do the math or look at the geometry. The bass wavelengths are more on
the order of the room size.

In this case, if indeed we are talking about a poured cement structure
(ie - modern multi-story apartment building) then that will be far less
likely.

But I still can't believe that a speaker sitting directly on a concrete
floor that is presumably 3 or more inches thick can possibly experience
enough of a vibration amplitude to be transmitted through the floor.

Believe what you will. The theory and practice are against you.

A quick search for (better) floor speakers.

http://www.google.com/products/catal...d=0CDcQ8wIwAg#

http://www.bestbuy.com/site/Polk+Aud...=1207352527510

Note the feet. What do you think they are for?

isolation cones, note the minimal contact area:

http://compare.ebay.com/like/2606668...=263602_304692

Beats the hell out of me why you keep pursuing these theories of yours.
The physics is more than you think.

You can just wait for Andy to report back.

Jeff
Who at one time spent a lot of time listening to room acoustics and has
friends with commercial recording studios.

On 12/12/2010 12:52 AM, Jeff Thies wrote:
On 12/11/2010 7:56 PM, Home Guy wrote:
Don Phillipson wrote:

Even if you suspend the speakers from the ceiling, the low
frequencies coming from the speakers will still couple with
the room acoustics and your floor and walls will still
probably vibrate almost as much as if the speakers were
in contact with the floor.

This suggests a non-standard physics.

No it doesn't.

The basic complaint is that the floor vibrates,

No - the basic complaint is that low frequency sound is heard either
above or below the room with the speakers. The theory is that this can
be reduced if the speakers are removed from direct contact with the
floor.

and we know the speaker cases are in direct contact with the
floor. HG now suggests that if the cases were separated from
the floor by a foot or two of (compressible) air the "floor
and walls will still probably vibrate almost as much."
We should be interested to learn how this could possibly occur.

Car speakers are not directly connected to the exterior surfaces of a
car, yet low-frequencies are easily transmitted by those surfaces to a
listener dozens or even hundreds of yards away.

A different and rather complex environment. The car is of smaller
dimensions and the bass wavelength are much larger than the car
dimension. In addition, there is little damping from the sheet metal.
And as previously mentioned, a 15" or larger woofer is more like to be
heard at a distance that an 8", this is roughly analogous to power
factor in house current. The "power factor" changes with distance from
the speaker. Just a "trick" to get more sound outside.


If the room's walls, floors and ceiling is made from compliant materials
(ie wood, sheetrock, etc) then it's quite likely that low frequency
sound from a suspended speaker will create standing waves that will
cause the walls, floors to resonate.

Unlikely to be significant. Such resonances that do occur seldom
couple out. Once more it is conductance that is of concern. A diffuse
wave bouncing off or being somewhat absorbed is not even coupling in
phase. Do the math or look at the geometry. The bass wavelengths are
more on the order of the room size.

In this case, if indeed we are talking about a poured cement structure
(ie - modern multi-story apartment building) then that will be far less
likely.

But I still can't believe that a speaker sitting directly on a concrete
floor that is presumably 3 or more inches thick can possibly experience
enough of a vibration amplitude to be transmitted through the floor.

Believe what you will. The theory and practice are against you.

A quick search for (better) floor speakers.

http://www.google.com/products/catal...d=0CDcQ8wIwAg#


http://www.bestbuy.com/site/Polk+Aud...=1207352527510


Note the feet. What do you think they are for?

isolation cones, note the minimal contact area:

http://compare.ebay.com/like/2606668...=263602_304692


Beats the hell out of me why you keep pursuing these theories of
yours. The physics is more than you think.

You can just wait for Andy to report back.

Jeff
Who at one time spent a lot of time listening to room acoustics and
has friends with commercial recording studios.

An anechoic chamber built from the right absorbtive materials can
isolate the acoustic energy, if you are willing to build "a room within
a room". This is economically (and aesthetically) very, very unlikely,
but will achieve isolation even at subsonic frequencies.

Most recording studios have the opposite problem, and will use such
methods to isolate low frequency / subsonic noise (from air
conditioning, trucks, elevators, etc.) to prevent it from entering and
destroying recordings.

