Ok, got a plan now for my sonosub

Discussion in 'Archived Threads 2001-2004' started by Justin Scott, Dec 31, 2002.

  1. Justin Scott

    Justin Scott Auditioning

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    i am going to build two of them cause it is cheaper to do that.
    this is what i have in mind
    two shiva 12's
    parts express 250 watt amp (I need a volume control for the amp, do I have to get the 300-793 for the volume control, does not have to be remotely controlled mind you)
    sonotubing i got is 22 inches wide, 31 inches tall, bear in mind that when/if you give me port ideas (which i need help with!)
    thanks
    gonna order this stuff tonight so the faster the help the better [​IMG]
    thanks again
     
  2. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    All of the PE plate amps have a gain control. But I do hope you're planning on sending it a variable line-in. Otherwise you'll have to try to match the sub volume up to the speakers everytime you adjust the speaker volume. If your receiver doesn't have a subwoofer output or pre-amp outputs then try using the headphone output. My brother-in-law is successfully using this for the sub I gave him for Christmas.

    Running two Shiva's off a single amp gets you an 8 ohm load (using series-parallel connection of 4 voice coils). You'll get 180 watts out of these amps at 8 ohms. 90 watts to each woofer - they'll put out some serious bass without getting anywhere near their excursion limits.

    Here's what I see with a 22 x 31 sonotube. This assumes you're putting both drivers in a single sonotube. Put one Shiva in the top endcap. The other Shiva and a 6 inch diameter port go in the bottom endcap. Encaps are made of 3/4 inch MDF disk inside the sonotube end plus 3/4 inch MDF disk laminated to the first but hanging out the end of the sonotube. This disk is slightly larger diameter to be flush with the sonotube or even wider. Throw in 1/4 inch plywood disk laminated to the inside to give T-nuts something to bite into. That leaves 29 inches of internal height. Subtract 6 liters for driver displacement. Now you've got room for a 6 inch diameter x 23 inch long port to tune the net 162L enclosure to 22Hz.

    This design will take up to about 500 watts so you can add power later if desired. But in the meantime your woofers will be cruisin.
     
  3. Justin Scott

    Justin Scott Auditioning

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    i just want the volume control for myself, not gonna need ot use it all the time.

    i am getting TWO of everything
    2 amps
    2 sonotubes
    2 shiva's

    what ports for this size? for HT and Music, one more for HT and the other for Music in two different systems.
     
  4. Justin Scott

    Justin Scott Auditioning

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    bump [​IMG]
    i basically need people to tell me that my sonosub is the right size and what kind of port to use. Width, length and the flare. I have all the tools you can imagine so don't not say something because I might lack it [​IMG]
    I also want to mount the amp onto the sonotube like this guy did in this picture (Warrick)
    http://members.optushome.com.au/wcallen/
    Consider this when telling me about the port because it takes up SOME volume in the sub. I pressume that will change the porting?
    I am NOT going to have the remote controlled version, just the 250 watt since it has a level (volume) control on the amp itself. Am I correct here?
    Do I buy the PartsExpress 250 Watt amp with Bass Boost or the other one without that? Or, would I be just as good off if I got the 120 Watt amp for each shiva instead of the 250 Watt amp for each shive? Seems to me that the Shiva's don't require too much power to put out massive output, and the 120 Watt amp is about $40 cheaper which since I am buying two, it would be $80 cheaper.
    I really need this help as soon as possible because I am on break right now and can build it next week if the parts get in in time.
    Expedited help requested hehe.
    I hate to ask this way for help, I hate it when people demand help from me, but sometimes it is a necessary evil LoL!
    Thanks again for you fast, curteous, long listed, insightful, friendly, economical, philosophical, helpful posts! LOL!!!! [​IMG]
     
  5. Joe Hsu

    Joe Hsu Supporting Actor

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    Justin, just curious, but where are you ordering your tube(s) from and how did you find the place? I have most of my parts ready for my sub, but can't find tubing around here...
     
  6. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    Okay, 2 of everything. I'd probably shoot for an EBS alignment - check the Shiva white pages on the Adire website. It'll tell you all the volume/tuning specifics. You'll likely have to cut the tube down since 22 x 31 would net you somewhere around 155-165 L with one woofer, a 4 inch port and flush mounted amp. You'll have to determine how tall it needs to be since I have no idea how much volume the flush mounted amp will take up. 3 to 5 liters, maybe?

    The 120 watt amp sells for $100. The 250 watt amp (#300-794) is on sale for $120. No, you don't want the bass boost at 30Hz, so if you buy the 120 watter you'll have to swap out a couple of resistors. The 300-794 has no bass boost so it'll work just fine. In my opinion $20 for an extra 100+ watts is worth it. Or in your case $40 for 200+ watts. Especially since it'll save you the minor hassle of modifying the pre-amp boards.

    Alright, I'm a sucker. Assuming 5L displacement for the flush amp. Also assuming 3/4 inch of the top endcap sits inside the tube and 1 inch of the bottom endcap sits inside the tube (you won't need T-nuts in the top so you won't need the extra 1/4 inch plywood disk). 142.5L net enclosure volume. 4 inch x 17 inch long straight port or, preferrably 4 x 18 inch flared port. You can get the flared port from Adire or from parts express (4 inch aeroport). That would require a total sonotube height of 26.5 inches. Total height with feet and encaps might be around 32 inches.

    This is the largest and deepest tuned of the recommended Shiva alignments. There's no need to go any larger. And as I mentioned in my last post, you could actually fit both in one 22 x 31 tube if you don't mind the slightly higher tuning and external amplification.
     
  7. Justin Scott

    Justin Scott Auditioning

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    About the ports. What I was going to do is use a router to flare them and then put PVC piping as the tube. Is this possible to do? I don't want a black port to show on this, even though it will be at the bottom.
    do i really need to make the sonotube shorter? i already had it cut once... [​IMG]
     
  8. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    I can't run WinISD pro here on my UNIX box at work so I can't give you a real detailed response. Yes you can router a flare and attach PVC. Several have done this. The flare won't be nearly as big as the aeroports, but its better than nothing. The aeroports flare from a 4 inch diameter out to about 6 or 6.5 inches. For these the rule of thumb is to make the total port length 1 inch longer than you would for a straight port. Depending on your flare size you may just want to add 1/2 or 1/4 inch.

    I'm sure you could find some porting/tuning that works with the 155-165L you'd get with the full 31 inch tube length. The alignments in the white paper are well designed and have been built many times with great success so I usually recommend them unless there are special needs. The EBS is the biggest and deepest. The only complaints I've ever heard about it are that it is physically too large for some people. Its not really hard to cut sonotube. You can sand the cut end to smooth it out. I used a belt sander.
     
  9. Justin Scott

    Justin Scott Auditioning

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    I think my problem is that i don't understand how to work those white papers. they are for a square box not a round one... thanks again
     
  10. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    When I say "the alignments in the white paper" I mean the net volume and port size. Use any enclosure shape you want. Sonotubes are easier than boxes to calculate accurately since they usually don't have any complicated bracing that requires either numerous calculations or pure guesstimates. In your case you'll still have to calculate or guesstimate the volume of the flush-mounted amp. I built a spreadsheet that calculates sonotube length for a desired subwoofer design. I used that to give you those detailed responses above. I'll email it to you when I get home, if you like. Combine that with a good, free subwoofer simulator like WinISD pro and you'll be a sub designing maniac like me. [​IMG]
     
  11. Justin Scott

    Justin Scott Auditioning

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    that would be wonderful!
    thanks!
    anyone else hehe [​IMG]
     
  12. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    You've got mail.
     

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