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First build complete (need some help)

1333 Views 5 Replies 4 Participants Last post by  Kevin Haskins
Just completed my first build. I attempted to load pictures but the first time they were enormus and then the second time you can barely see them so I give up with that.

I have a birch wood box externally meauring 18 x 20 x 52 with a slot port tuned to about 18hz. I have installed the Tempest-X2 15" powered by a PE 500w plate amp with about 20% poly-fill. I am getting a tremendous amount of low-end rumble but it tends to taper off quickly once it goes up past 30hz or so (kinda of guessing here). I have the amp configured as followed:
  • LFE direct input
  • low pass gain-approx 1/3
  • low pass freq-200hz
  • phase-0
  • eq freq-18hz
  • eq bandwidth-.5
  • eq level- -5 db

I ran Audyssey ( multeq-xt )from my Denon 4310 and set the crossover at 80hz and speakers set to small. Audyssey set the sub at +3db and then I bumped it up to +7 db.

So far this sub has more output down low than the MFW-15 it's replacing but doesn't come close after that. Any pointers in the right direction would be appreciated.

Dan
1 - 6 of 6 Posts
Just completed my first build. I attempted to load pictures but the first time they were enormus and then the second time you can barely see them so I give up with that.

I have a birch wood box externally meauring 18 x 20 x 52 with a slot port tuned to about 18hz. I have installed the Tempest-X2 15" powered by a PE 500w plate amp with about 20% poly-fill. I am getting a tremendous amount of low-end rumble but it tends to taper off quickly once it goes up past 30hz or so (kinda of guessing here). I have the amp configured as followed:
  • LFE direct input
  • low pass gain-approx 1/3
  • low pass freq-200hz
  • phase-0
  • eq freq-18hz
  • eq bandwidth-.5
  • eq level- -5 db

I ran Audyssey ( multeq-xt )from my Denon 4310 and set the crossover at 80hz and speakers set to small. Audyssey set the sub at +3db and then I bumped it up to +7 db.

So far this sub has more output down low than the MFW-15 it's replacing but doesn't come close after that. Any pointers in the right direction would be appreciated.

Dan
Something is wrong in the signal processing chain because there is no reason you wouldn't have the >30Hz content of the other sub. You need to dig into what the Audyssey is doing and make sure it isn't pushing the LP filter down. That would be first guess.

Kevin Haskins
Exodus Audio
Just completed my first build. I attempted to load pictures but the first time they were enormus and then the second time you can barely see them so I give up with that.

I have a birch wood box externally meauring 18 x 20 x 52 with a slot port tuned to about 18hz. I have installed the Tempest-X2 15" powered by a PE 500w plate amp with about 20% poly-fill. I am getting a tremendous amount of low-end rumble but it tends to taper off quickly once it goes up past 30hz or so (kinda of guessing here). I have the amp configured as followed:
  • LFE direct input
  • low pass gain-approx 1/3
  • low pass freq-200hz
  • phase-0
  • eq freq-18hz
  • eq bandwidth-.5
  • eq level- -5 db

I ran Audyssey ( multeq-xt )from my Denon 4310 and set the crossover at 80hz and speakers set to small. Audyssey set the sub at +3db and then I bumped it up to +7 db.

So far this sub has more output down low than the MFW-15 it's replacing but doesn't come close after that. Any pointers in the right direction would be appreciated.

Dan
Looking forward to seeing what you come up with. I am getting ready to build this exact same setup (tempest x2, PE 500W) and I have a denon 2310.

Hope you figure it out and post some pics of the build.
Did some more tweaking. I re-ran Audyssey. Raised the low-pass filter from 80hz to 120hz. Changed from L/R inputs to the LFE (mono) input on the sub amp. Speakers remain set to small with 80hz crossover for the front 3 & 100hz for the rear. Overall it sounds much better than before. The bottom end tightened up and I'm definately getting more mid-bass now. I will continue testing and possibly tweaking over the next couple of days to get the sub more dialed in.

link to some pics: keep in mind this is my first build and I don't own any fancy tools like routers, table saws, orbital sanders, etc. All the work was done with a circular saw, miter saw, jig saw and hand sanding.

http://gallery.avsforum.com/showgallery.php/cat/500/ppuser/7424317
Looking good...

The high frequency output is purely a signal processing issue. It is either a function of the settings on the plate amp (the single band PEQ) or something that is going on inn the processor. The Tempest-X2 is good out to something like 500Hz without any issues in terms of having the output attenuated by inductance any appreciable level.

Kevin Haskins
Exodus Audio
1 - 6 of 6 Posts
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