Room/Speaker interface

[Wylie Williams]

The vast majority of speakers are front firing, bipoles, or dipoles. For
these there seems to be general agreement that correct placement and also
room treatments are extremely important to maximize sound quality.

I am wondering about some other types of speakers,
Some speakers are designed to be placed against the wall ; e.g.- Roy Allison
designs, the Burwen Silent loudspeaker, the AR LST, or even high end inwall
speakers. Placement is certain. Do these speakers avoid the need for room
treatment? If not, are their needs different.

Another type is the omnidirectional speaker, like the Shahinians. What are
the placement and room treatmenat issues for these speakers? ( the
Shahinian example is problematic, as some of his designs are much more
omnidirectional than the others)

I am asking because I really don't want to do the speaker placement and
acoustic treatment solutions in my living room, and hope that a different
style of speaker would be able to avoid the placement and treatment issues.

Wylie Williams

[All Ears]

A diagonal set up will minimize the problems, and probably work well if you
have carpet, curtains and furniture.

KE

"Wylie Williams" > wrote in message
news:uO0Za.102283$Ho3.13424@sccrnsc03...
> The vast majority of speakers are front firing, bipoles, or dipoles. For
> these there seems to be general agreement that correct placement and also
> room treatments are extremely important to maximize sound quality.
>
> I am wondering about some other types of speakers,
> Some speakers are designed to be placed against the wall ; e.g.- Roy
Allison
> designs, the Burwen Silent loudspeaker, the AR LST, or even high end
inwall
> speakers. Placement is certain. Do these speakers avoid the need for
room
> treatment? If not, are their needs different.
>
> Another type is the omnidirectional speaker, like the Shahinians. What are
> the placement and room treatmenat issues for these speakers? ( the
> Shahinian example is problematic, as some of his designs are much more
> omnidirectional than the others)
>
> I am asking because I really don't want to do the speaker placement and
> acoustic treatment solutions in my living room, and hope that a different
> style of speaker would be able to avoid the placement and treatment
issues.
>
> Wylie Williams
>

[Wylie Williams]

About my room - it is open floor plan with 8 ft ceiling - 17.5' x 20', with
a 6' wide opening in one wall , a 10 ft wide opening in another, and a 4 ft
door opening in the next, and a fireplace in the 4th wall. Due to need to
pass through the room the furniture and audio area is 11.5 ft x 17 ft.
The most comfortable living arrangement has me 16 feet away from the
speakers, which are 6 ft apart. To separate them further means putting on
the other side of the 4 ft door way. In other words it can be a listening
room that can't be used as a living room, or it can be a living room that is
a poor listening room.
My hope was to discover if no speakers would work without room treatment.
But I do have some very large and ugly absorption and diffraction products
left over from my store for experimentation. I suppose I'll test my wife's
tolerance one more time and do some experimenting.
Wylie Williams

"Uptown Audio" > wrote in message
news:rblZa.110855$uu5.15258@sccrnsc04...
> Different designs have different placement recommendations as you have
> noticed, but they do not address room treatment which is a separate
> issue. Of course it is interelated as are most things acoustic which
> is what makes dealing with some problems effectively quite difficult.
> The real nuts and bolts of it is that you really won't know if or what
> room treatment will be needed until you place the speakers. I know
> that is not what you wanted to hear, but all you can do is speculate
> until you actually set things up and listen (or measure depending upon
> how you derive enjoyment from your gear ;-)). There are computer
> programs available that "model" the acoustics of a static environment
> within certain predetermined rules. Since you don't seem to want a lot
> of "hassle factor" added-in, then it is really as simple as getting
> what would couple best with your room set-up by the design choice and
> by where your placement options are. That choice will be limited by
> your budget and by the cosmetics if that comes in to play as well.
> Once you have decided on the speakers, then room treatment may be
> desired to make them a "more perfect" mate with the room. You don't
> say if there are "placement or room treatment issues" presently or
> what speakers you are presently using, so it is hard to say if a
> different style would be of any benefit at all. You could always just
> fill us in on what the room dims are, the speakers that you use and if
> there are any glaring issue with the situation presently. Then we
> could take turns either trying to help you choose a new set or
> relating how much of an idiot you are for making your present choices
> depending upon our individual demeanors!
> - Bill
> www.uptownaudio.com
> Roanoke VA
> (540) 343-1250
>
> "Wylie Williams" > wrote in message
> news:uO0Za.102283$Ho3.13424@sccrnsc03...
> > The vast majority of speakers are front firing, bipoles, or dipoles.
> For
> > these there seems to be general agreement that correct placement and
> also
> > room treatments are extremely important to maximize sound quality.
> >
> > I am wondering about some other types of speakers,
> > Some speakers are designed to be placed against the wall ; e.g.- Roy
> Allison
> > designs, the Burwen Silent loudspeaker, the AR LST, or even high end
> inwall
> > speakers. Placement is certain. Do these speakers avoid the need
> for room
> > treatment? If not, are their needs different.
> >
> > Another type is the omnidirectional speaker, like the Shahinians.
> What are
> > the placement and room treatmenat issues for these speakers? ( the
> > Shahinian example is problematic, as some of his designs are much
> more
> > omnidirectional than the others)
> >
> > I am asking because I really don't want to do the speaker placement
> and
> > acoustic treatment solutions in my living room, and hope that a
> different
> > style of speaker would be able to avoid the placement and treatment
> issues.
> >
> > Wylie Williams
> >
>
>

