Someone asked me for a pair of large woofers in separate
enclosures using 1.5" of structural plywood.
JBL make a large range, but I don't think their 15" top range with 800
watt capability
is what I neeed, since I only want to use about 2 watts max.

Anyone have any clues?

Patrick Turner.

Try looking for some Lyeco http://www.lyeco.com.tw/
They are chinese but AWERSOME speakers!!!!
You can buy EX WORKS a very small number of speakers as samples. (I did)

Bye



"Patrick Turner" ha scritto nel messaggio
...
Someone asked me for a pair of large woofers in separate
enclosures using 1.5" of structural plywood.
JBL make a large range, but I don't think their 15" top range with 800
watt capability
is what I neeed, since I only want to use about 2 watts max.

Anyone have any clues?

Patrick Turner.

"Patrick Turner" wrote in message
...
Someone asked me for a pair of large woofers in separate
enclosures using 1.5" of structural plywood.
JBL make a large range, but I don't think their 15" top range with 800
watt capability
is what I neeed, since I only want to use about 2 watts max.

Anyone have any clues?

Patrick Turner.




What about a JBL2235? Lower power handling, low FS and still fairly
sensitive.

May be out of prod, can't remember, but plenty of baskets out there and cone
kits are still readily available.

Chad

"Patrick Turner" wrote in message
...
Someone asked me for a pair of large woofers in separate
enclosures using 1.5" of structural plywood.
JBL make a large range, but I don't think their 15" top range with 800
watt capability
is what I neeed, since I only want to use about 2 watts max.

Anyone have any clues?

**You have not supplied (anywhere near) enough information. For instance:

* Size of enclosure.
* Lower 3dB point.
* Upper 3dB point.
* Cost.
* Does it have to be a 380mm driver? (Why?)
* Would an externally amplified bass system be an acceptable solution?
* Etc.


--
Trevor Wilson
www.rageaudio.com.au

"François Yves Le Gal" wrote:

On Wed, 01 Jun 2005 16:38:16 GMT, Patrick Turner
wrote:

Anyone have any clues?

What will be the application? A sub (BW limited to 150 Hz max.) or a bass
box (BW up to 300 or 500 Hz)?

I want 25Hz to 500Hz.

I already get 25 -300 with a pair of 1974 Electrovoice 12" in a
90 Kg box of 135L ported.

They are excellent bass speakers, but I am looking for
more sensitivity, large box size doesn't matter too much, they are for an
enormous room.

Patrick Turner.

Chad Wahls wrote:

"Patrick Turner" wrote in message
...
Someone asked me for a pair of large woofers in separate
enclosures using 1.5" of structural plywood.
JBL make a large range, but I don't think their 15" top range with 800
watt capability
is what I neeed, since I only want to use about 2 watts max.

Anyone have any clues?

Patrick Turner.




What about a JBL2235? Lower power handling, low FS and still fairly
sensitive.

May be out of prod, can't remember, but plenty of baskets out there and cone
kits are still readily available.

Chad

Thanks, I will check that one out.

The driver does not have to be able to cope with enormous power
like many professional PA speakers can.

Patrick Turner.

"Trevor Wilson" wrote

Anyone have any clues?

**You have not supplied (anywhere near) enough information. For
instance:

* Size of enclosure.
* Lower 3dB point.
* Upper 3dB point.
* Cost.
* Does it have to be a 380mm driver? (Why?)
* Would an externally amplified bass system be an acceptable
solution?

That's six clues. Should keep him busy for a while.

cheers, Ian

Ian Iveson wrote:

"Trevor Wilson" wrote

Anyone have any clues?

**You have not supplied (anywhere near) enough information. For
instance:

* Size of enclosure.
* Lower 3dB point.
* Upper 3dB point.
* Cost.
* Does it have to be a 380mm driver? (Why?)
* Would an externally amplified bass system be an acceptable
solution?

That's six clues. Should keep him busy for a while.

cheers, Ian

Its six questions, not clues.

Patrick Turner.

"François Yves Le Gal" wrote:

On Wed, 01 Jun 2005 16:38:16 GMT, Patrick Turner
wrote:

Anyone have any clues?

What will be the application? A sub (BW limited to 150 Hz max.) or a bass
box (BW up to 300 or 500 Hz)?

I am wanting 20Hz to 500Hz.

A quick look with Win ISD at using a JBL 2235 in a 250L box tuned to 20Hz
would do the job. If 0dB is at 300Hz, then 20Hz = -8dB.
But this is OK if we contour the response above 30Hz to give a flat
response to 300, which is then -5dB. To go low, one must always trade away
some
upper bass / lower midrange sensitivity.
A dedicated bass amp will be used.

Maybe a pair of Peerless XLS 12" would be OK,
170L would be about right, but the single 15" is simpler.

Patrick Turner.

On Thu, 02 Jun 2005 03:30:38 GMT, Patrick Turner
wrote:

I am wanting 20Hz to 500Hz.

People in Hell want ice water, mon. There ain't any woofs
that do five and 1/3 octaves convincingly, native.

Besides, do you *really* want a crossover at 500Hz? Very
much in voice range, mon, methinks. 'Course, it's your gig.

At small excursions, maybe you'd want to be looking at
musical instrument drivers. They're appropriately sensitive
and linear within their (restricted) excursion range.

My absolute top-most numero-uno recommendation to anyone
interested in speakers in any way is to read Siegfried
Linkwitz's revised papers in 1979/1980 Speaker Builder,
which are an improvement and elaboration on his AES and
WW earlier papers. All modern thought comes from here.
No ****. Not included in his web site, but that's otherwise
also great stuff.

Chris Hornbeck

"Patrick Turner" wrote in message
...


"François Yves Le Gal" wrote:

On Wed, 01 Jun 2005 16:38:16 GMT, Patrick Turner

wrote:

Anyone have any clues?

What will be the application? A sub (BW limited to 150 Hz max.) or a bass
box (BW up to 300 or 500 Hz)?

I want 25Hz to 500Hz.

**500Hz from a 380mm bass drive is, well, um, insane. At least for proper hi
fi applications, anyway. Do the math. For sound reinforcement, such a
crossover frequency would be (barely) acceptable, but not for hi fi
applications.


--
Trevor Wilson
www.rageaudio.com.au

"Patrick Turner" wrote in message
...

I am wanting 20Hz to 500Hz.

A quick look with Win ISD at using a JBL 2235 in a 250L box tuned to 20Hz
would do the job. If 0dB is at 300Hz, then 20Hz = -8dB.
But this is OK if we contour the response above 30Hz to give a flat
response to 300, which is then -5dB. To go low, one must always trade away
some
upper bass / lower midrange sensitivity.
A dedicated bass amp will be used.

Hey Patrick, I'm currently building a horn system using the 2235 in a
similarly sized box (with EBS tuning). I was also going to try the
JBL-recommended reflex box of 5 cu ft (non-EBS), but that wouldn't go down
to 20Hz. I haven't really done much so far (I have one driver in one 250L
chipboard box). You want to drive it with 2 watts?!? I think it will need
more than that. Are you building it for anyone I know (they are obviously a
SET freak like me)? Doogster

I'd give a try to these ones:

http://www.fostexinternational.com/d...W-Series.shtml

There's a full range of products, none made of Unobtainium, and a full .PDF
datasheet available for downloading

Ciao

Fabio

"Patrick Turner" ha scritto nel messaggio
...
Someone asked me for a pair of large woofers in separate
enclosures using 1.5" of structural plywood.
JBL make a large range, but I don't think their 15" top range with 800
watt capability
is what I neeed, since I only want to use about 2 watts max.

Anyone have any clues?

Patrick Turner.

"Patrick Turner" wrote

**You have not supplied (anywhere near) enough information. For
instance:

* Size of enclosure.
* Lower 3dB point.
* Upper 3dB point.
* Cost.
* Does it have to be a 380mm driver? (Why?)
* Would an externally amplified bass system be an acceptable
solution?

