Audiosource SW-15 Cabinet with Tempest + 250W Amp

Discussion in 'Home Theater Projects' started by Joe.Kuta, Sep 4, 2003.

  1. Joe.Kuta

    Joe.Kuta Stunt Coordinator

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    Greetings,
    this place keeps bringing me back
    (or maybe it's just my love of audio) [​IMG]

    !![Optional Reading]!!
    Yesterday I noticed the amp on my SW-15 was pretty hot,
    so I opened her up to see if I could help cool anything internally.
    I just read that 10ga wire between the amp and speaker is a good fix, but it's too late for that.
    When I tried to power up the amp again, something let out some smoke and afterwards the amp would not power up.
    I found the fuse blown, but replacement only resulted in more blown fuses.
    So I suspect (from visual inspection) 2 mosfets in the amp overheated and as a result the amp now shorts out.

    [Start Reading Here]
    I might be able to get the amp fixed,
    but am considering just buying a new amp and new driver while i'm at it.

    I've read great things about the Tempest and Dayton DVC drivers,
    but I want to make sure the Tempest would work with the ported SW-15 cabinet.

    Wayne Ernst posted here that the Dayton DVC works great with his SW-15
    http://www.hometheaterforum.com/htfo...91#post1739891

    I plan on making my own box (or tube), so the amp/sub will be good to have but I won't have time for this project till next summer.

    My cabinet already has dampening sheets (parts express #268-010) as well as acoustic foam (part#260-316B) inside the walls of the cabinet (attached with 3M adhesive part# 340-270) to tighten up response (+ Dayton Spikes, Part# 240-715 and speaker sealing caulk, part 269-300).

    Finally, the amp I was looking at is Parts Express Part Number 300-794,
    http://www.partsexpress.com


    Thanks in advance for any opinions.
     
  2. Joe.Kuta

    Joe.Kuta Stunt Coordinator

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    oops, this is supposed to be a Speakers and Subwoofers topic :b
     
  3. Neil Joseph

    Neil Joseph Lead Actor

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    Real Name:
    Neil Joseph
    Actually, this belongs in the DIY/Advanced area. I will move it.
     
  4. Joe.Kuta

    Joe.Kuta Stunt Coordinator

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    heh my bad,
    thanks

    I'll be here all night folks [​IMG]
     
  5. JeffB

    JeffB Extra

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    I replaced mine with the Dayton and cant believe the difference. definitely recommend. I also have considered upgrading the amp but have not done so yet. The driver is rated for 600W. If you will be doing a DIY box or tube I would pass on the plate amp and get a regular amp with more power. I spoke to Wayne before getting the Dayton, if you can find the thread it may have some more info. Also you might want to call Audiosource they were very helpful when my amp quit working (B4 driver change and mods)
     
  6. Joe.Kuta

    Joe.Kuta Stunt Coordinator

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    I'll admit I haven't really looked into speaker construction yet,
    saving that for summer when I'll have plenty of time to learn about everything involved, lookin forward to using those programs.

    From what I have gathered, a ported cabinet is tuned to a frequency,
    based on the port length/size and the box volume.

    I'm mainly worried that a new driver will not match the cabinet's specs,
    but so far the Dayton seems to be a drop-in replacement.

    Anybody know if the Tempest is better than the Dayton?
    I hear so much about the Tempest [​IMG]
    that's why I am leaning toward it.

    Will look into some regular amps, but I can't spend too much as I'm already in debt (college) :-0
     
  7. Joe.Kuta

    Joe.Kuta Stunt Coordinator

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    Wow, i'm reading about other amps.

    The Apex Senior (350W) and the Rythmic one (cannot find) are good deals,

    but then I saw for $300 i could get a Crown XLS-402 which provides 1140W in 4ohm bridged mono [​IMG] [​IMG]
    haven't heard anything bad about it.

    I also haven't seen any other amps (plated or external) that are better in value
    (including the PE 300-794 and Apex Senior).

    I am thinking whether the Stereo capability of this amp would be useful to have, but the better question to ask ::
    Can the Tempest handle a KiloWatt amp?

    Adire Audio on the 750W PMax-
     
  8. Brian Bunge

    Brian Bunge Producer

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    I haven't checked out the Audiosource sub in a while, but last time I checked it was sorely undersized to be used ported with a Dayton DVC 15 or a Tempest.

    The Rythmik amp is available from www.rythmikaudio.com

    In most cases 250W or so is plenty for a Dayton 15 or Tempest in a ported enclosure. The larger the enclosure, the more efficient the system. Therefore, you don't need as much power to get high SPL's or to bottom the driver. So a large ported enclosure shouldn't need a ton of power.

    As far as using an outboard pro amp to power a sub, if your receiver has a built-in crossover then you're fine. You probably won't have phase adjustment though.
     
  9. PaulDF

    PaulDF Second Unit

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    You can always swap speaker leads for a phase flip! Not as fine as a dial, but I still did it and left the dial at 0.
     
  10. Wayne Ernst

    Wayne Ernst Cinematographer

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  11. Brian Bunge

    Brian Bunge Producer

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    Wayne,

    There's nothing wrong with replacing the driver. It's just that it's hard to predict the performance of the sub by just arbitrarily swapping out drivers. That fact that you're happy with the performance is all that matters. Also, you've definitely upgraded the driver and can use it in a new enclosure down the road when you have more space and don't have to worry about neighbors.

