"randyb" wrote in message
...
I need some help with my failing memory here. I am pretty
certain
that I have read an article in one of the magazines (believe
S&V, but
not sure)lamenting the lack of popularity of full range
speakers vs.
sub/sat because it was not condusive to classical music.
Anybody
remember this?

I think the increasing popularity of the sub/sat is mostly due to
aesthetics.

The reason I ask is that it has been said that the position for
a sub
is not in the area of the satellites and that full range
speakers by
extension would be deficient. That surprised me with all of
the
speakers today that have powered bass modules coupled to
smaller
speakers i.e. NHT 5 and 6's. To those who know, is it true
that
basically full range speakers are a detriment to smooth bass
compared
to sub satellite combinations were the sub can be moved to any
location in the room to smooth response?

If you have true full range speakers (be honest here, there
aren't many) there are disadvantages. By definition the
left/right have to be placed properly for stereo imaging. For
bass frequencies this is usually not the best location (a single
sub in one corner is usually the best). Two sources of bass will
cause cancellations at specific locations in the listening
environment (which can be good but is usually not). With two
subs the cancellation can be used to your advantage by locating
the sub in specific locations but is very difficult to implement
in practice. With full range left/rights you can't move them to
get the best bass response. So usually the best result is
achieved by a sub/sat system where the sats are located for
proper stereo imaging and the sub(s) are located to provide the
smoothest bass response.

That said, the majority of sats on the market are woefully
inadequate. Their tiny drivers don't go low enough in frequency
and you wind up with huge hole in the midbass between where the
sats cut off and the sub picks up.

My preference is for full range speakers with a single sub
(almost always in a corner). You can use the preamp crossover to
redirect the bass to the subwoofer. The mains won't be deficient
in the midbass so you can achieve seamless transition between
them and the sub. The mains also won't have to reproduce the
lowest frequencies at high levels which increases their dynamic
range. It might seem that you are "wasting" the low frequency
ability of the full range speaker but that's not the case.

"C. Leeds" wrote in message
news:_2O9b.479775$o%2.212867@sccrnsc02...
Some of the best full range speakers are systems that use
separate but
integrated woofers, such as the Infinity IRS systems. These
offer the
best of both worlds.

I agree...but there aren't many who can afford the IRS.

Full range speakers don't need a sub. That's what makes them
full range.
As for a single subwoofer: yechh. Give me stereo bass anyday.

The point was although full range speakers don't need a sub they
can often benefit from having one and in most cases the result
will be better than a typical sub/sat or full range by itself.

What content do you listing to that allows true stereo bass? The
vast majority of recordings have mono bass. It takes extreme
effort by the recording engineer to allow stereo bass. I doubt
there are more than a dozen recordings in which bass content
measurably differs from left to right.

And spare
me the theorizing about how low frequencies are
non-directional.

OK, but I wouldn't have to theorize. It's a scientifically
proven, testable and measurable FACT that low frequencies are
omnidirectional. Of course, if you have a cheap sub that has
audible distortion harmonics then yes, you can localize the
sub...but not due to the fundamental frequencies involved. Get a
better sub.

My opinion on subs is the infinite baffle approach. For a
reasonable cost you can achieve reference levels down to sub
10Hz. Clean, undistorted output that will best the combined
output of a dozen or more traditional box subs.

On 16 Sep 2003 22:42:58 GMT, (randyb) wrote:

I need some help with my failing memory here. I am pretty certain
that I have read an article in one of the magazines (believe S&V, but
not sure)lamenting the lack of popularity of full range speakers vs.
sub/sat because it was not condusive to classical music. Anybody
remember this?

I've seen it claimed several times. It's just as nonsensical every
time I see it.......

The reason I ask is that it has been said that the position for a sub
is not in the area of the satellites and that full range speakers by
extension would be deficient.

Exactly so.

That surprised me with all of the
speakers today that have powered bass modules coupled to smaller
speakers i.e. NHT 5 and 6's. To those who know, is it true that
basically full range speakers are a detriment to smooth bass compared
to sub satellite combinations were the sub can be moved to any
location in the room to smooth response?

Yes. It's *extremely* unlikely that in any given room, a full-range
speaker which consists of a 'minimonitor' coupled to a powered sub
(common enough design, as you note above), will give as smooth a
response as the same units sawn in half and optimally positioned.
Perhaps the best 'single box' attempt I have seen is the NHT 3.3,
which places the woofer at the room boundary and the mid/treble units
on a narrow baffle well away from the wall.

However, let's be clear here. I'm not talking about something like the
KEF 'eggs' as the minimonitor, but something like the B&W N805 or
JMLabs Mini Utopia, i.e. a speaker which can put out top quality sound
down to 50-80Hz, but is not properly 'full range'. Of course, if you
have enough money and space, you often find that your 'full range'
soeakers *are* separate units, such as the top Infinity and
Martin-Logan systems with their bass towers. A simple call to the Laws
of Physics shows that for decent 110dB sound levels at 20-25Hz, you
have to move a *lot* of air, well beyond the ability of any single12"
driver.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Rusty Boudreaux wrote:

The point was although full range speakers don't need a sub they
can often benefit from having one...

Oh, no. Full range systems don't need a subwoofer. You don't put a
subwoofer on an Infinity Beta system, or on RS1Bs, or with the full
range Genesis systems. No one ever hears my Beta setup and says, "Gee,
wouldn't it sound better if the bass was enhanced with a subwoofer?"

.... It's a scientifically
proven, testable and measurable FACT that low frequencies are
omnidirectional...

That's a canard, and it's a "fact" that it's false. As jj would
occasionally point out when he was here, you can hear the effect of
phase at v-e-r-y low frequencies. They are not purely "omnidirectional."

My opinion on subs is the infinite baffle approach. For a
reasonable cost you can achieve reference levels down to sub
10Hz. Clean, undistorted output that will best the combined
output of a dozen or more traditional box subs.

You're entitled to your preference. I like the sound of genuine, full
range, fully integrated speaker systems, rather than systems cobbled
together from various parts.

Stewart Pinkerton wrote:

A simple call to the Laws of Physics shows that for decent 110dB sound
levels at 20-25Hz, you have to move a *lot* of air, well beyond the ability
of any single12" driver.

I wouldn't dare disagree with that, but are such high levels necessary for
acoustic music? I've measured many organs, and even close to the largest
pipes, 110dB is usually not reached to say nothing of out in the room
at reasonable microphone placements that result in nice overall sound. Most
good pipe organs are not really that loud. Yes, for sound effects in movies
it can be useful, but such high levels at low frequencies are hard on a persons
nerves in the hearing mechanism and I like to avoid them if at all possible
for that reason. It seems some compromise (read: cost savings) can be had here
with little detriment for those who don't like these louder sound effects.