That's six clues. Should keep him busy for a while.

Its six questions, not clues.

Clues are very often in the form of questions.

Trevor is trying to guide you through your own thought processes and
help you to cultivate new concepts in your own head. It is a much
better approach to education than giving answers.

Perhaps if you gave those matters some honest consideration, and
respectfully answer his questions, he will help you with the next
stage of the selection process.

cheers, Ian

Chris Hornbeck wrote:

On Thu, 02 Jun 2005 03:30:38 GMT, Patrick Turner
wrote:

I am wanting 20Hz to 500Hz.

People in Hell want ice water, mon. There ain't any woofs
that do five and 1/3 octaves convincingly, native.

Besides, do you *really* want a crossover at 500Hz? Very
much in voice range, mon, methinks. 'Course, it's your gig.

But quite a few folks use 500Hz.
Voice range is between 100Hz to 3 kHz, because there are harmonics of
voice within
that range at least; female voice harmonics go even higher...

The dude who wants the bass units wants to use horm mids and treble.

My two stereo systems I have set up here both have 20Hz to 300 Hz range
in the bass units.
it could be up to 2 khz, but the cone break up modes and rising unflat
effciency
of the bass speakers concerned prevent me from having a high Xover F.
The midrange I like to use are 5" SEAS or peerless units; there is no
need to use
large dia cones for anything above 200Hz for hi-fi at home.
One can squeeze the bass speaker output to 500Hz, then cross to a mid
horn,
its not too hard to make a horn which does 500Hz to 5k.





At small excursions, maybe you'd want to be looking at
musical instrument drivers. They're appropriately sensitive
and linear within their (restricted) excursion range.

Most musical instrument speakers are not what I want.
Too stiffly suspended, and Fs too high, and too much output as F
rises...



My absolute top-most numero-uno recommendation to anyone
interested in speakers in any way is to read Siegfried
Linkwitz's revised papers in 1979/1980 Speaker Builder,
which are an improvement and elaboration on his AES and
WW earlier papers. All modern thought comes from here.
No ****. Not included in his web site, but that's otherwise
also great stuff.

I shall give this consideration.

Patrick Turner.



Chris Hornbeck

Trevor Wilson wrote:

"Patrick Turner" wrote in message
...


"François Yves Le Gal" wrote:

On Wed, 01 Jun 2005 16:38:16 GMT, Patrick Turner

wrote:

Anyone have any clues?

What will be the application? A sub (BW limited to 150 Hz max.) or a bass
box (BW up to 300 or 500 Hz)?

I want 25Hz to 500Hz.

**500Hz from a 380mm bass drive is, well, um, insane. At least for proper hi
fi applications, anyway. Do the math. For sound reinforcement, such a
crossover frequency would be (barely) acceptable, but not for hi fi
applications.

Insane? Proper?

Not a reason for the above stated.

Patrick Turner.





--
Trevor Wilson
www.rageaudio.com.au

Doug Flynn wrote:

"Patrick Turner" wrote in message
...

I am wanting 20Hz to 500Hz.

A quick look with Win ISD at using a JBL 2235 in a 250L box tuned to 20Hz
would do the job. If 0dB is at 300Hz, then 20Hz = -8dB.
But this is OK if we contour the response above 30Hz to give a flat
response to 300, which is then -5dB. To go low, one must always trade away
some
upper bass / lower midrange sensitivity.
A dedicated bass amp will be used.

Hey Patrick, I'm currently building a horn system using the 2235 in a
similarly sized box (with EBS tuning).

Aha, our Master Experimenter speaks.....

I was also going to try the
JBL-recommended reflex box of 5 cu ft (non-EBS), but that wouldn't go down
to 20Hz.

EBS tuning? what is that?
20Hz is the -3dB point.
As F rises above 30Hz, the rate of response increase
is less than 3 dB/octave, and so the response can easily be attenuated by an RC
network
at an amp input to make it flat above 30Hz. One can hump the response at 40Hz.
(pardon the expression) The price to pay is sensitivity.
Its not very good as F goes lower than 40 Hz, but hey, its not woeful.
One can easily power a large woofer at below 40 hz for hi-fi,
where the actual power isn't beyound our means.

Many large dia speakers have excellent sensitivity, maybe 98 dB/W/M at 400 Hz.
We can afford to simply reduce the input voltage to the power amp.
The end result is that the power amp only has to produce a tiny amount of power
at 400hz, and at 30Hz, much more power is needed for the same SPL, but in
practice
we never need much high power there because most music has such a tiny amount
of energy below 40 hz; but ambient sounds of the venue may want to be
reproduced,
so that's what we get with full range bass. Many ppl use a subwoofer, I don't
myself
do it; the bass speakers i have *are* capable of what any sub I have made for
customers
can do. Ppl don't realise that a bass speaker such as the Peerless 12" XLS
is able to be used up to well above the cut off of say 100Hz as used in a sub.
I found the response I got with 86L and a port of about 450mm long
with Peerless 12" XLS was awesome. The WIN ISD program got it right.


I haven't really done much so far (I have one driver in one 250L
chipboard box). You want to drive it with 2 watts?!? I think it will need
more than that. Are you building it for anyone I know (they are obviously a
SET freak like me)? Doogster

Its for a guy in Sydney. He said wanted a horn speaker which would allow 16 Hz
organ notes.

I said he could have all that, but the horn size and cost went up exponentially
as F dips below 100Hz.
His interest and passion waivered when i explained what is involved.....

I have heard many bass speakers, and built a lot, so I kinda know what works for
me,
and 2 watts at 20Hz may be all that someone might actually use, if they are
using
only 0.2 watts average levels for the band between 100Hz and 1 kHz.

I once measured how little bass power below 50 hz was needed. Not much, really.

A friend with a 15" in a large ported box uses a 600 watt capable amp.
he gets a realistic reproduction of a recording of the Space Shuttle taking off.

Ahrgh, Real Grunt.

But church music? 120dB at 30Hz?

Nah, the little old ladies would be complaining at the priest after mass....

Low bass **needs** to just be there, but not above a level which makes ppl
spew, or complain, although young folks seem to like as much bass as can be
arranged,
until they become civilised, and learn to like the complexities of Bach,
and/or the best of the techno around.

The two systems I have myself go down very low.

I could get more by boosting the very low area, or doing
what Infinity appear to have done, place a resonant HPF in front of the woofer
tuned to
29Hz, thus peaking the very low bass.

Its cheating of course, but so what? it would make amps work a little harder
since the result of such a series resonant F is that the Z falls to say 1 of 2
ohms and
the input current for a given applied voltage is high. A really big organ note
of 32 Hz might
blow a fuse.

The two 12" drivers I have in 135L reflexes have more subjectively convincing
bass at really low F than the SEAS 8" in 55L, but they measure almost
identically.
One gets the feeling of air moving when loud drum beats occur with the larger
cones.
bas F contain lots of subtle transients....

The average listener using average recordings isn't at first sure there is good
bass
capability with my speakers, he may think, oh, not much bass, until
there is some really low good stuff, and wow, you could carve slices of it and
eat it for lunch.

If I put on the Stones Beggar's Banquet, the Stones seem like noisy kids,
which they were then, and not much bass.
Then i do Marley, and ye, there is bass.
Its still all mainly above 50 hz though, and the really low stuff
resides in the organ music, because few instruments go to 20Hz.

I set up the last sub I built set to an F2 cut off of 37Hz, and without the
other speakers used
I turned up the gain on various bits of music.
What came out the sub sounded like disembowelled LF crap, a kind of rumbly
cacophany, and not musical.
But added to the other speakers with the music and at the right volume,
the body of the music is obviously more natural and real.
Very low power is needed to fill in the gap between the 60Hz cut off
of many modern speakers and the lowest sine waves at 20Hz.
In many music recordings, the LF was simply filtered out,
since it was impossible or disadvantageous to include it on a vinyl recording.


