On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

(2) No double wall with sand fill ?:-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine Sometimes I even put it in the food

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

The ports are too small for the frequency range they will be hit at.
A long throw heavy foam (rubber or butyl) surround will last longer than
the paper surround type cone as well. They'll be good for live work, but
a "home stereo" setting would likely show some spectral 'colorations'.

The crossover arrangement looks a bit problematic as well.

You have the midrange driver firing to the side?

Where did you get the design from?

On Fri, 20 Mar 2009 18:54:21 -0700, Jim Thompson
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Agreed.

(2) No double wall with sand fill ?:-)


You are behind the curve. That went out of vogue a long time ago.

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

Why?

You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

What sort of distortion will increase with power due to small wires?

The ports are too small for the frequency range they will be hit at.
A long throw heavy foam (rubber or butyl) surround will last longer than
the paper surround type cone as well. They'll be good for live work, but
a "home stereo" setting would likely show some spectral 'colorations'.

The crossover arrangement looks a bit problematic as well.

You have the midrange driver firing to the side?

Isn't that an inductor?

Where did you get the design from?

--
John

On Sat, 21 Mar 2009 11:17:36 -0500, John O'Flaherty
wrote:

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

Why?

You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

What sort of distortion will increase with power due to small wires?

The ports are too small for the frequency range they will be hit at.
A long throw heavy foam (rubber or butyl) surround will last longer than
the paper surround type cone as well. They'll be good for live work, but
a "home stereo" setting would likely show some spectral 'colorations'.

The crossover arrangement looks a bit problematic as well.

You have the midrange driver firing to the side?

Isn't that an inductor?

Where did you get the design from?

"Capt. Cave Man" is AlwaysWrong. 'Nuff said ?:-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

Obama... another Carter, just more ego and less brains or talent

On Sat, 21 Mar 2009 10:18:09 -0700, Jim Thompson
wrote:

| James E.Thompson, P.E.
| Analog Innovations, Inc.


What idiot customer would buy anything from this twit after seeing the
CRAP he posts into these groups?

Your sig likely costs you business, not that you deserve any.

Maybe the economy will have its way with the likes of retards like Jim
Thompson.

On Sat, 21 Mar 2009 10:18:09 -0700, Jim Thompson
a.k.a WrongAgain wrote:

Obama... another Carter, just more ego and less brains or talent


No. He has more brains and talent. He is far better than Carter ever
was at stealing away tax payer dollars.

Carter had America's interests at heart at least.

This Obama asswipe has nothing but his own interests at heart.

So WrongAgain is, as usual.

Jim Thompson wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Yes, I'll agree with that 100%. The reasons for that being long and
complicated.


(2) No double wall with sand fill ?:-)

No need. The best structural material for speaker cabinets is a
composite made of a plywood outer ( for durability ) with an MDF inner
for damping. 'Honeycombing' the interior ( probably with MDF panels )
will also reduce panel resonances and provide additional structural
strength.

Graham

On Sat, 21 Mar 2009 20:31:23 +0000, Eeyore
wrote:



Jim Thompson wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Yes, I'll agree with that 100%. The reasons for that being long and
complicated.

The horn is 12db more sensitive than the woofer, so it will receive less than 50
watts max... bi-amping is not required under that condition. It's average music
power would be 10 to 20 watts.


(2) No double wall with sand fill ?:-)

No need. The best structural material for speaker cabinets is a
composite made of a plywood outer ( for durability ) with an MDF inner
for damping. 'Honeycombing' the interior ( probably with MDF panels )
will also reduce panel resonances and provide additional structural
strength.

Graham

On Sat, 21 Mar 2009 20:31:23 +0000, Eeyore
wrote:



Jim Thompson wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Yes, I'll agree with that 100%. The reasons for that being long and
complicated.


(2) No double wall with sand fill ?:-)

No need. The best structural material for speaker cabinets is a
composite made of a plywood outer ( for durability ) with an MDF inner
for damping. 'Honeycombing' the interior ( probably with MDF panels )
will also reduce panel resonances and provide additional structural
strength.