In article Xq1ab.490785$uu5.84085@sccrnsc04,
C. Leeds wrote:
Rusty Boudreaux wrote:

The point was although full range speakers don't need a sub they
can often benefit from having one...

Oh, no. Full range systems don't need a subwoofer. You don't put a
subwoofer on an Infinity Beta system, or on RS1Bs, or with the full
range Genesis systems. No one ever hears my Beta setup and says, "Gee,
wouldn't it sound better if the bass was enhanced with a subwoofer?"

.... It's a scientifically
proven, testable and measurable FACT that low frequencies are
omnidirectional...

That's a canard, and it's a "fact" that it's false. As jj would
occasionally point out when he was here, you can hear the effect of
phase at v-e-r-y low frequencies. They are not purely "omnidirectional."

Careful, people, we are mixing terminology here and getting
confused as a result.

1. This much can be said as demonmstrable fact: the RADIATION
pattern of the vast majority of subwoofers is, indeed,
omnidirectional. This is simply the case with ANY radiator whose
size is significantly smaller than the wavelength it is
radiating. That much of Mr. Boudreaux's statement is, indeed,
fact.

2. The ability of the ear to perceive the DIRECTION of the
source of very low frequency sound can be quite ambiguous,
especially in rooms.

3. MANY, and maybe even most older recordings did not have
significant L-R information recorded on them, for a variety of
technical reasons, therefore at those frequencies, had no
directional information.

4. It can be, despite the above, be fairly easy to determine the
direction of the source of low-frequency sound due to a number
of reasons, not the least of which is that in musical tones,
most low-freqqueny notes have significant higher frequency
partials and the ear CAN readily detect direction because of
those partials.

Be all that as it may, it would be my recommendation to most
people to purchase full-range systems as it leaves the
integration of the very low frequency portion with the rest of
the range, hopefully (and hope springs eternal, even for me),
in the hands of a designer that knew how to do it properly.
Separate subwoofers in the hands of most people, even alledgedly
competent ones, seldom if ever end up being prperly integrated.
The degrees of freedom considering crossover and placement
options results in many possible configurations, almost all of
which are less than optimum (translation: wrong).

--
| Dick Pierce |
| Professional Audio Development |
| 1-781/826-4953 Voice and FAX |
| |

"randyb" wrote in message
news:TC1ab.485591$YN5.328580@sccrnsc01...

On another forum, a member said that orchestral music is recorded in
such a way (more than one mike etc.) that stereo bass below typical
cutoffs is present. I think as best I can recall that this was the
point because so many people buy smaller sub sat combos and it is not
condusive to reproducing orchestral music which most classical is. In
any event, maybe Mr. Nousaine can chime in if he may have seen the
article I'm speaking. It wasn't that long ago I don't think-but I'm
old.

Just a quibble, but orchestral music is not the majority of classical music,
or even close. You can pick any example, but take Beethoven, who is fairly
famous for his Orchestral Music. This included 9 symphonies, 5 piano
concertos, a few concertos for other instruments, some choral music. This
is a very small fraction of his total output, which has 32 piano sonatas, 10
violin sonatas, 16 string quartets, piano trios, string trios, etc...
Other composers will show similar results -- Bach, Brahms, Chopin, Liszt,
Schubert, Haydn. The composers who wrote mostly orchestral music, like
Mahler and Strauss, are in a distinct minority.

Duffy

(Richard D Pierce) wrote:

In article Xq1ab.490785$uu5.84085@sccrnsc04,
C. Leeds wrote:
Rusty Boudreaux wrote:

The point was although full range speakers don't need a sub they
can often benefit from having one...

Oh, no. Full range systems don't need a subwoofer. You don't put a
subwoofer on an Infinity Beta system, or on RS1Bs, or with the full
range Genesis systems. No one ever hears my Beta setup and says, "Gee,
wouldn't it sound better if the bass was enhanced with a subwoofer?"

.... It's a scientifically
proven, testable and measurable FACT that low frequencies are
omnidirectional...

That's a canard, and it's a "fact" that it's false. As jj would
occasionally point out when he was here, you can hear the effect of
phase at v-e-r-y low frequencies. They are not purely "omnidirectional."

Careful, people, we are mixing terminology here and getting
confused as a result.

1. This much can be said as demonmstrable fact: the RADIATION
pattern of the vast majority of subwoofers is, indeed,
omnidirectional. This is simply the case with ANY radiator whose
size is significantly smaller than the wavelength it is
radiating. That much of Mr. Boudreaux's statement is, indeed,
fact.

2. The ability of the ear to perceive the DIRECTION of the
source of very low frequency sound can be quite ambiguous,
especially in rooms.

3. MANY, and maybe even most older recordings did not have
significant L-R information recorded on them, for a variety of
technical reasons, therefore at those frequencies, had no
directional information.

Few newer ones do either. I have a jazz ensemble recorded in the mid-60s where
the acoustic bass in contained entirely in the right channel but subjects were
unable to detect a difference in playback with full range systems (satellite
with subwoofer as base for left and right channels) when switched from mono to
stereo.


4. It can be, despite the above, be fairly easy to determine the
direction of the source of low-frequency sound due to a number
of reasons, not the least of which is that in musical tones,
most low-freqqueny notes have significant higher frequency
partials and the ear CAN readily detect direction because of
those partials.

Be all that as it may, it would be my recommendation to most
people to purchase full-range systems as it leaves the
integration of the very low frequency portion with the rest of
the range, hopefully (and hope springs eternal, even for me),
in the hands of a designer that knew how to do it properly.

This seems to happen rarely with full range systems. IME tower speakers seldom
are properly integrated and few have dealt reasonably well with the floor
bounce issue.

And few of them have competent low bass capability. I once listened to a system
that used $75k full range systems and $35k amplifiers in a dedicated room with
canted walls. Subjectively there was no significant output below 40 Hz which
was verifed with instrumentation.

Separate subwoofers in the hands of most people, even alledgedly
competent ones, seldom if ever end up being prperly integrated.
The degrees of freedom considering crossover and placement
options results in many possible configurations, almost all of
which are less than optimum (translation: wrong).

--
| Dick Pierce |
| Professional Audio Development |
| 1-781/826-4953 Voice and FAX |
| |

IME all the reasonably well and better integrated systems use separate
subwoofers.

But there is another issue often overlooked here....dynamic midbass compression
when you have a high output subwoofer coupled to a satellite system.

This occured to me when I made a subwoofer with 120 dB+ capability to match the
more dynamic modern bass recordings. When mated to a 7 channel surround system
there was significant midbass dynamic lack because the 2 6.5-inch woofers in
each of the left/right satellites just didn't have adequate SPL to match the
capability of the subwoofer (natural acoustic roll-off @ 70 Hz and a 120 Hz
electrical crossover.