The techniques are neither new nor especially complex. A little Google
searching on these anechoic room / chamber techniques will show how it
is done.

"Home Guy" wrote in message ...

I personally feel that any sound system with a sub-woofer is
sub-standard compared to having 2 or 4 large, full-range speakers. The
use of sub-woofers will almost certainly not accurately reproduce the
sonic content in recorded material - you will get an over-emphasis (to
the point of distortion) of the low frequency content.

You haven't heard the right sub-woofers. The popular use of subwoofers in
clubs (and automobiles) to provide ridiculously overblown bass doesn't mean
that subwoofers are inherently less capable of being hi-fi, it just means
the technology has been misused. Some of the finest hi-fi setups I've ever
heard use subwoofers, but they use them properly.

On 12/12/2010 1:41 AM, DGDevin wrote:
"Home Guy" wrote in message ...

I personally feel that any sound system with a sub-woofer is
sub-standard compared to having 2 or 4 large, full-range speakers. The
use of sub-woofers will almost certainly not accurately reproduce the
sonic content in recorded material - you will get an over-emphasis (to
the point of distortion) of the low frequency content.

You haven't heard the right sub-woofers. The popular use of
subwoofers in clubs (and automobiles) to provide ridiculously
overblown bass doesn't mean that subwoofers are inherently less
capable of being hi-fi, it just means the technology has been
misused. Some of the finest hi-fi setups I've ever heard use
subwoofers, but they use them properly.


I entirely agree. I have owned several (Velodyne, Hsu Research, Carver,
Dahlquist) and installed many others in some extremely high end systems.
They add a profoundly better and more realistic foundation to many types
of music and theater / video performance.

As 'Home Guy' states, true subwoofers installed and adjusted properly
are a joy to hear, but misused, misadjusted, or misnamed speakers
pretending to be subwoofers but are actually not suitable for subsonic
frequencies give true subwoofers an undeserved bad name.

"Smarty" wrote in message ...


I entirely agree. I have owned several (Velodyne, Hsu Research, Carver,
Dahlquist) and installed many others in some extremely high end systems.
They add a profoundly better and more realistic foundation to many types
of music and theater / video performance.

As 'Home Guy' states, true subwoofers installed and adjusted properly are
a joy to hear, but misused, misadjusted, or misnamed speakers pretending
to be subwoofers but are actually not suitable for subsonic frequencies
give true subwoofers an undeserved bad name.

I still have a Triphonic 3a system made in France several decades ago
(although it's in storage at the moment). It has three 12" woofers (with
accelerometers on the cones) driven by a built-in power amp. There is an
analog computer in effect that compares the motion of the cones to the input
single and corrects for errors, Philips used the same technology in their
Motional Feedback speaker systems. The satellites also had ribbon tweeters
(Celestion?) and the overall effect was of effortless, accurate sound
reproduction. So when somebody tells me subwoofers are inherently lo-fi,
well....

Of course many of the so-called subwoofers sold today are rubbish, meant
only to lay a thick, furry layer of *thump* over everything. Sadly, car
audio and home theatre have done a lot of damage to the whole concept of
hi-fi. But that doesn't mean that subwoofers as a species are a bad idea,
they just have to be properly executed.

Most recording studios have the opposite problem, and will use such
methods to isolate low frequency / subsonic noise (from air
conditioning, trucks, elevators, etc.) to prevent it from entering and
destroying recordings.

Largely done with double wall construction, at least the ones I've seen.
Where there is minimal connection between the two walls.

The techniques are neither new nor especially complex. A little Google
searching on these anechoic room / chamber techniques will show how it
is done.

Excatly.

Jeff

On 12/12/2010 2:29 AM, DGDevin wrote:
"Smarty" wrote in message ...


I entirely agree. I have owned several (Velodyne, Hsu Research,
Carver, Dahlquist) and installed many others in some extremely high
end systems. They add a profoundly better and more realistic
foundation to many types of music and theater / video performance.

