Could I build a better sub than the bic h100 inch for under 200?  

For under $200 that would be real tough to beat.

I wouldn't if I were you.

You could get this 300w BASH plate amp (twice as much wattage on tap as that BIC) for $105, at the moment. Shipping is free right now for >$99 orders, I believe.

You could then get one of these 350 watt 12" drivers, shipped for this much (the shipping is in $CAD, so in $US it is actually a bit less). That is just ~$65, all told.

So for those keeping track, that is only $170 for the driver/amp.

You put this driver into a 135 liter (net) enclosure tuned to 17.5 Hz, and you would have a sub that would walk all over that little bic H100. No doubt. It models in WinISD Pro at ~105dB @ 20Hz/1meter using 155 watts out of the amp. You would be excursion limited to just over 108dB @ 19Hz/1meter. Like I said, no doubt.

135L works out to about 4.76 cuft. You would need something like a 20X18X24 internal dimension box to account for port volume, bracing, and the driver. Add a bit to the back for the plate amp.

A 4" port (don't use smaller) in this design needs to be ~20.5" long for a 17.5Hz tune, so you could just front port it on a 1.5" front baffle, and you have 5" of clearance between the back of the interior of the enclosure and the inside end of the port. Works out perfectly.

I can get a 49"X97" 3/4" MDF sheet for $25 around here. Add the finish you want (spray texture or paint - whatever) and some glue and you are golden.

There is a thread with a similar design in progress here.



Good luck with what ever you decide.

Jon, good suggestion. Didn't happen to notice that amp on sale for so little. Whats the high pass filter like on that amp btw?

Who needs a high pass filter with a 17.5Hz tune?

lol

I don't know. I would doubt it had one, but seriously, the design I mention has an excursion bump centered at ~25Hz that causes over excursion beyond about 155 watts. At 155 watts, it does not exceed its x-max again until <15.7Hz. That seems fine to me.

You're not serious right? :)

If he plans on watching any of today's bass heavy DVD's a highpass with that driver in this allignment will be a must.

For a little extra, if going above $200 isn't a problem, I'd suggest a Rythmik 250 watt basic amp, with a highpass set to where you tell brian to set it to (an extra $5). You wont have to worry about exceeding excursion and you'll know how much power your amp puts out at 8ohms (rated at 150 watts) perfect for this project with this driver wired in series.

If you have a router, I would say it is easy. If you do not, it is still doable. It may require excessive sanding to get things to look good, however. I bought mine to make speakers. I am a complete noob, as well. I think I can do a 4-driver 3-way fullrange tower enclosure, so I think you can do a sub box if you have (or can borrow) the tools.

Let me see if I can do a Google Sketchup of a center cut-away view of the example enclosure I mentioned. If I can I will reply with some screenshots, maybe that will help.

Read: WoTW. It is the only DVD I know of that has <20Hz material that rivals the level of the >20Hz material. As I mentioned, this design exceeds x-max in a narrow range centered around 25Hz at only 155 watts. The problem is at 25Hz, and a reasonable highpass setting does not help that at all.

"Today's bass heavy DVD's" will not cause a problem unless the levels of <20Hz are very close to the levels of 25Hz. Even then, upon closer examination, it turns out that the drivers 350w power rating is exceeded before its x-max rating is in the 19.2 - 16.5Hz range. It will take the full driver rating of 350w in that range.

With the sole exception of WoTW (I believe that has very high levels of stuff around 13Hz, but my memory might be faulty), I do not see a problem. Again, the problem is at 25Hz, and a reasonable highpass setting does not help that at all. Still, the "problem" nets him >104.5dB from 18Hz on up @ 1meter with a 155 watt signal at those frequencies. That is a lot of sub for just $170 in driver/amp cost.

Guys, the HP filter on that Bash amp is entirely customizable.

http://www.partsexpress.com/pdf/300-750.pdf

lol

Both of us get what they want, then. :D

300w, $105, customizable HP. Nice ;)

Jon, true about WOTW. Although I wish I could see a graph showing the LFE content in U-571, particularly during the depth charge scenes towards the end. That scene makes me sweat every time haha :cool:

Yes, for $170 amp and driver (minus the enclosure, which is cheap) that is one hell of a deal!

Will, in that case I don't see how one could go wrong with this amp and this project.

Edit: Jon, the problem at 25hz, im not seeing it when I model with 150 watts. Everything looks perfect down to about 16hz with your given dimensions. Since wiring this driver in series is a must, I wonder how much power the Bash 300 is capable of producing at 8ohms? Probably somewhere in the neighborhood of 150watts anyway.

Thats because building speakers IS really cool ;)

At 150, there is no problem. By 155, excersion is over x-max around 25Hz, by a small fraction of a mm.

As you exceed 155, there is a problem centered around 25Hz. Until then, everything is fine.

I did forget about the 8-ohm load due to the 4-ohm DVC voicecoil. So, the BASH "300w" would be a perfect match for this project.