[Nousaine]

"Wylie Williams" wrote:

>
>The vast majority of speakers are front firing, bipoles, or dipoles. For
>these there seems to be general agreement that correct placement and also
>room treatments are extremely important to maximize sound quality.
>
>I am wondering about some other types of speakers,
>Some speakers are designed to be placed against the wall ; e.g.- Roy Allison
>designs, the Burwen Silent loudspeaker, the AR LST, or even high end inwall
>speakers. Placement is certain. Do these speakers avoid the need for room
>treatment? If not, are their needs different.
>
>Another type is the omnidirectional speaker, like the Shahinians. What are
>the placement and room treatmenat issues for these speakers? ( the
>Shahinian example is problematic, as some of his designs are much more
>omnidirectional than the others)
>
>I am asking because I really don't want to do the speaker placement and
>acoustic treatment solutions in my living room, and hope that a different
>style of speaker would be able to avoid the placement and treatment issues.
>
>Wylie Williams

Isn't it interesting that Mr Williams references only speakers that are
nolonger commercially available? I agree that people SHOULD take the operating
environment into account in the design stage; BUT most of them already do by
giving you a speaker that will be 'flat' anechoically.

There seems to be a lack of environmental 'knowledge' about real conditions in
realrooms.

[Stewart Pinkerton]

On Wed, 13 Aug 2003 04:17:21 GMT, (Nousaine) wrote:

>"Wylie Williams" wrote:
>
>>
>>The vast majority of speakers are front firing, bipoles, or dipoles. For
>>these there seems to be general agreement that correct placement and also
>>room treatments are extremely important to maximize sound quality.
>>
>>I am wondering about some other types of speakers,
>>Some speakers are designed to be placed against the wall ; e.g.- Roy Allison
>>designs, the Burwen Silent loudspeaker, the AR LST, or even high end inwall
>>speakers. Placement is certain. Do these speakers avoid the need for room
>>treatment? If not, are their needs different.
>>
>>Another type is the omnidirectional speaker, like the Shahinians. What are
>>the placement and room treatmenat issues for these speakers? ( the
>>Shahinian example is problematic, as some of his designs are much more
>>omnidirectional than the others)
>>
>>I am asking because I really don't want to do the speaker placement and
>>acoustic treatment solutions in my living room, and hope that a different
>>style of speaker would be able to avoid the placement and treatment issues.
>>
>>Wylie Williams
>
>Isn't it interesting that Mr Williams references only speakers that are
>nolonger commercially available?

This is not entirely accurate, as B&W, KEF and Dynaudio all make
'high end' inwall speakers, and of course Naim still make speakers
intended for boundary placement, as do Mission and NHT. Naturally,
there are also many currently available 'surround' speakers which are
so designed.

Further, there are numerous 'omni-directional' designs currently
available, including AFAIK the Shahinian range.

>I agree that people SHOULD take the operating
>environment into account in the design stage; BUT most of them already do by
>giving you a speaker that will be 'flat' anechoically.
>
>There seems to be a lack of environmental 'knowledge' about real conditions in
>realrooms.