A 10-inch bandpass "subwoofer" operating between 45 and 100 Hz was the
appropriate patch.

wrote:




Stewart Pinkerton wrote:

A simple call to the Laws of Physics shows that for decent 110dB sound
levels at 20-25Hz, you have to move a *lot* of air, well beyond the ability

of any single12" driver.

I wouldn't dare disagree with that, but are such high levels necessary for
acoustic music? I've measured many organs, and even close to the largest
pipes, 110dB is usually not reached to say nothing of out in the room
at reasonable microphone placements that result in nice overall sound. Most
good pipe organs are not really that loud. Yes, for sound effects in movies
it can be useful, but such high levels at low frequencies are hard on a
persons
nerves in the hearing mechanism and I like to avoid them if at all possible
for that reason. It seems some compromise (read: cost savings) can be had
here
with little detriment for those who don't like these louder sound effects.

That's true but there are many modern recordings with content to and below 10
Hz now. Telarc's famous cannons on the 1812 is the most famous I guess.

There are also recordings such as those produced by Aircraft Records ("Round
Sound") with recordings of radial engined aircraft with strong content in tne
20-30 Hz range. Plus many basshead cds have teriffic low frequency content;
ones that will set-off the 12 Hz resonance of my stick-framed house.

It's true that I only play these for demonstration but I need my system to have
the capability of playing any and all recordings in the way they were meant to
be heard. Even if the recordist of that aircraft, lift-off, thunderstorm or
train didn't have a mastering playback system that would do it justice.

(Stewart Pinkerton) wrote in message ...
On 16 Sep 2003 22:42:58 GMT, (randyb) wrote:

I need some help with my failing memory here. I am pretty certain
that I have read an article in one of the magazines (believe S&V, but
not sure)lamenting the lack of popularity of full range speakers vs.
sub/sat because it was not condusive to classical music. Anybody
remember this?

I've seen it claimed several times. It's just as nonsensical every
time I see it.......

The reason I ask is that it has been said that the position for a sub
is not in the area of the satellites and that full range speakers by
extension would be deficient.

Exactly so.

That surprised me with all of the
speakers today that have powered bass modules coupled to smaller
speakers i.e. NHT 5 and 6's. To those who know, is it true that
basically full range speakers are a detriment to smooth bass compared
to sub satellite combinations were the sub can be moved to any
location in the room to smooth response?

Yes. It's *extremely* unlikely that in any given room, a full-range
speaker which consists of a 'minimonitor' coupled to a powered sub
(common enough design, as you note above), will give as smooth a
response as the same units sawn in half and optimally positioned.
Perhaps the best 'single box' attempt I have seen is the NHT 3.3,
which places the woofer at the room boundary and the mid/treble units
on a narrow baffle well away from the wall.

However, let's be clear here. I'm not talking about something like the
KEF 'eggs' as the minimonitor, but something like the B&W N805 or
JMLabs Mini Utopia, i.e. a speaker which can put out top quality sound
down to 50-80Hz, but is not properly 'full range'. Of course, if you
have enough money and space, you often find that your 'full range'
soeakers *are* separate units, such as the top Infinity and
Martin-Logan systems with their bass towers. A simple call to the Laws
of Physics shows that for decent 110dB sound levels at 20-25Hz, you
have to move a *lot* of air, well beyond the ability of any single12"
driver.

So would that make designs like my old Martin Logan Sequels flawed in
comparison to a sub/sat combination or could you correct with say two
more subs crossed over fairly low. Also, it was said that there is
stereo bass (decorellated-spelling?)belwo say 80hz in a lot of
orchestral recordings that require two subs ro full range-true of
false? The article I was referring to and can't find I think was
referring to one sub/sat vs. full range speakers like used to be sold
as a standard.

"Richard D Pierce" wrote in message
...
4. It can be, despite the above, be fairly easy to determine
the
direction of the source of low-frequency sound due to a number
of reasons, not the least of which is that in musical tones,
most low-freqqueny notes have significant higher frequency
partials and the ear CAN readily detect direction because of
those partials.

Am I mistaken in assuming that if the crossover is implemented
properly the higher frequency partials will be voiced by the main
speakers and therefore not localized by a single sub? A 50Hz
24dB/octave lowpass will be -24dB down at 100Hz and -48dB down at
200Hz.

"Nousaine" wrote in message
...
This occured to me when I made a subwoofer with 120 dB+
capability to match the
more dynamic modern bass recordings. When mated to a 7 channel
surround system
there was significant midbass dynamic lack because the 2
6.5-inch woofers in
each of the left/right satellites just didn't have adequate SPL
to match the
capability of the subwoofer (natural acoustic roll-off @ 70 Hz
and a 120 Hz
electrical crossover.

A 10-inch bandpass "subwoofer" operating between 45 and 100 Hz
was the
appropriate patch.

I had the exact experience which is why my first post in this
thread pointed out the midbass issue.

My IB has over 17 liters of displacement at Xmax. When played
near reference volume the relatively small satellites just
couldn't keep up in the midbass. To be honest I didn't notice
the distortion per se. It just seemed a little thin. This was
confirmed via RTA. I was planning on upgrading the mains to more
capable ones anyway. After I did the midbass hole filled in
(measurably and audibly).

BTW, Tom, I really have you to thank for the IB. My first
encounter was your article in Stereo Review. I tucked that in
the back of my mind and a few years later found the IB forum.
Now my sub is just a small hole in the ceiling with the ability
to "peg" a Radio Shack SPL meter with very clean, smooth bass. I
do worry at times that the drywall may start falling down

(randyb) wrote in message ...
I need some help with my failing memory here. I am pretty certain
that I have read an article in one of the magazines (believe S&V, but
not sure)lamenting the lack of popularity of full range speakers vs.
sub/sat because it was not condusive to classical music. Anybody
remember this?

The reason I ask is that it has been said that the position for a sub
is not in the area of the satellites and that full range speakers by
extension would be deficient. That surprised me with all of the
speakers today that have powered bass modules coupled to smaller
speakers i.e. NHT 5 and 6's. To those who know, is it true that
basically full range speakers are a detriment to smooth bass compared
to sub satellite combinations were the sub can be moved to any
location in the room to smooth response?


Well I found letters in the June 03 S&V referring to Ken Pohlmans
article in April 03 S&V and talking about SMALL sub/sats vs. full
range and classical music. I have thrown the magazine away aso I will
have to go to the library to reread it but I am pretty sure it did not
suggest going from small sub/sats to larger sub/sats rather than full
range speakers. I generally agree with Ken's articles so definately
want to revisit in light of the debate that full range speakers are
not the best way to get smooth bass in the room.

