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Finding the calculation for speaker vents using a K-43 woofer in a 14"x16"x28" enclosure


bsacco1
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Yes, I have a WT.

 

I have not seen any X-over software worth buying.

 

I did the T/S parameters from memory, and guessed at the Qms. I think it is close enough. I lowered the filter Q to 1.8 for the flattest response. Purple is no filter, Yellow is with filter.

 

K43_zps923b32f0.jpg

Edited by djk
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I see now. You are using an active HPF to minimize the cone excursion, and adding a +6db EQ centered at 36Hz with a Q1.8. 

 

It took me a while... I'm a bit slow...........

 

I checked, and the safe voltage with those specs is about 30.  That's plenty loud, and likely more than the horns could keep up with.

 

bsacc01, If you are planning on using an electronic crossover with those shortcorns, you should consider these specs. 

 

If you are using these with a traditional system, and you are sticking with the ports I mentioned (we'll call that naturally aspirated, and djk's supercharged), then you will reach cone excursion max at as little as 75 watts if you send signals under 25Hz to this speaker system. These aren't subs.  :)

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Hey guys,

 

Can you please translate that into Luddite English for me.

 

I have no idea what you are talking about.

 

Here's what I do know:

 

I need the following replaced.

 

(2) 1.5uf 250v

(1) 3.0uf 250v

(1) 68uf 100v

 

The above is per speaker.

 

Please advise.

Edited by bsacco1
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"and adding a +6db EQ centered at 36Hz with a Q1.8. "

 

Q=1.8=5dB (max)

Q=1.414=3dB

Q=2=6dB

 

Peak output for dance music is about 55hz, and the filter will have about 3dB of boost, declining above there.

 

The Yellow curve on excursion reflects the boost, and shows that you should not use an amplifier bigger than 800W/4Ω or you will have problems around 50hz (in reality you will be well into power compression, so it shouldn't be an issue).

 

Should sound great on music (this is not a HT sub).

 

If you use a Waves MaxxBass it will convert notes as low as 12hz into 36hz and 60hz that will shake the room for HT.

Edited by djk
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bsacco1,

 

My post #17 explains how to make these general purpose speakers which as I stated: "When tuned correctly, these should be dead flat to 64Hz, and roll off to 43Hz at -5db. That's not bad for this cab, as the regular CW gets 38Hz using a K33 which has a lower fs." You wont be able to improve upon this with an eq.

 

djk's post gives details on using an active crossover and calculated "very specific" tuning instructions to make the enclosure good to around 36Hz. If you do not have the speakers connected to the electric crossover or DSP or computer or whatever you are using to tune them to 36Hz, then they will sound much worse than the ones in post 17. They will need a high pass filter and they will need an eq boost to get the 36Hz.

 

Hope that helps,

 

Craig

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Craig,

Sorry but I'm very confused with all this technical talk. It's over my head. I give up.

 

Thank you all for your input, but I can't use it if I don't understand how to implement it. 

 

I don't know how to tune a speaker. Or know what a high-pass band filter is. 

 

To me, this looks like an algebra problem where I need to solve for "Q":

 

"and adding a +6db EQ centered at 36Hz with a Q1.8. "

 

Q=1.8=5dB (max)

Q=1.414=3dB

Q=2=6dB

 

Not sure if anyone here can actually translate all this tech talk down to stuff like "buy this here with this link" and "click here for install instructions."

 

I can solder. I can follow instructions. I'm just not up for Linear Algebra if you know what I mean...;)

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Just use my post #17. It is on the first page of this thread:  https://community.klipsch.com/index.php?/topic/152881-finding-the-calculation-for-speaker-vents-using-a-k-43-woofer-in-a-14x16x28-enclosure/

 

You need two ports in each speaker. I gave you 3 different width's to choose from. Just select the one that is aesthetically pleasing in your enclosure.

 

I just happened to think of something. If the motorboard of your speaker is 3/4" plywood, then you might luck out with two 2 1/16" round holes in it. No need for a port. Look at post 17 and the 2 1/16" option...  

Edited by mustang guy
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"Not sure if anyone here can actually translate all this tech talk down to stuff like "buy this here with this link" and "click here for install instructions.""

 

Any piece of gear with a 'low filter' in it can be changed to suit by just changing two resistors per channel.

 

Most EQ's, crossovers, and pro power amps have such filters.

 

Older stereo receivers also have same.

 

An amplifier with an input cap (most on the market) may be changed by adding another input cap and adding a resistor.

 

Preamps can be changed.

 

The list is almost without end.

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That should be an excellent center speaker to your 'short-corns'. You can always upgrade the caps in any crossover. I haven't heard about people around here doing it, but that doesn't mean it doesn't happen. If you are upgrading the mains, you might want to buy extra caps and do the center at the same time. 

 

Here is the diagram for the Academy

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