cheap pair of 90W subwoofers for folded horn type thingie?

Discussion in 'Archived Threads 2001-2004' started by Drew_E, Aug 7, 2002.

  1. Drew_E

    Drew_E Agent

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    ok so first off i'm a college student and i am just tossin' together what i think could be a respectable sounding system, for real cheap. i live in an apartment BY MYSELF so it isn't going to be a theater and the neighbors wouldn't appreciate me getting 2kW of audio. i have a Harmon Kardon 120 receiver (50Wx5) and a Marantz 500 (somethin-er-other) (rated like 130W mono 8 ohm, 180W mono 4 ohm). i'm thinkin' about building this folded horn type deal designed by Steve Deckert, i'm not sure if you guys are familiar with his work... but they're pretty damn good designs. here's the idea:
    [​IMG]
    i'm going to build it this weekend for a pair of 12" i think. a pair of 8 ohm subs (parallel) on the mono Marantz amp would fit the ticket nicely i assume.
    now i have no experience with home audio subs at all but i do know my share about subs/car audio/etc. for a "real" horn i would need something with high EBP (high Fs, low Qts), a "compressoin driver." This thing looks more like a modified 4th order bandpass and i think those like lower EBP like a sealed box. I'm not too picky and i'd just as easily go to Radio Shack and use those. Does anyone know of a more "decent" alternative? i had considered the Adire Audio Shiva at $134 a pop but they're good for like 600W and i don't have or NEED anything near that. Anyone have a good solution for like $50 a pop or less? call me cheap, fine, but as they say "it's all in the install."
     
  2. Dustin B

    Dustin B Producer

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    You should post this in the DIY advanced section. I'm not sure what that design will do. But I'd guess that a single Shiva in a simple ported box would out gun that design with some really cheap drivers thrown in it.
    Here is what I think of as a folded bass horn.
    http://www.hometheaterforum.com/htfo...threadid=70277
     
  3. Drew_E

    Drew_E Agent

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    yeah the Deckert design is fundamentally the same thing as the link you posted. a rear chamber, throat, and mouth. simple enough. ported boxes sound like ass for movies i think. i'd rather have a fairly flat response. any ideas?
     
  4. Dustin B

    Dustin B Producer

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    Tune them low enough with a large enough enclosure and the right driver and they don't. The difference between my sub with the port open and plugged is extremely subtle (Tempest in 260L, tuned to just over 16hz with a 6" port).

    My comment on I'm not sure what that design will do is because the horn is so small. I thought bass horns needed to be big.
     
  5. Drew_E

    Drew_E Agent

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    deckert has a design for 12" drivers also. it appears suddenly that i'm on the defensive for some reason. I don't think you have to put a lot of money into a rather tame, entry level home theater. the "horn" like i said in the title is more of a "horn thingie," in other words, a modified design done by someone who really knows what he is doing. It is by no means a true horn, but it is a design which produces a fairly flat response and will run rings around any ported design (there i said it, you happy?). so i guess i get no suggestions on woofers best suited for a mere 90 watts in this box. i'll have to ask fellow car audio enthusiasts [​IMG]
     
  6. Mark Seaton

    Mark Seaton Supporting Actor

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    Hi Drew,

    Being that I work with someone who really knows what he's doing, I will suggest you take another look at the link above to the DIY forum. That is a real basshorn. The Decware box unfortunately is in reality a bandpass design which does not offer any real horn loading. The bass horn mentioned in the DIY forum will make for some rediculously high output. If you are just after a nice sounding sub for your apartment, I would suggest you download some of the free modeling software online, and start playing. You can tune a ported box to have a roll-off much like a sealed box, but this is rarely seen in value retail products. Keep an eye on MCM, Madisound and Parts Express for sales and deals, as both can provide some real steals. A good value example would be the SWAN 305 from Madisound at $58. This can sound great in a decent size ported box with as little as 150W.

    If you really want a horn, you could always do a search for John Sheerin's bass horn project where he basically made a similar style bass horn using 2x10s instead of the dual 12" drivers in the LAB subwoofer. Note that bass horns will never be small if they get deep.

    Regards,
     
  7. Dustin B

    Dustin B Producer

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    Well Drew, you have given a first for me. This is the first time I've seen someone argue that a bandpass enclosure will sound better than a good bass reflex enclosure. There are a lot of people here interested in sound quality that avoid bandpass like the plague.

    All three (well for sure Jack and I, I'd imagine Mark would to) of us are advising you look at a $100 driver like the Dayton DVC12" in an appropriate ported enclosure vs two lesser $50 drivers in that bandpass enclosure.

    You'll get more output and it will sound better. If you think we are wrong, don't take our advice. But that is our advice.
     
  8. Jack Gilvey

    Jack Gilvey Producer

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  9. Drew_E

    Drew_E Agent

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    thanks for your thoughts. except for Jack, who thinks he knows more than he does.
     
  10. Dustin B

    Dustin B Producer

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    Drew, you need to know a little more about Jack then. There aren't many people on this board who know more about subs than Jack (although he won't admit that and will hate the fact that I just said it [​IMG]).
     
  11. Drew_E

    Drew_E Agent

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    i have yet to be impressed.
     
  12. John Garcia

    John Garcia Executive Producer

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    Sorry man, but I agree completely with Jack. There's no reason for your comment, you ASKED did you not?

    As mentioned more than once, just sticking ANY 12" driver into an enclosure tuned to with a specific driver's specs in mind, will not yeild ideal results. You need to either use the same driver or one with very similar specs to achieve published results. Bandpass boxes are OK for cars, but not for HT. I prefer sealed even in my car...
     
  13. Mark Seaton

    Mark Seaton Supporting Actor

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    Let me put it this way. While this box may make for an interesting bandpass alignment, I would strongly argue that you can make much better use of this much box volume. I could easily put together a sub where you would still not see the drivers, be easier to construct, and yield MUCH more output. From what I recall reading about this sub probably 5 years ago, he claimed then that the design nulls out the concerns of the T/S parameters, so who knows, any cheap drivers might make some bass for you. FYI, if you want to find some cheap woofers, check MCM and PE's sales.
     
  14. Drew_E

    Drew_E Agent

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    i would be interested to hear what you think would make better SPL with a flat response in that volume. I would just as easily go with sealed for a quick and accurate response but i wanted to get my 180W worth. What's MCM?
     

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