One other gentleman here in town has Altec horns and a large 15" woofer in a
large ported box
and he uses about 2 milliwats from the SET amps to do above 500Hz.

The SET choice is a very sensible one in this case, since at such low power the
SET amps
are in their region of very low thd.

As I mentioned, I have some distance to go before this gentleman gets the full
benefit of his horned system. It is going to take some doing.
So far it sounds best when it measures best.

Anyway, now I have heard two guys saying JBL 2235 are OK.

What do they cost?

Patrick Turner.

Fabio Berutti wrote:

I'd give a try to these ones:

http://www.fostexinternational.com/d...W-Series.shtml

There's a full range of products, none made of Unobtainium, and a full .PDF
datasheet available for downloading

The FW405 looks like a sensible choice.
Its response graph shows 101 dB at 1.4kHz, 96dB at 400Hz, 93dB at 60Hz, and
84dB at 30 Hz, and 82 dB at 20Hz.
Its Fs is 20Hz, and its Qts is 0.34, so it looks suitable.
I will have to enter all the T&S data into my WINISD to see how she tunes up
with a ported box.
The response is a straight line between 60Hz and 1.4 khz.,
so there is 8 dB roll off below 1.4 khz
Now to flatten that and have an effective damping factor, the best way
is to have a direct coupled amp with a filter at the input.

If one tried to have a passive filter between amp and driver, the
series R between the amp and driver at 1.4 khz would be considerable, and the
DF would be poor by 500Hz, and reactive bcause of a crossover around a kHz.
Not a good scene.
But lets think more about using just one amp....

Its simpler to have a smaller bass F band and have a crossover at no higher
than 500Hz
if we are to have a passive Xover, and mid between 500Hz and 5kHz is better
produced by a midrange speaker.
but we have to relate how we set things up to a reference where amp voltage is
2.83v at 400Hz.
The voltage at the driver will be lower at 500Hz, about 1.7v, to get the
response level
with what happens at 30Hz, the start of the flat portion of the response
where 2.83v is all applied to the bass speaker.
The 2.83v at 30Hz gives only 84dB/W/M.

At say 1 khz, in the middle of a midrange speakers's range, 2.83v might give
90 dB/W/M so we need some way of reducing this by 6 dB to 84 dB.
This is 4 times less power so we want 1/2 the voltage, so 1.4v is needed to be
applied
to the mid speaker. If the mid Z was 6 ohms at 1kHz, a 6 ohm resistor would do,

but then we are wasting an awful lot of power in a 6 ohm R, and effective
sensitivity
is reduced to pitful levels, although the input Z is very nice for tube amps at
12 ohms.
We may not be able to make a speaker thus configured go loud.
But we could use two midranges in series, each having a sensitivity
with power less than 90 dB/W.
Not easy to find maybe.

Now here is the opportunity where a speaker tranny might work wonders
if the mids and tweeters were conventional drivers of around 90dB/W/M.


We wouldn't be looking for a full BW tranny because there is only a need to
lower the midrange (and tweeter) signal voltages.
So if we have 6 ohms connected to the CT of a speaker tranny,
we won't waste much power because tranny efficiency can be 95%
and the efficiency of the midrange will stay at around 90 dB/W/M.
But the amp will see 4 x 6 ohms, or 24 ohms as a load, and the
damping factor of the amp will be improved 4 times, since Ro of the amp is
transformed
by a speaker step down tranny.
We would need an amp capable of a wide volatge swing.
The impur impedance of the bass unit will average 10ohms because of the
attentuation of the upper bass. The 2:1 mid/treb tranny will increase Z,
so an amp with a 16 ohm outlet will do well.


In the case of horn speakers used for mid/treble with a much more insensitive
bass speaker,
we would need taps of a speaker tranny at much lower levels.
The tranny would increase Z to 80 ohms perhaps, and we could not get enough
voltage
head room to get the 104 db wanted from the horns after transforming down the
input voltage about 10 times.

So the point i have to make is that its difficult to achieve simplicity, low
damping factor at all F,
and good load matching and goor power/current/voltage headrooms all at the same
time if the speakers
widely vary with sensitivity.

There is more optimization and versatility to be had if we used a bass amp to
drive a bass speaker
directly with a contour filter ahead of it, and if we have a pair of horns for
the rest
with around equal high sensitivity then a single 300B amp will be plenty, and
one set
up so that 5k to 2 ohms is available will allow an excellent damping factor and
low thd
if the horn Z = about 8 ohms average.

Patrick Turner.





Ciao

Fabio

"Patrick Turner" ha scritto nel messaggio
...
Someone asked me for a pair of large woofers in separate
enclosures using 1.5" of structural plywood.
JBL make a large range, but I don't think their 15" top range with 800
watt capability
is what I neeed, since I only want to use about 2 watts max.

Anyone have any clues?

Patrick Turner.

Ian Iveson wrote:

"Patrick Turner" wrote

**You have not supplied (anywhere near) enough information. For
instance:

* Size of enclosure.
* Lower 3dB point.
* Upper 3dB point.
* Cost.
* Does it have to be a 380mm driver? (Why?)
* Would an externally amplified bass system be an acceptable
solution?

That's six clues. Should keep him busy for a while.

Its six questions, not clues.

Clues are very often in the form of questions.

Trevor is trying to guide you through your own thought processes and
help you to cultivate new concepts in your own head. It is a much
better approach to education than giving answers.

Trevor isn't much of a guide, he leadeth me blindly....



Perhaps if you gave those matters some honest consideration, and
respectfully answer his questions, he will help you with the next
stage of the selection process.

Er, not while he retains a genuine dislike for much of what we do with
tubes.
He has an irrational tendency to **** on anyone who uses a single triode
tube to
amplify anything.

Oinkerton didn't last around here because he had the same stupid
attitude.
And what did Oinky give to us? a paper SS amp?


Trevor's posts are short, undetailed, and with ZERO information to allow

users of vacuum tubes to get better results.
I fear he cannot calculate anything accurately, and he doesn't really
know
the real details about amplifiers because he doesn't ever design or
build anything.

As regards other matters regarding such things as the Behringer digital
active Xover, I take the point he makes, and I leave folks to decide.

I would still suggest a tubed active crossover can be just as good and
probably
simpler and better as anything analog with SS. Since I have not tried
the Behringer, and
nobody has related any experiences, whether it makes better music is
unknown
to us here now.

Patrick Turner.





cheers, Ian

"Patrick Turner" wrote in message
...


Trevor Wilson wrote:

"Patrick Turner" wrote in message
...


"François Yves Le Gal" wrote:

On Wed, 01 Jun 2005 16:38:16 GMT, Patrick Turner

wrote:

Anyone have any clues?

What will be the application? A sub (BW limited to 150 Hz max.) or a
bass
box (BW up to 300 or 500 Hz)?

I want 25Hz to 500Hz.

**500Hz from a 380mm bass drive is, well, um, insane. At least for proper
hi
fi applications, anyway. Do the math. For sound reinforcement, such a
crossover frequency would be (barely) acceptable, but not for hi fi
applications.

Insane?

**For hi fi use, yes.

Proper?

Not a reason for the above stated.

**Absolutely for the reason stated above. If you want a driver to extend to
500Hz, I would suggest you restrict the bass driver size to 200 or 220mm
tops. 380mm drivers will not perform up to 500Hz, with any kind of fidelity.


--
Trevor Wilson
www.rageaudio.com.au

"Ian Iveson" wrote in message
. uk...
"Trevor Wilson" wrote

Anyone have any clues?

