PE 300-794 and port kits recieved... tempest on the way-- some questions...

Discussion in 'Archived Threads 2001-2004' started by John Parris, Oct 2, 2002.

  1. John Parris

    John Parris Stunt Coordinator

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    Ok guys (and gals?), my plate amp and port kits have arrived... Tempest was, as you probably know, backordered until today on Acoustic Visions, so it should be on the way shortly... have a few questions, though.
    Well, I know I've seen dozens of install pics with this amp (PE 300-794) or similar plate amps installed on boxes... but forgive me for being new to DIY... this thing is HEAVY... how exactly would one go about safely installing this in the side of an enclosure? I know MDF is tough, but... wow.... it was heavier than I expected. [​IMG]
    Also, on the precision port kit from acoustic visions (Kyle, I bet you can answer this one for me [​IMG] ) the plans from Adire refer to *thier* port kits and that they should have 11" long cut center tubes... Would these work similarly? or are they actually one in the same? Would I just remove the rings and flared ends and cut the center part to 11" exactly or is it slightly more complicated?
    Also, the Tempest has dual voice coils if I'm not mistaken... so I'd just wire them in parallel to the outputs of the 300-794? What would be the easiest way to go about that without snipping those lovely pre-attatced connectors on the amp? If it's actually a SVC sub then disregard this section... I'm an idiot. [​IMG]
    Thanks in advance guys... and a big thanks for turning me on to DIY [​IMG]
     
  2. Andrew Bowzer

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    I mounted my PE 700-396 on the back of my MDF box. I just cut the 9.5"x9" rectangle, and screwed it into the box. It won't go anywhere, there are 8 screws to hold it in.
    Can't answer the port kit question, i just went the Home Depot way, 4" PVC pipe.
    The Tempest is a DVC 8 ohm, and you will be able to parallel the coils, and then on one coil, just connect the female connectors to the + and - prongs on the tempest. Right now, I have my P.E. amp running an old Orion XTR 12" until I can run it to the ground. Thats when my Adire Audio Shiva comes into play. [​IMG]
    I also just turned to the home theater crowd, and it's so much more rewarding than my old hobby, Car Audio. The wierd thing with me was that the change happened at 17, rather than mid to late 20s.
     
  3. Kyle Richardson

    Kyle Richardson Screenwriter

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    If you are doing the Adire alignment then the center tube length should be 11" for each port so you'll just need to cut 1" from the standard 12" tube. After it is cut then just use PVC cement to attach the connector rings to the tube then the flared ends to the tube/connector ring assembly.
    You will be fine mounting the amplifier directly into the MDF using the screws provided.
    Just as Andrew says, wire the Tempest in parallel by using jumper wires from one voice coil to the other then connect the amp to either voice coil.
     
  4. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    What confused me was the "installation process" paperwork that came with the (Precision Products) 3" ports. I tried to follow the formula but it's written rather vague. For an adire alignment the calculation came up to about Lv = 7.5" Then it says to subtract 5" from that number so the center tube would be 2.5" which is a very short port.

    I emailed Adire audio and they told me to use an 11" center tube for the parts express port (#268-350) so that's what I went with.

    Is there an explanation for the calculation? I tried it in several ways and still didn't get close to an 11" center tube:

    Lv = [8466.4R^2] / [(Vb)Fb^2] - 1.463R

    Lv = port length in inches
    Vb = volume box in cubic feet
    Fb = tuning frequency
    R = radius of port (1/2 port diameter)
     
