Build your own 2x12" TH (The Kraken 212 TH) - Page 9 - diyAudio
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Old 27th October 2011, 06:21 PM   #81
18Hurts is offline 18Hurts  United States
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Quote:
Originally Posted by Spuddy View Post
Sounds like you're making a heck of a thing there- Is that all set up for some heavy jam sessions? Neighbors must love you haha.
I went with 6 foot tall arrays to take up little garage floor space, the design reduces metal garage reflections and the big sound of them works well when working in the garage. Since I'm using low power, the 96dB at one watt/one meter level makes a great party speaker. The local church wants to run the array system with the tapped horn to evaluate that design... amazing how people come out of the wood work when arrays are sitting in your garage.

They NEED bass support and considering how arrays "throw", the bass support needs to be L O U D. I'm not into pro sound anymore but the 2x12 TH would give me enough bass (at 120 watts in the garage) and it would mesh well with the arrays.

Out of all the designs, the Kraken would give me 16 Hz performance for classical music/HT sound, it has enough output to be used as a PA type bass bin (around 98 dB at one watt) it will easily handle the 600 watts RMS I would provide with my Carver amp for PA/block party use and the 6 foot height and 14" width is almost a perfect match for the arrays within an inch. It also fits nicely in one corner of my garage so as an "all-in-one" design--it's a keeper.

Normally, the garage arrays are running about 3 to 10 watt peaks when playing music...the 12" sub strains if I play classical so since I'm in MY garage, the WAF is not in play. Always wanted to get into pipe organ music but that is another league--the league that dual 12" tapped horns play in.

As far as building one, I have a table saw, Roto-Zip, jig saw and other various things. Looked at the design and noted the critical dimension: the "leaves" of the horn to include the sides. My plan is to cut them on the table saw slightly oversize and take them to a cabinet maker for planing to perfect dimension. Have two guitar playing buddies that will help assemble the beast so I'm laying out the plan at this point. The JBLs will be my Christmas present to bypass the wife objections to such a beast. "Not in the house!"
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Old 28th October 2011, 06:20 PM   #82
Spuddy is offline Spuddy  United States
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Quote:
Originally Posted by 18Hurts View Post
I went with 6 foot tall arrays to take up little garage floor space, the design reduces metal garage reflections and the big sound of them works well when working in the garage. Since I'm using low power, the 96dB at one watt/one meter level makes a great party speaker. The local church wants to run the array system with the tapped horn to evaluate that design... amazing how people come out of the wood work when arrays are sitting in your garage.

They NEED bass support and considering how arrays "throw", the bass support needs to be L O U D. I'm not into pro sound anymore but the 2x12 TH would give me enough bass (at 120 watts in the garage) and it would mesh well with the arrays.

Out of all the designs, the Kraken would give me 16 Hz performance for classical music/HT sound, it has enough output to be used as a PA type bass bin (around 98 dB at one watt) it will easily handle the 600 watts RMS I would provide with my Carver amp for PA/block party use and the 6 foot height and 14" width is almost a perfect match for the arrays within an inch. It also fits nicely in one corner of my garage so as an "all-in-one" design--it's a keeper.

Normally, the garage arrays are running about 3 to 10 watt peaks when playing music...the 12" sub strains if I play classical so since I'm in MY garage, the WAF is not in play. Always wanted to get into pipe organ music but that is another league--the league that dual 12" tapped horns play in.

As far as building one, I have a table saw, Roto-Zip, jig saw and other various things. Looked at the design and noted the critical dimension: the "leaves" of the horn to include the sides. My plan is to cut them on the table saw slightly oversize and take them to a cabinet maker for planing to perfect dimension. Have two guitar playing buddies that will help assemble the beast so I'm laying out the plan at this point. The JBLs will be my Christmas present to bypass the wife objections to such a beast. "Not in the house!"
It's always encouraging when the local community is interested in your set up! Is this your church or did a random member happen to see your system and see use for it in the building?

Interesting how you use the word "throw" for sound distribution; While the Kraken's output doesn't seem much affected by your position in the area (it always sounds somehow "distant" despite its volume level) it certainly has the characteristic of really throwing the bass out there. I don't know if this is due to infrasonic frequencies traveling farther or something to do with the horn resonance lining up the waves, but it is every bit as loud in the theater as it is in any other part of the house. It's way too big to use as a mobile sub (you're only gonna want to haul it to the church once ) but it should match up with the arrays quite nicely for that reason.


As far as making sure the inner "leaf" panels are all exactly the same, you should be able to do that with your table saw no problem as long as you can rely on the cut being at a consistent 90* angle to the table surface. Just make all of your length cuts first (or do them with a skill saw guided with a straight edge like I did,) and when it's time to do width, set up the table saw to the correct width (either use a fixture if you have one, or clamp a straight edge to the table if you don't) and do them all at once. As long as the saw is cutting at a 90* right angle, all of the leaves will be the same width and will be perpendicular to the face you screw them onto, lining up perfectly with the other face sheet to be installed on the other side.