**You have not supplied (anywhere near) enough information. For instance:

* Size of enclosure.
* Lower 3dB point.
* Upper 3dB point.
* Cost.
* Does it have to be a 380mm driver? (Why?)
* Would an externally amplified bass system be an acceptable solution?

That's six clues. Should keep him busy for a while.

**It should, but Patrick is incapable of separating his hatred for me
(because I challenge his ideas) and common sense. He will ignore me and my
suggestions.


--
Trevor Wilson
www.rageaudio.com.au

"Patrick Turner" wrote in message
...


Fabio Berutti wrote:

I'd give a try to these ones:

http://www.fostexinternational.com/d...W-Series.shtml

There's a full range of products, none made of Unobtainium, and a full
.PDF
datasheet available for downloading

The FW405 looks like a sensible choice.
Its response graph shows 101 dB at 1.4kHz, 96dB at 400Hz, 93dB at 60Hz,
and
84dB at 30 Hz, and 82 dB at 20Hz.
Its Fs is 20Hz, and its Qts is 0.34, so it looks suitable.
I will have to enter all the T&S data into my WINISD to see how she tunes
up
with a ported box.
The response is a straight line between 60Hz and 1.4 khz.,
so there is 8 dB roll off below 1.4 khz

**YIKES! It is easy to stuff up a speaker system, by hand. To REALLY stuff
up, you need a computer. Computers and computer aided speaker design is a
great way to go, as long as you ask the right questions. Tell us what your
WINISD shows for a (say) 45o OFF-axis response from that woofer. When you
examine that response, you may begin to understand why you cannot use a
380mm bass driver up to 500Hz. You sure as Hell wouldn't let it get anywhere
near 1kHz. This all quite apart from the fact that preventing cone break-up
at such high frequencies, when using a lightweight cone, is a monumentally
difficult task.

Use a smaller driver.


--
Trevor Wilson
www.rageaudio.com.au

On Thu, 02 Jun 2005 12:30:18 GMT, Patrick Turner
wrote:

Most musical instrument speakers are not what I want.
Too stiffly suspended, and Fs too high, and too much output as F
rises...

My absolute top-most numero-uno recommendation to anyone
interested in speakers in any way is to read Siegfried
Linkwitz's revised papers in 1979/1980 Speaker Builder,
which are an improvement and elaboration on his AES and
WW earlier papers. All modern thought comes from here.
No ****. Not included in his web site, but that's otherwise
also great stuff.

I shall give this consideration.

One of the things that Linkwitz discusses is the simple design
of a single stage F-sub-c and Q-sub-tc correcting inverting amp
stage. For closed boxes, box size doesn't matter; only driver
linear excursion.

Basically, you measure (from impedance measurements, very easy,
only needs a signal gen, ACDVM, scope) F and Q, in box, plug
into simple algebra with desired F and Q, output R's and C's.

Guaranteed to revolutionize your thoughts about speakers.
BTW, he's the Linkwitz in Linkwitz-Riley crossovers. Riley
was apparently a deep math guy.

Chris Hornbeck

Trevor Wilson wrote:

"Ian Iveson" wrote in message
. uk...
"Trevor Wilson" wrote

Anyone have any clues?

**You have not supplied (anywhere near) enough information. For instance:

* Size of enclosure.
* Lower 3dB point.
* Upper 3dB point.
* Cost.
* Does it have to be a 380mm driver? (Why?)
* Would an externally amplified bass system be an acceptable solution?

That's six clues. Should keep him busy for a while.

**It should, but Patrick is incapable of separating his hatred for me
(because I challenge his ideas) and common sense. He will ignore me and my
suggestions.

I do not ignore you Trevor.
Unlike people with an open mind who come to this group to talk about tube usage
and speakers for tube amps, you come with a closed mind, and ****
on anyone who dares to use a triode for an amplifier.

Now you will always be hated for ****ing and ****ting all around the place
while insisting your opinions are just the facts.

Patrick Turner.



--
Trevor Wilson
www.rageaudio.com.au

Trevor Wilson wrote:

"Patrick Turner" wrote in message
...


Fabio Berutti wrote:

I'd give a try to these ones:

http://www.fostexinternational.com/d...W-Series.shtml

There's a full range of products, none made of Unobtainium, and a full
.PDF
datasheet available for downloading

The FW405 looks like a sensible choice.
Its response graph shows 101 dB at 1.4kHz, 96dB at 400Hz, 93dB at 60Hz,
and
84dB at 30 Hz, and 82 dB at 20Hz.
Its Fs is 20Hz, and its Qts is 0.34, so it looks suitable.
I will have to enter all the T&S data into my WINISD to see how she tunes
up
with a ported box.
The response is a straight line between 60Hz and 1.4 khz.,
so there is 8 dB roll off below 1.4 khz

**YIKES! It is easy to stuff up a speaker system, by hand. To REALLY stuff
up, you need a computer. Computers and computer aided speaker design is a
great way to go, as long as you ask the right questions. Tell us what your
WINISD shows for a (say) 45o OFF-axis response from that woofer.

A client has 15" woofers, and Altec horns. He does not listen 45d off axis.

I measured the response and it is OK up to 7 kHz.
He is getting other horns to fill in the 7k to 20k

WINISD doesn't show us everything about any driver, but i have found it useful
for the box match at LF; for the upper bass and midrange
the only way to make sure the response is ok is to build it and trim it all by
careful in-house measuring and calculated /tested filter apps.

I am a hands-on engineer. I don't take too much notice of what a computer tells
me.

..

When you
examine that response, you may begin to understand why you cannot use a
380mm bass driver up to 500Hz.

Quite a few ppl do use 380mm woofers.

You sure as Hell wouldn't let it get anywhere
near 1kHz.

No intention to do so

This all quite apart from the fact that preventing cone break-up
at such high frequencies, when using a lightweight cone, is a monumentally
difficult task.

We know all that.

Many old time 12" speakers were also hopeless above a certain flat region of
operation.

My Foster 12" woofers i used in my first speakers sounded better when limited to
250Hz and with a
sharp cut off above 400Hz. I prefer small midranges.

But the client wanting the 15" woofers wants them, and wants to use horns above
500Hz.

So I will attempt to give him the best i can, and I have pointed out
the pitfalls.

The JBL 2235 looks a reasonable candidate for my woofer.
Although is has a rising acoustic output above the F1 point, it rises
as a flat line, not in a series of high Q peaks and troughs, which are
impossible to iron out.



Use a smaller driver.

I'll do what I think I have to.

Patrick Turner.





--
Trevor Wilson
www.rageaudio.com.au

Chris Hornbeck wrote:

On Thu, 02 Jun 2005 12:30:18 GMT, Patrick Turner
wrote:

Most musical instrument speakers are not what I want.
Too stiffly suspended, and Fs too high, and too much output as F
rises...

My absolute top-most numero-uno recommendation to anyone
interested in speakers in any way is to read Siegfried
Linkwitz's revised papers in 1979/1980 Speaker Builder,
which are an improvement and elaboration on his AES and
WW earlier papers. All modern thought comes from here.
No ****. Not included in his web site, but that's otherwise
also great stuff.

I shall give this consideration.

One of the things that Linkwitz discusses is the simple design
of a single stage F-sub-c and Q-sub-tc correcting inverting amp
stage. For closed boxes, box size doesn't matter; only driver
linear excursion.

Basically, you measure (from impedance measurements, very easy,
only needs a signal gen, ACDVM, scope) F and Q, in box, plug
into simple algebra with desired F and Q, output R's and C's.

You have lost me.



Guaranteed to revolutionize your thoughts about speakers.

It takes time to be revolutionized, time i don't have,
unless I could be God for a minute, and then I'd invent a 240 hr day
immediately.



BTW, he's the Linkwitz in Linkwitz-Riley crossovers. Riley
was apparently a deep math guy.

Chris Hornbeck

Linkwitz doesn't like ported boxes.....

Patrick Turner.