  5. John Parris

    John Parris Stunt Coordinator

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    Thanks guys... think i'm a little more confident now.
    Andrew-- I got into home theater when I was 15, so it was kind of hard to be into car audio... with no car and all. I did get into car audio a while back (16?) and am still into it, but as far as my hard earned dollars go, there's not enough to spread around and produce desirable results in both right now... Having subs in my car and then trying to get my JBL S-312s to pick up the pace in my home theater just isnt cutting it... especially driven by a somewhat scrawny amp (an old JVC that I suspect is putting out less than 40W RMS per channel... maybe 50 in stereo operation but I doubt it)... so hopefully the Tempest project will pick up the pace and ... supply the bass... so to speak. That's the short and dirty on why I got turned on to DIY in the first place... coming from a car audio forum where everyone raves about the Shiva and Brahma (ClubRSX), the decision to go with a Tempest came pretty naturally. Oh, and just in case you're wondering, I'm only 18... and there's tons of users on the board under 20, so you're definately not alone in your age group.
    Chris-- I just had a calculus exam on teusday and am in no mood to attempt that in my free time [​IMG] Similar feelings on just going with what Adire says to do...
    Just as a general addition... I'm pleasantly suprised at the quality of the components in the PE amp... the transformer is nice and hefty and are those dual 6800uF capacitors? I think so! [​IMG] Sorry... just my amp nerdiness rearing its ugly head...
     
  6. Baldemar Garcia

    Baldemar Garcia Stunt Coordinator

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    Chris,

    I just checked the numbers in LspCad, and I guess there's a mistake in your math. Are you accounting for TWO 3 inch ports in the 214L box?

    John,
    I just built a Shiva EBS design, following the Adire design. Make sure of every dimension called out in the drawing, though most are probably correct. I found that the diameter called out for the port hole was too big. I too ordered the PE ports, but I'm sure the Adire version is identical (more than likely also sourced from Precision Port). Of course I didn't find this until after I'd routed out the hole! The Adire drivers make it easy to connect voice coils, since they offer dual terminals for each coil. Plan on where you will be mounting the plate amp. In my case, I have it staddling one of the internal braces, due to the transformer and wiring extending more than 3/4" into the cabinet. Just my thoughts and tips. Have fun and work safely.
     
  7. John Parris

    John Parris Stunt Coordinator

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    Baldemar-- so you mounted it right in the middle of the panel? I figured I'd have to alter the plans SLIGHTLY since the braces get in the way of the amp... I'm planning on doing the Adire Alignment myself since I want that little extra bit of SPL, but the idea is the same on the side panels/braces... Ive seen several people who just cut a small peice out of the side bracing for the extra depth of the plate amp-- that's what I had planned on unless someone can come up with a better solution...
     
  8. Bryan Michael

    Bryan Michael Supporting Actor

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    i just bught flaired ends and bult my own flaired ports it was less than 5 bucks for each a buck for each of the ends and 5 for a 8 ft piece of thinwall pvc alot cheaper than the areo ports
     
  9. Geoff L

    Geoff L Screenwriter

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    Bryan,

    Where are you finding just flaired port ends & in what size or sizes, 3"- 4" -6"????

    Are they flaired as much as the Areo ports?

    And lastly is the flange pre drilled or solid?

    Thanks
    Geoff
     
  10. Baldemar Garcia

    Baldemar Garcia Stunt Coordinator

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    John,

    My plate amp is mounted off center on the 'back' panel. Looking over the Tempest Adire Alignment plans, I see a difference between our boxes' bracing. The Shiva EBS design actually uses two braces that run 'front to back' in its design, so I had the amp straddle one of them. In your case, you can just have the amp straddle the one brace that runs down the center. It won't be prefectly centered unless you follow your plan of cutting into the brace. I didn't think it was worth that trouble.

    One other thing...I didn't use ABS cement to assemble my port. I didn't want it permanently bonded, in case I ever had to disassemble in the future. I simply used RTV instead. Something to think about.

    One last thing, if you need help optimizing your 'rumble' filter in the plate amp, let me know. LspCad allows simming this somehow, but I haven't gone through the trouble. I use BassBox Pro which gives the option easily, so I'd be happy to help.
     
  11. John Parris

    John Parris Stunt Coordinator

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    Not exactly sure what the rumble filter does... if it's not asbolutely nessasary, I'd really rather not take a soldering iron to my shiney new amp [​IMG]
     
  12. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    The 300-794 already has the rumble filter built-in. Folks will often modify this filter to change its "Q". This allows you to add a specific amount of boost at a specific frequency. The 300-794 filter has no boost in the stock configuration. But it does indeed have a rumble filter with Fc somewhere just below 20Hz (I can't remember the exact number off the top of my head and I don't have my filter calculator handy).
     