On Wed, 17 Sep 2003 18:08:55 GMT, "C. Leeds"
wrote:

Rusty Boudreaux wrote:

.... It's a scientifically
proven, testable and measurable FACT that low frequencies are
omnidirectional...

That's a canard, and it's a "fact" that it's false. As jj would
occasionally point out when he was here, you can hear the effect of
phase at v-e-r-y low frequencies. They are not purely "omnidirectional."

Actually, what JJ did say was that bass below 50Hz or so *is*
omnidirectional, and that this is as high as he'd ever want to put a
steep-cut subwoofer crossover.

Naturally, if you accept the Stereophile definition of 'full range' as
extending flat to 20Hz at high SPLs, then of course you don't need a
subwoofer - although you are in a very rarified market here!

My opinion on subs is the infinite baffle approach. For a
reasonable cost you can achieve reference levels down to sub
10Hz. Clean, undistorted output that will best the combined
output of a dozen or more traditional box subs.

You're entitled to your preference. I like the sound of genuine, full
range, fully integrated speaker systems, rather than systems cobbled
together from various parts.

I like the sound of a system which is specifically tailored to the
listening room. Typically, this is not best served by a pair of big
'off the shelf' commercial boxes.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On 17 Sep 2003 19:14:50 GMT, wrote:

Stewart Pinkerton wrote:

A simple call to the Laws of Physics shows that for decent 110dB sound
levels at 20-25Hz, you have to move a *lot* of air, well beyond the ability
of any single12" driver.

I wouldn't dare disagree with that, but are such high levels necessary for
acoustic music? I've measured many organs, and even close to the largest
pipes, 110dB is usually not reached to say nothing of out in the room
at reasonable microphone placements that result in nice overall sound. Most
good pipe organs are not really that loud. Yes, for sound effects in movies
it can be useful, but such high levels at low frequencies are hard on a persons
nerves in the hearing mechanism and I like to avoid them if at all possible
for that reason. It seems some compromise (read: cost savings) can be had here
with little detriment for those who don't like these louder sound effects.

I guess it depends what you want from your system. While you will
certainly not engage such levels for 99% of available recordings, it's
good to have the *capability* when you need it. Kinda like a Corvette.

My own main system peaks at around 108dB, but I seldom feel that it
doesn't go loud enough, because the distortion is very low up to that
point. Interestingly, the 'TV sound' system peaks at around 115dB, but
it sounds 'louder' at the same 100-105dB levels because the speakers
have significantly higher distortion.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Thu, 18 Sep 2003 01:38:11 GMT, (randyb)
wrote:

So would that make designs like my old Martin Logan Sequels flawed in
comparison to a sub/sat combination or could you correct with say two
more subs crossed over fairly low. Also, it was said that there is
stereo bass (decorellated-spelling?)belwo say 80hz in a lot of
orchestral recordings that require two subs ro full range-true of
false? The article I was referring to and can't find I think was
referring to one sub/sat vs. full range speakers like used to be sold
as a standard.

Personally, I'd add one big sub to those Sequels, crossed over at
30-40Hz and plonked in a room corner. I pretty well guarantee that you
won't be able to locate the sound source, but your music *will* have a
much more solid foundation - even chamber music, weirdly enough.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

(Nousaine) wrote in message ...
"Rusty Boudreaux"
wrote:


BTW, Tom, I really have you to thank for the IB. My first
encounter was your article in Stereo Review. I tucked that in
the back of my mind and a few years later found the IB forum.
Now my sub is just a small hole in the ceiling with the ability
to "peg" a Radio Shack SPL meter with very clean, smooth bass. I
do worry at times that the drywall may start falling down

You're welcome. Of course, I wasn't the first to implement such a system. But
AKAIK I was the first person to response map a room (for Tom Parazella) for the
specific purpose of locating the IB throat locations in a given room. This
occured approximately 2 years before I did my own system.

After several years of operating a system that will deliver more than 120 dB
SPL @ 2 (TWO) meters in-room from 12 to 62 Hz I'm very surprised that there is
no real wall damage other than a few baseboard paint joint breaks in the
basement stairs. There are a few drywall cracks but no more than one would
expect after 7 years in a brand new house. There's only 1 nail pop that I've
ever found.

How much noise in terms of room resonances are you getting? How do you
test?

I'm finding I can't even measure THD at higher volumes, because of
room gack. (My horn loaded subs don't go as low as your IBs, only to
high 20s, but they can pump out several *acoustic horsepower*) The
pretty well built room seems to generate harmonics quite a bit
stronger than the subs' harmonics. Guess I should have hired a
acoustic building consultant.....

I've found this whole sub/sat thread very interesting. IME, a main
that can reach 50-80 along with a separate sub, as Stewart says, is
probably the easiest way to good full range sound. And your IBs are
probably the easiest way to a great sub. However, if space and
dollars permit, I do like Rusty's suggestion of truly full range mains
with separate sub for all the reasons he mentioned, and for the extra
degrees of freedom in choosing xover freq/slope. Also, which is worse;
room nulls from a single sub, or cancellations induced by multiple
subs. IME, the cancellations from multiple subs don't seem to be as
deep as the room nulls from a single sub, so sometimes I'm finding I
let the mains run full range without a xover. I know this is supposed
to be a major no-no.....

IMO, the prosound DSP xover/loudspeaker managers that have become
standardplace in live-sound are simply great for dialing in subs, or
playing around like this. But I must admit, Dick is on fair ground
when talks about reducing operator error by keeping full range design
in the hands of the manufacturer. It's not surprising a bunch of
prosound manufacturers want to lockup dsp settings and throw away the
key.

I guess I've rambled enough ..... Mark

(Stewart Pinkerton) wrote in message ...
On Thu, 18 Sep 2003 01:38:11 GMT, (randyb)
wrote:

So would that make designs like my old Martin Logan Sequels flawed in
comparison to a sub/sat combination or could you correct with say two
more subs crossed over fairly low. Also, it was said that there is
stereo bass (decorellated-spelling?)belwo say 80hz in a lot of
orchestral recordings that require two subs ro full range-true of
false? The article I was referring to and can't find I think was
referring to one sub/sat vs. full range speakers like used to be sold
as a standard.

Personally, I'd add one big sub to those Sequels, crossed over at
30-40Hz and plonked in a room corner. I pretty well guarantee that you
won't be able to locate the sound source, but your music *will* have a
much more solid foundation - even chamber music, weirdly enough.

Thanks Stewart. I actually sold the Sequels but I have a similiar
set-up with full range speakers (sort of not true deep bass) and think
that your suggestion makes perfect sense.