Graham

As does a slathering with a foamy polyurethane material, as is the
habit with Polk and many other makers.

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

Thanks

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

The wood is what I could get, it's more of a prototype at the moment but yes I
would use the best wood... I don't like hardwood for speakers... I heard some
Oak boxes once and they were terrible!

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

Not required.

You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

I don't, just relating specs!

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

Wires are 14 gauge, good enough.

The ports are too small for the frequency range they will be hit at.

The ports are fine according to both Eminence and WInISD... they are actually
below the usable range of the speaker.

A long throw heavy foam (rubber or butyl) surround will last longer than
the paper surround type cone as well. They'll be good for live work, but
a "home stereo" setting would likely show some spectral 'colorations'.

These are Pro, not home... not many homes require 127dbSPL...

The crossover arrangement looks a bit problematic as well.

Prototype with what I had! (I rebuilt it from another system.)

You have the midrange driver firing to the side?

Duh? The horn and woofer are visible?

Where did you get the design from?

It was a committee plan of 3 members, Eminence, WinISD, and me. (And some help
from P.A. over at AAPLS)

On Fri, 20 Mar 2009 18:54:21 -0700, Jim Thompson
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Bi-amp not really required at the 50 watt horn level... there will be bi-amp
between this box and the sub.

(2) No double wall with sand fill ?:-)

Most people tell me that they want low weight! I am considering covering this
with a veneer ply, 1/4" maybe...

...Jim Thompson

On Sat, 21 Mar 2009 20:59:36 -0400, wrote:

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

Thanks

After seeing that you were not worried about the sharp corners, I want
to take it back.

I would use a non-parallel wall design, which is no more than a few
degrees pyramidal box, which would lean the driver back a few degrees as
well, but mainly cancels reflections caused by parallel walls.

I also can see how four ports of that length and size equal what I was
thinking would be needed.

I'd still round the corners, sort of like what it would look like with
a bladder inflated inside.

The horn's transducer is back far enough to keep the phase accurate, so
no need to make a dual cabinet design,or move it back.

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

The wood is what I could get, it's more of a prototype at the moment but yes I
would use the best wood... I don't like hardwood for speakers... I heard some
Oak boxes once and they were terrible!

Well, thickness is a factor too, and internal tooling can modify overall
'density' and resonance point (on the hardwoods).

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

Not required.

100 kilos each doesn't sound appealing? :-]


You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

I don't, just relating specs!

I remember an EV, paper edge driver I saw that fooled me before too.

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

Wires are 14 gauge, good enough.

Silver plated copper PTFE (Teflon) military wire is pretty cheap in
large gauges even. Customers like such special considerations. You said
"Pro",so how could it be "good enough"?

The ports are too small for the frequency range they will be hit at.

The ports are fine according to both Eminence and WInISD... they are actually
below the usable range of the speaker.

Yeah,I referred to that above. oops.

A long throw heavy foam (rubber or butyl) surround will last longer than
the paper surround type cone as well. They'll be good for live work, but
a "home stereo" setting would likely show some spectral 'colorations'.

These are Pro, not home... not many homes require 127dbSPL...

You'd be surprised what "well to do" folks have placed into their
homes.

The crossover arrangement looks a bit problematic as well.

Prototype with what I had! (I rebuilt it from another system.)

You have the midrange driver firing to the side?

Duh? The horn and woofer are visible?

I thought the toroid was a mid driver for some reason. It's a two-way.

Where did you get the design from?

It was a committee plan of 3 members, Eminence, WinISD, and me. (And some help
from P.A. over at AAPLS)

Cool. Good job, so far. I just thought that parallel walls were so...
seventies. I am sure they'll work fine though.

On Sat, 21 Mar 2009 19:00:38 -0700, Capt. Cave Man
wrote:

On Sat, 21 Mar 2009 20:59:36 -0400, wrote:

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

Thanks

After seeing that you were not worried about the sharp corners, I want
to take it back.