  13. John Parris

    John Parris Stunt Coordinator

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    Wouldnt a bass boost cause a really obvious peak at whatever frequenct you set it to?
     
  14. Bryan Michael

    Bryan Michael Supporting Actor

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    i got them form parts expres they are solid no drilled holes and they have a good flair on them they are in 4 and 3 in modles
    http://www.partsexpress.com/pe/showdetl.cfm?&DID=7
    it is a 4X4 flaired port i broke off all the ribs and just glued to the mdfb and used silicone coak to hold it in place
     
  15. Bryan Michael

    Bryan Michael Supporting Actor

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    i hate it it is hard to link to parts express that link dint work what i used is a 4 by 4 in flaired port tube it cost a 1.09 each
     
  16. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    "Wouldnt a bass boost cause a really obvious peak at whatever frequenct you set it to?"
    That is exactly the point, when you design the average box for a tempest, there is usually a roll off in the mid 20hz region. By adding 1-5db boost to 20-23hz you can then smooth the roll off into a more linear response from 20 and up. It depends on the box design, some smaller boxes might lack 30hz and the room might be sucking that out as well. A solution could be adding a few decibels of boost to that band.
    The ports I bought were the flared precision ports and they were only $11.25 each. The flared diameter is about 5 inches and the inner diameter is 3 inches. If I could find just the flared end separates, I would have gone that route.
    Link
    Here is a link to my two of a kind frustum tempest. My solution to the amps were to make it separate from the enclosure. This way when I'm tuning 2 subs I can have the amps right next to eachother, in addition to them being better ventilated in the back. The box I made was a simple 10 3/4" x 4" high box made of Birch laminated plywood. I used brads and glue to hold it together and then added screws with ebony plugs for looks.
    What's nice about the separate amp is I can swap amps and also access the bass boost easily.
     
  17. John Parris

    John Parris Stunt Coordinator

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    Chris-- thanks for the explanation... I'll try it without the boost mod first and if I have a problem with the roll-off I'll go back and add it in.
     
  18. John Parris

    John Parris Stunt Coordinator

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    Ok guys... the Tempest should be here tomorrow *hope hope*... a few final questions before I head to home depot for the materials:
    Polyfill: have had some box building experience but never used polyfill... not exactly sure what to do with it... where should I put it?
    The Glue: Any particular kind work best or just get whatever wood glue they have? For the poly-fill... spray adhesive seems to be what everyone recommends... yes?
    The wood: I've got this one... 3/4" MDF... no problem.
    The screws: people seem to recommend mounting the driver with "t-nuts"... should I mount the plate amp and ports with t-nuts while I'm at it? [​IMG]
    I have (or at least can borrow) all the nessasary tools and clamps I think, so no problems there... anything I'm forgetting?
     
  19. John Parris

    John Parris Stunt Coordinator

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    Anyone?
     
  20. Baldemar Garcia

    Baldemar Garcia Stunt Coordinator

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    Q[​IMG]olyfill: have had some box building experience but never used polyfill... not exactly sure what to do with it... where should I put it?
    A:I usually just 'fluff' it a little and just fill the enclosure.
    Q:The Glue: Any particular kind work best or just get whatever wood glue they have? For the poly-fill... spray adhesive seems to be what everyone recommends... yes?A:Titebond II is what I use for the wood. Spray adhesive is good for the fiberfill IF you're worried about it moving around.
    Q:The wood: I've got this one... 3/4" MDF... no problem.
    A:Yes, you got this one right [​IMG]
    Q:The screws: people seem to recommend mounting the driver with "t-nuts"... should I mount the plate amp and ports with t-nuts while I'm at it?
    A:IMHO, t-nuts are not worth the trouble unless you plan on repeatedly removing/replacing your driver. Having to give the t-nuts something to 'bite' into is just a step I'd rather skip, along with worrying about perfect screw alignment and the bigger hole they require for install. Then again, I don't build just one enclosure and repeatedly swap drivers. MDF should hold up well through several installs. There's no need to tighten the mounting screws using superman strength, just use a good seal under the driver (I use rope caulk). So the same answer would apply to the port (#6 coarse thread drywall screws) and amp.
    Hope some of this helps.
     

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