Cabinet Design Database?

Discussion in 'Amps [BG]' started by stettoman, Sep 8, 2003.


  1. stettoman

    stettoman

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    I have an Ampeg 15" that needs a cab built around it. I remember there used to be a dimension table online years ago, but haven't seen it since then.

    Anyone know of a CAD design database or just plain old cab plans available online? I'm not opposed to buying a pre-built cab either, if a quality manufacturer is out there selling cabs without speakers...

    Thanks
     
  2. Scott D

    Scott D

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    WinISD is the program you are looking for. search for it. also, Avatar makes cabs without speakers...
     
  3. Petebass

    Petebass

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    WinISD is good because it's free. Remember that it automatically uses the "Flat Alignment". Don't be affraid to manually type in alternative cab volumes and porting arrangements and see what happens to the graphs. You may even come up with something that suits your needs better than the standard flat allignment. You can also come up with something worse, but it's all part of the learning experience.

    If you have any dramas, post them here. There are a number of guys on TB who can help you with this.
     
  4. stettoman

    stettoman

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    That should more than help.

    I already run through an Ampeg SVT50DL (loaded with an 18, not two 15s, can't even find documentation...), but I have this great 15" speaker from Ampeg (don't know the driver's manufacturer, I don't remember Ampeg making their own) and I'd like to build a mid/full range compliment to the 50DL and something for smaller rooms.

    The speaker is in a "box" right now, non-ported and stuffed with fiberglass, and though it seems to do alright I'd rather have a design-specific instead of a "box"...
     
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  6. ESP-LTD

    ESP-LTD

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    If you want to buy and empty box contact Avatar (http://www.avatarspeakers.com/). You'll find that after you consider hardware and stuff, their boxes are pretty cheap.
     
  7. bgavin

    bgavin Supporting Member

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    You will find the sealed, stuffed box to be much more forgiving than a wronly tuned vented box.
     
  8. stettoman

    stettoman

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    ...And just to clarify on the 50DL, I just took the grills off for a cleaning (UGH! Dustbunny Hell! Any suggestions as to how to best remove stuck-on dust from the cones?) and found the the cab had been modified. The 18" EV was somebody's idea of an upgrade, I guess. Still sounds great though.

    The drivers on the 10"s are Edens, so I figure the lone 15" has an Eden driver as well, though I'll pull it to make sure. The peizo is dead, but I don't particularly notice the lack...;)

    I have access to a full woodshop so building a cab isn't a problem, but if Avatar makes a well tuned unit it may be worth the $140 for one of theirs.
     
  9. bgavin

    bgavin Supporting Member

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    The tuning will not be right.

    You will have to measure the driver and figure out its actual Thiele-Small data. Then you can design and tune a matching cabinet.

    The chances of an Avatar cab being both the correct volume and correct tuning frequency are nil.
     
  10. stettoman

    stettoman

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    With that being the case bg, and considering my limited knowledge of the gozintas involved, might I be better off to build a simple sealed cabinet? Being as I aleady have my low end setup (the SVT 50DL), my main goal for the 15" is for a little added volume, clarity and punch, not the lower register.

    The current "box" that the 15" resides in is small, no larger than enough to house the speaker. Does that make a difference in a sealed environment? Being sealed I assume that the predominance of air displacement takes place outside the unit (though I'm aware that some pressure changes occur inside as well)...

    Also, impedance will be a concern. The two 10s are 16 ohm wired in parallel, so I'm pretty sure the 50DL is an 8 ohm enclosure. If the 15" is also 16 ohm, will I need to add a resistor circuit to compensate?

    Excuse my ignorance here, but I've always been a "shut up and play yer bass" kind of musician. Only now, in my more mature and settled age do I have an interest in the intricacies of the gear...
     
  11. bgavin

    bgavin Supporting Member

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    Without knowing even the model number of the driver in question, I cannot guess at the T/S data.

    The simplest guess is put the driver into the largest sealed box you can tolerate hauling around. Stuff the box with fiber fill (Hancock Fabrics, et al) at 1 pound per cubic foot internal volume. This will make the box appear acoustically 'larger' to the driver.

    Big drivers take big sealed enclosures. The only exceptions are those subwoofers designed for automotive use. The tip off here, is the driver is VERY inefficient, and makes very little noise compared to other drivers. Inefficient drivers that go down low work in small cabs.

    I assume the Ampeg driver to be an efficient type design, and wanting for a large cabinet. I doubt Ampeg is making car subwoofers. Check out my spread sheet for 15" drivers and note the Vb (box volume) requires for B2 and D2 sealed alignments. A lot of volume is required.
     
  12. stettoman

    stettoman

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    I went through your database, Bruce, and I believe the 15" to be an Eminence, but the model # isn't on your sheet (I'm assuming the model # here)...

    Here are all the numbers on the speaker;

    86-118-08
    15729
    (I assume to be the model #) -8 ohm
    67-94510911 G1


    I arrived at the conclusion that it's an Eminence because their model numbers are the only ones on your database that are similar--there is a #12729, but it's a 12" speaker. The closest 15", number-wise, are 15710 & 15735.

    Am I close?

    --edit--I've inquired to the Eminence Company to see if they can help. I'm assuming that if it is an Eminence speaker if it's not a custom design for Ampeg, as that was the name on the box when I purchased it. Ampeg does not make their own...
     
  13. stettoman

    stettoman

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    Well, here's the response I got from Eminence;

    Eric,

    This speaker has been obsolete for so long that it's been purged from our system and the hard copy is missing. In other words, I don't have any
    information to share with you. Maybe Ampeg still has some params on this
    speaker.


    I have a message in to Ampeg.
     
  14. stettoman

    stettoman

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    They tell me that the driver is a custom design and Eminence is not allowed to release any related data, hence they had none.

    I'm told the speaker is still made for them. The specs are forthcoming...

    Oh, yay!
     
  15. stettoman

    stettoman

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    Well, Ampeg sent me the neccessary info on the speaker...But with an EBP of 97.8 it looks to be best suited for a BP6th style cab...

    Not sure how I want to proceed at this point. I know I can still build a vented cab for the driver, and though somewhat large (41" high) it would work ok, but I wonder if it wouldn't be more practical to shop for a higher power speaker (the 15729 is rated @ 150 watts @ 6.2 ohms).

    No, I'm not really interested in building a BP6th cab....Got one already (the SVT50DL)
     
  16. bgavin

    bgavin Supporting Member

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    If you don't mind, email me the specs and I will add it to my spread sheet.
     
  17. stettoman

    stettoman

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    I'll be more than happy to. They didn't release all the specs, but more than enough to get the job done.

    Thanks for all the help guys!
     
  18. bgavin

    bgavin Supporting Member

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    I question the 0.375" Xmax. Other than that, this driver is a typical, efficient driver that wants a big cabinet. 4 to 8 cubic feet. The sealed B2 alignment is 4 cubic feet also. No tiny boxes for this guy.

    If you want mids-highs, do a Legend B102. It is killer in 0.6 cubic feet, and has plenty of highs.
     

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