I would use a non-parallel wall design, which is no more than a few
degrees pyramidal box, which would lean the driver back a few degrees as
well, but mainly cancels reflections caused by parallel walls.

I also can see how four ports of that length and size equal what I was
thinking would be needed.

I'd still round the corners, sort of like what it would look like with
a bladder inflated inside.

The horn's transducer is back far enough to keep the phase accurate, so
no need to make a dual cabinet design,or move it back.

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

The wood is what I could get, it's more of a prototype at the moment but yes I
would use the best wood... I don't like hardwood for speakers... I heard some
Oak boxes once and they were terrible!

Well, thickness is a factor too, and internal tooling can modify overall
'density' and resonance point (on the hardwoods).

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

Not required.

100 kilos each doesn't sound appealing? :-]


You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

I don't, just relating specs!

I remember an EV, paper edge driver I saw that fooled me before too.

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

Wires are 14 gauge, good enough.

Silver plated copper PTFE (Teflon) military wire is pretty cheap in
large gauges even. Customers like such special considerations. You said
"Pro",so how could it be "good enough"?

The ports are too small for the frequency range they will be hit at.

The ports are fine according to both Eminence and WInISD... they are actually
below the usable range of the speaker.

Yeah,I referred to that above. oops.

A long throw heavy foam (rubber or butyl) surround will last longer than
the paper surround type cone as well. They'll be good for live work, but
a "home stereo" setting would likely show some spectral 'colorations'.

These are Pro, not home... not many homes require 127dbSPL...

You'd be surprised what "well to do" folks have placed into their
homes.

The crossover arrangement looks a bit problematic as well.

Prototype with what I had! (I rebuilt it from another system.)

You have the midrange driver firing to the side?

Duh? The horn and woofer are visible?

I thought the toroid was a mid driver for some reason. It's a two-way.

Where did you get the design from?

It was a committee plan of 3 members, Eminence, WinISD, and me. (And some help
from P.A. over at AAPLS)

Cool. Good job, so far. I just thought that parallel walls were so...
seventies. I am sure they'll work fine though.

Did I say these were prototypes? I was thinking of a wedge box, and maybe the
next version will be so. I really wanted to hear how these Eminence drivers
sound, and will run them in conjunction (and comparison) with some Mackies
soon... 450's I think... not sure what the DJ has yet...

I listened to this one a bit today, listened to Sting a bit, and M C Hammer, and
was listening to Tchaikovsky when I had to quit... should do the Barbara
Striesand test... (If she sounds good your HF is fine!)

Need 2 boxes the same to compare, so I'll build another one. Sounded Ok so
far...

On Sat, 21 Mar 2009 22:54:01 -0400, wrote:


I listened to this one a bit today, listened to Sting a bit, and M C Hammer, and
was listening to Tchaikovsky when I had to quit... should do the Barbara
Striesand test... (If she sounds good your HF is fine!)

Need 2 boxes the same to compare, so I'll build another one. Sounded Ok so
far...


Her digital disc.

"Bit By Bit, Putting it Together" sounds quite appropriate.

Thanks for that memory. I am going to have to dig her out now. :-]

On 2009-03-21, Eeyore wrote:


Jim Thompson wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Yes, I'll agree with that 100%. The reasons for that being long and
complicated.


(2) No double wall with sand fill ?:-)

No need. The best structural material for speaker cabinets is a
composite made of a plywood outer ( for durability ) with an MDF inner
for damping. 'Honeycombing' the interior ( probably with MDF panels )

Huh? MDF is harder than pine ply.

wrote:

Eeyore wrote:
Jim Thompson wrote:
On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Yes, I'll agree with that 100%. The reasons for that being long and
complicated.

The horn is 12db more sensitive than the woofer, so it will receive less than 50
watts max... bi-amping is not required under that condition.

Bi-amping is ALWAYS an EXCELLENT idea since electronic crossovers can match and sum
far better than passive ones (component tolerances plus insensitivity to driver
impedance change with frequency), plus the amplifier power to each driver can be
tailored to each driver without lossy pads. Tri or quad amping are better still.