"Patrick Turner" wrote in message
...



**It should, but Patrick is incapable of separating his hatred for me
(because I challenge his ideas) and common sense. He will ignore me and
my
suggestions.

I do not ignore you Trevor.

**Sure you do. I asked several pertinent, reasonable, rational questions.
You ignored me.

Unlike people with an open mind who come to this group to talk about tube
usage
and speakers for tube amps, you come with a closed mind, and ****
on anyone who dares to use a triode for an amplifier.

**More lies from you Patrick. Triodes make EXCELLENT amplification devices.
Low distortion, wide bandwidth and low ouput impedance. Trouble is, that
they are not suitable for SE use. In PP, they're bloody excellent. I do not
"**** on anyone who dars to use a triode for an amplifier". I just state
facts. SET amplifiers are VASTLY inferior to a PP amp using the same tubes.
Understand yet?


Now you will always be hated for ****ing and ****ting all around the place
while insisting your opinions are just the facts.

**What does RDH4 say about PP vs. SE? Where does it say that PP is inferior
to SE? Please quote the page number.

I guess you'll ignore that question too.


--
Trevor Wilson
www.rageaudio.com.au

"Patrick Turner" wrote in message
...


Trevor Wilson wrote:

"Patrick Turner" wrote in message
...


Fabio Berutti wrote:

I'd give a try to these ones:

http://www.fostexinternational.com/d...W-Series.shtml

There's a full range of products, none made of Unobtainium, and a full
.PDF
datasheet available for downloading

The FW405 looks like a sensible choice.
Its response graph shows 101 dB at 1.4kHz, 96dB at 400Hz, 93dB at 60Hz,
and
84dB at 30 Hz, and 82 dB at 20Hz.
Its Fs is 20Hz, and its Qts is 0.34, so it looks suitable.
I will have to enter all the T&S data into my WINISD to see how she
tunes
up
with a ported box.
The response is a straight line between 60Hz and 1.4 khz.,
so there is 8 dB roll off below 1.4 khz

**YIKES! It is easy to stuff up a speaker system, by hand. To REALLY
stuff
up, you need a computer. Computers and computer aided speaker design is a
great way to go, as long as you ask the right questions. Tell us what
your
WINISD shows for a (say) 45o OFF-axis response from that woofer.

A client has 15" woofers, and Altec horns. He does not listen 45d off
axis.

**How about 30o or 15o?


I measured the response and it is OK up to 7 kHz.

**No, it is not. The sound would be horrific.

He is getting other horns to fill in the 7k to 20k

WINISD doesn't show us everything about any driver, but i have found it
useful
for the box match at LF; for the upper bass and midrange
the only way to make sure the response is ok is to build it and trim it
all by
careful in-house measuring and calculated /tested filter apps.

I am a hands-on engineer. I don't take too much notice of what a computer
tells
me.

.

When you
examine that response, you may begin to understand why you cannot use a
380mm bass driver up to 500Hz.

Quite a few ppl do use 380mm woofers.

**Sure. They're deluded.


You sure as Hell wouldn't let it get anywhere
near 1kHz.

No intention to do so

**Really? What kind of filter are you using? 100dB/octave?


This all quite apart from the fact that preventing cone break-up
at such high frequencies, when using a lightweight cone, is a
monumentally
difficult task.

We know all that.

**Then you already know that a 380mm woofer should not be used past 150Hz.


Many old time 12" speakers were also hopeless above a certain flat region
of
operation.

My Foster 12" woofers i used in my first speakers sounded better when
limited to
250Hz and with a
sharp cut off above 400Hz. I prefer small midranges.

But the client wanting the 15" woofers wants them, and wants to use horns
above
500Hz.

**He's deluded.


So I will attempt to give him the best i can, and I have pointed out
the pitfalls.

The JBL 2235 looks a reasonable candidate for my woofer.
Although is has a rising acoustic output above the F1 point, it rises
as a flat line, not in a series of high Q peaks and troughs, which are
impossible to iron out.



Use a smaller driver.

I'll do what I think I have to.

**That is the smart thing to do.


--
Trevor Wilson
www.rageaudio.com.au

On Fri, 03 Jun 2005 04:04:34 GMT, Patrick Turner
wrote:

One of the things that Linkwitz discusses is the simple design
of a single stage F-sub-c and Q-sub-tc correcting inverting amp
stage. For closed boxes, box size doesn't matter; only driver
linear excursion.

Basically, you measure (from impedance measurements, very easy,
only needs a signal gen, ACDVM, scope) F and Q, in box, plug
into simple algebra with desired F and Q, output R's and C's.

You have lost me.

Sorry. Shortcuts in postings bite both ways. Assume... etc.

Linkwitz, in addition to conceiving a useful, practical, real-
world model of idealized drivers combining in imperfect spacial
relationships (all included in his earlier WW and AES papers)
also describes a simple inverting stage that *anyone* can use
to make any driver in any sealed box have any desired F and Q.

To me, it was revolutionary. Still is, 'cause lotsa folks
still haven't read it. Correction on my earlier post: the
Speaker Builder articles are all in the 1980 quarterly frame.
AFAIK, no internet versions are available; sorry. There were no
1979's.

Speaker designs, like everything else for we poor mortals, must
begin by simplifying; for speakers, we begin by idealizing drivers
as rigid pistons; this is the take-off point for Linkwitz's
work. Joe D'Appolito followed up with a geometric solution to
the summing problem that Linkwitz raised; another story.

Linkwitz doesn't like ported boxes.....

Jah don' like ported boxes, mon. Jus' ain' right.
Word.

Chris Hornbeck

"Patrick Turner" wrote in message
...

Anyway, now I have heard two guys saying JBL 2235 are OK.

What do they cost?

Patrick Turner.

They are discontinued. I paid A$200 for one (new) and A$350 for the other
(a recone). You have to shop around. Doug

Trevor Wilson wrote:

"Patrick Turner" wrote in message
...



**It should, but Patrick is incapable of separating his hatred for me
(because I challenge his ideas) and common sense. He will ignore me and
my
suggestions.

I do not ignore you Trevor.

**Sure you do. I asked several pertinent, reasonable, rational questions.
You ignored me.

I'm not ignoring an arsole like yourself.

Do yourself a favour, and STFU.



Unlike people with an open mind who come to this group to talk about tube
usage
and speakers for tube amps, you come with a closed mind, and ****
on anyone who dares to use a triode for an amplifier.

**More lies from you Patrick. Triodes make EXCELLENT amplification devices.
Low distortion, wide bandwidth and low ouput impedance. Trouble is, that
they are not suitable for SE use. In PP, they're bloody excellent. I do not
"**** on anyone who dars to use a triode for an amplifier". I just state
facts. SET amplifiers are VASTLY inferior to a PP amp using the same tubes.
Understand yet?

I see you just dropped large pile of **** onto SE triode amps.
Even though you hang out in Hurstville in Sydney, the people of the world
far away can smell your droppings.

Sure I understand.

I understand you deny what you are while a foot is stuck in your mouth.

You **** all over the many people who use SET amps in preference to anything
PP.

So how about you just **** OFF OUT OF THIS NEWS GROUP!!!


Trevor Wilson is a Dunderhead Extraordinaire when it comes to tube understanding

and as soon as things get technical in any amplifier discussions, he is
incapable of rational discussions.

He has repeatedly attacked anyone and everyone for years over the issue of SET
amplifiers,
and here he goes again.

There is ample record in the Google records of the news groups to
indicate what my tolerant and open minded point of view is about SET amps,
and I don't want to spend any time repeating myself.

But our trevor just likes to talk on a news group, any news group,
even though he is never going to build any tube amps, and
secretly thinks tubes are ****.

Triodes are used in many preamps and power amps
and there is no need to condemn them as inferior.

I know what is inferior; it is Trevor Wilson.