Before doing that though, cut the two faces together (cut one out, put it on the next sheet, then trace it and cut the second,) then line them up as well as you can, clamp em, and drill all of your pilot holes. With the pilots drilled, unclamp the sheets and do your counter sinks, making sure they are drilled on the proper side according to which way the panels will be screwed down as a finished product. Do it right and everything will line up perfectly
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Old 29th October 2011, 04:15 AM   #83
18Hurts is offline 18Hurts  United States
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Quote:
Originally Posted by Spuddy View Post
It's always encouraging when the local community is interested in your set up! Is this your church or did a random member happen to see your system and see use for it in the building?
I talk to the sound guy at the church on occasion--small church and the dual JBLs on stands work. Someone told him I built these really tall speakers that look like coffins so he asked about what I was doing. He just wants to stack them to 12+ feet high, run the dual 12" TH for bass support and kill two birds with one stone...line arrays and tapped horns. They won't be used in a service, just an experiment.

I've been eyeballing the design for the dual 12" JBL for about the last year. Figure the perfect dimensions and 90 degree angles would be assured with a planer at a cabinet shop--my table saw is decent but one less thing to worry about leaking. The wood will be perfect so it might make up for my wood working skills or lack of them.

I am guessing here but am assuming the Kraken weighs around 250 pounds? If so, the hook the arrays up at the church with bass support will be a one time good deal. I'm sure after building the beast--I won't be too hip about moving it around for awhile.

So the entire sub can be built with 3 sheets of 4x8 plywood by joining the "scrap"? My plan is to use 1/2" ply for braces, Titebond II wood glue for the wood pieces and finish up by applying the expanding foam wood glue along the seams just in case.

My Christmas present will be the JBL woofers so the project starts in January. Thanks for your report on the Kraken, it pushed me over the edge and would be the perfect addition for the garage system.
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Old 2nd November 2011, 06:52 PM   #84
Spuddy is offline Spuddy  United States
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@18Hurts-

While I do believe it possible to get good results with your table saw alone, it certainly doesn't hurt to have the pieces professionally sized up (especially if that will give you greater peace of mind!)

I have no idea what this thing actually weighs, but it is undoubtedly a very heavy object and was no fun moving out from my basement back door, around the house, and back inside to the theater upstairs. Good thing I did it before this happened-
Click the image to open in full size.
(the day before Halloween, of all times!!)


Yes you can build the whole thing with 3 sheets of 4x8 3/4" void-free plywood, and in fact you can even do the bracing with remnants from said sheets, though I don't know how much that affects the internal dimensions. I personally used my 3/4" scraps for bracing and still have far more than enough wood to spare, and of course the sound quality has remained phenominal even if that did happen to affect the target internal dimensions, so it might not be a bad idea to just go that route to begin with and save a few bucks. Not to mention, since everything has to line up right when you screw the face sheet down at the end, it doesn't hurt to have an extra 1/4" width to lesson the chances of a screw missing its target (since you can't see anything more than your pilot holes at that point)

Here's my version of translating this build to inches. Double check everything as you draw it out on the plywood before diving right in, but it should be pretty accurate barring any major screw ups. Can't wait to see yours up and running!

Click the image to open in full size.
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Old 2nd November 2011, 07:51 PM   #85
18Hurts is offline 18Hurts  United States
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Originally Posted by Spuddy View Post
@18Hurts-

While I do believe it possible to get good results with your table saw alone, it certainly doesn't hurt to have the pieces professionally sized up (especially if that will give you greater peace of mind!)

Yes you can build the whole thing with 3 sheets of 4x8 3/4" void-free plywood, and in fact you can even do the bracing with remnants from said sheets, though I don't know how much that affects the internal dimensions. Not to mention, since everything has to line up right when you screw the face sheet down at the end, it doesn't hurt to have an extra 1/4" width to lesson the chances of a screw missing its target (since you can't see anything more than your pilot holes at that point)
Good points and thank you for the conversion!
The church sound guy asked a good question, can you make it with a single JBL? I'm assuming the only change would involve the 46 1/8th depth would drop to around 24" since the width of the horn path could be cut in half? Basically, a single version would be around 14"W x 24"D x 72"H ? I'm aware that the horn path would actually be slightly longer so tuned slightly lower which is not a bad thing.

Asked him why and his reasoning is sound, the Kracken would be impossible to move around and way too deep at 46" to fit in the corner. Having four singles would fit better than two full sized Krackens and not break anyone's back.

