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Discussion Starter #1
Here are a few subs that I have at my place now. Just finished putting my firend's sub together and thought I would post some pics since I've not done that in the past.

Mine is on the bottom. ED 19Ov.2 ~12.5^ft tuned to 15 hz. 8 inch sonotube port with double front .75 baffle. Weighs somewhere around 200-250 lbs. Just running that one now with an old receiver for power. Only getting about 150 watts, but it still rocks. Would've took pictures during the build, but I have an old digital camera that wouldn't stop fogging up on the day I built it (it was around 10 degrees when I was putting it together). Getting it ready for a layer or two of black semi-gloss paint after I sand it down some more.

The middle sub is the one I just finished for my friend. It's a Dayton 15" DVC in a 7.5 sealed enclosure. Being pushed by a PE 500W BASH amp. Buddy doesn't know much about subs and he wanted something decently cheap and easy. Seemed like an alright way to go. It's leaving my place today after he gets off work and take it to his place for sanding and staining. It'll look nice along side his new 73" Mitsubishi TV.

On top is my old sub that's now being used as my PC sub. It's a 10 inch RCA ported in about a 1^ft enclosure. No idea the tuning on it, but I would imagine it's around 40 hz going by the frequency rolloff after that. It was my first sub I bought. Picked it up about 5 years back at Radio Shack for $90 clearance. It worked well, at least I thought, for that time until I started listening to real subwoofers.

Question about the Bash amp. I read somewhere there's a limiter or HPF at 30 hz on it and that there's resisters that can be replaced to eliminate that. Anyone know how to do that if my friend needs that low end?

Will post some more pics later with a better camera.

Better get to cleaning this up. Wife comes home and finds me power sanding inside she'll be, well, like a wife who came home and found her husband sanding inside on carpet.
 

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The P.E. Bash 500 has a default HPF at 30 hz. By changing 2 resistors the frequency can be altered along with various amounts of boost at specific frequencies. The documentation is here:

http://www.parts-express.com/pdf/300-752.pdf

Her's a pic of the board that identifies the resistors:

Bash 500.JPG
 

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Discussion Starter #3
So other than giving a boost there's no way to take the HPF completely off. You just have to boost a frequency that's already being reduced? I didn't have a chance to run full test signals to his before he left with his sub today, but it was up to his liking so that's good. Do you know what kind of rolloff there is below 30 hz?
 

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You don't want to take the HPF off as that is what is what protects the sub from bottoming out at the lower frequencies. You choose the right one that gives you the most output from the sub without it exceeding Xmax. What model number is the Dayton sub? I post some modeling to show you.
 

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Discussion Starter #5
Dayton DVC385-88 15" DVC Series Subwoofer. I think the 30 hz HPF is a little too high. I guess it's put in for a reason, but just seems like setting at say 20 hz would give a bit more oomph to their amps.
 

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EDIT: Wrong parameter entered. The graph has been redone with correct parameters.

Here is some modeling of the Dayton DVC385-88 15" in 7.5 cu.ft. sealed.

Yellow is what the amp has now, a HPF at 30 hz and 2 db of boost from 36-40 hz.
Green is a HPF at 20.7 hz and 1 db of boost from 31-35 hz. The lower HPF gives you slightly less output from 30 hz and up, but more output from 30 hz and down.

Brandon.JPG
 

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Discussion Starter #7
So really very little difference. A couple dB's and that's it on the low end. I guess room gain will help it some. As soon as I figure out REW I'll run it and see what the response is like.
 
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