Now you will always be hated for ****ing and ****ting all around the place
while insisting your opinions are just the facts.

**What does RDH4 say about PP vs. SE? Where does it say that PP is inferior
to SE? Please quote the page number.

I am doubtful that you can read either.




I guess you'll ignore that question too.

Go try to sell pork in some other synagogue.

Patrick Turner.





--
Trevor Wilson
www.rageaudio.com.au

Trevor Wilson wrote:

"Patrick Turner" wrote in message
...


Trevor Wilson wrote:

"Patrick Turner" wrote in message
...


Fabio Berutti wrote:

I'd give a try to these ones:

http://www.fostexinternational.com/d...W-Series.shtml

There's a full range of products, none made of Unobtainium, and a full
.PDF
datasheet available for downloading

The FW405 looks like a sensible choice.
Its response graph shows 101 dB at 1.4kHz, 96dB at 400Hz, 93dB at 60Hz,
and
84dB at 30 Hz, and 82 dB at 20Hz.
Its Fs is 20Hz, and its Qts is 0.34, so it looks suitable.
I will have to enter all the T&S data into my WINISD to see how she
tunes
up
with a ported box.
The response is a straight line between 60Hz and 1.4 khz.,
so there is 8 dB roll off below 1.4 khz

**YIKES! It is easy to stuff up a speaker system, by hand. To REALLY
stuff
up, you need a computer. Computers and computer aided speaker design is a
great way to go, as long as you ask the right questions. Tell us what
your
WINISD shows for a (say) 45o OFF-axis response from that woofer.

A client has 15" woofers, and Altec horns. He does not listen 45d off
axis.

**How about 30o or 15o?

He carefully set up his listening seat to be on axis.

Don't try to place words and meanings into the thread to justify
an eroneous point of view, or suggest you know more about
the happy co-operation between me and my client.

You know SFA, that's what you know.




I measured the response and it is OK up to 7 kHz.

**No, it is not. The sound would be horrific.

You were not present during the day where my client and I set the
the speakers up.

Don't make a fool of yourself any more than you already have
by suggesting that you know more about a listening test
where you were not present.

We do have the intelligence to discern if a system with 7 kHz BW
is OK or not.
The rest of the missing BW will make it better of course, and this is obvious to
all
but you......



He is getting other horns to fill in the 7k to 20k

WINISD doesn't show us everything about any driver, but i have found it
useful
for the box match at LF; for the upper bass and midrange
the only way to make sure the response is ok is to build it and trim it
all by
careful in-house measuring and calculated /tested filter apps.

I am a hands-on engineer. I don't take too much notice of what a computer
tells
me.

.

When you
examine that response, you may begin to understand why you cannot use a
380mm bass driver up to 500Hz.

Quite a few ppl do use 380mm woofers.

**Sure. They're deluded.

Er, you are the one who is deluded.




You sure as Hell wouldn't let it get anywhere
near 1kHz.

No intention to do so

**Really? What kind of filter are you using? 100dB/octave?

At this point folks, what Trevor is asking is irrelevant.

He cannot trip me up so he begins to bait me,
and show his arse to all.

Trevor is a control freak.

Pity help anyone who builds a system differently
to the Trevor Wilson Guide to Hi-Fi, a torrid read
and an extremly thin volume........

The thing Trevor cannot accept is that there are some really great sounding
systems to be heard using
15" drivers, and SET amplifiers, and the speakers are only two way as well.

While Trevor foams at the mouth about this could someone fetch a straightjacket?

Patrick Turner.



This all quite apart from the fact that preventing cone break-up
at such high frequencies, when using a lightweight cone, is a
monumentally
difficult task.

We know all that.

**Then you already know that a 380mm woofer should not be used past 150Hz.


Many old time 12" speakers were also hopeless above a certain flat region
of
operation.

My Foster 12" woofers i used in my first speakers sounded better when
limited to
250Hz and with a
sharp cut off above 400Hz. I prefer small midranges.

But the client wanting the 15" woofers wants them, and wants to use horns
above
500Hz.

**He's deluded.


So I will attempt to give him the best i can, and I have pointed out
the pitfalls.

The JBL 2235 looks a reasonable candidate for my woofer.
Although is has a rising acoustic output above the F1 point, it rises
as a flat line, not in a series of high Q peaks and troughs, which are
impossible to iron out.



Use a smaller driver.

I'll do what I think I have to.

**That is the smart thing to do.

--
Trevor Wilson
www.rageaudio.com.au

Chris Hornbeck wrote:

On Fri, 03 Jun 2005 04:04:34 GMT, Patrick Turner
wrote:

One of the things that Linkwitz discusses is the simple design
of a single stage F-sub-c and Q-sub-tc correcting inverting amp
stage. For closed boxes, box size doesn't matter; only driver
linear excursion.

Basically, you measure (from impedance measurements, very easy,
only needs a signal gen, ACDVM, scope) F and Q, in box, plug
into simple algebra with desired F and Q, output R's and C's.

You have lost me.

Sorry. Shortcuts in postings bite both ways. Assume... etc.

Linkwitz, in addition to conceiving a useful, practical, real-
world model of idealized drivers combining in imperfect spacial
relationships (all included in his earlier WW and AES papers)
also describes a simple inverting stage that *anyone* can use
to make any driver in any sealed box have any desired F and Q.

To explain what you have said so any of us here could understand would
take
a page or two and a few drawings, no?


To me, it was revolutionary. Still is, 'cause lotsa folks
still haven't read it. Correction on my earlier post: the
Speaker Builder articles are all in the 1980 quarterly frame.
AFAIK, no internet versions are available; sorry. There were no
1979's.

I don't even have any picture frames let alone 1980 quarterly frames....



Speaker designs, like everything else for we poor mortals, must
begin by simplifying; for speakers, we begin by idealizing drivers
as rigid pistons; this is the take-off point for Linkwitz's
work. Joe D'Appolito followed up with a geometric solution to
the summing problem that Linkwitz raised; another story.

Well simple pistons or complex ones, it don't matter.
What the driver makers make we are stuck with,
so like many things, we take in hand and make what we can of it.

When God made man, he made him out of string;
He had a bit leftover, so He made a little thing.

Man sure ain't a perfect concept, and as for woman,
well, that's incomprehensible.

But even with faults, we can make very good sound with speakers
if we fiddle round long enough.





Linkwitz doesn't like ported boxes.....

Jah don' like ported boxes, mon. Jus' ain' right.
Word.

Trouble is I have heard too much good bass from ported boxes.
Sure, there are poopy samples out there, usually bookshelfs which
have a high Fb, and when you turn up the volume it goes to mud.

I've had big arguments with people with transmission lines.
That's where the port becomes so big, and box so small, and ppl slow
down the speed of sound in the port,
which is filled with a low density of wool from black faced Scottish
sheep that
have been specially cared for by a left handed sheppard on the eastern
side of the Highlands.............

Not to mention a double bass, man that has two funny F shaped ports,
but it makes great bass.

I don't like sealed box subwoofers like Linkwitz, but
that's only a dislike, I am sure there must be good bass possible with a
sealed box,
maybe with a little eq to make it go a little lower than it wants to
without any eq.

Anyway, this is a tube discussion group, not a speaker discussion group.

There is a large amount of discussions about speakers at

www.pispeakers.com.

People need not look to me for all the answers, when there are
far greater resources around.

Patrick Turner.





Chris Hornbeck

Doug Flynn wrote:

"Patrick Turner" wrote in message
...

Anyway, now I have heard two guys saying JBL 2235 are OK.

What do they cost?

Patrick Turner.