Graham

"Capt. Cave Man" wrote:

Eeyore wrote:
Jim Thompson wrote:

(2) No double wall with sand fill ?:-)

No need. The best structural material for speaker cabinets is a
composite made of a plywood outer ( for durability ) with an MDF inner
for damping. 'Honeycombing' the interior ( probably with MDF panels )
will also reduce panel resonances and provide additional structural
strength.

As does a slathering with a foamy polyurethane material, as is the
habit with Polk and many other makers.

That would be another way. Various synthetic and non-synthetic materials
can be used to good effect to reduce driver cone rear radiation. Personally
I'm rather fond of the absorbent transmission line enclosure that simply
absorbs most of the rear radiation.

This form of design is currently probably best implemented by PMC (the
Professional Monitor Company ) who make designs for both studio and home
use. They sound lovely.
http://www.pmc-speakers.com/

I think the number of awards speaks for itself.


Graham

Jasen Betts wrote:

Eeyore wrote:
Jim Thompson wrote:
On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Yes, I'll agree with that 100%. The reasons for that being long and
complicated.


(2) No double wall with sand fill ?:-)

No need. The best structural material for speaker cabinets is a
composite made of a plywood outer ( for durability ) with an MDF inner
for damping. 'Honeycombing' the interior ( probably with MDF panels )

Huh? MDF is harder than pine ply.

Define 'harder' ! MDF is far better damped but prone to environmental plus
knocks and bumps damage.

Graham

On Mon, 23 Mar 2009 17:39:40 +0000, Eeyore
wrote:



wrote:

Eeyore wrote:
Jim Thompson wrote:
On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Yes, I'll agree with that 100%. The reasons for that being long and
complicated.

The horn is 12db more sensitive than the woofer, so it will receive less than 50
watts max... bi-amping is not required under that condition.

Bi-amping is ALWAYS an EXCELLENT idea since electronic crossovers can match and sum
far better than passive ones (component tolerances plus insensitivity to driver
impedance change with frequency), plus the amplifier power to each driver can be
tailored to each driver without lossy pads. Tri or quad amping are better still.


No ****.

On Mon, 23 Mar 2009 17:39:40 +0000, Eeyore
wrote:



wrote:

Eeyore wrote:
Jim Thompson wrote:
On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Yes, I'll agree with that 100%. The reasons for that being long and
complicated.

The horn is 12db more sensitive than the woofer, so it will receive less than 50
watts max... bi-amping is not required under that condition.

Bi-amping is ALWAYS an EXCELLENT idea since electronic crossovers can match and sum
far better than passive ones (component tolerances plus insensitivity to driver
impedance change with frequency), plus the amplifier power to each driver can be
tailored to each driver without lossy pads. Tri or quad amping are better still.


Graham

Bi-amping a horn for less than 50 watts, over 2500 hz, for live sound, is a
waste of money... Find 0ne person in the crowd that could tell...

On 2009-03-23, Eeyore wrote:


Jasen Betts wrote:

Eeyore wrote:
Jim Thompson wrote:
On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Yes, I'll agree with that 100%. The reasons for that being long and
complicated.


(2) No double wall with sand fill ?:-)

No need. The best structural material for speaker cabinets is a
composite made of a plywood outer ( for durability ) with an MDF inner
for damping. 'Honeycombing' the interior ( probably with MDF panels )

Huh? MDF is harder than pine ply.

Define 'harder' !

use any hardess gauge you want.
(eg hit it with a ball hammer and observe the size of the mark left
measure the force needed to push nails in etc...)

MDF is far better damped but prone to environmental plus
knocks and bumps damage.

the MDF we have in NZ is harder (and denser) than the plywood.

I'm thinking you've got some low density stuff there, or some hard ply.

wrote:

Eeyore wrote:
wrote:
Eeyore wrote:
Jim Thompson wrote:
On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Yes, I'll agree with that 100%. The reasons for that being long and
complicated.

The horn is 12db more sensitive than the woofer, so it will receive less than 50
watts max... bi-amping is not required under that condition.

