Next project: twin DPL12 sonotube 75L sealed.

Discussion in 'Home Theater Projects' started by Justin Ward, Mar 12, 2004.

  1. Justin Ward

    Justin Ward Supporting Actor

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    For my next project I am going to construct two 75L sonotube based DPL12 subs. I was really interested in doing a dipole sub but the process was looking just a bit too involving and the placement was going to be impractical.

    So, what I'm planning on doing is making two sealed 75L subs. So I'm thinking that 16" sonotubes 2 feet tall should net me about 80L, subtract driver volume and should be pretty close to 75L. Their use would be 90% music. Until I move out I'll throw them in the corner with my Tempest.

    I just have some questions about the sonotube enclosures. I'm worried about their weight, is it normal for the enclosures to be very light? I'm also wondering if it would be ok to run the subs in stereo and use them as speaker stands to achieve true stereo bass?
     
  2. ThomasW

    ThomasW Cinematographer

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  3. Justin Ward

    Justin Ward Supporting Actor

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    Thanks Thomas,
    I actually had read that FAQ previously. I'm just concerned with the overall weight lacking and allowing the sub to jump or slide around a bit.

    Also, regarding the stereo subs, are there any major disadvantages to doing this? ie, would I be better off just throwing them into a corner, electronically summing the bass and have them play the same thing?
     
  4. ThomasW

    ThomasW Cinematographer

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    DLP12"s are some of my favorite drivers. But I doubt that they have enough 'umph' to walk across the floor [​IMG]

    You'll need to experiment, you may get weird room modes using them as stands. It all depends on the speaker placement, the XO frequency, and the geometry of the room.

    So play around and see what sounds best........
     
  5. Justin Ward

    Justin Ward Supporting Actor

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    That's a bit of a relief. Because sometimes when I push my SBB4 Tempest really hard I swear it seems like it could jump right up(and it is nearly 200 lbs).

    In terms of overall output what can I expect? I'm thinking that the two DPL12s will be a bit shy of my ported Tempest but more than capable for music, is this a good assumption?
     
  6. ThomasW

    ThomasW Cinematographer

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    A pair of DLP12"s have more combined Sd, 1012cm^2 vs 779cm^2 for the Tempest. So they have the potential to play louder and lower depending on the box Fb. To do so they'll need more power given their lower efficiency.

    The best way avoid any walking is just to use an attached bottom plate.....

    I make mine slightly bigger than the end caps since I think it balances out the look. It also makes a very stable platform

    [​IMG]
     
  7. ScottDIY

    ScottDIY Agent

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    I was just considering doing the same thing. I already have one 75L dpl12 build and was considering the possible advantages or disadvantages of having two and using them as stands for my Heresy’s.
    As far as bass, would a second sub add more volume, punch or detail? I have been running the dpl for about a month now and as far as shear volume the single is fine, in my perspective. I was wondering if two would give a more presence rather than just volume. I have been running it with a NAD 3150 which produces ~ 60 watts/ch – 3db of headroom (left ch & right ch to each voice coil = ~120 watts). This quality of base is incredible, very dynamic. The sub is actually more dynamic than my mains, which leads me to my only complaint I have for the Denon 1603. The Denon is very clean and more than enough power to run my Klipsch Heresy, of course with 96db @ 1 watt it doesn’t require much power, but it is not as dynamic as the NAD.
    I don’t have a sound meter yet, out of stock, but I ran a 12th octave cd and found that the sub is peaking around 47hz and is strong down to 27hz. She has dropped significantly by 25hz. As I am writing this, I think that I have decided that I will invest in a bdf and see what I can do about flattening and extending the sub I have before investing in a second.

    I apologize for the ramblings, but I will post this in hoses that I might answer someone’s questions.
     
  8. KyleGS

    KyleGS Second Unit

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    Stereo subs will be fine- just make sure to take your time in placement and calibrating (phase, gains, EQ, etc). I haven't seen any SONOTUBES bounce around due to lack of weight. The weight of the driver and enclosure is usually more than enough (per sonotube) unless you have a very macho sub like the Tumult in a cardboard box. [​IMG]

    SCOTT-I don't think two will add more "punch." I think if properly placed, the dual set-up will sound similar to what you have with more output. However- it is nice to know that you would have the extra headroom if needed. Dual DPL12's (or #4) is very close to my idea perfect stereo reproduction. [​IMG]

    - Do the Heresy's have a sealed 15" driver? I'm from Baton Rouge, LA and recently went to New Orleans and have seen two jazz/blues clubs using the Heresy's as main spks. I was very impressed to see such prominent New Orleans jazz clubs using these. How deep do they extend?
     
  9. ScottDIY

    ScottDIY Agent

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    The Original Heresy (1957-1985), 96db spl, 50 to 17,000hz
    The Heresy II (1985 - ), 96db spl, 63 to

    the Heresy is sealed, but has a 12" woofer not 15. The Cornwall, it's bigger brother has a 15" woofer, although the Cornwall is a ported. (stats 98db spl, 38 to 17,000hz). The rest of the heritage line are folded horn design.
     

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