Exponential transmission lines
 

On Fri, 19 Sep 2003 09:12:46 +0100, Jim Lesurf
wrote:

In article , The Old
Fogey wrote:
Anyone come across an exponentially tapered transmission line, apart
from the B&W Nautilus? It looks like it would be an amusing project. An
infinite length exponential taper has a finite internal volume so all I
need is to find a wall material with zero thickness :-)

It has just occurred to me that another problem in use would be the
propagation delay along an infinitely long transmission line might mean
you'd have to wait some time after starting to play the music before you
heard anything! Might be best to press 'play' then go and have your
dinner... :-)

Um, the line absorbs the back radiation.......
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Exponential transmission lines
 

On Fri, 19 Sep 2003 05:43:57 GMT, "malcolm"
wrote:


"The Old Fogey" wrote in message
m...
"malcolm" wrote in message
news:PPQ9b.480052$Ho3.81431@sccrnsc03...


try here http://www.t-linespeakers.org/projects/index.html

No good. They are almost all quarter-wave lagged organ-pipes and the
tapered ones are so short that they are really closed-boxes or
bass-reflex.

This is more the thing:


http://www.bwspeakers.com/index.cfm/.../label/Model%2
0Nautilus

Though a TL for a tweeter is rather pointless, it looks good.

Actually, since the point of all the TLs on the Nautilus range is to
absorb back radiation without producing excess pressure on the back of
the diaphragms, they are certainly applicable to all drivers, even
tweeters. Indeed, the TL tweeter is the most widely used of them all
across the N800 range.

Roger.

yes , but what price?
they look like they are made of plastic!!

They're made of a highly specified engineering composite, certainly
not 'plastic' in any normal sense. Prices range from about £1500 for
the N805 through £10,000 for the N800 to £35,000 for the 'original'
Nautilus.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Exponential transmission lines
 

On Fri, 19 Sep 2003 05:43:57 GMT, "malcolm"
wrote:


"The Old Fogey" wrote in message
m...
"malcolm" wrote in message
news:PPQ9b.480052$Ho3.81431@sccrnsc03...


try here http://www.t-linespeakers.org/projects/index.html

No good. They are almost all quarter-wave lagged organ-pipes and the
tapered ones are so short that they are really closed-boxes or
bass-reflex.

This is more the thing:


http://www.bwspeakers.com/index.cfm/.../label/Model%2
0Nautilus

Though a TL for a tweeter is rather pointless, it looks good.

Actually, since the point of all the TLs on the Nautilus range is to
absorb back radiation without producing excess pressure on the back of
the diaphragms, they are certainly applicable to all drivers, even
tweeters. Indeed, the TL tweeter is the most widely used of them all
across the N800 range.

Roger.

yes , but what price?
they look like they are made of plastic!!

They're made of a highly specified engineering composite, certainly
not 'plastic' in any normal sense. Prices range from about £1500 for
the N805 through £10,000 for the N800 to £35,000 for the 'original'
Nautilus.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Exponential transmission lines
 

"Stewart Pinkerton" wrote in message
...
On Fri, 19 Sep 2003 09:12:46 +0100, Jim Lesurf
wrote:

In article , The Old
Fogey wrote:
Anyone come across an exponentially tapered transmission line, apart
from the B&W Nautilus? It looks like it would be an amusing project. An
infinite length exponential taper has a finite internal volume so all I
need is to find a wall material with zero thickness :-)

It has just occurred to me that another problem in use would be the
propagation delay along an infinitely long transmission line might mean
you'd have to wait some time after starting to play the music before you
heard anything! Might be best to press 'play' then go and have your
dinner... :-)

Um, the line absorbs the back radiation.......
--

Stewart Pinkerton | Music is Art - Audio is Engineering


is this radiation dangerous ?,

and why dont they have warning labels on normal speakers!

Exponential transmission lines
 

"Stewart Pinkerton" wrote in message
...
On Fri, 19 Sep 2003 09:12:46 +0100, Jim Lesurf
wrote:

In article , The Old
Fogey wrote:
Anyone come across an exponentially tapered transmission line, apart
from the B&W Nautilus? It looks like it would be an amusing project. An
infinite length exponential taper has a finite internal volume so all I
need is to find a wall material with zero thickness :-)

It has just occurred to me that another problem in use would be the
propagation delay along an infinitely long transmission line might mean
you'd have to wait some time after starting to play the music before you
heard anything! Might be best to press 'play' then go and have your
dinner... :-)

Um, the line absorbs the back radiation.......
--

Stewart Pinkerton | Music is Art - Audio is Engineering


is this radiation dangerous ?,

and why dont they have warning labels on normal speakers!