Bi-amping is ALWAYS an EXCELLENT idea since electronic crossovers can match and sum
far better than passive ones (component tolerances plus insensitivity to driver
impedance change with frequency), plus the amplifier power to each driver can be
tailored to each driver without lossy pads. Tri or quad amping are better still.

Bi-amping a horn for less than 50 watts, over 2500 hz, for live sound, is a
waste of money... Find 0ne person in the crowd that could tell...

A 50W continuous rated horn ? There are plenty of commercial products that bi-amp at
that level. The second amp is probably cheaper to build than a decently made passive
crossover.

I'm a pro-audio consultant so I should know !

Graham

Jasen Betts wrote:

Eeyore wrote:
Jasen Betts wrote:
Eeyore wrote:
Jim Thompson wrote:
On Fri, 20 Mar 2009 21:47:35 -0400, wrote:

(1) Passive crossover... Yecch!

Yes, I'll agree with that 100%. The reasons for that being long and
complicated.


(2) No double wall with sand fill ?:-)

No need. The best structural material for speaker cabinets is a
composite made of a plywood outer ( for durability ) with an MDF inner
for damping. 'Honeycombing' the interior ( probably with MDF panels )

Huh? MDF is harder than pine ply.

Define 'harder' !

use any hardess gauge you want.
(eg hit it with a ball hammer and observe the size of the mark left
measure the force needed to push nails in etc...)

MDF is far better damped but prone to environmental plus
knocks and bumps damage.

the MDF we have in NZ is harder (and denser) than the plywood.

I'm thinking you've got some low density stuff there, or some hard ply.

Well ply does come in many grades. I was thinking primarily of corner damage to
cabinets using MDF.

You can get a 'ply' of plwood bonded to MDF now btw to combine the relative
advantages of each.

Graham

"Capt. Cave Man" wrote:

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases.

Not many people know that. I found the same effect with some new dummy load
resistors too that were using some new type of resistance wire.

Graham

On Sat, 21 Mar 2009 11:17:36 -0500, John O'Flaherty
wrote:

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

Why?

---
Air is compressible, and when there's a pressure wave which propagates
into a corner, the pressure will tend toward infinity as the wave is
squeezed into the line describing the corner, with the result that the
wood will move and, by doing so, modulate the pressure wave, creating
sidebands.
---

You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

What sort of distortion will increase with power due to small wires?

---
If the temperature of the wires is caused to change by the charge
flowing through them, then their resistance will be modulated by the
power being dissipated by the load, and distortion products will be
generated as sidebands.

JF

On Wed, 25 Mar 2009 16:50:51 -0500, John Fields
wrote:

On Sat, 21 Mar 2009 11:17:36 -0500, John O'Flaherty
wrote:

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

Why?

---
Air is compressible, and when there's a pressure wave which propagates
into a corner, the pressure will tend toward infinity as the wave is
squeezed into the line describing the corner, with the result that the
wood will move and, by doing so, modulate the pressure wave, creating
sidebands.

Is there some research that that actually happens? I understand your
reasoning, but it seems a stretch that it would affect the sound
coming out of the front of the speaker.



You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

What sort of distortion will increase with power due to small wires?

---
If the temperature of the wires is caused to change by the charge
flowing through them, then their resistance will be modulated by the
power being dissipated by the load, and distortion products will be
generated as sidebands.

To get sidebands, the temperature would have to change significantly
(compared to the DC resistance of the voice coil) within each cyle of
the waveform. Does that actually happen?

--
John

On Wed, 25 Mar 2009 16:50:51 -0500, John Fields
wrote:

On Sat, 21 Mar 2009 11:17:36 -0500, John O'Flaherty
wrote:

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

Why?

---
Air is compressible, and when there's a pressure wave which propagates
into a corner, the pressure will tend toward infinity as the wave is
squeezed into the line describing the corner, with the result that the
wood will move and, by doing so, modulate the pressure wave, creating
sidebands.
---

You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

What sort of distortion will increase with power due to small wires?

