Building Shiva for music...... help?

Discussion in 'Archived Threads 2001-2004' started by Brian Womble, Sep 4, 2001.

  1. Brian Womble

    Brian Womble Extra

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    Hello everyone!
    I want to build a DIY sub using the
    Shiva driver. This is my first DIY sub project and
    the internal volume of the cabinet seems to make so
    much difference in sound. I have read the articles
    on the Shiva site considering different sealed and vented
    designs, but for the most part they focused on home
    theater sound reproduction. I really don't know where
    to start. This sub will be for 100% music
    reproduction, not Home Theater. I want mostly tight
    (not muddy or boomy) defined bass, down to 20Hz.
    my room is pretty small, about 16' x 10'. I already have a
    cheap 150 watt amp from parts express, so I want a front ported design for greater output and sensitivity, but I don't want the boomy bass. (is this good, or should i stick with decresed output from a sealed design?) Please help me with a target internal volume, and port
    length. I can make the thing pretty big (but not sonosub size.)
    Thanks alot for any input you have to offer.
    Brian Womble
     
  2. Geoff L

    Geoff L Screenwriter

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    Hi Brian and welcome
    If music only is what your looking into, I prefer a sealed design with a Q around .550 to .6. But your cabnit volume will definitly increase.
    How big a cabnit are you willing to go?
    Given your amplifier power at present you might consider an EBS design or (PR set up if you got a few more bucks to spend). ~(Others here with far more knowledge than I)~ will surly chime in. Wheres Pat, Jack, Dustin, Greg, and of course Dan the man when you need them. These guys and many others can offer much more insite on the many proven designs for the Shiva than I, and are much better at explaining things in terms one is able understand. [​IMG]
    But any way, for music only I much prefer the sealed low Q. Your gona give up some output, alot compared to say an EBS, but for music and if your not needing major output given your amp size, I say a fair trade. This is not to say other alinements wont sound as good, many do music very very well. But when talking 1 driver 1 box and just muisic, give me a good sealed Shiva sub.
    Let the boys give you some more to chew on. [​IMG]
    Regards
    Geoff
     
  3. Rob Lloyd

    Rob Lloyd Stunt Coordinator

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    I was in your situation except I also wanted it for movies. I ended up building the 85L PR Shiva. I had to go w/ the 85 for size reasons but it is far better than I thought it would be. Music is fast and tight and it easily plays 20hz at levels over 120db. I am using the PE 250w amp, but it's only set around 1/2 way.
    With the PR it really is responsive and worth the extra money. You can tune it to the freq you want easily.
    -Rob Lloyd
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    Rob Lloyd
    Rob's Web Page
     
  4. Kyle Richardson

    Kyle Richardson Screenwriter

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    Brian, the Shiva is such a versatile driver there are several alignments that you can go with that will provide the performance you are looking for.
    Sealed designs are the easiest to build and usually provide the tightest bass for your music only application but do not have the extension of ported or PR designs. For sealed designs I would first recommend the 88.5 liter or the 101.5 liter followed by the 54 liter for a little more punch at the expense of some "tightness".
    If you would like to stick to a vented design then I would recommend the 85 liter Adire alignment or the 142.5 EBS if you can handle a sub that large. If designed and built properly, a ported design can have very tight, punchy bass with the added output and extension that a ported application provides.
    If a PR interests you then the 85 liter Adire alignment that Rob Lloyd built and mentions above is the way to go.
    All of these designs can be found on Adire's site and even give you detailed drawings to make them. They can be found in their white paper section.
    ------------------AOL Instant Messenger Name: kyler70
     
  5. Patrick Sun

    Patrick Sun Moderator
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    Go with a sealed sub enclosure if your only objective is music. Sure, the F3 is higher, but the roll-off is much more gradual, and including room gain, a sealed sub will get low enough while retaining the transient response performance you are looking for.
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    PatCave; HT Pix; Gear; DIY Mains; DIY CC; Sunosub I + II + III; DVDs; LDs
     
