Two Tempest Sonosubs Or One Dual Tempest Sonosub

Discussion in 'Archived Threads 2001-2004' started by Jeffrey_S, Mar 9, 2002.

  1. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Hi everyone,

    OK,

    I've got my two Tempest drivers. I'm about to pick up my sonotube. I'm upgrading to separate components and I think I'm going to end up with a pre/pro that has two sub-outs. This got me thinking again about the advantages/disadvantages of a single dual Tempest sonosub vs two single driver sonosubs.

    My hometheater room is in an L shaped basement. The listening area is about 13' x 28'. I really have no space limitations and my wife would be fine with either choice as she allows me to do anything I want in our basement. :b

    Which way should I go?

    Thanks for the advice!

    Jeff
     
  2. ThomasW

    ThomasW Cinematographer

    Joined:
    Nov 6, 1999
    Messages:
    2,282
    Likes Received:
    0
    Trophy Points:
    0
    Are you intending to use sealed or ported designs?
     
  3. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Ported.
     
  4. Scott Simonian

    Scott Simonian Screenwriter

    Joined:
    Jun 20, 2001
    Messages:
    1,281
    Likes Received:
    0
    Trophy Points:
    0
    What kind of sound are you looking for? Tight and articulate? HT boombox? EBS?
     
  5. Dustin B

    Dustin B Producer

    Joined:
    Mar 10, 2001
    Messages:
    3,126
    Likes Received:
    0
    Trophy Points:
    0
    I don't have any really good reasons. But personally I'd go with a single 480L enclosure tuned to 16hz with a pair of 6" ports. Just mirror the top and bottom.

    The only reason I can come up with for a single enclosure is since we generally recommend that a person stack multiple subs, why have two tubes in a corner when you can have one. They should couple to the full affect possible, and you shouldn't have to worry about any cancellation issues.
     
  6. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Scott,

    I'm going to use the sub for about 70%HT/30%Music.

    Dustin,

    The more I think about it, the more I agree with your reasoning. I'm pretty sure I'll go with the dual Tempest as was the original plan.

    Thanks to everyone for the help!

    Jeff
     
  7. Scott Simonian

    Scott Simonian Screenwriter

    Joined:
    Jun 20, 2001
    Messages:
    1,281
    Likes Received:
    0
    Trophy Points:
    0
     
  8. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Scott,

    I was thinking of using a HS500 from Adire Audio. If you have any alternative suggestions, I'd appreciate it as this amp is pretty pricey.

    I was planing on building a box in which to mount it. I don't want to mount it directly to the sub.

    Jeff
     
  9. Scott Simonian

    Scott Simonian Screenwriter

    Joined:
    Jun 20, 2001
    Messages:
    1,281
    Likes Received:
    0
    Trophy Points:
    0
    Hmmm, I dont know. It looks like the right amp for the job to me. $500 for that is okay in my book but is indeed pricey.

    Are those features on the amp ALL important to you? Is it just the power that you are concerned with? The amp has a Para EQ built in. That will make it more expensive. Do you want an EQ? I dont see why not. An EQ is allways important with subs so it wouldnt hurt.
     
  10. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Scott,

    The para EQ is a nice feature, however, I don't have a problem getting a Behringer FD which I think is more versatile. If you know of another amp that would give me the other features minus the para EQ I'd be interested.

    Thanks,

    Jeff
     
  11. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    0
    Trophy Points:
    0
    I don't know of an amp with those features and that power.

    Certainly looks worth the asking price, but you'd have to ask yourself if you'll use enough of the features to make it worthwhile. It's supposed to be very quiet, also. The full HP/LP crossover is beautiful, but if you're using the sub-out from a reciever, you won't use it. The single parameteric eq band included is boost-only, 6db, half-octave width, and will almost certainly not obviate the need for a BFD.

    Also, the amp is rated into 4 ohms, and dual Tempests can either be wired as a 2-ohm or 8-ohm load...so you're stuck with 8 ohms, or a 500 watt amp. That may well be enough depending on the alignment, but there may be cheaper amps with more wattage available (QSC,etc.) if the features don't sell the plate amp.

    I'd do dual 300 liter tubes tuned to 18Hz with a 6" port each, that'd be pretty amazing with the HS500.
     