As 'Home Guy' states, true subwoofers installed and adjusted properly
are a joy to hear, but misused, misadjusted, or misnamed speakers
pretending to be subwoofers but are actually not suitable for subsonic
frequencies give true subwoofers an undeserved bad name.

I still have a Triphonic 3a system made in France several decades ago
(although it's in storage at the moment). It has three 12" woofers (with
accelerometers on the cones) driven by a built-in power amp.

Yow, that's something!


There is an
analog computer in effect that compares the motion of the cones to the
input single and corrects for errors, Philips used the same technology
in their Motional Feedback speaker systems. The satellites also had
ribbon tweeters (Celestion?) and the overall effect was of effortless,
accurate sound reproduction. So when somebody tells me subwoofers are
inherently lo-fi, well....

Of course many of the so-called subwoofers sold today are rubbish, meant
only to lay a thick, furry layer of *thump* over everything. Sadly, car
audio and home theatre have done a lot of damage to the whole concept of
hi-fi. But that doesn't mean that subwoofers as a species are a bad
idea, they just have to be properly executed.


Let alone badly clipped systems where the distortion is just masked
by more distortion. And the owner is oblivious.

I've had my house sound down for a while and am unfamiliar with what
is on the market. Anything frugal that you know of that can do multizone
(4) and have a remote? Alas all I have is old and analogue. I want to
keep all the speakers and amps and just upgrade the tuner/preamp. I'm
sort of trending towards a dedicated PC and was going to track down an
old bud of mine that does home theater installs that I used to run sound
with... Lucky I didn't go deaf, his hearing rattles...


Jeff
Out of date on what's new. Way out of date.

DGDevin wrote:

Some of the finest hi-fi setups I've ever heard use subwoofers,

There are two types of audiophiles.

Those that seek technical accuracy in sound reproduction, and those that
seek pleasant or pleasing sound reproduction.

If I'm presented with a sound system that is technically accurate (as
measured by suitable equipment far more capable than any human ear) then
I will be satisfied with the system, and I will let the actual musical
content please me.

If my own audio input system (ie - my ears) does not have an ideal or
normal response curve, then I suppose that's another matter.

"Jeff Thies" wrote in message ...

I've had my house sound down for a while and am unfamiliar with what is
on the market. Anything frugal that you know of that can do multizone (4)
and have a remote? Alas all I have is old and analogue. I want to keep all
the speakers and amps and just upgrade the tuner/preamp. I'm sort of
trending towards a dedicated PC and was going to track down an old bud of
mine that does home theater installs that I used to run sound with...
Lucky I didn't go deaf, his hearing rattles...

Jeff
Out of date on what's new. Way out of date.

I know the feeling. Back in the day I subscribed to several audio
magazines, had quite an impressive hi-fi system and hung out with a bunch of
like-minded goofballs. We even set up a club with a private lending library
of super-duper audiophile recordings. But today my last "holy cow" audio
system is packed up in boxes and I do most of my music listening on the
computer (which does have a subwoofer). I've upgraded our "home theatre"
system lately to make it more hi-fi as and I'm going to do more in that
direction (we need better speakers). But I also want to put a proper stereo
in our home office/library, but I have little idea of the hardware that's on
the market these days. I should probably some of the gear that's in storage
since it's already paid for.

A friend of mine went the PC route, put his thousands of albums (LP, CD,
DVD-A etc.) on a hard drive(s) in a dedicated music server (Apple Lossless
format) and uses a Sonos music system to direct music to built-in speakers
located around his house. There is a remote that looks like an oversized
iPod, and they have remote control apps for iPhone, laptops etc. It's quite
slick to be able to call up any music you please while reading the paper and
sipping coffee but without leaving your chair. The demo on the site below
explains it well.

http://sonos.com/Default.aspx?rdr=true&LangType=1033

"Home Guy" wrote in message ...

There are two types of audiophiles.

Those that seek technical accuracy in sound reproduction, and those that
seek pleasant or pleasing sound reproduction.

