My 1st DIY sub...........SUCCESS!!!

Discussion in 'Archived Threads 2001-2004' started by Scott Simonian, Mar 29, 2002.

  1. Scott Simonian

    Scott Simonian Screenwriter

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    Oh my gawd. This is absolutly the best Ive had in my theater. :b
    I just finished a vented Tempest tuned to 15.4hz in a 7.3cf cabinet. WOW! All I can say is WOW! This is sooo cool!
    I havent even broken it in yet! The first thing I did was run test tones, I was curious to see what it could do first. Then I started watching all the cool trailers I had on my computer and ran bass test tracks I got off the internet. The first thing I noticed; is that it could go a whole octave (or two!!!) below my last sub. The bass was noticably more articulate too. Quite so compared to what Ive heard in an average home, including mine. I did this for about an hour or two. When I wheeled the sub out, I noticed that I had blown some stuffing out. [​IMG]
    Unfortunatly, I had a snag before I got it up and running so I had not much time tonight to play with it. At 10:00pm WST, I had told my dad that I was just going to watch 1 dvd. I would have watched more but he was going right to bed and his work time pays for my stuff so I didnt argue.
    Okay, I put the Haunting DTS in and start up with the trailers first. I didnt have the receiver up too much during these. The improvment was slight at first. Then comes some rumbles under other rumbles that I had not heard before. Ohhhh, that was cool. But I was a little underwhelmed. Then, I start up the movie (and turn up the volume about 10 db [​IMG])and I watch the opening credits. There is some nice bass in this part so, why skip it? During this part, my last sub could show it with average charm but I would hear it stress lightly. Not with the sub I have now! Right away I noticed that there was more deep bass and the room would pressurize. Cool. The sub did not show any sort of strain at all.
    Skip to the "Creaky Pipes" chapter (or whatever its called). Whoa! The intial bass slams werent a whole lot more but there was more athourity and lower bass. Then when everything is shaking, the room shakes like in the movie it would. OMG!!! I love the part in this scene were there is this panning around the room of this
     
  2. NickSo

    NickSo Producer

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    Wow, sounds great..

    how much did it cost you? I might think of going this route, but i wanna know approx how much it would be...

    Could you list how much approx how muhc each ting cost? like the driver and such?
     
  3. Scott Simonian

    Scott Simonian Screenwriter

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    Sure.

    All around, it cost a little over $400. The value is in the thousands. Really!

    The driver was an Adire Tempest - $150

    Amp Adire AVA250 - $180

    Some MDF - $40

    (2) 3" flared ports - ~$30-40

    Glue, liquid nails, etc - $30

    You do need a source of woodworking tools and machinery. I was lucky to have a crafty friend with a master craftsman dad on hand.

    Of course, you could go with an easier alignment, make a sealed sub or whatever. I say, go for it. It is very cheap and you feel great afterwards for making a great sub yourself.
     
  4. Kyle Richardson

    Kyle Richardson Screenwriter

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    I'm glad to hear that you are pleased with the results! There is nothing quite like hearing your first DIY sub for the very first time [​IMG]
    Kyle Richardson
    Acoustic Visions
     
  5. Scott Simonian

    Scott Simonian Screenwriter

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    Wow! Ive been watching more this morning. Great sub. I love it.
    So far Ive watched TPM, Titan AE, and more of the Haunting. Oh my, I havent even got to SPR yet!
    Dilemma: Right now I have the Tempest hooked up to the AVA250 at 180w or an 8ohm load. I was considering putting a 4ohm load on the amp but I dont know what to expect. All I know is that it will be 250w power. What will change when I hook it up this way? Will it be louder? Will it have more or less headroom? More or less excursion? Will the second voice coil control the driver better? Worse? Will it go deeper?
    I dont know what would happen. I thought I remember hearing that the Tempest would increase (decrease?) in sensitivity. Is this true? If it increases, then Ill hook it up like this for sure.
    What do you suggest I do?
    PS- Is there anyway to disable the crossover on the AVA250? I thought I saw that there was a trick to defeat it.
    EDIT:Im looking at the Tempest white paper right now. It looks like the sensitivity goes up about 3db. That sounds good, but I dont really know how to read all these T/S parameters yet. I see that the Qes is cut in half but the Qms raises. Also the EBP doubles to 47. Of course, I dont know what EBP means. [​IMG] The No also doubles to .51% (dont know that one either)
    I just dont know. If someone reads this and has a good idea, please reply. I need to know.
     
  6. Pete Mazz

    Pete Mazz Supporting Actor

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    The only way to hook a Tempest up as an 8 ohm load would be to only wire one voice coil. Wire the two VCs in parallel for a 4 ohm load(recommended) or series wire for 16 ohm.

