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[Randy Frierson]

My design guy is playing with Leap but really needs help using it and was wondering if there was something else you guys have found that is good....thanks in advance.  Randy

[Jeff Bankston]

FaitalPro speakers recomended > WinISD , and its a free download. The Eminence can be bought from www.usspeaker.com for about $80. i was comparing the 2 using a faitalpro 18xl1600 and ciare 12ndh4 and both plotted graphs and port deminsions very very close to each program. look at the port velocity graph. you can have a good response but a rise on the port graph and that would mean noise. i ended up using 2 large ports for the 18xl1600 to get a nice roll off.

[Brian Elstro]

WinISD is the one to use, for free that is. WinISD Pro is nice too, and will give you x-max figures but you need to  know all your drivers specs or have a driver measurement program to give you those specs. I should also say that you can use the pro version without all parameters, but it will not be as accurate and its just easier to use the standard version with those same parameters in the first place.

[Jeff Bankston]

heres what i mean about port size for different woofers. this is for faitalpro 18xl1600. the 1st port design gives ideal results. the 2nd port design could produce audible wind noise.imagine that > my camera fone takes decent fotos of stuff on my monitor and i transfer it to a data card and the stick in my pc and download and post !!! wattle thay think of next !!!!

[Jeff Bankston]

WinISD is the one to use, for free that is. WinISD Pro is nice too, and will give you x-max figures but you need to  know all your drivers specs or have a driver measurement program to give you those specs. I should also say that you can use the pro version without all parameters, but it will not be as accurate and its just easier to use the standard version with those same parameters in the first place.

yep you gotta have the specs and those can be gotten from the driver manufacterer website

[David Morison]

.imagine that > my camera fone takes decent fotos of stuff on my monitor and i transfer it to a data card and the stick in my pc and download and post !!! wattle thay think of next !!!!

Even simpler, use the Print Screen button (Sometimes abbreviated Prnt Scrn etc, next along from F12 on the top row) to copy the screen image directly to clipboard then paste it into any image editor as a new image.

[John Halliburton]

My design guy is playing with Leap but really needs help using it and was wondering if there was something else you guys have found that is good....thanks in advance.  Randy

LEAP is a great application, what exactly is your guy having problems with?

Best regards,

John

[John Halliburton]

heres what i mean about port size for different woofers. this is for faitalpro 18xl1600. the 1st port design gives ideal results. the 2nd port design could produce audible wind noise.imagine that > my camera fone takes decent fotos of stuff on my monitor and i transfer it to a data card and the stick in my pc and download and post !!! wattle thay think of next !!!!

Jeff,

Those images aren't of vent velocity, they're response(magnitude) curves of whichever design you're looking at. 

Bassbox(OEM app for Eminence, btw) for instance has a dozen or so different graph functions, including vent velocity in speed v. frequency, and even has a maxima to show when this is over a fairly accepted level, resulting in vent noise.

Also, these programs won't predict things like impulse response, or port resonances, which are things that have to be measured and evaluated at the other end when a prototype cabinet is built.

Best regards,

John

[Ivan Beaver]

My design guy is playing with Leap but really needs help using it and was wondering if there was something else you guys have found that is good....thanks in advance.  Randy

The simulation programs are just like the acoustic prediction programs.

They do not tell you what to do.  THey show you results of the data that you input.

They will not tell you if the box design/size/port size etc is bad-they simply show you the result of your numbers.

Just like Smaart or any of the other measurement programs tell you.  They show you the amplitude and phase-but don't tell you what to do to go about correcting it.

If you think that a particular issue is "fine" then so be it.  But others may see that as a problem-and go about trying to fix it.

It is all up to the designers understanding of the all of the particular issues at hand.  And the understanding of how to go about changing or fixing it.

The end result all depends on the knowledge of the designer and how all of the different parameters/issues tie together.

You may "fix" one issue-but cause a bigger one somewhere else in the design.  It is all the art of compromise.

Such as tuning a box to go lower-making it larger etc.  Yes it may go lower-but not at all power levels.

And as John said- you STILL have to make some sawdust and actually measure the box to see what it is doing.

Remember that the programs are APPROXIMATIONS-NOT actual end results.

[Guillaume Boda]

Another program, an oldie though, which doesn't work on the latest Windows OS (Vista, Seven),
is Akabak, designed by Joerg Panzer (http://www.randteam.de/).

Quite tricky to get into, but when you figure out how it all works,
it is brilliant and very accurate.  (it's not very user friendly I have to say)
It is basically a 1D system, where you can articulate elements, in the order you want,
acoustic elements such as volumes, vents, drivers, passive radiators, or RLC components
for filter design. You can then monitor and plot voltage/current in every location of your system,
plot SPL, vent velocity... very complete in one word!

