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diy sub build need help

12325 Views 77 Replies 12 Participants Last post by  smoggysky
hello guys. my mal-x is on its way. in the app notes for the mal-x a ported sonotub is recommended at 22x50 inches w/ 8"by32" port tuned to 17hz. i have access to sonotub sizes 20,24 or 30 inches. if possible i would prefer to use 24" or 30". my room sealing is 86 inches high. any help would be appreciated. note if this cannot work i have plans for a sealed 28inch cube, however i would like to try the sonotub...thank you...
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Here's a link to the Sonosub software that does all the figuring for you. It's a free download.

Use the link Mike supplied, and you might take a look at the other link he had of the subwoofer database, if you haven't already. One of the ways that differ among sono's is the baseplate/leg configuration, and members have used different methods that you can peruse. If you're going to use 30" dia tube, you could easily go bigger (LLT) without adding too much height, and tune lower, say 13hz, and negate the need for a hpf, but you're going to need a hpf if you tune to 17hz. I have a tough space to fill, and my mains are wimpy, but most people wouldn't want more spl watching movies, which is the tradeoff for going LLT without doubling up on subs. I wish I could have used the other half to build another sub, I just don't have room for two. If I could have, I'd have built the two and bought the second Mal-X later. Just my opinion.

There's a thread on required/desireable tools for building- you might check before deciding on the type of build.

What do you plan to drive it with?
i have tried the software. both winisd and sonotub. i must be "mentally challanged", i cannot get any coheret results. (an i cannot spell:scratchhead:) for example with winisd, will the software calculate the port size & lenght for the box after i input the driver specs,desired volume and desired tuning? or are all input values supposed to be known before hand?
i am powering this with a qscrmx2450. i ordered the mal-x and a sms-1 from exodus audio.
i can build this:yes:, i just need some help:ponder:
I'm taking a shot at answering you questions, any others correct me if mistaken:

You might familiarize yourself with the sonosub program by entering exodus' parameters and measurements. Then, use the calculations in the winisd and you should get it to work. Once there, you can save it, then open the file again and use the new file to 'tinker' with the response. You can then go back and forth between the programs to fine tune, and meet your requirements of sound and enclosure size/build materials.

The answer to your questions are given the driver parameters, and enclosure volume and tuning, you can look at the important characteristics: freq response & spl, cone excursion, and port air speed. After you like what you see there, you go to sonosub and use the tube's diameter along with the driver specs, net volume, and calculated tuning. With a bit more specific info, Sonosub gives you the build specs so everything fits nicely (and should sound as calculated in winisd).
with winisd, will the software calculate the port size & length for the box after i input the driver specs,desired volume and desired tuning?
You enter what tuning frequency and box size that you want. Switch to the cone excursion graph and enter how much power you will be using in the Signal tab. Adjust the power input until the sub is within its Xmax.
Switch to the Rear Port - Air Velocity graph. Change the port diameter until the air speed is under 30 m/s, 26 m/s being optimum.
The file for your sub is at the link below. Make sure you download the correct version, either Generation 1 or Generation 2.
in the app notes for the mal-x a ported sonotub is recommended at 22x50 inches w/ 8"by32" port tuned to 17hz.
That should say 19 hz. The recommended box size is 9.35 cu.ft. A 22 inch sonotube is the largerst diameter tube that will make this work. The net volume needs to be increased abit from 9.35 to 9.75 to have enough clearance between the end of the port and the back of the sub.

The bottom right of the pic shows the SoundSplinter sub dimensions which is in the programs database. The key dimension is the mounting depth which is about the same as the Maelstrom.

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mike i really appreciate this. i input the numbers exactly as you displayed them in sonotub. i got the same results:yay2:. i then began to alter only one parameter(height from endcap to endcap) and i began to get predictable movement in the volume & tuning freq. sec.:yes::yes: i guess i am not a village idiot(not yet:dizzy:) next i opened winisd and input the variables from sonotub. winisd displayed the same results.what a relief.
now what to do next. when i go to the cone excursion graph.with the power signal at 1500w my graph shows a low point 6.566mm peak @ 19.05hz then rises to 26.212mm @ 28.58hz. from 26.212 the graph slopes downward to 0 mm @ 500hz. i noticed as i lower the power the gap between the 19hz and 26hz narrows. however i am not getting a change in the sound velocity #. what would be my next step??
thank you...
dont laugh but i just realized why your graph plots looked so different from mine. my winisd graph plots are set to default. 78db to 105db on the left plot and 0hz to 500hz. i just set the points to 78db to 140db and hz to 0 - 150. wow the spl graph now looks like yours.:jump::jump:. amazing...where is that village???
now i will try to calculate a 24in sonotub. what is the minimum distance between rear of driver and vent port bottom?
ironglen thank you. i have been going over your build post..wow..
now i will try to calculate a 24in sonotub. what is the minimum distance between rear of driver and vent port bottom?
I believe the sonosub program will warn if the distance is too short; it will flag you by having the display warnings text become red (like the example above), if you click on the red text it will give more info, just be sure your driver input parameters are correct.

Thanks, I've been enjoying it, and I just had a friend over and demo'ed LOTR 1- the look on his wife's face was worth it!
well, 24inch will not work in my room because of ceiling. so i calculated a 30inch model.
1) 30inch diameter sonotube
2)55.47inches endcap to endcap
3)8inch dia. internal port x 30.08inches long
5)tuning freq-13.7hz
cone excursion graph shows-8.809mm @ 13.9hz
25.544mm @ 20.92hz
at what point do i set a filter (hpf or lpf)
does this setup look do-able???:scratchhead::scratchhead:
Generally looks good: the hpf seems to be around 1-4hz lower than tuning. You'll want to look at where the excursion surpasses the driver's limit below tuning-that's the important thing. A suitable hpf slope and freq will bring the excursion within the driver limit. If it doesn't occur, well you've really got a llt!
does this setup look do-able???
Yes, you have lots of room between the back of the sub and the port. This sub would be a monster, 118 db down to 14 hz, plus room gain. :yes: :hsd:
:jump::jump::jump::jump:i just received a delivery from ups...its here..all i can say is W-O-W.. i had no idea.my god is this thing HUGE!!!!!. it came as i was out ordering my sonotub. my local material supply company charged me $25.00 per foot for the 30inch sonotub. they billed me for 6 ft and cut it down to 55 inches. the 8 inch sonotub was $4.00 per ft, again they billed me for 3 ft and cut it down to 30 inches.
i am just busting :yay2::yay2::yay2:. i cant stop :yes:..
i also orderd a sms-1. i know the older ones had a distortion problem at low hz levels that was corrected with a software update. the unit i ordered had a inspection tag of june 10,2009 and appears to be physically different than the picture in the manual.the manual with the unit is dated from 2005 with software version 2.1 which is the bad version. the update version is 2.1.3. would anyone know if the newer sms-1 units have the update already installed?
if kevin is around, how do you know if your maelstrom-x is gen1 or gen2. i received no documentation with the driver. i download the doc supplied on the diy web site.
diy cable great company,with very good service.+++.thankyou...
mike will post pic..:yes:
any advice on binding posts that is the only piece i dont have. of course the sonotubs will be here today:bigsmile:
Kevin will have to answer the SMS-1 question, I'm not familiar with the unit.

If you just got your Maelstrom-X then it's a Gen II.

P.E. has a big selection of speaker terminals.

i am not a wood guy,my dad is helping me with the wood work.the attachment is my design for a brace/port support. (dont laugh). he is trying to figure out how to safely cut the center 8" inch cut after all other cuts are done. any ideas:scratchhead::scratchhead:


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