  12. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Jack,

    I've been thinking about possibly doing two Tempests in conventional boxes using Baltic Birch plywood for the braces and maybe for the external shell as well. I've already made a center channel based on the NorthcreekMusic formula and like working with baltic birch. Using the Northcreek formula, I could laminate 3/4 inch MDF to 3/4 inch baltic birch for the baffle using their glue. Do you think I'd have to laminate any other areas? If I wanted, I could use 1 inch MDF for other external panels. I don't have a problem doing woodwork as I have most of the power tools and this is also one of my hobbies, and when adding up all the materials of the endcaps and sonotube, the cost of a conventional box may actually be less especially if MDF is used to the maximum extent.

    So this is my latest thinking. Why don't I build conventional Adire Alignment Tempests, one at a time, and decide later if I'm going to stack them or place them in different locations? I could then use AVA250's to power them and save by not having to get an HS500. I will probably need a BFD anyhow so I don't think I'd benefit from some of the EQ features of the HS unit.

    What do you think???

    Jeff
     
  13. Scott Simonian

    Scott Simonian Screenwriter

    Joined:
    Jun 20, 2001
    Messages:
    1,281
    Likes Received:
    0
    Trophy Points:
    0
    Go for it man. [​IMG]
     
  14. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    0
    Trophy Points:
    0
    Jeffrey,
    I like the idea of the dual subs, much easier to build and position. As far as the Adire alignment, I like things a little flatter in the low-end myself, and that one is a little overdamped, relying on room gain. Also, the recommended two 3" ports are about all you'll fit in a box, and I always like more than that. I like a little more Vb, like 300L, tuned to 16-18Hz for more sensitivity down low (important if using plate amps), and then a 6" port becomes feasible. Still, all rooms are different, and people have had great success with the Adire alignment.
    I'm not familiar with the Northcreek system, but it sounds like it should work extremely well. I love that baltic birch, and I'd use it any excuse I got. [​IMG] Greg Monfort would have much better input on this than I, but constructing the cabs from 3/4" BB alone, with good bracing (keep spans under 12"), should be adequate to push any resonances well beyond a sub's range, making it functionally "dead" in the intended bandwidth. I do like the idea of the double-thickness baffle, especially if you plan on countersinking. I think this would be considerably lighter, but considerably more expensive.
     
  15. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Jack,

    I'm going to use these subs for 70%Movies/30%Music. I have no problem going bigger than 214L if it would improve the sound. I also have no problem modifying/redesigning the enclosure. I was a little nervous using 3 inch ports and would prefer to use a larger diameter. I plan on using PVC for the ports and only flaring the ends that will be mounted in MDF with a router.

    If you or others could make some specific recommendations as to:

    1. Internal Enclosure Volume

    2. Port Inside Diameter and length

    3. Stuffing amount and type

    I've decided to use a sandwich of 1/2 inch Baltic Birch plywood and 3/4 inch MDF for the baffle. Yes I will recess the driver. The braces will be 3/4 inch Baltic Birch plywood. The rest of the cabinet will be 1 inch MDF or 3/4 inch Baltic Birch ply (I haven't decided yet).

    Thanks for your input!

    Jeff
     
  16. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    0
    Trophy Points:
    0
    Well, if size is not an issue, I don't like to skimp on it. More efficiency as you approach Fb, and the less power you need to pour into the voice coils the better. The larger Vb allows you to use 6" porting, which is nice, if not absolutely necessary.

    I like the alignment I posted before, 300L tuned to 18Hz with a 6" port. An EBS is also very nice for exceptionally deep bass. For Tempest I think it's 340 liters tuned to 16Hz.

    See how those look to you.
     
  17. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Jack,

    Thanks again for the info. I guess I'm only unsure of the 6" port length to tune to 18hz in the 300L configuration. If you could help me out with that I'd appreciate it.

    Thanks,

    Jeff
     
  18. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    0
    Trophy Points:
    0
    Well, in 300 liters for an 18Hz tune with the walls covered, a 6" port with "one flared end" would need to be 17" long according to Unibox. It'd be best to confirm this with whatever program you use, as usual. In fact, since there's variation in the numbers arrived at by some programs, I recommend going a little long and fine-tuning the length once it's up and running. You could even start with a 23" length (16Hz), and see how that does in your room, might even work better with your room gain.

    With an AVA250, this should be good for over 110dB @ 20Hz and above anechoic (a pair would probably be good for well over reference levels in-room), with an F3 of 18Hz and port airspeed and excursion looking excellent. The 18Hz HP filter on the AVA250 should work nicely to handle the expected overexcursion seen below 16Hz or so.
     
  19. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Thanks Jack!
     

Share This Page