Indeed so, particularly if you believe that a speaker designed to be
flat in an anechoic chamber, will also be flat when radiating into
quarter-space.................
--

Stewart Pinkerton | Music is Art - Audio is Engineering

[Wylie Williams]

"Nousaine" > wrote in message
news:kZi_a.91208$Oz4.22499@rwcrnsc54...
> "Wylie Williams" wrote:
>
> >
> >The vast majority of speakers are front firing, bipoles, or dipoles. For
> >these there seems to be general agreement that correct placement and also
> >room treatments are extremely important to maximize sound quality.
> >
> >I am wondering about some other types of speakers,
> >Some speakers are designed to be placed against the wall ; e.g.- Roy
Allison
> >designs, the Burwen Silent loudspeaker, the AR LST, or even high end
inwall
> >speakers. Placement is certain. Do these speakers avoid the need for
room
> >treatment? If not, are their needs different.
> >
> >Another type is the omnidirectional speaker, like the Shahinians. What
are
> >the placement and room treatmenat issues for these speakers? ( the
> >Shahinian example is problematic, as some of his designs are much more
> >omnidirectional than the others)
> >
> >I am asking because I really don't want to do the speaker placement and
> >acoustic treatment solutions in my living room, and hope that a different
> >style of speaker would be able to avoid the placement and treatment
issues.
> >
> >Wylie Williams
>
> Isn't it interesting that Mr Williams references only speakers that are
> no longer commercially available?

Shahinian is in business with a full line. Burhoe is in business with the
Silent Speaker. Allison speakers again in production.

>I agree that people SHOULD take the operating
> environment into account in the design stage; BUT most of them already do
by
> giving you a speaker that will be 'flat' anechoically.

I have been under the impression that typical listening rooms are so
different from anechoic chambers that usually great care in speaker
placement and room treatment are needed to get the best from a speaker.
Thus my question asking if the speakers that are designed to be placed
against or on a wall avoid the need for room treatment.

> There seems to be a lack of environmental 'knowledge' about real
conditions in
> realrooms.
>
True, but surely there are anecdotal reports from owners. Which is why I
mentioned the AR LST.

Wylie Williams

[Howard Ferstler]

(Nousaine) wrote in message news:<kZi_a.91208$Oz4.22499@rwcrnsc54>...
> "Wylie Williams" wrote:
>
> >
> >The vast majority of speakers are front firing, bipoles, or dipoles. For
> >these there seems to be general agreement that correct placement and also
> >room treatments are extremely important to maximize sound quality.
> >
> >I am wondering about some other types of speakers,
> >Some speakers are designed to be placed against the wall ; e.g.- Roy Allison
> >designs, the Burwen Silent loudspeaker, the AR LST, or even high end inwall
> >speakers. Placement is certain. Do these speakers avoid the need for room
> >treatment? If not, are their needs different.
> >
> >Another type is the omnidirectional speaker, like the Shahinians. What are
> >the placement and room treatmenat issues for these speakers? ( the
> >Shahinian example is problematic, as some of his designs are much more
> >omnidirectional than the others)
> >
> >I am asking because I really don't want to do the speaker placement and
> >acoustic treatment solutions in my living room, and hope that a different
> >style of speaker would be able to avoid the placement and treatment issues.
> >
> >Wylie Williams

> Isn't it interesting that Mr Williams references only speakers that are
> nolonger commercially available? I agree that people SHOULD take the operating
> environment into account in the design stage; BUT most of them already do by
> giving you a speaker that will be 'flat' anechoically.

Actually, commercially available or not, the acoustic behavior of
speakers in typical listening rooms should not be all that mysterious.

Roy Allison once indicated that the most important thing for a speaker
to do (assuming low distortion and a wide enough bandwidth) was to
"input" flat power to the listening room.

However, "flat anechoically" is not really a cut-and-dried performance
goal. For example, anechoic direct-field response (be in on axis or at
any number of off-axis angles) is going to vary considerably as you
move around a speaker, so trying to get a definitive flat direct-field
response in an anechoic chamber is probably impossible. It would
change at every microphone position. Even if you could get it zeroed
in at one location, that would only work for one ear. The other ear
would not get the same direct-field perfection. On the other hand, the
basic starting point might be to opt for flat power input, and the
designer could then build upon that foundation with his assorted
performance embellishments - embellishments that give his speakers a
degree of character that sets them apart from the competition.

Now "flat power input" cannot take into account such things as
room-generated standing waves. A speaker may be flat as hell in the
bass range in terms of actual anechoic output, but room standing waves
will radically impact that flatness, and impact it differently at
different listening positions. The only way to deal with this is with
careful room design, perhaps a small amount of electrical equalization
(which, unfortunately, would only work well at the preferred listening
position), and a listening position that minimizes standing-wave
extremes.