    I just wanted to make sure that people knew that this is a less than optimum alignment for this driver. The enclosure is undersized, the tuning frequency is a bit high from what I remember, and the ports are rather small. If you'll give me the enclosure's internal dimensions, the ports' internal diameter and length I'll double check what the tuning frequency is and give you an idea of what the response should be for this driver in this enclosure.
     
  12. Joe.Kuta

    Joe.Kuta Stunt Coordinator

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    These are the measurements of my SW-15.
    I heard there are different sizes however, based on the year.

    Height 20"
    Width 16-3/4"
    Depth 19-1/4"
    Port Diameter 3"
    Port Length 5"

    These are the external dimensions,
    3/4" MDF is used so subtract 1.5" from each dimension for the internal size.
    I calculated a volume of 2.9ft^3


    On a side note, adding 2" to each dimension would yield a 4CU volume,
    an additional 2" would yield 5.45CU, 2" more would yield 7.15CU, and 2 more for 9.18CU.

    In other words, an extra 2" gives 37% more volume,
    + 2" gives 88% more,
    + 2" gives 147% more,
    + 2" gives 217" more,
    etc.

    I guess the sub was already too big for most people to allow for an extra 2" or 4",
    good to know for when I build my own box though.
     
  13. Joe.Kuta

    Joe.Kuta Stunt Coordinator

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    I am thinking one of the Rythmik amps would be best,
    1) I don't have a lot of money now (no job @ school)
    2) 1140 watts isn't really necessary and wouldn't make that big of a difference

    What about a Stryke AV15

    I heard they like a smaller box,
    and the 23mm Xmag is pretty nice

    Does it even matter w/ an 82L / 2.9ft^3 box though?

    Might be good to have for the future when I make my own larger box though . . .
     
  14. Jack Gilvey

    Jack Gilvey Producer

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  15. Joe.Kuta

    Joe.Kuta Stunt Coordinator

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    Yup you are dead on,
    I am playing around with WinISD and came up with these graphs ::

    [​IMG]

    Green is the Dayton DVC,
    Yellow is the Stryke AV15,
    and Red is the Adire Audio Tempest

    It looks like I could eliminate some of that bass hump (2.4dB from a 6dB peak = 3.6dB gain) by extending the ports 4 inches (tuned to 34Hz),
    which would also bring the (flattened) peak back 4 Hz as well as allowing the sub to hit lower.

    [​IMG]

    I only have 4-3/4" additional length before a stuctural support covers 1/2 of the port unfortunately (see pic),
    I'm not sure how close to the support I can have the port opening (or any obstruction for that matter) before it begins to block airflow.


    I could either extend the port the entire 4-3/4",
    Cut the end of the tube at a 45° angle (leaving a ~3" opening).

    Or I could use new ports-
    3" x 9" PORT TUBE DUAL FLARED (PE# 269-930) - allows 3/4" between port opening and MDF support

    PRECISION PORT 3" FLARED PORT TUBE KIT (PE# 268-350) - allows for custom length port

    The use of 2 90° PVC fittings would allow at least 18" of port length.
    With the box tuned to 25Hz you can see the improvement.
    [​IMG]

    Wow it took me all night to finish this post,
    but I ended up with only 1 question to ask instead of about 50 [​IMG]
    Thanks [​IMG]


    How close can the port inlet be to any obstruction?
     
  16. Frank Carter

    Frank Carter Screenwriter

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    The general rule of thumb is keep any obstructions at least one port diameter away from the end.

    While "bending" the port isn't considered optimal, however, in your case I think it would help a great deal to get rid of that hump.
     
  17. Joe.Kuta

    Joe.Kuta Stunt Coordinator

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    Ok thanks, that's what I figured.
    I read that the actual port should be kept at least one diameter away from the walls,
    and that the outlet in sonotubes should be one diameter away from the plate,
    but nothing about the inlet.
    Just making sure [​IMG]

    I'll have to test how various lengths sound in my room,
    but here is my planned layout.
    Note I can angle the ports upward if necessary for extra length.

    Additionally, I can angle the ports independent of eachother so they are not within 1 diameter of eachother
    (which they most likely will be based on the size of 3" 90° PVC fittings)

    Please anyone let me know if you see a problem.

    [​IMG]
     
  18. Joe.Kuta

    Joe.Kuta Stunt Coordinator

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    OH I should note that this subwoofer is -mostly- for music,
    as my current "home theater" places the listening position (my bed)
    to the right of the right speaker :p)

    Testing Drum+Bass mixes (my music of choice) with SpectraPLUS revealed most frequencies to be above 30Hz,
    which is good because my sub really starts to dive below that frequency, according to WinISD.

    [​IMG]
     
  19. Joe.Kuta

    Joe.Kuta Stunt Coordinator

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    Here are a few possible combinations ::

    Dayton DVC 15"
    Rythmik 380W
    Total $300

    Stryke AV15
    Rythmik 380W
    Total $395

    Stryke AV15
    CROWN XLS-402
    Total $525

    The thing to note is that I don't have a HT receiver,
    rather a stereo Yamaha RX-595.
    So in order for the Crown to work I would need at least a crossover in addition.
    I would not have phase adjustment more than 0 or 180°,
    and no rumble filter.

    I am hoping to order tonight or tomorrow morning.
     
  20. Jack Gilvey

    Jack Gilvey Producer

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    I'd go with the Stryke/Rythmic.
     

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