---
If the temperature of the wires is caused to change by the charge
flowing through them, then their resistance will be modulated by the
power being dissipated by the load, and distortion products will be
generated as sidebands.

JF

Not if you use Monster Cable... SCNR ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

All Hail King Obama, The Resurrected Messiah :-(

On Wed, 25 Mar 2009 11:26:53 +0000, Eeyore
wrote:



wrote:

Eeyore wrote:


A 50W continuous rated horn ? There are plenty of commercial products that bi-amp at
that level. The second amp is probably cheaper to build than a decently made passive
crossover.

I'm a pro-audio consultant so I should know !

Graham


I haven't built an amp since the 70s.. or 80s using 70s designs! I remember the
Tiger series...

Do you have a schemo for a decent 50 watt or so amp? A "simpler than an xover"
amp? I hear power FETs have simplified things somewhat.

Plus I need to make a filter, got something on the latest in Link-Riley what
evers?

Thanks!

On Wed, 25 Mar 2009 16:50:51 -0500, John Fields
wrote:

On Sat, 21 Mar 2009 11:17:36 -0500, John O'Flaherty
wrote:

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

Why?

---
Air is compressible, and when there's a pressure wave which propagates
into a corner, the pressure will tend toward infinity as the wave is
squeezed into the line describing the corner, with the result that the
wood will move and, by doing so, modulate the pressure wave, creating
sidebands.

Thats funny! What audio store do you work for?

You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

What sort of distortion will increase with power due to small wires?

---
If the temperature of the wires is caused to change by the charge
flowing through them, then their resistance will be modulated by the
power being dissipated by the load, and distortion products will be
generated as sidebands.

Wow! Explain the fact no one can hear the tweeter protection lamp, which
changes resistance about a million times more than the feed wire can??

JF

Does that stand for Jerk-****er?

Please go away... please...

On Wed, 25 Mar 2009 20:24:41 -0400, wrote:

On Wed, 25 Mar 2009 11:26:53 +0000, Eeyore
wrote:



wrote:

Eeyore wrote:


A 50W continuous rated horn ? There are plenty of commercial products that bi-amp at
that level. The second amp is probably cheaper to build than a decently made passive
crossover.

I'm a pro-audio consultant so I should know !

Graham


I haven't built an amp since the 70s.. or 80s using 70s designs! I remember the
Tiger series...

Do you have a schemo for a decent 50 watt or so amp? A "simpler than an xover"
amp? I hear power FETs have simplified things somewhat.

Plus I need to make a filter, got something on the latest in Link-Riley what
evers?

Thanks!

Power FET's are to BJT's as Monster Cable is to zip-cord... only for
the gullible to waste their money on ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

Lord protect me from queers, fairies and Democrats

On Wed, 25 Mar 2009 20:31:09 -0400, wrote:

On Wed, 25 Mar 2009 16:50:51 -0500, John Fields
wrote:

On Sat, 21 Mar 2009 11:17:36 -0500, John O'Flaherty
wrote:

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

Why?

---
Air is compressible, and when there's a pressure wave which propagates
into a corner, the pressure will tend toward infinity as the wave is
squeezed into the line describing the corner, with the result that the
wood will move and, by doing so, modulate the pressure wave, creating
sidebands.

Thats funny! What audio store do you work for?

You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

What sort of distortion will increase with power due to small wires?

---
If the temperature of the wires is caused to change by the charge
flowing through them, then their resistance will be modulated by the
power being dissipated by the load, and distortion products will be
generated as sidebands.

Wow! Explain the fact no one can hear the tweeter protection lamp, which
changes resistance about a million times more than the feed wire can??

JF

Does that stand for Jerk-****er?

Please go away... please...

You first. Bye!

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

Lord protect me from queers, fairies and Democrats

On Wed, 25 Mar 2009 17:43:45 -0500, John O'Flaherty
wrote:


Is there some research that that actually happens? I understand your
reasoning, but it seems a stretch that it would affect the sound
coming out of the front of the speaker.


Cabinet internal shape is a MAJOR factor in speaker performance.