Remember a few things, whatever software you're using:
- always validate a basic design with a real measurement (then you can adjust your software) parameters
- absorbing foam can not be modelised, you can only modify a few other parameters in function:
        a decent amount of foam in your box will increase your volume by 5% (very approximate)
        it will attenuate, if not cancel internal resonances, hard to do in a modelisation software.

Cheers.

[Jeff Bankston]

jeffs backwoods test facilities ! NOT !!! but they wauz gittin muzic played thew them !!! the one in the 5 gallon paint bucket is a ciare 12ndh 4 8ohm , the one settin in the 16x18 all birch 1980's tama superstar floor tom is a faitalpro 18xl1600 4 ohm. hay i was born and raised in south missippi , watt can i say ?!

[Ivan Beaver]

jeffs backwoods test facilities ! NOT !!! but they wauz gittin muzic played thew them !!! the one in the 5 gallon paint bucket is a ciare 12ndh 4 8ohm , the one settin in the 16x18 all birch 1980's tama superstar floor tom is a faitalpro 18xl1600 4 ohm. hay i was born and raised in south missippi , watt can i say !!!

I saw a guy once that had monitors that he "built".  He took a couple of drawers from his dresser-cut a hole in a piece of wood and nailed it to the top of the drawer.  Put in a single JBLE130 and was "done".

Buzzed like crazy.  But it did what it was "supposed to"  Cheap and quick and made sound.

[Martyn ferrit Rowe]

Hey Guys,
another excellent freeware is Dave McBeans Hornresp
available at:
http://www.hornresp.net.ms/
models horns, tapped horns etc. There's tutorials out on the net - use google

cheers,
ferrit

[Jeff Bankston]

I saw a guy once that had monitors that he "built".  He took a couple of drawers from his dresser-cut a hole in a piece of wood and nailed it to the top of the drawer.  Put in a single JBLE130 and was "done".

Buzzed like crazy.  But it did what it was "supposed to"  Cheap and quick and made sound.

i'v seen some stuff in my day !!!

[Ivan Beaver]

jeffs backwoods test facilities ! NOT !!! but they wauz gittin muzic played thew them !!! the one in the 5 gallon paint bucket is a ciare 12ndh 4 8ohm , the one settin in the 16x18 all birch 1980's tama superstar floor tom is a faitalpro 18xl1600 4 ohm. hay i was born and raised in south missippi , watt can i say ?!

I just remembered some "cheap" cabinets that I did.

Back in the mid 70's I worked at a gift shop on the Cherokee Indian reservation.  I was mainly a cashier-but also fixed the electronic stuff around the store and was a "barker" for the Red Star Shooting Gallery-the one where you shoot out a red star with a automatic BB machine gun.  Ever wonder how come the operator could shoot out the star (using the same guns)-while normal buyers had a hard time?  The secrect lies in the length of the tubes holding the BB's-there were longer ones used to load the guns when the operator used it to shoot out the star-more BB's to shoot. 

We needed a system so I could call the people in-and the owner did not want to spend any money.  So I went to the local Radio Shack and bought a couple of raw 12" full range speakers with whizzer cones.

No money for cabinets-so I cut holes in the boxes they came in to mount the speakers and used duct tape to seal up all the seams.  We laid some 2x4's on the rafters and pointed the speakers straight down.  I used an old stereo receiver (maybe 20 watt/ch) to power them.  My "mic" was a 3" speaker I took out of an old TV that I held in my hand.  I built a 2 or 3 transistor preamp to boost the level to go into the line inputs.

 It worked fine the whole time I was there.  Then the store burnt down and all that great work was lost. HA-HA.  At least nobody go hurt by speakers falling out of carboard boxes.

I didn't need no stinkin' speaker program!

[Jeff Bankston]

I just remembered some "cheap" cabinets that I did.

Back in the mid 70's I worked at a gift shop on the Cherokee Indian reservation.  I was mainly a cashier-but also fixed the electronic stuff around the store and was a "barker" for the Red Star Shooting Gallery-the one where you shoot out a red star with a automatic BB machine gun.  Ever wonder how come the operator could shoot out the star (using the same guns)-while normal buyers had a hard time?  The secrect lies in the length of the tubes holding the BB's-there were longer ones used to load the guns when the operator used it to shoot out the star-more BB's to shoot. 

We needed a system so I could call the people in-and the owner did not want to spend any money.  So I went to the local Radio Shack and bought a couple of raw 12" full range speakers with whizzer cones.

No money for cabinets-so I cut holes in the boxes they came in to mount the speakers and used duct tape to seal up all the seams.  We laid some 2x4's on the rafters and pointed the speakers straight down.  I used an old stereo receiver (maybe 20 watt/ch) to power them.  My "mic" was a 3" speaker I took out of an old TV that I held in my hand.  I built a 2 or 3 transistor preamp to boost the level to go into the line inputs.

