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Old 15th July 2006, 04:02 PM   #1
epalla is offline epalla  United States
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Default help me reverse engineer this sub

all right, for my party sub you guys convinced me to go with an 18" Peavey to hit some crazy SPL levels on the power that I already have. I will be underpowering it a little bit, but it leaves room for expansion and it shouldn't be so bad that I get clipping all over the place.
http://www.partsexpress.com/pe/showd...number=294-301

In looking around for what would be the most suitable box design, I discovered that Peavey sells an already boxed version of the same subwoofer:
http://www.peavey.com/products/brows...+Subwoofer.cfm

That's basically the sub that I want. I'm not too concerned about the size of the box I guess (though they've managed to keep it very small), but what do you guys think is going on in there as far as venting and construction is concerned?
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Old 15th July 2006, 05:05 PM   #2
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Quote:
it shouldn't be so bad that I get clipping all over the place.
What makes you think that?

Clipping is strongly advised against, if you're going that way you will soon find out why. An undersized clipping amp can easily destroy the VC. A more powerful amp will just speed things up a bit.

You will also find out that your warranty is useless when clipping is determined as the cause of failure.

As far as bracing concerned I don't think there is much more going on in there than some pieces of ply (3/4" x 4/6") on their sides, dividing the panels in halves or perhaps even thirds.
The vent is a typical one with such one bracing in the middle.

With kind regards Johan
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Old 15th July 2006, 05:28 PM   #3
epalla is offline epalla  United States
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I don't think I'll get clipping because I'm not underpowering it by that much. If it's noticeable I can always turn it down until I can put more power into it, but I really don't think it'll be a problem.

For construction - the box is trapezoidal and I'll want to maintain that. I'll use 3/4" Ply or MDF for construction. The vent is split in two by a brace, but I'm not sure how deep the vent goes. This one isn't exactly adjustable so is there anyone who could shine some light on that? (one of the modeling programs maybe?) The specs on the page say the vent has a long path length, but that could mean 8" or some complicated horn apparatus in there.

I'll probably do a rib brace in the main compartment, combined with the vent shelf and the brace that splits it I think that should be plenty sturdy..
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Old 15th July 2006, 10:15 PM   #4
badman is offline badman  United States
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Quote:
Originally posted by Rademakers
What makes you think that?

Clipping is strongly advised against, if you're going that way you will soon find out why. An undersized clipping amp can easily destroy the VC. A more powerful amp will just speed things up a bit.

You will also find out that your warranty is useless when clipping is determined as the cause of failure.

As far as bracing concerned I don't think there is much more going on in there than some pieces of ply (3/4" x 4/6") on their sides, dividing the panels in halves or perhaps even thirds.
The vent is a typical one with such one bracing in the middle.

With kind regards Johan

I think there's a miscommunication here: He means "It's not so badly underpowered that the amp will clip much or often", not "I'll get clipping all the time, but that's not a big deal."
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Old 15th July 2006, 10:19 PM   #5
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You can download the pdf with the dimensions and response curves, so I would just have a play with WinIsd and see what you can come up with.
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Old 16th July 2006, 06:49 AM   #6
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Hey i just bought 2 of the same exact subs. I'm planning on a 250 liter enclousre tuned to 25Hz. I'll probably build it out of birch ply and double the front and rear of the box. Let me know if you have any other plans.

I'm also planning on 2 of the EP2500's each running in bridged mono mode, it seems like the best bang for the buck.
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Old 16th July 2006, 04:21 PM   #7
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Actually I lied, I meant a 450 liter enclosure, about 16 cubic feet, each tuned to 25 Hz. I'm also still contemplating a sonosub, but I'm not sure how well defined the bass is when you use them. I think it becomes more of a muffled bass response better suited for home theaters because its firing into the ground as opposed to at you. But I could be wrong, actually I do hope I am because it would be a lot cheaper to build it with sonotube. I just wish someone would tell me the difference, if there is any at all.
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Old 16th July 2006, 09:10 PM   #8
Relax is offline Relax  United States
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A single EP2500 will send 1500 watts rms into the low rider- rated for 800 wrms. Doesn't sound like a good plan to me.
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Old 16th July 2006, 09:17 PM   #9
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The low rider takes 800 watts rms, 1600 watts program, and 3200 watts max. Well thats according to its user manual.

http://www.partsexpress.com/pdf/294-301s.pdf
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Old 16th July 2006, 09:55 PM   #10
Relax is offline Relax  United States
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No problem there, its just that the EP2500 will output 1500 wrms, almost twice the rating of the lowrider. So the urge to turn it up will have to be quelled in order to keep the subs alive. If the EP2500 were to input its 1500 wrms, the sub would melt. In fact, I doubt the peavy could take its full rms rating if given it.

I do not have experience with Peavy, but several subs I have owned previously (none worth mentioning as I learned) cooked when they recieved their true rms rating.

Basically, just wanted to offer up the advice to watch how high you turn the dial, since the EP2500 (if rated correctly) could cook those subs in that configuration.
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