(Mark Wilkinson) wrote:

(Nousaine) wrote in message
...
"Rusty Boudreaux"
wrote:


BTW, Tom, I really have you to thank for the IB. My first
encounter was your article in Stereo Review. I tucked that in
the back of my mind and a few years later found the IB forum.
Now my sub is just a small hole in the ceiling with the ability
to "peg" a Radio Shack SPL meter with very clean, smooth bass. I
do worry at times that the drywall may start falling down

You're welcome. Of course, I wasn't the first to implement such a system.
But
AKAIK I was the first person to response map a room (for Tom Parazella) for
the
specific purpose of locating the IB throat locations in a given room. This
occured approximately 2 years before I did my own system.

After several years of operating a system that will deliver more than 120
dB
SPL @ 2 (TWO) meters in-room from 12 to 62 Hz I'm very surprised that there
is
no real wall damage other than a few baseboard paint joint breaks in the
basement stairs. There are a few drywall cracks but no more than one would
expect after 7 years in a brand new house. There's only 1 nail pop that
I've
ever found.

How much noise in terms of room resonances are you getting? How do you
test?

Room modes are always an issue. In my case I response mapped the room to
determine the best sub/ listening position (I've response mapped over a dozen
different rooms) to find the smoothest in-room response and all SPL figures are
made there (happens to be 2-meters from the sub location.) In my room modes are
observable at 17,25,34,53 and 73 Hz which is a good distribution.


I'm finding I can't even measure THD at higher volumes, because of
room gack. (My horn loaded subs don't go as low as your IBs, only to
high 20s, but they can pump out several *acoustic horsepower*) The
pretty well built room seems to generate harmonics quite a bit
stronger than the subs' harmonics.

I use the Keele 6.5-cycle ramped sine bursts at 1/3 octave frequencies for SPL
measurements. I keep increasing the gain until a scope trace captured by MLSSA
shows 10% distortion. The distortion sensing microphone is placed in the direct
field of the subwoofer and the SPL microphone at the listening position.

Guess I should have hired a
acoustic building consultant.....

I've found this whole sub/sat thread very interesting. IME, a main
that can reach 50-80 along with a separate sub, as Stewart says, is
probably the easiest way to good full range sound. And your IBs are
probably the easiest way to a great sub. However, if space and
dollars permit, I do like Rusty's suggestion of truly full range mains
with separate sub for all the reasons he mentioned, and for the extra
degrees of freedom in choosing xover freq/slope.

Sure. There's no difficulty with full-range capable speakers everywhere. It
does give you considerable implementation latitude at the cost of having paid
for bandwidth you may not need or be able to use.

Also, which is worse;
room nulls from a single sub, or cancellations induced by multiple
subs.

The interdriver and boundary cancellations occur at lower-midrange frequencies.
All the rest are modal functions. IME problems are exacerbated by multiple
spaced subwoofers. For example 5 subwoofers placed at L,C,R,RS,LS positions all
fail to excite the 2nd axial mode in a 12 x 22 x 8 foot room at 45 Hz producing
a hole at that frequency at every listening position.

But a null is a null. The main problem at low frequencies is there arent enough
room modes so if you fail to excite one or more you have an acoustic hole at
certain frequencies. But that hole can't get "deeper" by pouring in more energy
or introducing another cancelling signal.


IME, the cancellations from multiple subs don't seem to be as
deep as the room nulls from a single sub, so sometimes I'm finding I
let the mains run full range without a xover. I know this is supposed
to be a major no-no.....

The only advantage I can see from more subwoofers is that you may be closer to
the direct field of one of them with an array. That often introduces another
set of issues though.

There's a new theory about using 4 subwoofers at 1/2 wall distance on the four
walls of a shoebox room. The idea is to cancel the length, width and maybe even
the height modes, thereby smoothing in-room response.

I've done this experiment as well. It is true that such an array will produce a
slightly smoother in-room dynamic response capability (notice the operative
word ....slightly) at a quite significant SPL penalty (typically 3 dB in an
area where getting enough is a big issue) at a 4 times cost increase.



IMO, the prosound DSP xover/loudspeaker managers that have become
standardplace in live-sound are simply great for dialing in subs, or
playing around like this. But I must admit, Dick is on fair ground
when talks about reducing operator error by keeping full range design
in the hands of the manufacturer. It's not surprising a bunch of
prosound manufacturers want to lockup dsp settings and throw away the
key.

I guess I've rambled enough ..... Mark

This is an interesting thread.

Stewart Pinkerton wrote:
On 16 Sep 2003 22:42:58 GMT, (randyb) wrote:

I need some help with my failing memory here. I am pretty certain
that I have read an article in one of the magazines (believe S&V, but
not sure)lamenting the lack of popularity of full range speakers vs.
sub/sat because it was not condusive to classical music. Anybody
remember this?

I've seen it claimed several times. It's just as nonsensical every
time I see it.......


The article in question is "Roll Over, Beethoven' by Ken Pohlmann,
in the April 2003 issue of Sound & Vision.

His argument is that most of the work of reproducing classical music
(symphonic, chamber, opera),which he says mostly lacks extreme bass content,
is being done by the satellites; and since 'small cabinets without
real woofers simply cannot reproduce the all-important bottom end of
classical music...to put it bluntly , classical music sounds bad
on typical home theater speaker systems."

Reading a bit between the lines, even though he doesn't
mention frequencies specifically, it appears he's talking
about a mid/upper bass trough at the crossover region of
the satellites and sub.

He stresses that he's talking about *typical* setups...e.g.
the $1000 6-channel home-theater-in-a-box price point -- and
says that these can't provide 'the same smooth frequency response
as a pair of traditional stereo speakers'.

It's not a totally un-nuanced article, but I wonder if he's
simply set HT up for a fall by his choice of the criterion
*typical*. Apples must be compared to apples.
What would he call a *typical* 'all in one '
two-speaker stereo system at the $1000 price point,
and would it be *likely* to outperform the HT? Would it
tend to include speakers that are smooth down to 50 Hz at that
price point for a package? And what are the chances that
smoother speaker response at the crossover region would be offset
by the likelihood of sub-optimal woofer placement in such systems?





--
-S.

Steven Sullivan wrote in message ...
Stewart Pinkerton wrote:
On 16 Sep 2003 22:42:58 GMT, (randyb) wrote:

I need some help with my failing memory here. I am pretty certain
that I have read an article in one of the magazines (believe S&V, but
not sure)lamenting the lack of popularity of full range speakers vs.
sub/sat because it was not condusive to classical music. Anybody
remember this?

I've seen it claimed several times. It's just as nonsensical every
time I see it.......