    To, sort of, defeat the Xover of the amp, turn it all the way up.

    Pete
     
  7. Dustin B

    Dustin B Producer

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    Don't worry about it. Wire those voice coils in parallel and hook them up to the AVA250 as a 4ohm load. It's how the Tempest and AVA250 were intended to be used in a vented allignment.
     
  8. Kyle Richardson

    Kyle Richardson Screenwriter

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    Do as Dustin says and your jaw will drop even further! [​IMG] Excursion will go up but thats a good thing (to a point) so if you start to hear distortion or bottoming of any sort just turn it down just a touch and you are set.
    Turn up the crossover all of the way if you are not using it.
    Kyle Richardson
    Acoustic Visions
     
  9. Scott Simonian

    Scott Simonian Screenwriter

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    Wont the sound change in some way? I was planning on doing this. Since the amp was rated 180w @ 8ohms then go to 250w @ 4ohms, it sounds like the amp would be stressing. Since the power goes up less than 50%. Isnt that bad. Well, not bad but not swell ?
    Well, whatever. I just watched the Matrix and the helicopter crash [rant]FINALLY[/rant] sounds good.
    I just need more affirmation before I change the hookup. You could just yell at me or something. Everyone else does it. Nobody likes me. [​IMG]
     
  10. Dustin B

    Dustin B Producer

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    Just send an email to Dan W. He will tell you the same thing we have. If the word of the designer of the driver and the person who decided to carry that amp isn't good enough for you then yes I'll start yelling at you [​IMG]
     
  11. Kerry Hackney

    Kerry Hackney Stunt Coordinator

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    Ahhh... another soul turned to the bass side of the force. Welcome to the club. [​IMG]
    As for the amp, it has sufficient voltage supply to power the 4 ohm load. Go for it.
     
  12. Scott Simonian

    Scott Simonian Screenwriter

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    Okay, I do trust you guys. I just want to make sure.

    Well, I off to put a 4ohm load on my amp. Ill come back later to tell how it has gone.

    Kerry - Im glad to be in it too. :b
     
  13. jeff lam

    jeff lam Screenwriter

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    The amp has enough juice for the tempest. Dan W. recommends it all the time and it was designed to drive a 4 ohm load. Parallel those coils!!!
     
  14. Scott Simonian

    Scott Simonian Screenwriter

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    Ah crap. I cant get my 12g wire to fit in the little hole. Im trying to solder it but I can only get the front 1/8" of the wire to go over the little "speaker wire wing thingy". I have some 16g wire. Could or should I use that?
     
  15. jeff lam

    jeff lam Screenwriter

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    Don't use the little hole in the speaker terminal. Run down to RS and buy some female spade connectors(disconnects). Looks like this:
    [​IMG]
    The crimp end may not be big enough for 12 ga. use plires or something to pull the blue shield off and open it up a little till the wire fits, then crimp it. The package at RS has some with the blue shield and some without. I just pull the blue stuff off anyway, so it does no good to me to have the blue on there.
     
  16. Brian Bunge

    Brian Bunge Producer

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    Or buy the 12 gauge crimp-on connectors that have the protective shielding over the entire connector. I always use those for subwoofers. Well, except for the drivers that have the spring loaded, gold plated terminals. Those are a God send!

    BTW, the new Dayton DVC 12's have this! I imagine that's why they sold off all those drivers for $75 back before Christmas. They were making room for the new batch!

    Brian
     
  17. Scott Simonian

    Scott Simonian Screenwriter

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    Argh! Too late. I just soldered the wire on, nicely too. Just now I put the woofer back in the cabinet.

    So, is the sound going the be louder? How am I going to tell if it hooked it up correctly? (yes I hooked it up right, I just mean changing the load.)
     
  18. Brian Bunge

    Brian Bunge Producer

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    Scott,

    If you wired the voice coils in parallel then you have created a 4 ohm load. A wire jumper from one positive lead to another and a wire jumper from one negative lead to another. The connect the positive and negative wires from the amp to the driver as normal.

    Brian
     
  19. Scott Simonian

    Scott Simonian Screenwriter

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    Yes, thats how I did it. I almost wired it in a series too. [​IMG]
    What should I notice when I fire it up?
     
  20. Scott Simonian

    Scott Simonian Screenwriter

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    OMG! [​IMG]
    I just ran the Matrix "helicopter crash" again. Wooeeeee! Much more powerful.
    [yes,youwererightsarcastictone/] Thank you. [​IMG][/yes,youwererightsarcastictone]
     

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