Simplexx 212 build w/ Pics

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CoronaOperator
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Location: Medicine Hat, Alberta, Canada

Re: Simplexx 212 build w/ Pics

#76 Post by CoronaOperator »

Electric Wisdom wrote: Wed Mar 14, 2018 3:44 pm Ah ok that calculator is like a recommendation startpoint then, i get it thanks :)
But the caps for tweeters are not close to the values on that calculator isnt it?
The other ones seems close tho
Crossover design is an entire discipline in and of itself. Part science, part art.

For example, your 8 ohm woofer is not 8 ohms. Look at the specification sheet for the 3012HO. The impedance in free air varies from a low of about 7 ohms, up to a high of about 120 ohms depending on frequency. Once you put that driver in a box that impedance changes depending on the box design. When you design a filter you take into account the actual impedance of the woofer/box system at the frequency that you want to crossover. Again that is your starting point and you fine tune to taste after that. You can't just enter 8 ohms into a crossover calculator and get a great result because your driver won't be 8 ohms at the frequency where you want to crossover.

The tweeter array in the simplex is also a 4th order crossover which will have very different cap values than the 2nd order crossover on that page you are looking at.

There are also different crossover types, there are Bessel, LR, Butterworth, etc. Each type will have different cap and inductor values to get the desired slope and phase response.

Also, doing the above doesn't guarantee great results. You need to look at the phase responses of the woofer and the tweeter after your crossovers to make sure that they play well with each other and take into account any lobing that might happen. Designing crossovers is very involving and makes or breaks your design. A simple calculator doesn't cut it in a good design.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

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Electric Wisdom
Posts: 127
Joined: Thu Mar 01, 2018 2:18 pm
Location: Montreal

Re: Simplexx 212 build w/ Pics

#77 Post by Electric Wisdom »

CoronaOperator wrote: Wed Mar 14, 2018 10:09 pm
Electric Wisdom wrote: Wed Mar 14, 2018 3:44 pm Ah ok that calculator is like a recommendation startpoint then, i get it thanks :)
But the caps for tweeters are not close to the values on that calculator isnt it?
The other ones seems close tho
Crossover design is an entire discipline in and of itself. Part science, part art.

For example, your 8 ohm woofer is not 8 ohms. Look at the specification sheet for the 3012HO. The impedance in free air varies from a low of about 7 ohms, up to a high of about 120 ohms depending on frequency. Once you put that driver in a box that impedance changes depending on the box design. When you design a filter you take into account the actual impedance of the woofer/box system at the frequency that you want to crossover. Again that is your starting point and you fine tune to taste after that. You can't just enter 8 ohms into a crossover calculator and get a great result because your driver won't be 8 ohms at the frequency where you want to crossover.

The tweeter array in the simplex is also a 4th order crossover which will have very different cap values than the 2nd order crossover on that page you are looking at.

There are also different crossover types, there are Bessel, LR, Butterworth, etc. Each type will have different cap and inductor values to get the desired slope and phase response.

Also, doing the above doesn't guarantee great results. You need to look at the phase responses of the woofer and the tweeter after your crossovers to make sure that they play well with each other and take into account any lobing that might happen. Designing crossovers is very involving and makes or breaks your design. A simple calculator doesn't cut it in a good design.
Oh yeah right, i forgot about the ohm not being the same at different freq, that makes perfect sense thank you :) But then what is this calculator used for in real life?

And about the phase response, if i follow the design for simplex 212, all drivers well secured on the baffle there will have no phase problems right? :)

Grant Bunter
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Location: Ilfracombe Queensland Australia
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Re: Simplexx 212 build w/ Pics

#78 Post by Grant Bunter »

Electric Wisdom wrote: Wed Mar 14, 2018 11:48 pm And about the phase response, if i follow the design for simplex 212, all drivers well secured on the baffle there will have no phase problems right? :)
Right.

Bill addresses so many things in the design stage of his cabs that so many people are unaware of.
Phase response is one of those things...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Simplexx 212 build w/ Pics

#79 Post by CoronaOperator »

Electric Wisdom wrote: Wed Mar 14, 2018 11:48 pm But then what is this calculator used for in real life?
Same reason you had to learn about taking home the recorder! To learn about music!
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

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Electric Wisdom
Posts: 127
Joined: Thu Mar 01, 2018 2:18 pm
Location: Montreal

Re: Simplexx 212 build w/ Pics

#80 Post by Electric Wisdom »

CoronaOperator wrote: Thu Mar 15, 2018 5:16 am
Electric Wisdom wrote: Wed Mar 14, 2018 11:48 pm But then what is this calculator used for in real life?
Same reason you had to learn about taking home the recorder! To learn about music!
I'm french, what this means? "taking home the recorder!"