The article in question is "Roll Over, Beethoven' by Ken Pohlmann,
in the April 2003 issue of Sound & Vision.

His argument is that most of the work of reproducing classical music
(symphonic, chamber, opera),which he says mostly lacks extreme bass content,
is being done by the satellites; and since 'small cabinets without
real woofers simply cannot reproduce the all-important bottom end of
classical music...to put it bluntly , classical music sounds bad
on typical home theater speaker systems."

Reading a bit between the lines, even though he doesn't
mention frequencies specifically, it appears he's talking
about a mid/upper bass trough at the crossover region of
the satellites and sub.

He stresses that he's talking about *typical* setups...e.g.
the $1000 6-channel home-theater-in-a-box price point -- and
says that these can't provide 'the same smooth frequency response
as a pair of traditional stereo speakers'.

It's not a totally un-nuanced article, but I wonder if he's
simply set HT up for a fall by his choice of the criterion
*typical*. Apples must be compared to apples.
What would he call a *typical* 'all in one '
two-speaker stereo system at the $1000 price point,
and would it be *likely* to outperform the HT? Would it
tend to include speakers that are smooth down to 50 Hz at that
price point for a package? And what are the chances that
smoother speaker response at the crossover region would be offset
by the likelihood of sub-optimal woofer placement in such systems?

Thanks Steven,

I received a new copy of Sensible Sound over the weekend and David
Rich refers to Pohlmans article. He agrees with Pohlman based on the
criteria of $1000. He goes on though about crossover problems and
room set-up and says a lot of interesting things. It is well worth a
read.

Randy

The article in question is "Roll Over, Beethoven' by Ken Pohlmann,
in the April 2003 issue of Sound & Vision.

His argument is that most of the work of reproducing classical music
(symphonic, chamber, opera),which he says mostly lacks extreme bass content,
is being done by the satellites; and since 'small cabinets without
real woofers simply cannot reproduce the all-important bottom end of
classical music...to put it bluntly , classical music sounds bad
on typical home theater speaker systems."

Reading a bit between the lines, even though he doesn't
mention frequencies specifically, it appears he's talking
about a mid/upper bass trough at the crossover region of
the satellites and sub.

He stresses that he's talking about *typical* setups...e.g.
the $1000 6-channel home-theater-in-a-box price point -- and
says that these can't provide 'the same smooth frequency response
as a pair of traditional stereo speakers'.

It's not a totally un-nuanced article, but I wonder if he's
simply set HT up for a fall by his choice of the criterion
*typical*. Apples must be compared to apples.
What would he call a *typical* 'all in one '
two-speaker stereo system at the $1000 price point,
and would it be *likely* to outperform the HT? Would it
tend to include speakers that are smooth down to 50 Hz at that
price point for a package? And what are the chances that
smoother speaker response at the crossover region would be offset
by the likelihood of sub-optimal woofer placement in such systems?



I have heard a few of these systems play classical music. IME he is being kind.
They were one step above the quality of a boom box on symphonic classical
music. I think it would be just about a mathematical fact that for the same
money you will inevitably get better performance with two chanel systems using
full range speakers. for a thousand dollars one could put together a system
using Vandersteen 1s. That would make for a night and day iimprovement over the
low end HT systems I have heard if classical music is the source. I think the
cheap HT might have the edge on car crashes. Actually i have heard some HT
systems costing much more than a thousand bucks that were still awful with
classical music not to mention jazz and other genres.

S888Wheel wrote:


The article in question is "Roll Over, Beethoven' by Ken Pohlmann,
in the April 2003 issue of Sound & Vision.

His argument is that most of the work of reproducing classical music
(symphonic, chamber, opera),which he says mostly lacks extreme bass content,
is being done by the satellites; and since 'small cabinets without
real woofers simply cannot reproduce the all-important bottom end of
classical music...to put it bluntly , classical music sounds bad
on typical home theater speaker systems."

Reading a bit between the lines, even though he doesn't
mention frequencies specifically, it appears he's talking
about a mid/upper bass trough at the crossover region of
the satellites and sub.

He stresses that he's talking about *typical* setups...e.g.
the $1000 6-channel home-theater-in-a-box price point -- and
says that these can't provide 'the same smooth frequency response
as a pair of traditional stereo speakers'.

It's not a totally un-nuanced article, but I wonder if he's
simply set HT up for a fall by his choice of the criterion
*typical*. Apples must be compared to apples.
What would he call a *typical* 'all in one '
two-speaker stereo system at the $1000 price point,
and would it be *likely* to outperform the HT? Would it
tend to include speakers that are smooth down to 50 Hz at that
price point for a package? And what are the chances that
smoother speaker response at the crossover region would be offset
by the likelihood of sub-optimal woofer placement in such systems?



I have heard a few of these systems play classical music. IME he is being kind.
They were one step above the quality of a boom box on symphonic classical
music. I think it would be just about a mathematical fact that for the same
money you will inevitably get better performance with two chanel systems using
full range speakers. for a thousand dollars one could put together a system
using Vandersteen 1s.

Except, Vandys would not consitute part of a 'typical' two channel system...
except perhaps among *highly informed consumers*.

I'm talking about Joe Sixpack walking into Best Buy with $1000 . Today the
blueshirts would direct him to drop that on an HT all-in-one package,
maybe by Sony or Yamaha (I overheard one the other day insisting that
the customer needed a 6.1 or 7.1 setup) . If the customer only wanted
two-channel he'd be directed to a Sony/Yamaha etc
receiver + two BIG similarly-branded 'full range' speaker towers +
a CD player. He wouldn't be told to go to a boutique and spend it on
Vandersteens.

*THAT'S* the sort of two-channel system that's 'typical' in the
stereo-consumer home...it's now being replaced by a 'typical' HT setup.
I'm skeptical that the former outperforms the latter vastly on
classical music.

IMO that's comparing 'typical to typical'. You and I aren't 'typical'
audio consumers. A highly informed consumer
could of course spend his $1000 and get better HT performance than he would
from a 'typical' setup purchased by a naive consumer; ditto with stereo.
I agree that he'd probably end up spending more for the HT system, though
with judicious monitoring of ebay or other used equipment fora, he
*could* manage to get five
good satellites and a decent sub for circa $1K (e.g., Atoms or discontinued
NHT, and maybe an old Velodyne) He'd have to drop a few hundred more for the
power supply/preamp/source).



--
-S.

(Stewart Pinkerton) wrote in message ...
On 18 Sep 2003 02:47:41 GMT, (randyb) wrote:

One other thing. If it is true that it is almost always better to
have the bass produced in a different place than the monitor part,
does this mean that S. Linkwitz's Orion design is flawed in your
opinion. These are full range speakers?