They are discontinued. I paid A$200 for one (new) and A$350 for the other
(a recone). You have to shop around. Doug

The guy who wants one wants a speaker that's in current production,
and after a trail of unhappy experiences with reconed speakers,
the last thing he'd want is a second hand item that has been reconed.
I may end up using a pair of Peerless 12"XLS in 170L;
they won't cost a bomb, and the cone area is about the same as a single 15",
the box can have a narrow front, and although sensitivity is not
marvellous, they will do the job with a decent amp, and it looks like they
will be
produced for awhile, and if not, there are plenty of other 12" around.
Solid state for the bass is a serious option, and there is no reason why the
SET and horns
can be used for the top end; he does not want head banger volume, just good
bass.

As I explained in other posts, any 15" speaker suffers from a decline in
sensitivity
as F goes below 100Hz, and usually its very low at 20Hz, for a given voltage
input.
Usually a 15" speaker will have a very high Z at 20 Hz because that's where
there will be a peak in the Z due to driver/box resonance.
But for a given input voltage, output isn't high if the maker response graphs
are anything to go by.
These graphs are rarely done using a ported box, but are done using a flat
baffle of some specified size,
so unless somebody has tried to use the speaker in a certain box and measured
it, exactly
what one ends up with isn't 100% clear.
But at least if the Fs is 20Hz, and Qts is below 0.4, there is some hope the
speaker
can be used in a box to get down to an F1 -3dB point of 20 Hz.

I agree about recones and second hands with my client, since the reconed hi-fi
speakers i have re-repaired from Etone in Sydney can possibly leave a lot to
be desired; I have seen some come back as 4 ohms instead of 8 ohms, and very
different
sensitivity, ( usually its lower ). In this case the midrange went AWOL It
rebuilding crossovers and trimming things to get the sound from each to match,
but its never a perfect solution to do this, but when i finished the response
was not to bad.
But then each of a pair of old speakers are often very different to each other
even though
the drivers are functionally OK and the Xovers are identical. The responses of
each can vary
up to 6 dB SPL, which is a lot....
One can test one with the same mic, same noise signal, same positions, same
day, same temp,
same method, but get two different response curves.
Repairing speakers can be quite exasperating, but when you do get a crummy set
of speakers to each
measure flat, and very close to the same, voila, decent imaging, and good
music,
and clients are very well pleased.

On the other hand I have seen a couple of 15" Etone recones which looked very
nice and sounded very well,
until the owner fused them again at a techno gig, along with the horn tweeters
i'd added.

Then he went to using about 100 drivers for two channels and 2,400 watts of SS

and the sound was like a continual stream of jumbo jets crashing around you in
this venue
where the system was used.
Even with good ear plugs I couldn't remain in there for more than 2 minutes.

Not exactly my scene.

When i was 17, the sound in venues was never so loud that I could not
walk up to a girl and go " Would you care to dance with me my dear ?"

In 2040, there will be a lotta deaf ppl around, or ppl driven mad
with tinnitus.

Patrick Turner.

"Trevor Wilson" wrote in message
...

"Patrick Turner" wrote in message
...


"François Yves Le Gal" wrote:

On Wed, 01 Jun 2005 16:38:16 GMT, Patrick Turner

wrote:

Anyone have any clues?

What will be the application? A sub (BW limited to 150 Hz max.) or a
bass
box (BW up to 300 or 500 Hz)?

I want 25Hz to 500Hz.

**500Hz from a 380mm bass drive is, well, um, insane. At least for proper
hi fi applications, anyway. Do the math. For sound reinforcement, such a
crossover frequency would be (barely) acceptable, but not for hi fi
applications.

Done all the time in pro audio, the more common crossover points are 800Hz
for a 2" throat hors to 1.6K for a 1 inch throat.

Chad

"Patrick Turner" wrote in message
...


Chad Wahls wrote:

"Patrick Turner" wrote in message
...
Someone asked me for a pair of large woofers in separate
enclosures using 1.5" of structural plywood.
JBL make a large range, but I don't think their 15" top range with 800
watt capability
is what I neeed, since I only want to use about 2 watts max.

Anyone have any clues?

Patrick Turner.




What about a JBL2235? Lower power handling, low FS and still fairly
sensitive.

May be out of prod, can't remember, but plenty of baskets out there and
cone
kits are still readily available.

Chad

Thanks, I will check that one out.

The driver does not have to be able to cope with enormous power
like many professional PA speakers can.

Patrick Turner.


It's a cool driver but it is intended for theatre subwoofer use, There may
even be a mass ring.

Chad

"Patrick Turner" wrote in message
...


Doug Flynn wrote:

"Patrick Turner" wrote in message
...

Anyway, now I have heard two guys saying JBL 2235 are OK.

What do they cost?

Patrick Turner.

They are discontinued. I paid A$200 for one (new) and A$350 for the
other
(a recone). You have to shop around. Doug

The guy who wants one wants a speaker that's in current production,
and after a trail of unhappy experiences with reconed speakers,
the last thing he'd want is a second hand item that has been reconed.
I may end up using a pair of Peerless 12"XLS in 170L;
they won't cost a bomb, and the cone area is about the same as a single
15",
the box can have a narrow front, and although sensitivity is not
marvellous, they will do the job with a decent amp, and it looks like they
will be
produced for awhile, and if not, there are plenty of other 12" around.
Solid state for the bass is a serious option, and there is no reason why
the
SET and horns
can be used for the top end; he does not want head banger volume, just
good
bass.

As I explained in other posts, any 15" speaker suffers from a decline in
sensitivity
as F goes below 100Hz, and usually its very low at 20Hz, for a given
voltage
input.
Usually a 15" speaker will have a very high Z at 20 Hz because that's
where
there will be a peak in the Z due to driver/box resonance.
But for a given input voltage, output isn't high if the maker response
graphs
are anything to go by.
These graphs are rarely done using a ported box, but are done using a flat
baffle of some specified size,
so unless somebody has tried to use the speaker in a certain box and
measured
it, exactly
what one ends up with isn't 100% clear.
But at least if the Fs is 20Hz, and Qts is below 0.4, there is some hope
the
speaker
can be used in a box to get down to an F1 -3dB point of 20 Hz.

I agree about recones and second hands with my client, since the reconed
hi-fi
speakers i have re-repaired from Etone in Sydney can possibly leave a lot
to
be desired; I have seen some come back as 4 ohms instead of 8 ohms, and
very
different
sensitivity, ( usually its lower ). In this case the midrange went AWOL It
rebuilding crossovers and trimming things to get the sound from each to
match,
but its never a perfect solution to do this, but when i finished the
response
was not to bad.
But then each of a pair of old speakers are often very different to each
other
even though
the drivers are functionally OK and the Xovers are identical. The
responses of
each can vary
up to 6 dB SPL, which is a lot....
One can test one with the same mic, same noise signal, same positions,
same
day, same temp,
same method, but get two different response curves.
Repairing speakers can be quite exasperating, but when you do get a crummy
set
of speakers to each
measure flat, and very close to the same, voila, decent imaging, and good
music,
and clients are very well pleased.

On the other hand I have seen a couple of 15" Etone recones which looked
very
nice and sounded very well,
until the owner fused them again at a techno gig, along with the horn
tweeters
i'd added.

Then he went to using about 100 drivers for two channels and 2,400 watts
of SS

and the sound was like a continual stream of jumbo jets crashing around
you in
this venue
where the system was used.
Even with good ear plugs I couldn't remain in there for more than 2
minutes.

Not exactly my scene.

When i was 17, the sound in venues was never so loud that I could not
walk up to a girl and go " Would you care to dance with me my dear ?"

In 2040, there will be a lotta deaf ppl around, or ppl driven mad
with tinnitus.

Patrick Turner.




JBL recones have very tight tolerances and they just don't sell them to
anyone. I have a pair of 2245's (18" version of 2235) that got reconed at
the same time but baskets were of different vintage by a few years. both are
well matched.

I do trust JBL recones.

Chad

Chad Wahls wrote:

"Patrick Turner" wrote in message
...