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Electric Wisdom
Posts: 127
Joined: Thu Mar 01, 2018 2:18 pm
Location: Montreal

Re: Simplexx 212 build w/ Pics

#81 Post by Electric Wisdom »

Grant Bunter wrote: Thu Mar 15, 2018 3:45 am
Electric Wisdom wrote: Wed Mar 14, 2018 11:48 pm And about the phase response, if i follow the design for simplex 212, all drivers well secured on the baffle there will have no phase problems right? :)
Right.

Bill addresses so many things in the design stage of his cabs that so many people are unaware of.
Phase response is one of those things...
I'm aware of what is phase problems, also in daw when recording drums, same concept, just wanted to confirm since both drivers are on the baffle at the same place but one higher.

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Electric Wisdom
Posts: 127
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Location: Montreal

Re: Simplexx 212 build w/ Pics

#82 Post by Electric Wisdom »

Electric Wisdom wrote: Thu Mar 15, 2018 11:55 am
Grant Bunter wrote: Thu Mar 15, 2018 3:45 am
Electric Wisdom wrote: Wed Mar 14, 2018 11:48 pm And about the phase response, if i follow the design for simplex 212, all drivers well secured on the baffle there will have no phase problems right? :)
Right.

Bill addresses so many things in the design stage of his cabs that so many people are unaware of.
Phase response is one of those things...
I'm aware of what is phase problems, also in daw when recording drums, same concept, just wanted to confirm since both drivers are on the baffle at the same place in axis but one is higher.

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Bill Fitzmaurice
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Re: Simplexx 212 build w/ Pics

#83 Post by Bill Fitzmaurice »

Electric Wisdom wrote: Thu Mar 15, 2018 11:54 am I'm french, what this means? "taking home the recorder!"
America's answer to the bagpipes:
Image

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Electric Wisdom
Posts: 127
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Location: Montreal

Re: Simplexx 212 build w/ Pics

#84 Post by Electric Wisdom »

Bill Fitzmaurice wrote: Thu Mar 15, 2018 1:20 pm
Electric Wisdom wrote: Thu Mar 15, 2018 11:54 am I'm french, what this means? "taking home the recorder!"
America's answer to the bagpipes:
Image
haha omg you guys lost me haha

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Electric Wisdom
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Re: Simplexx 212 build w/ Pics

#85 Post by Electric Wisdom »

So it uses 3012lf, datasheet says 11.06" hole in the baffle right?
Because i did that at exactly 11.06" and when fitting the speaking in the hole i can move it around a bit in the hole, it's normal that it is a bit bigger than a perfect fit?
Thanks!
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Electric Wisdom
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Re: Simplexx 212 build w/ Pics

#86 Post by Electric Wisdom »

The back is 1/8 off on one side but i'll sand it to make it good, hoping the baffle will fit inside, i did a fit test, seems good but let's see tomorow.
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Electric Wisdom
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Re: Simplexx 212 build w/ Pics

#87 Post by Electric Wisdom »

It's all dry now. Damn that glue is super strong haha :hyper:

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Electric Wisdom
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Re: Simplexx 212 build w/ Pics

#88 Post by Electric Wisdom »

Ok it's completely wrong compared to the workflow on the build guide but my helper suggested installing the back first so yea i had to measure everything to the end reversed, looks like it fits well tho... i won't be as easily distracted for the second cab loll #RULE1 haha ;)
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Tom Smit
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Re: Simplexx 212 build w/ Pics

#89 Post by Tom Smit »

There is a reason to do the baffle first, but, it looks like you found a way around that judging by the pencil marks on the back panel. :clap:
TomS

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Bill Fitzmaurice
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Re: Simplexx 212 build w/ Pics

#90 Post by Bill Fitzmaurice »

There's another reason. Doing the baffle first you can see the joints of the baffle and ducts. It's critical that they be airtight. Now when he attaches the baffle he can't tell if they're airtight, unless he happens to have a gooseneck mounted camera to look inside the cab. He'll also have to install the damping working through the speaker holes, a royal PITA.
It's a good idea to ignore advice from 'helpers'. :cop:

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