On the other hand, speaker design can take into account things like
boundary-related power cancellations and inter-speaker cancellations
in the low and middle bass. Such cancellations, rather than being
listening-position dependent, are dependent upon the location of the
speaker in relation to large boundary surfaces and to other speakers
handling the same bass frequencies.

The suckout cancellations those speaker/boundary reflections generate
will impact flat power input to the room (usually from the middle bass
on up) and the ones that exist between a spaced pair of speakers will
behave similarly (although usually at frequencies somewhat below the
middle-bass range). In order to have a speaker (or speakers) generate
that flat power it has to have a "stabilized" relationship with those
boundaries, which was the key to how Allison designed his earlier
models to be positioned in a very specific relationship with room
floor/wall surfaces.

Regarding inter-speaker (or rather inter-woofer) cancellations, the
solution appears to be to use a subwoofer and place it in such a way
that any cancellations it would generate would be above its operating
range (in this case, the most logical position is a corner), while any
that the satellite speakers working with the sub would generate would
be below their operating ranges. This would allow for those satellites
to be optimally positioned for good imaging, soundstaging, etc. A
combination of those solutions should insure "flat power input" to the
listening room.

Another approach is to build speakers with controlled directivity, and
have them generate a much stronger direct-field signal at the
listening position than what you would have with very wide-dispersing
speakers like what Allison produced. Dunlavy comes to mind in this
area, and the only drawback to his design is that for optimal imaging
and soundstaging (the primary reason for such designs) the listener
should occupy a solid, sweet-spot position. The result can be
sensational, and if the system is designed properly (and the Dunlavy
models I have reviewed seem to be that way) and the listener sits
where he should the direct-field signal can be very flat, indeed. Note
that the bass-suckout problem will still exist, but that can be
resolved by making use of a properly placed subwoofer.

My current main system has adopted the Allison approach (with
subwoofer assistance, too), and a revamped listening room I am
building in another part of my house will make use of the Dunlavy
approach, again with subwoofer assistance. Pretty much the best of
both worlds in two different listening rooms.

> There seems to be a lack of environmental 'knowledge' about real conditions in
> realrooms.

Allison has published several papers on this topic in both popular and
technical publications:

"The Best Place for Your Speakers? Your Computer Knows," Audio,
August, 1994.

"The Delicate Question of Speaker Placement," Stereo Review, August,
1975

"The Influence of Room Boundaries on Loudspeaker Power Output," JAES,
June, 1974.

"Loudspeakers and Real Rooms," "Room For Improvement," and "Marking
the Boundaries," in Hi-Fi News and Record Review, December, 1989,
February, 1990, and April, 1990. (Three-part series.)

"The Sound Field in Home Listening Rooms," JAES, July-August, 1972.

"The Sound Field in Home Listening Rooms, Part 2," JAES Jan-Feb, 1975.

Howard Ferstler

[Nousaine]

(Howard Ferstler) wrote:

....snips....

>> There seems to be a lack of environmental 'knowledge' about real conditions
>in
>> realrooms.
>
>Allison has published several papers on this topic in both popular and
>technical publications:
>
>"The Best Place for Your Speakers? Your Computer Knows," Audio,
>August, 1994.
>
>"The Delicate Question of Speaker Placement," Stereo Review, August,
>1975
>
>"The Influence of Room Boundaries on Loudspeaker Power Output," JAES,
>June, 1974.
>
>"Loudspeakers and Real Rooms," "Room For Improvement," and "Marking
>the Boundaries," in Hi-Fi News and Record Review, December, 1989,
>February, 1990, and April, 1990. (Three-part series.)
>
>"The Sound Field in Home Listening Rooms," JAES, July-August, 1972.
>
>"The Sound Field in Home Listening Rooms, Part 2," JAES Jan-Feb, 1975.
>
>Howard Ferstler

Yes Roy has been great. But I was meaning something more along the lines of
what is a typical room size, layout and how would one use a given loudspeaker
in that situation with verification data.

Everybody gives recommendations in the owners manual BUT I never see anything
that has verified the recommendations. Subwoofers manufacuturers
recommendations are often incredibly far off and it seems obvious that the
company has never bothered to actually perform even perfunctory measurements or
bias controlled listening tests to confirm them.