You should examine the original Klipschorn speaker. The cavity in it
was like 37 feet long, stretched out.

http://www.klipsch.com/news-center/p...-speakers.aspx

On Wed, 25 Mar 2009 20:31:09 -0400, wrote:


Thats funny! What audio store do you work for?

You're an idiot.

You're one of those know nothing twits that think all salesmen know
nothing.

It is, in fact, you that has no clue.

On Wed, 25 Mar 2009 20:31:09 -0400, wrote:

Wow! Explain the fact no one can hear the tweeter protection lamp, which
changes resistance about a million times more than the feed wire can??


You're an utter idiot. Mainly because you use a speaker that
incorporated a 'tweeter protection lamp'. You're about as stupid as it
gets.

JF

Does that stand for Jerk-****er?


No, jerk, it doesn't, so you'll have to find someone else to **** you.

Please go away... please...

Grow the **** up, and go the **** away, and die while you're gone.

On Wed, 25 Mar 2009 17:43:45 -0500, John O'Flaherty
wrote:

On Wed, 25 Mar 2009 16:50:51 -0500, John Fields
wrote:

On Sat, 21 Mar 2009 11:17:36 -0500, John O'Flaherty
wrote:

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

{trimmed for clarity}

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

What sort of distortion will increase with power due to small wires?

---
If the temperature of the wires is caused to change by the charge
flowing through them, then their resistance will be modulated by the
power being dissipated by the load, and distortion products will be
generated as sidebands.

To get sidebands, the temperature would have to change significantly
(compared to the DC resistance of the voice coil) within each cyle of
the waveform. Does that actually happen?

I decided to do some calculations as a reality check.
Assume worst case non-linear distortion due to modulation of
resistance of wires due to temperature change due to power will be
felt at the lowest frequency, say 20 Hz. Assume 100W, 8 ohm speaker
system. A relatively large change in temperature of the wire within a
cycle would occur if the waveform was square, on for 12.5 ms, off for
12.5 ms., on negative for 12.5 ms and off again for 12.5 ms; at least
it's easier to figure that way.
Assume 18 ga copper hookup wire is used (not the stoutest wire), and 5
feet of it is needed (this is just the hookup wire, not the choke or
voice coil resistance). This will have a resistance of
..00639 ohm/ft * 5 ft = .03195 ohm.
If the RMS power is 100 W, and it's concentrated into equal on/off
times, the on-time power is 200 W. The power dissipated in the wire
will be about 200 W * .03195 ohms / 8 ohms (wire resistance / speaker
resistance) = 0.798 W. The duration is 12.5 ms, so the energy dumped
into the wire is ~10 mJ.
The density of the hookup wire is 1 lb / 203.4 ft. With 5 feet,
5 ft / 203.4 ft * 453 g/lb = 11.16 g is the mass of the hookup wire.
The heat capacity of copper is .385 J/(g C). That gives
10 mJ / 11.16 g / (.385 J/g/C) = 0.00233 C temperature rise.
Copper has a TCR of 3930 ppm/C, so the net resistance change is
..00233 C * 3930 / 1e6 / C * .03195 ohms = 0.29 microohms. In an 8 ohm
system, that's a change of 2.9e-7 / 8 or 3.7 micropercent.
How could that cause perceptible distortion? The assumptions above
assume heat gain for 1/4 period, and complete loss of that gain in the
next 1/4 period, so that's kind of worst case for change. Of course,
I've ignored impedance, but that won't materially affect the result.

On the radiusing question, usually, features that affect waves are not
too much smaller than the waves. Worst-case (shortest) wavelength for
audio @ 20 kHz in air is 1100 ft/sec / 20 kHz = .055 ft = 0.6 inches.
I suspect that any compression into a corner is going to be averaged
over audible wavelengths. It's hard to see how smoothing a corner is
going to make a difference at audible frequencies, unless you're a
dolphin, and then you'll have to use teak and spar varnish for your
cabinet.

--
John
(I may have egg on my face if I've divided when I should have
multiplied. It won't be the first time.)