 It worked fine the whole time I was there.  Then the store burnt down and all that great work was lost. HA-HA.  At least nobody go hurt by speakers falling out of carboard boxes.

I didn't need no stinkin' speaker program!

that faitalpro 18xl1600 4ohm version just hit the market about a month ago. i wanted to hear it now and decided to put it on top of an extra 18" tom shell. it is rated for 1600 watts rms at 4ohms. the qsc 3800 is rated at 1700 watts rms bridged mono at 4ohms so 1 amp and 1 woof are a great match. i am going to use 8 of those woofs. i have 10 3800 amps. it didnt sound to bad and i cranked it till the clip indicators just barely lit and then backed off a tad. i put a 12" ciare 12ndh4 8ohm rated at 500 watts rms in a 5 gallon bucket and hooked it to a qsc 3500 rated at 1100 watts bridged mono into 4 ohms. crossed them at 130hz with my ashly xr4001 and played music while running cabnet numbers for about 4 hours straight last night trying to find a cabnet design for the 18xl1600. man thats a muthu of a driver to get good flat low end down to 40 in a small cabnet. i wound up with a 6cuft design with (2)3"h x 12.75"w x 23.23"l ports. one bad thing is i live up stairs and hauling speaker cabnets up and down stairs by mysef is a no no !!! my above garage house was built with 2x6 and double insulated and double sheer walled is sound proof. the few windows are tripple pain airport type. the freeway soundwall is where my backyard ends, my landlord has a 2 story soundproof house on one side , the neighbors house on the other side is a good distance away with the garage first and our houses are set about 80 feet back from the street so it can let it rip !!!

[Curtis H List (Too Tall)]

LspCAD is what I use for all my modeling, both volume box and crossover design,
The Pro v6 I use is EUR800. Perhaps more then you want?

Look at the Std (Standard version) for EUR 160.
Here is a sheet showing which features the standard version does not have.
http://www.ijdata.com/LspCAD_feature_list.html
 
For box modeling LspCAD has one of the most complex and powerful programs I have ever seen. 
http://www.ijdata.com/LspCAD_box.html
Now that you have seen it do you understand it?
Right, me neither.
 
But there is  solution.
LspCAD v6 comes with the old version 5.25.
It is very powerful also, but a joy to use for modeling boxes.

LspCAD also comes with a measurement program called JustMLS.
http://www.ijdata.com/LspCAD_justMLS.html
It is stripped down, but it has most of what you need including  gated response and impedance for crossover design.

Back to box modeling.
If you do not have access to the T/S parameters of a driver you are up the creek unless you have a measurement program that can measure impedance and change that measurement into T/S data.

Lucky for us there is a program that does this for free.
www.libinst.com

Praxis in free demo mode will measure the impedance of the woofer and convert into T/S parameters.
These you plug into LspCAD to design your box volume, ports, Xmax overload , etc.
Note if you want to use winISD or any other free modeling program you still need Praxis if you do not have the T/S parameters in hand.
Or the specs have changed because it is too old or too new (Break-in on a new driver is often necessary.

 NOTE: You should use very low frequency for breaking in so that the surround is moved somewhat.
I use 10Hz at a very low volume. Can’t harm the driver, but gets a good workout.
Turn the volume down all the way and then increase slowly so you do not exceed Xmax.
Cheers

PS_ I didn't talk on it much because everyone seemed to have box modeling on their mind, but using LspCAD on xover desgnis just great.

[Jeff Bankston]

 NOTE: You should use very low frequency for breaking in so that the surround is moved somewhat.
I use 10Hz at a very low volume. Can’t harm the driver, but gets a good workout.
Turn the volume down all the way and then increase slowly so you do not exceed Xmax.
Cheers

PS_ I didn't talk on it much because everyone seemed to have box modeling on their mind, but using LspCAD on xover desgnis just great.

i play music through the drivers for a total of about 20 hours at just below max power to break them in, see my fotos above.

[Ivan Beaver]

LspCAD is what I use for all my modeling, both volume box and crossover design,
The Pro v6 I use is EUR800. Perhaps more then you want?


PS_ I didn't talk on it much because everyone seemed to have box modeling on their mind, but using LspCAD on xover desgnis just great.

I agree.  You can see instantly how the different crossover parts values change the response/phase and impedance of the overall cabinet.

When you start to "do it the right way", it becomes quickly apparent that crossover design is not as easy as a simple "calculator".

[Bruce Burke]

There is also Unibox, which runs under Excel. Gives 4 designs per driver: Sealed, Vented, Passive Radiator, and Single Tuned Bandpass.

[ProSoundWeb Community]