Accurate Sub for Under $400

Discussion in 'Home Theater Projects' started by joe-e, Dec 6, 2003.

  1. joe-e

    joe-e Auditioning

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    I've been banging my head against the wall deciding what to do about a subwoofer. I can't decide whether I should custom build one or buy a pre-built one. I'm more interested in accuracy and tight bass than creating cracks in the Earth's crust. Front-firing would be preferred because there is an apartment below me.

    My current HT setup has JBL ND310II front L/R, an old Harman Kardon center channel, and a pair of Bose 201 Series III in the rear, with a Kenwood VR6060 running the show. Room limitations make it so I can't put up a Surround Rear speaker, so I'm working with 5.0 sound for now.

    The room is 13'x16', and my TV is located on the 16' wall. 3' is lost to hallway on the 13' dimension. The room is horribly designed. I will be moving somewhere else in 12-14 months and I will have a much larger room to work with and I don't want to have to rebuy.

    Here's what I'm considering at the moment...
    --Dayton 10" sub from PartsExpress ($150 shipped). It seems silly to buy a 10" subwoofer when I already have 4 10" woofers in my front L/R speakers. 12" or 15" would be preferred but PartsExpress doesn't have any reasonably priced 12-15" subs.
    --Fluance DB-200 ($280 shipped). Everyone says good things about their other speakers but I can't find any reviews about the sub. Has anyone listened to this?
    --Adire Rava ($440 shipped). Expensive.
    --Build a home theater sub with parts from PartsExpress. Probably around $350 when all is said and done. I just don't know if I have the mechanical ability to do it and have it look good and sound good. I think I can do everything but I don't know about the enclosure.
    --Build a car sub. This would probably run me $200-250. I have an old receiver I can use as an amp that would be great if I can find a good DVC driver. It can put out 100w/channel and can drive 4ohm speakers. I've heard a setup like this before and it sounded like a good idea, as long as the speakers are decent quality. I'm looking at the Infinity Kappa Perfect 12.1d.
    --Use a car sub enclosure and the amp from above with a HT-oriented sub driver. Would this sound better than if I used a really good car sub? Is there a difference between car boxes and HT boxes? I think I could get the price down to the $150-200 range on this, and I would have a known quality driver. Can anyone recommend a good speaker to use in such a configuration?

    Thanks a lot!
    Joe

    (edit: misspelled Dayton.. oops!)
     
  2. VinhT

    VinhT Second Unit

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    I think the key statement is:
     
  3. Sebastian

    Sebastian Second Unit

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  4. joe-e

    joe-e Auditioning

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    The box would be sealed. From what I've read, sealed boxes sacrifice volume for flat response. I'll lurk around these forums for a bit for opinions on the AV-12 vs Shiva vs Tempest vs Titanic... the $90 price on the original Titanic is tempting, but the Shiva might be worth the extra $35.

    For an enclosure, I'm looking at something like a
    Q-Logic QLH-1.7512SE which has a volume of 1.75 cu ft or contacting Ebay sellers who custom manufacture boxes, and ask them to make me a 2-2.5 cu ft box. I do not currently own a box so I'll be getting a box to match the driver. At a price like $60 or so it's tough for me to justify building my own.

    When subwoofers say they handle 1000w or whatever, what voltage is that measured at? The little bit of physics that I remember says p=iv so since I know p=1000, I can find out current if I know voltage. I'm actually thinking about getting a car audio amp to plug into this mess (again, much cheaper than a HT amp) and then using a 120vac-12vdc power supply. I'm sure my current solution (sorry, bad pun) of using an old receiver would work, but if I went with a separate amp I wouldn't have to worry about getting a dual voice coil driver so I can get the impedence high enough to make the receiver happy.

    Are there any good 12-15" drivers out there that are natively 8ohm, or DVC 4ohm so I can wire it to 8? I'm less and less worried that 100w won't be enough power for how I listen to it, for now at least. I can always upgrade the amp later on. That's why I like DIY...
     
  5. Joe Ku

    Joe Ku Stunt Coordinator

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    Car amp and converter is a costly propisition, You will need a 25a-30a power supply minimum, you have to factor in the power the sub comsumes and account for the efficiency of the amp, also you will need a 13.8-14.4 volt supply. an easy way to figure out what size supply you need is to see what size fuse is on the amp.

    you can buy a 350 watt rms amp from rythmikaudio for $150 or a 250 watt rms amp from parts express for $120 (onsale sometimes for $99). this is a much better way to go, looks better too.

    don't worry about max power, it is simply a measure of how much power the voice coil can take before it melts, excursion is the limiting factor in home subs.

    avoid the infinity sub, while a good car sub, it is a bad home sub. the FS is much too high to be a sealed home sub (won't play low) and only a mediocre ported sub.

    If you want an awesome audiofile quailty sealed sub run, don't walk, to partsexpress and buy the titanic for $89 (onsale till 6pm) It is superrior to the shiva in a sealed enclosure IMO. the 250 watt amp PE sells is more than adequate to power this sub.

    The best bang for your buck IMO would be to buy the dayton 12" DVC and power it with your old reciever. the dayton DVC is on the same level an the shiva in every respect, with the advantage that it is dual voice coil so you can use your old reciever to power it.