From a designer's perspective I agree that it's pretty hard to make a good
sounding speaker for an acoustic enviroment where you have no control over
where it will be placed or any idea of the basic physical aspects of the room.

[Nousaine]

"Wylie Williams" wrote:

>"Nousaine" > wrote in message
>news:kZi_a.91208$Oz4.22499@rwcrnsc54...
>> "Wylie Williams" wrote:
>>
>> >
>> >The vast majority of speakers are front firing, bipoles, or dipoles. For
>> >these there seems to be general agreement that correct placement and also
>> >room treatments are extremely important to maximize sound quality.
>> >
>> >I am wondering about some other types of speakers,
>> >Some speakers are designed to be placed against the wall ; e.g.- Roy
>Allison
>> >designs, the Burwen Silent loudspeaker, the AR LST, or even high end
>inwall
>> >speakers. Placement is certain. Do these speakers avoid the need for
>room
>> >treatment? If not, are their needs different.
>> >
>> >Another type is the omnidirectional speaker, like the Shahinians. What
>are
>> >the placement and room treatmenat issues for these speakers? ( the
>> >Shahinian example is problematic, as some of his designs are much more
>> >omnidirectional than the others)
>> >
>> >I am asking because I really don't want to do the speaker placement and
>> >acoustic treatment solutions in my living room, and hope that a different
>> >style of speaker would be able to avoid the placement and treatment
>issues.
>> >
>> >Wylie Williams
>>
>> Isn't it interesting that Mr Williams references only speakers that are
>> no longer commercially available?
>
>Shahinian is in business with a full line. Burhoe is in business with the
>Silent Speaker. Allison speakers again in production.

I apologize; I was unaware of Shahinian still making speakers. It's been a
long, long time since I've seen one or knew anyone who has purchased one.

The last time I heard about someone trying to buy some Shahinian wouldn't take
an order. But that was a while ago.

It is true that the brand name Allison appears from time to time but I've never
noted an actual appearance of Allison-style speakers actually being built and
sold.

But that's not the point anyway. Please accept my apology for appearing to make
it one.

>
>>I agree that people SHOULD take the operating
>> environment into account in the design stage; BUT most of them already do
>by
>> giving you a speaker that will be 'flat' anechoically.
>
>I have been under the impression that typical listening rooms are so
>different from anechoic chambers that usually great care in speaker
>placement and room treatment are needed to get the best from a speaker.
>Thus my question asking if the speakers that are designed to be placed
>against or on a wall avoid the need for room treatment.

There is an advantage to knowing that a speaker will radiate into half space in
advance. But in-wall speakers have other major disadvantages that generally
completely disqualify them as hi-fi.

>> There seems to be a lack of environmental 'knowledge' about real
>conditions in
>> realrooms.
>>
> True, but surely there are anecdotal reports from owners. Which is why I
>mentioned the AR LST.
>
>Wylie Williams

I didn't make my point very well. What I meant was that other than a 250 room
survey of a speaker manufacturers customers with size, layout, ceiling style
and speaker layout that to which I had inside access I have NEVER seen any
statistics about typical rooms and how they're used.

So let's play a game. What do you think the median and mean average room
dimensions of 250 North American listening rooms might have been?

[Nousaine]

"Wylie Williams" wrote:

...snips......

>> >I am asking because I really don't want to do the speaker placement and
>> >acoustic treatment solutions in my living room, and hope that a different
>> >style of speaker would be able to avoid the placement and treatment
>issues.

Well you'll still have low frequency room/placement issues with any speaker.
And no radiating "style" will give you freedom from acoustic shadowing, slap
echo or overly-live rooms.

Treatments are only necessary when thet are needed and that can be more a
function of the room than the speaker or placement.

So I'm guessing that the short and simple answer is "No."

But thank you for raising this as an issue because room/speaker interface IS
one of the largest unsolved audio problems facing high quality sound
enthusiasts today.

[Wylie Williams]

"Nousaine" > wrote >
> ....other than a 250 room survey of a speaker manufacturers customers with
size, layout, ceiling style
> and speaker layout that to which I had inside access I have NEVER seen any
> statistics about typical rooms and how they're used.
>
> So let's play a game. What do you think the median and mean average room
> dimensions of 250 North American listening rooms might have been?
>

I have no idea. I did not ask that question and the answer doesn't interest
me.