I've known both types, including engineers who designed and built hi-fi
gear. The former are never satisfied, they discover a new brand of solder
or capacitor or whatever that will give them a 3% improvement somewhere and
they aren't happy until they get it. Such people seem more impressed with
the hardware than with the music they're listening to.

I feel there is a point of diminishing returns, where it just doesn't make
sense to chase vanishingly small improvements, much less improvements that
might exist only in the imagination of someone who just paid a silly amount
of money for speaker cable that even the pickiest listeners can't identify
in a blind listening test.

If I'm presented with a sound system that is technically accurate (as
measured by suitable equipment far more capable than any human ear) then
I will be satisfied with the system, and I will let the actual musical
content please me.

But, but, but--vacuum tubes sound *warmer*! ;~)

On 12/12/2010 2:29 AM, DGDevin wrote:
"Smarty" wrote in message
...


I entirely agree. I have owned several (Velodyne, Hsu Research,
Carver, Dahlquist) and installed many others in some extremely high
end systems. They add a profoundly better and more realistic
foundation to many types of music and theater / video performance.

As 'Home Guy' states, true subwoofers installed and adjusted properly
are a joy to hear, but misused, misadjusted, or misnamed speakers
pretending to be subwoofers but are actually not suitable for
subsonic frequencies give true subwoofers an undeserved bad name.

I still have a Triphonic 3a system made in France several decades ago
(although it's in storage at the moment). It has three 12" woofers
(with accelerometers on the cones) driven by a built-in power amp.
There is an analog computer in effect that compares the motion of the
cones to the input single and corrects for errors, Philips used the
same technology in their Motional Feedback speaker systems. The
satellites also had ribbon tweeters (Celestion?) and the overall
effect was of effortless, accurate sound reproduction. So when
somebody tells me subwoofers are inherently lo-fi, well....

Of course many of the so-called subwoofers sold today are rubbish,
meant only to lay a thick, furry layer of *thump* over everything.
Sadly, car audio and home theatre have done a lot of damage to the
whole concept of hi-fi. But that doesn't mean that subwoofers as a
species are a bad idea, they just have to be properly executed.

Putting a servo / feedback loop with an accelerometer around a sub
woofer cone is a very effective way to limit excessive excursions and
reduce harmonic distortion. Two very expensive sub woofers I have used
employ this same technique, one from Velodyne and the other from Carver.
My Carver "Amazing" speaker systems use long ribbons with dynamically
controlled woofer excursion as well as does the Velodyne (crossed over
the Martin Logan panels). If I remove the sub woofers, the bottom end
just drops out, leaving an entirely imbalanced and unnatural spectrum
below 100 Hz.

On Sat, 11 Dec 2010 23:29:34 -0800, "DGDevin"
wrote:

"Smarty" wrote in message ...


I entirely agree. I have owned several (Velodyne, Hsu Research, Carver,
Dahlquist) and installed many others in some extremely high end systems.
They add a profoundly better and more realistic foundation to many types
of music and theater / video performance.

As 'Home Guy' states, true subwoofers installed and adjusted properly are
a joy to hear, but misused, misadjusted, or misnamed speakers pretending
to be subwoofers but are actually not suitable for subsonic frequencies
give true subwoofers an undeserved bad name.

I still have a Triphonic 3a system made in France several decades ago
(although it's in storage at the moment). It has three 12" woofers (with
accelerometers on the cones) driven by a built-in power amp. There is an
analog computer in effect that compares the motion of the cones to the input
single and corrects for errors, Philips used the same technology in their
Motional Feedback speaker systems. The satellites also had ribbon tweeters
(Celestion?) and the overall effect was of effortless, accurate sound
reproduction. So when somebody tells me subwoofers are inherently lo-fi,
well....

Of course many of the so-called subwoofers sold today are rubbish, meant
only to lay a thick, furry layer of *thump* over everything. Sadly, car
audio and home theatre have done a lot of damage to the whole concept of
hi-fi. But that doesn't mean that subwoofers as a species are a bad idea,
they just have to be properly executed.

Generically referred to as "kickers" - after a brand name unit of the
same name (or "punchers")