  6. Brian Womble

    Brian Womble Extra

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    Hello, and thank you everyone for your combined input. I have some questions: what is EBS? and how exactly does a passive radiator work? The max cabinet size can be about 30h x 20w x 26d. Also I want it loud, will a sealed design with only 150 watts really deliver??? the sub cutoff will be about 70hz.
    Thank You!!
    Brian Womble
     
  7. AjayM

    AjayM Screenwriter

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    Well, that's about 7.47cu/ft gross internal volume assuming 3/4" material. So you could get a low-Q dual-shiva setup in that space and get around .6 or so Q out of it. And with 150 watts you should still easily get over 100+db out of it.
    You could also look at a Tempest, you'd get the same .6 Q (give or take a little) out of that size enclosure maybe a hair more extension and maybe a little more output.
    The above are all sealed design's, and will offer you pretty much the best "audiophile" like bass.
    EBS is a vented design, but if you are looking for a music only sub you'll want to look very hard at going sealed. As Porsche says, there is no substitute. If you really need extension into the teens, then look at something like the Adire alignment with the Tempest in vented, it's tuned very low (like 15Hz) in a 220l (around 7.5cu/ft) cabinet and the response is very similiar to a sealed .577Q, just a lot lower. You get some of the benefits of a sealed design, like a lower group delay, etc....however you take a hit in mid-bass response (I believe the 50+Hz range), so if your mains will drop that low it may be a good way to go.
    Andrew
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  8. Bob Ahlberg

    Bob Ahlberg Agent

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    Hi...
    You can build a very musical sub that is ported or sealed. The ported sub is just a bit less forgiving about mistakes made in the construction.
    I can't imagine what you will use "loud" 20hz for in music reproduction unless you listen to alot of demo discs or are a organ music fan. Most commercial discs tend not to have alot of output below 30hz...although some synth music can go pretty low...and Enya tends to have some very low bass on her discs.
    Loud is also a relative term. For some 100db is loud and for others it's just starting to get going. I'm sure you're also aware that listening in excess of 105 db for periods of 30min can cause permanent, non-reversable hearing loss. (my wife is an audiologist and is always after me).
    So...bottom line is you can go sealed or ported. Ported will go louder and lower, possibly at the expense of tightness, but that is more a design factor issue than a ported vs. sealed issue. 150 watts will do very well, but if you want to really feel it in you chest, you need more power and more drivers.
    Have fun.
    Bob
     
  9. Kyle Richardson

    Kyle Richardson Screenwriter

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    Brian, to answer your questions: EBS is an extended bass shelf and is just a type of alignment. The construction is the same as any other sub but its called EBS because of the type of performance curve.
    A passive radiator is similar to a vented design but it uses another woofer without a motor structure to perform the tuning duties. The amount of weight of the PR determines the tuning so you can change the tuning if you add or remove weight.
    Hope this helps a bit.
    ------------------AOL Instant Messenger Name: kyler70
     
  10. Jack Gilvey

    Jack Gilvey Producer

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    You've gotten all excellent responses already, but I'd recommend you read through this page, as it's got a wealth of info.
    http://216.150.71.139/audioinnovation/theories.html
    I'd say the best bet, since you're working with 150 watts (I'm assuming the amp is the 300-800?) and want to get appreciable 20hz response, is the Shiva EBS alignment, which you can find in the Shiva Applications paper on the Adire site. Since you're new to this, having the design all laid out is a distinct advantage. You'll also want to defeat the amp's bass-boost.
    In your allotted volume, a sealed Tempest would also be excellent.
    I've got another Shiva on the way which I think I'm going to try in an EBS, but with the Adire passive radiator, since I've never used a PR.
    Finally, I just finished a tiny sub based on the PE Dayton 12" DVC woofer, # 295-185. This is a very impressive performer also, currently powered by an Adire AVA250 in a heavily-stuffed, 1.05ft.^3(net) cabinet. I was originally going to use my 300-800 in it, but the thing isn't sealed (much to my surprise and chagrin), so I enlarged the hole and installed the Adire. I posted some impressions and measurements here .
    [Edited last by Jack Gilvey on September 06, 2001 at 04:15 PM]
     

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