I am curious about speakers intended to be placed against, on, or in a wall.
These are not very common so I hoped that the RAHE newsgroup would include
some contributors with experience on how they performed. Obviuosly the
placement issue is resolved and I windered whether they needed as much
attention to room treatment as conventional speakers. I don't expect
research; I am content with anecdotal reports.

Wylie Williams

P.S. - www.allisonacoustics.com New owner, Roy Allison consulting, old
speakers updated. Showed at CES 2002

[All Ears]

Wylie,

Sound waves are sound waves, no matter what they come from. The more
directional the sound, the easier it is to treat eventual problems. You have
to watch out for direct reflections from side walls, hard floors, tables
etc.

You should probably not move the speakers much further apart than 6-8 ft, or
the centre image will disappear, but you should consider to find a way to
sit closer to the speakers than 16 feet away.

Move around in the room as the music is playing, and listen for standing
waves, especially in the corners. Another good thing is to do a freq. sweep
(don't burn your tweeters!!) and listen for items playing along and
resonances in the room.

Mostly this is a matter of trial and error, small changes in speaker
placement can change a lot. Take a look at www.echobusters.com they have
some useful hints for room treatment.

KE

"Wylie Williams" > wrote in message
news:ElP_a.102941$Oz4.24228@rwcrnsc54...
> "Nousaine" > wrote >
> > ....other than a 250 room survey of a speaker manufacturers customers
with
> size, layout, ceiling style
> > and speaker layout that to which I had inside access I have NEVER seen
any
> > statistics about typical rooms and how they're used.
> >
> > So let's play a game. What do you think the median and mean average room
> > dimensions of 250 North American listening rooms might have been?
> >
>
> I have no idea. I did not ask that question and the answer doesn't
interest
> me.
>
> I am curious about speakers intended to be placed against, on, or in a
wall.
> These are not very common so I hoped that the RAHE newsgroup would include
> some contributors with experience on how they performed. Obviuosly the
> placement issue is resolved and I windered whether they needed as much
> attention to room treatment as conventional speakers. I don't expect
> research; I am content with anecdotal reports.
>
> Wylie Williams
>
> P.S. - www.allisonacoustics.com New owner, Roy Allison consulting, old
> speakers updated. Showed at CES 2002
>

[Howard Ferstler]

(Nousaine) wrote in message >...
> (Howard Ferstler) wrote:
>
> ...snips....
>
> >> There seems to be a lack of environmental 'knowledge' about real conditions
> in
> >> realrooms.
> >
> >Allison has published several papers on this topic in both popular and
> >technical publications:
> >
> >"The Best Place for Your Speakers? Your Computer Knows," Audio,
> >August, 1994.
> >
> >"The Delicate Question of Speaker Placement," Stereo Review, August,
> >1975
> >
> >"The Influence of Room Boundaries on Loudspeaker Power Output," JAES,
> >June, 1974.
> >
> >"Loudspeakers and Real Rooms," "Room For Improvement," and "Marking
> >the Boundaries," in Hi-Fi News and Record Review, December, 1989,
> >February, 1990, and April, 1990. (Three-part series.)
> >
> >"The Sound Field in Home Listening Rooms," JAES, July-August, 1972.
> >
> >"The Sound Field in Home Listening Rooms, Part 2," JAES Jan-Feb, 1975.
> >
> >Howard Ferstler

> Yes Roy has been great. But I was meaning something more along the lines of
> what is a typical room size, layout and how would one use a given loudspeaker
> in that situation with verification data.
>
> Everybody gives recommendations in the owners manual BUT I never see anything
> that has verified the recommendations. Subwoofers manufacuturers
> recommendations are often incredibly far off and it seems obvious that the
> company has never bothered to actually perform even perfunctory measurements or
> bias controlled listening tests to confirm them.

There are optimum placement requirements for nearly any kind of
speaker. Most subs do best in the corner, but if a manufacturer said
that the corner is where the sub should go for the very best results
they would lose some customers, because they would not be able to use
a corner. They would go buy a sub from a company that said that a sub
could be placed anywhere, or that somewhere other than a corner was
best. The laws of acoustics would remain the same, but some customers
would figure that some subs would bypass those laws and work best
where they intended to place them. Both subs might perform equally
well, but the company with the vague recommendations gets the sale.