I'm not familiar with the Orion, but it's true for any speaker that
the best low bass reproduction will occur with the speaker differently
placed than for the best midrange reproduction. More specifically, al
most all conventional speaker designs work best in free space over
most of the frequency range, i.e. well off the floor and well away
from the walls, but the smoothest low bass will be obtained by placing
a subwoofer in one room corner. Hence, many serious audiophiles argue
that for ultimate sound quality, you do *not want a pair of Grande
Utopias or Grand SLAMMS, but a pair of monitors one step down in size
from those behemoths (think B&W N800 or WATT/Puppy) combined with a
truly humungous subwoofer crossing over not higher than 40Hz via a
4th-order filter.

I have a friend who is smitten with his LS3/5As, but has been tempted
to try adding a subwoofer. Obviously he'd need a much higher crossover
than 40 Hz. Based on the discussion here, I wonder if he'd be
disappointed in the results.

RN

In article , Rick says...
I have a friend who is smitten with his LS3/5As, but has been tempted
to try adding a subwoofer. Obviously he'd need a much higher crossover
than 40 Hz. Based on the discussion here, I wonder if he'd be
disappointed in the results.

With most subs, he will, IMHO.

The LS3/5a does in bass what it can, no going over their limits.
He needs a sub with the same frame of mind

Think REL.

--
"We still have much to learn about the art of sound reproduction;
ultimately, our responsibility is to our ears,not to established
precepts." - Martin Colloms, January 1998

In article ,
Stewart Pinkerton wrote:
On 18 Sep 2003 02:47:41 GMT, (randyb) wrote:

One other thing. If it is true that it is almost always better to
have the bass produced in a different place than the monitor part,
does this mean that S. Linkwitz's Orion design is flawed in your
opinion. These are full range speakers?

I'm not familiar with the Orion, but it's true for any speaker that
the best low bass reproduction will occur with the speaker differently
placed than for the best midrange reproduction.

http://www.linkwitzlab.com/orion_challenge.htm

They're a fully active 3-way open baffle dynamic driver speaker thought by
many to be the best speaker they've heard/owned including examples with five
figure price tags. You can buy plans+boards and build your own or in the
US order a complete package including crossover + amplifier + all cables for
$6500 + shipping from SL. I built a pair and found the buzz to be true.

The relevant part here is that they have a dipole radiation pattern for
everything below 1440Hz. The dipole/driver equalization ends with a pair of
poles @ 20Hz with Q=.5, making the -3dB point about 32Hz, -6dB 20Hz, and
-10dB about 14Hz. They don't benefit/suffer from room gain. Driver
complement is a TMWW configuration with a pair of Peerless XLS 10"
sub-woofers.

While the integrated bass drivers may provide for sub-optimal position (see
below), they are an enabling technology allowing for both time-alignment using
an analog cross-over and a higher XO frequency which allows sufficient output
from a single midrange.

I have a modest sized room (13' W x 19' L x 8' H) in which speakers with
bass do not (should not) perform well. In my room I find the Orion bass
to be the most natural (compared to the local live music scene where I get
regular jazz with upright bass and some symphonic music with bass drums,
kettles, bass, etc.) I've heard from any speaker in any room. This includes
what I get with stand-mounted monitors using a 4th order acoustic cross over @
80Hz to a corner loaded sub with some parametric sub equalization.

Dipole bass is a very different beast. I had a nasty room-mode
arround 70Hz which disappeared on my SPL meter leading me to the conclusion
that the directional radiation wasn't really exciting room modes. There are two
current threads on the madisound board surrounding this, with other people's
more thorough measurements suggesting that room-mode excitation is different but
not necessarily less

http://www.madisound.com/cgi-bin/dis...gi?read=270052
http://www.geocities.com/kreskovs/DipoleW.html

and SL responding

http://www.madisound.com/cgi-bin/dis...gi?read=270125

"The steady-state low frequency room response is most probably an
insufficient description of what we perceive.

My take on what is happening is summarized at the link below."

http://www.linkwitzlab.com/frontiers.htm#C

IMNSHO if you haven't heard dipole bass in a smaller room you really ought
to. It's surprising in a very good way. The caveat is that you need
ludicrous displacement to reach home theater levels in the last octave,
although it's fine for music (I don't know about organs).
--
a href="http://www.poohsticks.org/drew/"Home Page/a
Life is a terminal sexually transmitted disease.

(Nousaine) wrote in message ...
(Mark Wilkinson) wrote:

snip

How much noise in terms of room resonances are you getting? How do you
test?

Room modes are always an issue. In my case I response mapped the room to
determine the best sub/ listening position (I've response mapped over a dozen
different rooms) to find the smoothest in-room response and all SPL figures are
made there (happens to be 2-meters from the sub location.) In my room modes are
observable at 17,25,34,53 and 73 Hz which is a good distribution.



I use the Keele 6.5-cycle ramped sine bursts at 1/3 octave frequencies for SPL
measurements. I keep increasing the gain until a scope trace captured by MLSSA
shows 10% distortion. The distortion sensing microphone is placed in the direct
field of the subwoofer and the SPL microphone at the listening position.


Interesting. How does a distortion sensing mic work? Any links?
Don't mean to barrage you with questions, but how do you attribute
response to modes? IOW, how do you separate sub response from room
response? Does MLSSA work indoors in small/medium rooms 10-50hz --
can it resolve phase? I haven't yet learned either MLS or dual FFT
techniques well enough to feel I'm getting good data indoors down real
low, although FFT sine sweeps look encouraging. The only method that
I'm confident in, is to measure outdoors and compare that trace to
indoors. But that sure ain't gonna work for a built in IB, huh ?


Also, which is worse;
room nulls from a single sub, or cancellations induced by multiple
subs.

The interdriver and boundary cancellations occur at lower-midrange frequencies.
All the rest are modal functions. IME problems are exacerbated by multiple
spaced subwoofers. For example 5 subwoofers placed at L,C,R,RS,LS positions all
fail to excite the 2nd axial mode in a 12 x 22 x 8 foot room at 45 Hz producing
a hole at that frequency at every listening position.

But a null is a null. The main problem at low frequencies is there arent enough
room modes so if you fail to excite one or more you have an acoustic hole at
certain frequencies. But that hole can't get "deeper" by pouring in more energy
or introducing another cancelling signal.


IME, the cancellations from multiple subs don't seem to be as
deep as the room nulls from a single sub, so sometimes I'm finding I
let the mains run full range without a xover. I know this is supposed
to be a major no-no.....

The only advantage I can see from more subwoofers is that you may be closer to
the direct field of one of them with an array. That often introduces another
set of issues though.