My issues with the single version would it loses the push/pull of the duals so I'd assume the response would not be as smooth. Not sure about the tapped horn mouth either, would cutting the width in half while keeping the height the same create issues? It sounds like a simple solution on the surface but it can't be that simple--can it?

Great to know the Kracken was worth the build and now you can hide from the snow with a few movies--keep an eye on the dry wall!
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Old 2nd November 2011, 08:57 PM   #86
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I did a re-CAD drawing today. Unfortunatilly, I does not have the original any
more, Some minor changes were done but nothing that will affect the
preformance negativly. Will post that one together with a better drawing soon.
I am also making a drawing for the 10" JBL GTO 1014. Same SPL performance
but some 5 Hz less low freq. extention. About 100x160x32 cm. Will try to
translate it into inches aswell.

The advantage of push pull is reduced harmonic distorsion due to assymetrical
behavion inwards and outwards movement.

Spuddy, what did your friends say about your new build?

Is it okay to post your images and comments on a swedish forum where I also posted the Kraken?
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Old 2nd November 2011, 09:00 PM   #87
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Can have a look if a single would be possible. Mut so much weight will be saved since the internal will be almost the samt though...
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Old 2nd November 2011, 09:28 PM   #88
18Hurts is offline 18Hurts  United States
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Originally Posted by Petter Persson View Post
Can have a look if a single would be possible. Mut so much weight will be saved since the internal will be almost the samt though...
Petter,

It won't be a drastic drop in weight, I calculated it would take one sheet less of plywood (32 KG or 70 pounds) and the weight of the driver (7.7 KG or 17 pounds)

A wild guess calculation is the proper dual JBL Kraken weighs around 115 KG so cutting it down to 75 KG would be quite noticeable--and considering it is half the size it can be squeezed through doors easier etc.

Looking forward to your modified drawings and the dual 10" GTO. The Kraken has me pulling out my pipe organ CDs, dusting them off and pondering what 120 dB of the big pipe firing would do to my garage.
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Old 3rd November 2011, 12:19 AM   #89
Spuddy is offline Spuddy  United States
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Petter (and anyone else), You are more than welcome to post my images wherever people want to listen I'll try to get some better ones when I can, unfortunately my camera is toast, so I'm stuck with the phone camera for now. As for my friends, the comments with this sub are more in the "weird faces" category than verbal comments- It seems like I've finally built a sub so big that they don't need words anymore, cause what's the point??? Just gotta be there and you'll understand

Also, I now have a video for you! Since I can't make any data charts and measurements, recording some water dancing at single digit frequencies is the least I could do. 6-7 hertz is about where you can start actually feeling bass, then around 15-16 hertz it starts getting a lot more powerful. The video shows a bit of a dead spot around 11-14 hertz, but despite the apparent calm, there's definitely still some bass being made, just no room violently shaking. My favorite is 18 hertz when it makes some beautiful ocean-style waves, as well as 23hz+ when the water starts going airborne http://www.youtube.com/watch?v=g-NRo2KMwrY


18Hurts- It appears Petter has come to the rescue for your design ideas, so I'm gonna step back and leave you in his more capable hands. Let us know what you're doing though!
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Old 3rd November 2011, 01:18 AM   #90
18Hurts is offline 18Hurts  United States
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Quote:
Originally Posted by Spuddy View Post
As for my friends, the comments with this sub are more in the "weird faces" category than verbal comments- It seems like I've finally built a sub so big that they don't need words anymore, cause what's the point??? Just gotta be there and you'll understand

My favorite is 18 hertz when it makes some beautiful ocean-style waves, as well as 23hz+ when the water starts going airborne

18Hurts- It appears Petter has come to the rescue for your design ideas, so I'm gonna step back and leave you in his more capable hands. Let us know what you're doing though!
Kraken 2x12 looks great--no mistaking it for serious firepower--great job! So are you going to build another one for more output or would that require major room reconstruction at this point? I guess when you have the Velodyne hooked up to your computer speakers and people ask why, point at the Kraken 2x12 for the explanation. The beast has been unleashed in the east!

I do like the sound of my Isobarik face-to-face push-pull 15 inch sub with passive radiator--easy to understand why Petter designed the Kraken to use two 12's in push-pull to limit distortion. Since my use would be for pipe organs, various deep bass music and the odd "teenaged son with bass head stuff" on his phone, the Kraken should do it for me.

At this point, Petter's design is a keeper but I am curious about the single JBL version, would a pair of singles sitting next to each line array sound better trading balance for push-pull distortion reduction?

A front roared through and rain is turning into snow flakes--not a good time to build things in the garage but the time of year to get better with horn response. Eventually I'll fully understand the design concepts so will feel confident when the saw blades meet wood.
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