Satellites are in the same boat. Allison was pretty emphatic in his
initial designs and the systems were designed for placement close to
wall boundaries, in order to keep mid-bass suckout artifacts under
control. (The systems somewhat simulated what you would get with
in-wall speakers, at least in terms of boundary interactions.) The
result was a number of lost sales, simply because some customers had
no such wall space available and wanted to place the speakers further
out into the room. The advent of subwoofers has made this
out-into-room placement viable, but in the old days this was not the
case - and Allison lost sales. He never had a chance to produce a
super-duper sub/sat package, that would allow for out-into-room
satellite positioning.

> From a designer's perspective I agree that it's pretty hard to make a good
> sounding speaker for an acoustic enviroment where you have no control over
> where it will be placed or any idea of the basic physical aspects of the room.

And the result is that the manufacturer is forced to produce user's
manuals that are vague as hell about where to locate speakers. The
more precise the requirements (as stated in a manual), the better
chance that some potential customers will go shopping for speakers
that offer up a larger number of placement options, even though the
end results will still be the same as what we have with the company
who has more rigorous guidelines.

Most customers want the rules written vaguely, so they can position
the speakers where they look best.

Howard Ferstler

[chris]

"All Ears" > wrote in message
...

Take a look at www.echobusters.com they have
> some useful hints for room treatment.
>
> KE
>
hi Ears
what do you know about their double busters ? they look interesting.
Do you know how they work ?
I wonder if they will work with a low angle of incidence?

any comments, thought, welcome.
Chris.

[All Ears]

"chris" > wrote in message
news:QKy%a.131216$cF.34730@rwcrnsc53...
> "All Ears" > wrote in message
> ...
>
> Take a look at www.echobusters.com they have
> > some useful hints for room treatment.
> >
> > KE
> >
> hi Ears
> what do you know about their double busters ? they look interesting.
> Do you know how they work ?
> I wonder if they will work with a low angle of incidence?
>
> any comments, thought, welcome.
> Chris.

Chris,

First a quick copy paste from their web page:

"The Double Buster serves the dual purpose of both absorption and diffusion.
The Double Buster's design is based on that of a bicylindrical diffuser,
composed of a center beam down the length of the panel and two bent "wings"
of plywood extending rearward from the center beam to the panel's edges.
This constitutes a convex surface which diffuses impinging plane waves by
reflecting them back into the listening environment in a hemispherical
pattern. Externally, the Double Buster is a rectangular, fabric covered
panel, similar in appearance to an Echo Buster."

I have some in my listening room, and they are very efficient in eliminating
resonances in the corners of the room. They do not suck up all the energy in
the sound, but seems to distribute it more evenly.

Anybody who wants to build a serious system, should start with two simple
things.

1. Make sure that the room has a suitable acoustics.
2. Make sure that clean unchoked mains power is available, which normally
means a dedicated mains line, since power conditioners often introduces more
problems than they solve.

KE

[All Ears]

"chris" > wrote in message
...
> "All Ears" > wrote in message
> news:EpA%a.135046$Oz4.26844@rwcrnsc54..
>
>
> Anybody who wants to build a serious system, should start with two simple
> > things.
> >
> > 1. Make sure that the room has a suitable acoustics.
> > 2. Make sure that clean unchoked mains power is available
>
> Yep Im going for item 1. 2 is undercontrol
>
> > First a quick copy paste from their web page:
> >
> > "The Double Buster serves the dual purpose of both absorption and
> diffusion.
> > The Double Buster's design is based on that of a bicylindrical diffuser,
> > composed of a center beam down the length of the panel and two bent
> "wings"
> > of plywood extending rearward from the center beam to the panel's edges.
> > This constitutes a convex surface which diffuses impinging plane waves
by
> > reflecting them back into the listening environment in a hemispherical
> > pattern. Externally, the Double Buster is a rectangular, fabric covered
> > panel, similar in appearance to an Echo Buster."
> >
> > I have some in my listening room, and they are very efficient in
> eliminating
> > resonances in the corners of the room. They do not suck up all the
energy
> in
> > the sound, but seems to distribute it more evenly.
>
> But Im confussed, if they are bent sheets of plywood would'nt they just
act
> as a convex reflector and not befave as a typical RPG or QRD diffuser.
> Unless ive got the wrong end of the stick (if so im sorry) I also thought
> that they absorb some of the sound as well hence the "double" word.
> so how does this work ? by the way, How deep is the curve ?
>
> Chris

Chris,

I'm not an expert in how these things really work. You could give Michael
Kaufmann @ Echo Busters a call, he is normally more than willing to spend
some time on explaining, why, how and where.

However I know that the Double Busters do both absorbe and diffuse, there is
a layer of foam material in the DB also.