There's a new theory about using 4 subwoofers at 1/2 wall distance on the four
walls of a shoebox room. The idea is to cancel the length, width and maybe even
the height modes, thereby smoothing in-room response.

I've done this experiment as well. It is true that such an array will produce a
slightly smoother in-room dynamic response capability (notice the operative
word ....slightly) at a quite significant SPL penalty (typically 3 dB in an
area where getting enough is a big issue) at a 4 times cost increase.



Yea, a lot of work/equipment for little gain. But I do like the idea
behind the cancelling modes concept. IMO, the best bass, by far, that
i ever hear is when I set up outdoors. So in my thinking, the problem
with rooms is that there ARE modes, not that there are too few of
them. If there were too few, then logically the solution would be a
mode at every freq, but that is the same thing as no modes at all. Or
so it seems to me.



IMO, the prosound DSP xover/loudspeaker managers that have become
standardplace in live-sound are simply great for dialing in subs, or
playing around like this. But I must admit, Dick is on fair ground
when talks about reducing operator error by keeping full range design
in the hands of the manufacturer. It's not surprising a bunch of
prosound manufacturers want to lockup dsp settings and throw away the
key.

I guess I've rambled enough ..... Mark

This is an interesting thread.

One last tidbit you might be interested in ... i just tried pointing a
pair of large hornloaded prosound subs into a room's corner -- subs
were stacked on top of each other, against a side wall. Freq response
was smoother and lower than anywhere I've tried in the room ---
corners work, just as you've found for conventional subs.
Unbelievable efficiency -- at 1w (2.4v into 5.75ohm nominal) bandwidth
limited pink noise, mic 2m from room corner on floor, bottom sub alone
110 db, top alone 108, 1 watt to both, 114 db!

(Mark Wilkinson) wrote:

(Nousaine) wrote in message
...
(Mark Wilkinson) wrote:

snip

How much noise in terms of room resonances are you getting? How do you
test?

Room modes are always an issue. In my case I response mapped the room to
determine the best sub/ listening position (I've response mapped over a
dozen
different rooms) to find the smoothest in-room response and all SPL figures
are
made there (happens to be 2-meters from the sub location.) In my room modes
are
observable at 17,25,34,53 and 73 Hz which is a good distribution.



I use the Keele 6.5-cycle ramped sine bursts at 1/3 octave frequencies for
SPL
measurements. I keep increasing the gain until a scope trace captured by
MLSSA
shows 10% distortion. The distortion sensing microphone is placed in the
direct
field of the subwoofer and the SPL microphone at the listening position.


Interesting. How does a distortion sensing mic work? Any links?

I just meant that I use a separate microphone near the subwoofer itself to grab
a distortion trace. You could use the same microphone for both SPL and
distortion but that would take more time and require twice as much work.

Don't mean to barrage you with questions, but how do you attribute
response to modes? IOW, how do you separate sub response from room
response?

Keele showed that near-field techniques will effectively simulate anechoic
results.

Does MLSSA work indoors in small/medium rooms 10-50hz --
can it resolve phase?

Depends on what you call 'work.' It will measure all acoustical properties
needed including phase. But for in-room placement optimization you really don't
need to separate acoustical source and the room.

I haven't yet learned either MLS or dual FFT
techniques well enough to feel I'm getting good data indoors down real
low, although FFT sine sweeps look encouraging. The only method that
I'm confident in, is to measure outdoors and compare that trace to
indoors. But that sure ain't gonna work for a built in IB, huh ?

Measure the subwoofer at the IB throat and you'll get a good representation of
its steady state capability. This is the equivalent of the near-field
technique.

...snips....

There's a new theory about using 4 subwoofers at 1/2 wall distance on the
four
walls of a shoebox room. The idea is to cancel the length, width and maybe
even
the height modes, thereby smoothing in-room response.

I've done this experiment as well. It is true that such an array will
produce a
slightly smoother in-room dynamic response capability (notice the operative
word ....slightly) at a quite significant SPL penalty (typically 3 dB in an
area where getting enough is a big issue) at a 4 times cost increase.



Yea, a lot of work/equipment for little gain. But I do like the idea
behind the cancelling modes concept. IMO, the best bass, by far, that
i ever hear is when I set up outdoors. So in my thinking, the problem
with rooms is that there ARE modes, not that there are too few of
them. If there were too few, then logically the solution would be a
mode at every freq, but that is the same thing as no modes at all. Or
so it seems to me.

You're getting the idea now. Standing waves occur at all frequencies between
any pair of opposingf surfaces. Play a 1000 Hz sine wave in your room and
you'll hear the sound pressure change as you move your head about. That's a
standing wave but because is has a wavelength of about a foot you'll get the
same effect everywhere in the room. The modes are statisticially dense.

At frequencies below a couple hundred Hz the wavelengths are long enough that
the pressure variations are measured in feet instead of inches. Below 100 Hz
there will only be about 5 modes (3 primary axial and sometimes 2 2nds).
Because of the long wavelengths pressure will always vary but if you fail to
excite any of the modes you get even larger variations PLUS you are throwing
away sound pressure in a frequency reange where its the hardest to attain.

Yes, if modes occur at every frequency that would be the ideal situation. But
cancelling all of them would be similar to moving outside BUT we tend to forget
that to get the same SPL outside takes a lot more displacment than inside
because the sound is allowed to dissipate into thin air, as it were.

Bass outside, a propagating wave, doesn't suffer from standing waves and room
modes but when was the last time you actually "heard" 20 Hz from a subwoofer
outside? It's not easy to produce at a reasonable SPL at 2 meters because all
the energy goes off into space.

As I said earlier placing 4 woofers at 1/2 wall difference can produce a
somewhat smoother in-room dynamic capability BUT you need to double even that
displacement to attain equivalent SPL of a single subwoofer placed in a corner.
IOW you'll need 8 subwoofers.

IMO that's not a fair trade.

One last tidbit you might be interested in ... i just tried pointing a
pair of large hornloaded prosound subs into a room's corner -- subs
were stacked on top of each other, against a side wall. Freq response
was smoother and lower than anywhere I've tried in the room ---
corners work, just as you've found for conventional subs.
Unbelievable efficiency -- at 1w (2.4v into 5.75ohm nominal) bandwidth
limited pink noise, mic 2m from room corner on floor, bottom sub alone
110 db, top alone 108, 1 watt to both, 114 db!

Interesting.

With most subs, he will, IMHO.

The LS3/5a does in bass what it can, no going over their limits.
He needs a sub with the same frame of mind

Think REL.

Indeed. i recall several years back spending hours trying out literally a
dozen different subwoofers to augment the content below 40hz on my Maggie
1.6s. it was not until i dialed in a REL Storm did i finally have
something that added the low end without messing up what my Maggies did
beautifully higher up.