Exponential transmission lines
 

On Fri, 19 Sep 2003 21:25:19 GMT, "malcolm"
wrote:

"Stewart Pinkerton" wrote in message
...
On Fri, 19 Sep 2003 09:12:46 +0100, Jim Lesurf
wrote:

In article , The Old
Fogey wrote:
Anyone come across an exponentially tapered transmission line, apart
from the B&W Nautilus? It looks like it would be an amusing project. An
infinite length exponential taper has a finite internal volume so all I
need is to find a wall material with zero thickness :-)

It has just occurred to me that another problem in use would be the
propagation delay along an infinitely long transmission line might mean
you'd have to wait some time after starting to play the music before you
heard anything! Might be best to press 'play' then go and have your
dinner... :-)

Um, the line absorbs the back radiation.......

is this radiation dangerous ?

Yup - it makes you deaf.

and why dont they have warning labels on normal speakers!

Because they don't contain tobacco.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Exponential transmission lines
 

On Fri, 19 Sep 2003 21:25:19 GMT, "malcolm"
wrote:

"Stewart Pinkerton" wrote in message
...
On Fri, 19 Sep 2003 09:12:46 +0100, Jim Lesurf
wrote:

In article , The Old
Fogey wrote:
Anyone come across an exponentially tapered transmission line, apart
from the B&W Nautilus? It looks like it would be an amusing project. An
infinite length exponential taper has a finite internal volume so all I
need is to find a wall material with zero thickness :-)

It has just occurred to me that another problem in use would be the
propagation delay along an infinitely long transmission line might mean
you'd have to wait some time after starting to play the music before you
heard anything! Might be best to press 'play' then go and have your
dinner... :-)

Um, the line absorbs the back radiation.......

is this radiation dangerous ?

Yup - it makes you deaf.

and why dont they have warning labels on normal speakers!

Because they don't contain tobacco.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Exponential transmission lines
 

In article , Stewart Pinkerton
wrote:
On Fri, 19 Sep 2003 09:12:46 +0100, Jim Lesurf
wrote:

In article , The Old
Fogey wrote:
Anyone come across an exponentially tapered transmission line, apart
from the B&W Nautilus? It looks like it would be an amusing project. An
infinite length exponential taper has a finite internal volume so all I
need is to find a wall material with zero thickness :-)

It has just occurred to me that another problem in use would be the
propagation delay along an infinitely long transmission line might mean
you'd have to wait some time after starting to play the music before you
heard anything! Might be best to press 'play' then go and have your
dinner... :-)

Um, the line absorbs the back radiation.......

Blast! That ruins the joke. :-/ I was assuming that the actual speaker
unit was located a fraction of the length of the line away from the open
end - i.e. some way downline given that infinity/something = infinity. :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Exponential transmission lines
 

In article , Stewart Pinkerton
wrote:
On Fri, 19 Sep 2003 09:12:46 +0100, Jim Lesurf
wrote:

In article , The Old
Fogey wrote:
Anyone come across an exponentially tapered transmission line, apart
from the B&W Nautilus? It looks like it would be an amusing project. An
infinite length exponential taper has a finite internal volume so all I
need is to find a wall material with zero thickness :-)

It has just occurred to me that another problem in use would be the
propagation delay along an infinitely long transmission line might mean
you'd have to wait some time after starting to play the music before you
heard anything! Might be best to press 'play' then go and have your
dinner... :-)

Um, the line absorbs the back radiation.......

Blast! That ruins the joke. :-/ I was assuming that the actual speaker
unit was located a fraction of the length of the line away from the open
end - i.e. some way downline given that infinity/something = infinity. :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Exponential transmission lines
 

"Jim Lesurf" wrote in message
...
In article , Stewart Pinkerton
wrote:
On Fri, 19 Sep 2003 09:12:46 +0100, Jim Lesurf
wrote:

In article , The Old
Fogey wrote:
Anyone come across an exponentially tapered transmission line, apart
from the B&W Nautilus? It looks like it would be an amusing project.
An
infinite length exponential taper has a finite internal volume so all
I
need is to find a wall material with zero thickness :-)

It has just occurred to me that another problem in use would be the
propagation delay along an infinitely long transmission line might mean
you'd have to wait some time after starting to play the music before
you
heard anything! Might be best to press 'play' then go and have your
dinner... :-)

Um, the line absorbs the back radiation.......

Blast! That ruins the joke. :-/ I was assuming that the actual speaker
unit was located a fraction of the length of the line away from the open
end - i.e. some way downline given that infinity/something = infinity.
:-)

Slainte,

Jim

how about a hybrid Horn TL speaker !?
anybody ever made these ? might be fun.