KE

>
> > "chris" > wrote in message
> > news:QKy%a.131216$cF.34730@rwcrnsc53...
> > > "All Ears" > wrote in message
> > > ...
> > >
> > > Take a look at www.echobusters.com they have
> > > > some useful hints for room treatment.
> > > >
> > > > KE
> > > >
> > > hi Ears
> > > what do you know about their double busters ? they look interesting.
> > > Do you know how they work ?
> > > I wonder if they will work with a low angle of incidence?
> > >
> > > any comments, thought, welcome.
> > > Chris.
> >
> > Chris,
> >
>

[chris]

Check out An interesting set of article on in-wall/ceiling speakers
http://www.keithyates.com/articles.htm

"Wylie Williams" > wrote in message
...
> About my room - it is open floor plan with 8 ft ceiling - 17.5' x 20',
with
> a 6' wide opening in one wall , a 10 ft wide opening in another, and a 4
ft
> door opening in the next, and a fireplace in the 4th wall. Due to need to
> pass through the room the furniture and audio area is 11.5 ft x 17 ft.
> The most comfortable living arrangement has me 16 feet away from the
> speakers, which are 6 ft apart. To separate them further means putting on
> the other side of the 4 ft door way. In other words it can be a
listening
> room that can't be used as a living room, or it can be a living room that
is
> a poor listening room.
> My hope was to discover if no speakers would work without room treatment.
> But I do have some very large and ugly absorption and diffraction products
> left over from my store for experimentation. I suppose I'll test my
wife's
> tolerance one more time and do some experimenting.
> Wylie Williams
>
> "Uptown Audio" > wrote in message
> news:rblZa.110855$uu5.15258@sccrnsc04...
> > Different designs have different placement recommendations as you have
> > noticed, but they do not address room treatment which is a separate
> > issue. Of course it is interelated as are most things acoustic which
> > is what makes dealing with some problems effectively quite difficult.
> > The real nuts and bolts of it is that you really won't know if or what
> > room treatment will be needed until you place the speakers. I know
> > that is not what you wanted to hear, but all you can do is speculate
> > until you actually set things up and listen (or measure depending upon
> > how you derive enjoyment from your gear ;-)). There are computer
> > programs available that "model" the acoustics of a static environment
> > within certain predetermined rules. Since you don't seem to want a lot
> > of "hassle factor" added-in, then it is really as simple as getting
> > what would couple best with your room set-up by the design choice and
> > by where your placement options are. That choice will be limited by
> > your budget and by the cosmetics if that comes in to play as well.
> > Once you have decided on the speakers, then room treatment may be
> > desired to make them a "more perfect" mate with the room. You don't
> > say if there are "placement or room treatment issues" presently or
> > what speakers you are presently using, so it is hard to say if a
> > different style would be of any benefit at all. You could always just
> > fill us in on what the room dims are, the speakers that you use and if
> > there are any glaring issue with the situation presently. Then we
> > could take turns either trying to help you choose a new set or
> > relating how much of an idiot you are for making your present choices
> > depending upon our individual demeanors!
> > - Bill
> > www.uptownaudio.com
> > Roanoke VA
> > (540) 343-1250
> >
> > "Wylie Williams" > wrote in message
> > news:uO0Za.102283$Ho3.13424@sccrnsc03...
> > > The vast majority of speakers are front firing, bipoles, or dipoles.
> > For
> > > these there seems to be general agreement that correct placement and
> > also
> > > room treatments are extremely important to maximize sound quality.
> > >
> > > I am wondering about some other types of speakers,
> > > Some speakers are designed to be placed against the wall ; e.g.- Roy
> > Allison
> > > designs, the Burwen Silent loudspeaker, the AR LST, or even high end
> > inwall
> > > speakers. Placement is certain. Do these speakers avoid the need
> > for room
> > > treatment? If not, are their needs different.
> > >
> > > Another type is the omnidirectional speaker, like the Shahinians.
> > What are
> > > the placement and room treatmenat issues for these speakers? ( the
> > > Shahinian example is problematic, as some of his designs are much
> > more
> > > omnidirectional than the others)
> > >
> > > I am asking because I really don't want to do the speaker placement
> > and
> > > acoustic treatment solutions in my living room, and hope that a
> > different
> > > style of speaker would be able to avoid the placement and treatment
> > issues.
> > >
> > > Wylie Williams
> > >
> >
> >