On Wed, 25 Mar 2009 18:19:40 -0700, StickThatInYourPipeAndSmokeIt
wrote:

On Wed, 25 Mar 2009 17:43:45 -0500, John O'Flaherty
wrote:


Is there some research that that actually happens? I understand your
reasoning, but it seems a stretch that it would affect the sound
coming out of the front of the speaker.


Cabinet internal shape is a MAJOR factor in speaker performance.

You should examine the original Klipschorn speaker. The cavity in it
was like 37 feet long, stretched out.

http://www.klipsch.com/news-center/p...-speakers.aspx

I think shape must important (whether the walls are parallel or not,
for example), but I doubt it is important at scales way smaller than
the wavelength at the highest audio frequency.
--
John

On Wed, 25 Mar 2009 21:26:08 -0500, John O'Flaherty
wrote:

On Wed, 25 Mar 2009 18:19:40 -0700, StickThatInYourPipeAndSmokeIt
wrote:

On Wed, 25 Mar 2009 17:43:45 -0500, John O'Flaherty
wrote:


Is there some research that that actually happens? I understand your
reasoning, but it seems a stretch that it would affect the sound
coming out of the front of the speaker.


Cabinet internal shape is a MAJOR factor in speaker performance.

You should examine the original Klipschorn speaker. The cavity in it
was like 37 feet long, stretched out.

http://www.klipsch.com/news-center/p...-speakers.aspx

I think shape must important (whether the walls are parallel or not,
for example), but I doubt it is important at scales way smaller than
the wavelength at the highest audio frequency.


Corner struts and other elements of current cabinet construction does
impede pure sound. Such subtle changes can be detected by some.

On Wed, 25 Mar 2009 20:31:09 -0400, wrote:

On Wed, 25 Mar 2009 16:50:51 -0500, John Fields
wrote:

On Sat, 21 Mar 2009 11:17:36 -0500, John O'Flaherty
wrote:

On Fri, 20 Mar 2009 19:34:11 -0700, Capt. Cave Man
wrote:

On Fri, 20 Mar 2009 21:47:35 -0400, wrote:


Fairly decent cabinet design.

I hope you are using marine type plywood.

A fine grain, high density particle board might be better. I use solid
hardwoods throughout.

You should also use a thicker glue between ALL of the elements, and you
should coat the entire inside with a thick polyurethane so thick that ALL
of the sharp corners inside become rounded.

Why?

---
Air is compressible, and when there's a pressure wave which propagates
into a corner, the pressure will tend toward infinity as the wave is
squeezed into the line describing the corner, with the result that the
wood will move and, by doing so, modulate the pressure wave, creating
sidebands.

Thats funny! What audio store do you work for?

---
I don't work for an audio store, I work for a consulting firm.
Besides, what makes you think it's funny? Do you have some data you can
use to prove my hypothesis incorrect or are you just flapping your jaws?
---

You should not assume that your max wattage is equal to the wattage
capacity stated on the driver(s).

The wiring certainly will NOT handle your claimed power handling
capacity. It will introduce distortion as power increases. You need
bigger feed lines, and they should be kept as short as can be feasibly
done.

What sort of distortion will increase with power due to small wires?

---
If the temperature of the wires is caused to change by the charge
flowing through them, then their resistance will be modulated by the
power being dissipated by the load, and distortion products will be
generated as sidebands.

Wow! Explain the fact no one can hear the tweeter protection lamp, which
changes resistance about a million times more than the feed wire can??

---
What makes you think no one can hear the tweeter lamp?

If its resistance changes _that_ much then surely it affects the dynamic
range of the tweeter's SPL, which means that it colors the tweeter's
output, which means that one would certainly be able to hear the
difference between a lamped and non-lamped tweeter.
---

JF

Does that stand for Jerk-****er?

---
Why do you want to know?

Are you looking for a dick up your ass?
---

Please go away... please...

---
Nope; I'm here for the long haul.

I notice though, this is your first post here.

Too bad about that first chance...


JF