DIY sub needs x-over, volume, phase, etc

gidrah
gidrah Posts: 3,046
I'm gonna (someday) build a subwoofer. I have a 10" Dayton driver, tube, ports, stuffing, and a couple of full range amps to consider between. What I need is the x-over of a standard sub amp and all the goodies that go along with it. Just not the amp portion. If I put in in my 2-ch rig I have dual line outs. If I put it in my 5.1 rig I can have LFE or un-filtered with volume control.

In your opinions should I:
Buy a cheap sub and gut it?
Just go ahead and buy a decent plate amp?
Buy a cheap plate amp and use the speaker level ins?
Buy a variable 2/3 way crossover often used for bands? This is where I'm leaning as I would like to do some more DIY and bi-amping in the future and don't feel like doing the math for each x-over.

All replies and suggestions are appreciated. Please keep in mind that I am a cheap ****. I am also trying to put together a DIY/tweak rig. The cheaper (without compromising sound or versatility) the better out of principle.
Make it Funky! :)
Post edited by gidrah on

Comments

  • gidrah
    gidrah Posts: 3,046
    edited April 2003
    Thanks for the help guys! Let me get out my pen and write this all down. Oh, wait...
    Make it Funky! :)
  • tryrrthg
    tryrrthg Posts: 1,896
    edited April 2003
    I would just buy the 250 watt plate amp at parts express. It has all the things you'll need: good power, crossover, and all the necessary connections you're looking for. here are all their amps:

    http://www.partsexpress.com/webpage.cfm?&Webpage_ID=3&DID=7&CAT_ID=43&ObjectGroup_ID=505&SO=2

    I would also just build a cabinet out of MDF. it's pretty cheap. Or you could go the sonotube route... Lots of examples here:

    http://members.tripod.com/~terryctheater/shivaphotoalbum/page12.html

    You might want to head on over the the HT forum in the DIY section. They know a hell of a lot more than I do!
    Sony KDL-40V2500 HDTV, Rotel RSX-1067 Receiver, Sony BDP-S550 Blu-ray, Slim Devices Squeezebox, Polk RTi6, CSi3 & R15, DIY sub with Atlas 15
  • goingganzo
    goingganzo Posts: 2,793
    edited April 2003
    i would recomend the 30-794 amp great price and free shiping. ron-p has that amp driveing his tempest. now the problem you would also need phase control and a sub-sonic filetr to prevent over excurshon below tuneing. when i went woth a pro amp for my sub i had to spend extra on a ss filter and phase control.
  • burdette
    burdette Posts: 1,194
    edited April 2003
    Originally posted by gidrah

    Buy a cheap sub and gut it?
    Just go ahead and buy a decent plate amp?
    Buy a cheap plate amp and use the speaker level ins?
    Buy a variable 2/3 way crossover often used for bands? This is where I'm leaning as I would like to do some more DIY and bi-amping in the future and don't feel like doing the math for each x-over.

    Gutting a cheap sub... you get what you pay for. I'd *certainly* spend the $120 on the PE amp before I spent $100 on a cheap sub to gut.

    Not sure where you draw the line between decent and cheap. The PE amp isn't the most expensive on the market, but it sure seems to be used by a lot of DIYers. Not sure why you'd need any MORE of an amp considering the driver. It isn't like you're trying to power a $500 sub driver.

    I don't see how buying a 2/3 way crossover would help you at all. The low xover point is going to be something like 800Hz or so. I looked into building a passive sub crossover a couple of years ago.. the expense of the chokes alone was enough to kill that idea.

    Given what you said.. what you have.. that you're a cheap **** like me... I'd buy the $120 PE 250Watt amp. I did.. bought the one WITHOUT the bass boost. It does have phase control, by the way.. built-in crossover from 40-160Hz.

    Only problem.. and I asked around and this is sort of common.. the auto-on feature doesn't work very well. Way too INsensitive in most instances. Mine clicked on with a 20Hz test tone, and occasionally with certain movies.. but I just leave it on all the time now. A couple of guys said they had to have their sub at the receiver set to like +8-10 to get auto-on to work consistently.
  • gidrah
    gidrah Posts: 3,046
    edited April 2003
    Thanks guys. I very well may end up getting a sub amp from PE.

    burdette: I forgot to include that this x-over would need to be stereo and have the necessary sub-out. Good catch though.
    Make it Funky! :)