Doug Flynn wrote:

"Patrick Turner" wrote in message
...

Anyway, now I have heard two guys saying JBL 2235 are OK.

What do they cost?

Patrick Turner.

They are discontinued. I paid A$200 for one (new) and A$350 for the
other
(a recone). You have to shop around. Doug

The guy who wants one wants a speaker that's in current production,
and after a trail of unhappy experiences with reconed speakers,
the last thing he'd want is a second hand item that has been reconed.
I may end up using a pair of Peerless 12"XLS in 170L;
they won't cost a bomb, and the cone area is about the same as a single
15",
the box can have a narrow front, and although sensitivity is not
marvellous, they will do the job with a decent amp, and it looks like they
will be
produced for awhile, and if not, there are plenty of other 12" around.
Solid state for the bass is a serious option, and there is no reason why
the
SET and horns
can be used for the top end; he does not want head banger volume, just
good
bass.

As I explained in other posts, any 15" speaker suffers from a decline in
sensitivity
as F goes below 100Hz, and usually its very low at 20Hz, for a given
voltage
input.
Usually a 15" speaker will have a very high Z at 20 Hz because that's
where
there will be a peak in the Z due to driver/box resonance.
But for a given input voltage, output isn't high if the maker response
graphs
are anything to go by.
These graphs are rarely done using a ported box, but are done using a flat
baffle of some specified size,
so unless somebody has tried to use the speaker in a certain box and
measured
it, exactly
what one ends up with isn't 100% clear.
But at least if the Fs is 20Hz, and Qts is below 0.4, there is some hope
the
speaker
can be used in a box to get down to an F1 -3dB point of 20 Hz.

I agree about recones and second hands with my client, since the reconed
hi-fi
speakers i have re-repaired from Etone in Sydney can possibly leave a lot
to
be desired; I have seen some come back as 4 ohms instead of 8 ohms, and
very
different
sensitivity, ( usually its lower ). In this case the midrange went AWOL It
rebuilding crossovers and trimming things to get the sound from each to
match,
but its never a perfect solution to do this, but when i finished the
response
was not to bad.
But then each of a pair of old speakers are often very different to each
other
even though
the drivers are functionally OK and the Xovers are identical. The
responses of
each can vary
up to 6 dB SPL, which is a lot....
One can test one with the same mic, same noise signal, same positions,
same
day, same temp,
same method, but get two different response curves.
Repairing speakers can be quite exasperating, but when you do get a crummy
set
of speakers to each
measure flat, and very close to the same, voila, decent imaging, and good
music,
and clients are very well pleased.

On the other hand I have seen a couple of 15" Etone recones which looked
very
nice and sounded very well,
until the owner fused them again at a techno gig, along with the horn
tweeters
i'd added.

Then he went to using about 100 drivers for two channels and 2,400 watts
of SS

and the sound was like a continual stream of jumbo jets crashing around
you in
this venue
where the system was used.
Even with good ear plugs I couldn't remain in there for more than 2
minutes.

Not exactly my scene.

When i was 17, the sound in venues was never so loud that I could not
walk up to a girl and go " Would you care to dance with me my dear ?"

In 2040, there will be a lotta deaf ppl around, or ppl driven mad
with tinnitus.

Patrick Turner.




JBL recones have very tight tolerances and they just don't sell them to
anyone. I have a pair of 2245's (18" version of 2235) that got reconed at
the same time but baskets were of different vintage by a few years. both are
well matched.

I do trust JBL recones.

I probably would trust JBL too.
But what happens here is that ppl blow up their speakers
and turn cones inside out etc and they don't like JBL replacement costs.
So they take them to some guy who does generic repair jobs, and after the repair
it cannot be the same speaker
at all; different voice coil, cone material, suspension, etc.
There are a few cowboys in the speaker repair industry.

With domestic speakers, complete re-coning is seldom worth the effort;
The most common speaker I often repair is 8", and its the surround that needs
the fix,
and once done the speaker will go another 20 years with luck if teenagers are
kept
away from the volume control and bass boost of dad's old system.

Where the voice coil is stuffed, I always buy new drivers which are usually
better than the originals
for most hi-fi speakers that are now 20 years old.
But I have never had to buy new JBL drivers. This would be a costly exercise.

One guy I know had large JBL monitors with 2 x 15" woofers per speaker unit in
different volume ported
boxes with a bipolar horn loaded tweeter shaped like a mans' bum in the front
baffle,
to go from 1khz to 20 kHz.
One had a cracked titanium diaphragm, and it cost the client aud $700
to get it fixed by the authorized JBL repairer here in Oz.

But the owner was very happy with the sound, once the repair was made, even
though he had two yamaha 2200 amps
with biamping and active JBL Xover.

Patrick Turner.




Chad

On Fri, 03 Jun 2005 11:16:01 GMT, Patrick Turner
wrote:

Trevor Wilson wrote:

Patrick Turner wrote:

Unlike people with an open mind who come to this group to talk about tube
usage
and speakers for tube amps, you come with a closed mind, and ****
on anyone who dares to use a triode for an amplifier.

**More lies from you Patrick. Triodes make EXCELLENT amplification devices.
Low distortion, wide bandwidth and low ouput impedance. Trouble is, that
they are not suitable for SE use. In PP, they're bloody excellent. I do not
"**** on anyone who dars to use a triode for an amplifier". I just state
facts. SET amplifiers are VASTLY inferior to a PP amp using the same tubes.
Understand yet?

I see you just dropped large pile of **** onto SE triode amps.
Even though you hang out in Hurstville in Sydney, the people of the world
far away can smell your droppings.

Sure I understand.

I understand you deny what you are while a foot is stuck in your mouth.

You **** all over the many people who use SET amps in preference to anything
PP.

That seems perfectly reasonable to anyone who understands the history
and development of *real* tube amps, as opposed to the fashionista SET
crap flooding the so-called 'high end' market.

So how about you just **** OFF OUT OF THIS NEWS GROUP!!!

What, P-P triode amps don't use tubes? Why don't you grow up and get a
life, you pathetic old whinger?

Trevor Wilson is a Dunderhead Extraordinaire when it comes to tube understanding

and as soon as things get technical in any amplifier discussions, he is
incapable of rational discussions.

He has repeatedly attacked anyone and everyone for years over the issue of SET
amplifiers,
and here he goes again.

Actually, that implies a pretty *good* knowledge of tube
technology.............

There is ample record in the Google records of the news groups to
indicate what my tolerant and open minded point of view is about SET amps,
and I don't want to spend any time repeating myself.

Which indicates that *you* are the tube dunderhead, no?

BTW, anyone who recommends a 15" woofer operating above 100-150 Hz is
also a speaker dunderhead.

Furthermore, anyone who claims that they've measured such a driver as
'pretty good out to 7kHz' is either lying or has no idea how to use
the measuring equipment.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Fri, 03 Jun 2005 11:32:22 GMT, Patrick Turner
wrote:

Trevor Wilson wrote

Patrick wrote:

I measured the response and it is OK up to 7 kHz.

**No, it is not. The sound would be horrific.

You were not present during the day where my client and I set the
the speakers up.

So what? I canna' change the laws o' physics, cap'n!

Don't make a fool of yourself any more than you already have
by suggesting that you know more about a listening test
where you were not present.

Irrelevant, simply proof that you are as incompetent as your 'client'.

We do have the intelligence to discern if a system with 7 kHz BW
is OK or not.
The rest of the missing BW will make it better of course, and this is obvious to
all
but you......

No, you *don't* have any discernible intelligence, or you wouldn't
even *attempt* such an abortion.

The thing Trevor cannot accept is that there are some really great sounding
systems to be heard using
15" drivers, and SET amplifiers, and the speakers are only two way as well.

Bull**** - only if you are deaf as well as dumb............

--

Stewart Pinkerton | Music is Art - Audio is Engineering