    I personally own the AV-12 and the 12" titanic MK-II. Both excellent subs well worth the money. The AV-12 with the 350 watt rythmik amp is an awesome combo.

    another dirt cheap option would be the dayton 12" ($38) or 8" ($22) DVC shielded drivers (completely different than the non shielded). the 12" in a 3.25 cuft box tuned to 29hz will giva an F3 of 30hz with an in room F3 in the low to mid 20hz range and produce 106db at 30hz. The 8" in a 1.5cuft box tuned to 28hz will give a F3 of 29hz with an in room F3 in the low to mid 20hz range and produce 98db at 30hz. either one of there could be powered by your old reciever quite nicely.

    My father in law has the dayton 10" powered sub and is sounds quite good for the money. It doesn't go super low but is quite impressive for its price. It does not sound boomy at all. I would highly reccomend it if you don't go the DIY route. You would be hard pressed to find a better prebuilt sub at that price.
     
  6. JarrettVance

    JarrettVance Auditioning

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  7. Frank Carter

    Frank Carter Screenwriter

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  8. Joe Ku

    Joe Ku Stunt Coordinator

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    Oops :b , well nevermind about the DVC vs shiva thing then , just buy the one you can get a better deal on if you go that route, yeah thats what I meant to say [​IMG]
     
  9. joe-e

    joe-e Auditioning

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    For the enclosure, I'm pretty sure now that I'm going to have a car audio shop build one for me. It seems like the easiest choice. I'll have them leave off the lame carpet and I'll finish it myself. However, I'm starting to waffle on whether to get it ported or sealed... I'm running this all through WinISD and ported boxes keep on coming up with flat response. That's what I'm looking for, right?

    For the amp, I vastly underestimated the size of a power supply required to drive such a large DC device. I was thinking I'd be able to get away with an old AT-style PC power supply, until I saw that it only spits out 10A on its 12V line! Thanks for bringing that to my attention. I'm leaning much more toward using the receiver to drive the speaker, so I'm more and more limited by available power and by impedance.

    If I don't plan to crank up the volume TOO high, do I need more than 100w? How good is the DVC Dayton speaker, especially compared to the Shiva? I like it that they're both 8ohms per voice coil. Are there any other subwoofers out there with DVC 8ohms each?

    On a side note, I picked up a Kappa Perfect 12.1d for a steal on ebay before I came here and heard from you folks. I'm planning to try it out, and if it doesn't stun me (and it probably won't), I'll either resell it or throw it in my car. Don't you love it when one project splits into two?

    Thanks again!
    Joe
     
  10. Joe Ku

    Joe Ku Stunt Coordinator

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    The shiva is no longer as close to the specs of the DVC as I remembered as adire is now selling the shiva MK4 (not the MK3 that I was thinking of) in any case I modeled the new shiva VS the dayton DVC and they still model extremely close to one another in both frequency responce and output. You can't really go wrong either way. I know the dayton carries a 5 year replacement warrenty, I am not sure what adire offers, you may want to call them and ask, could be a tie breaker.

    with 100w in a 90l enclosure (tuning optimised for each driver)
    Shiva 100db @ 20hz
    DVC 99.5db @ 20hz

    with 100w in a 124l enclosure
    Shiva 102db @ 20hz
    DVC 102db @ 20hz

    and one more just for fun, a 15" dayton DVC in a 230l enclosure yealds 105db @ 20hz with 100w, you would probibly want to go with a sonotube if you wanted to build this one, they are really easy to build if you have a buddy with basic tools, jigsaw or router w/circle template, a circular saw, & a truck to bring it home in, you could do it.

    going from 100w to 250w will gain you about 4db of output with any of these drivers. Loud enough is really a subjective thing. My AV-12 does about 108db @20hz and it is very rarely at that level.

    I should also say that all these are modeled responces and do not account for room gain or distance to listening position, your mileage may vary.
     
  11. Craig Treusdell

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    I was never impressed with ported boxes until I tried the Adire Tempest using the Adire alignment. Add a 250 watt plate amp from parts express and I believe you will be more than satisfied. It's not a Tumult, but it is an excellent sub.

    Tempest: $125 shipped from acoustic-visions
    250W plate amp: $128 + shipping
    Box - exact specs in Adire pdf download, have someone build it. I've built sub boxes from both mdf and fiberglass for several people and never charged a penny. You should be able to find someone to do it for you. (Read: built, not finished.)
     
  12. joe-e

    joe-e Auditioning

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    I decided to be lame and buy from an Ebay auction. There was a Shiva-based sub going for nothing, built into a nice-looking cabinet. It's actually dual Shivas, configured isobaric. I put it through WinISD and it looked great, plus it didn't break the bank. And heck, if I don't like its sound, I can yank out the drivers and put them in a different enclosure.

    My current receiver will work as an amp for this one, but I might end up trying to find an extrenal amp anyway. Or maybe I'll get a subwoofer amp and put it in a box, or something. Thanks for all of your help and recommendations... they really pointed me toward the Shiva and put me where I wanted to be.

    One last question, since I know I'm not going to want to go with a car amp hooked up to a power supply, can anyone recommend good, cheap external component amps? What's the story with pro audio amps, are the low end ones any good?
     

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