I have a feeling I will end up building several SonoTube versions of this design over the next couple of years for various friends. Most wouldn't know deep bass if it jumped out and bit them. My feeling is that an introduction is in order, in those cases. ;)

Got a Google SketchUp done of a basic box design that would work. It has single layer 3/4" MDF sides/top/bottom/back, but you could double up for 1.5" thickness on those five walls, as well, if you like. I can also get you the file if you are interested.

It is 21.5" tall, 19.5" wide, and 26.25" deep. On to the visuals.

This one is an overview of the size of the box. It has an actual-sized woman in the shot:

http://jonathanb3478.tripod.com/imag...h5-12-box2.jpg




This one is a shot of some internal detail through the "window" I put in one of the enclosure sides:

http://jonathanb3478.tripod.com/imag...h5-12-box3.jpg





The last one is another internal detail shot, this time from the front:

http://jonathanb3478.tripod.com/imag...h5-12-box1.jpg




Others can chime in with comments/improvements, but this is along the lines of what I would do for a box style enclosure. I would likely make all six sides 1.5" thick, not just the baffle. I like super large and very heavy, however. :D

Feel free to ask any questions you have regarding the enclosure.

It's the internal bracing. You can also use "window pane" bracing like in this design - 5th pic on the right.

Port.

With the right tools, a couple of hours and that includes letting the glue dry. If you don't have all of the tools or are just inexperienced it could take months of working on weekend.

-Robert

There are 9 largish 3/4" MDF panels, 14 little MDF brace pieces (12 for the enclosure walls and two for the port tube), and a pair of 1.5" diameter dowel pieces. You would need to cut all those to the right dimensions (or slightly oversized for flush-trim routing to the exact size after assembly, for some of the panels). That should take a few hours, I would think.

After that, there are 20 holes to router out of the panels. They range from 2.5" diameter to the outside diameter of the driver (guessing at 13", that is what is in the SketchUp). If you have something easy, like a Jasper Model 200 router jig, that will take another hour or two. If you are using another method for cutting the circles, it could take much longer.

Plus, you could route a hole in the back for something like this to use to connect an external amp to the sub, or you would need to make an add-on to the rear of the enclosure for the plate amp.

Then there is assembly. That could take a few days, depending on how many glue joints you can clamp at the same time, while they set. I guess that would depend on how many clams you have. If you have 6, that could take a while. If you have a lot, much less time in total, since you are waiting for the previous step to set before moving to the next step less often.




As far as what different pieces do, the three panels with the 4 8" circles in each are the main enclosure braces to prevent the enclosure walls from flexing. There are also 12 2"X3/4" braces between those, running perpendicular to the main braces to assist in preventing the enclosure walls from flexing under pressure.

The tube is the 20.5" long, 4" diameter, port tube that tunes the enclosure to about 17.5Hz. It is only 19" into the enclosure, since it goes through the 1.5" thick front baffle, first. It also has a pair of 3/4" brace panels, each with a pair of 2.5" diameter holes in them. One braces the tube from moving up/down, the other from moving left/right. There was only one of these, with no 2.5" holes, in the first pictures I posted. I updated the SketchUp, and took new internal detail shots after I did. I like the new shots better, and I thought the second port-tube brace was a good idea.

That about cover it?

The port could be made from a couple of these, connected together end-to-end.

The MDF is $25 for a 4'X8' sheet at both the Lowes and Home Depo around here.

I got a table saw, plunge router, Jasper Model 200 circle jig ($29, at the moment), and a power sander. Those are the basics, I would think. You could substitute a circular saw with some saw horses for the table saw, in a pinch.

I saw someone actually make a tall and wide, but not very deep, seperate box for a plate amp with a speaker terminal cup on the bottom of it. He then mounted that on the wall near the sub, and ran speaker cables from the terminals on that box to terminals on the sub's enclosure.

That approach would give you a smaller/easier to build enclosure for the sub. The smaller enclosure might be nice, plus you get more placement flexibility. That is the way I would go.

If you do not, you would need to modify one of the dimensions (depth, for instance) to add as much volume of air as the back of the plate amp subtracted from the internal dimensions of the enclosure.


I agree!

:D

I just had an idea. You might want to think about dual 3" ports, instead of a single 4" one. I notice that a pair of 24" long 3" ports will tune this enclosure to 17.5Hz. If you extend the depth of the enclosure by one inch, and have the ports stick out the front by an inch, you can get 24" ports into this box. It would look something like this:

http://jonathanb3478.tripod.com/imag...h5-12-box4.jpg

You would need to help take up the extra volume in the enclosure by reducing the height by 3/4". This version is 27.25" deep, 19.5" wide, and 20.75" tall. It has just about the same volume.

Just a thought.

I'd rather run a single shorter 4" port myself, but thats just my opinion.

The dual 3"ers flow with >10% less peak velocity. I like the symetrical look better, also.

Like I said, just a thought. Doesn't really matter. ;)