DIY Sub - This seems to be a trend

[xboxweasel]

I too am thinking about building myself a subwoofer. In all honestly, I want something that goes lower than my current sub. A Paradigm PW-2100. Here is a link to Paradigms webpage:
http://www.paradigm.com/Website/SiteParadigmProduct/ParadigmModels/SubWoofers/PW_Specs.htm

The components I am currently looking at include a Dayton HPSA1000 1000W subwoofer amplifer. From Parts Express. And a JL Audio 13W7-D1.5 driver.

I don't want to spend money/time on something that won't outperform the PS-2100. Using the Rives test CD and my RS SPL meter I found out the PS-1200 can go down to 30Hz. How does this rate with other HT subs? Are my goals of <=20Hz foolish? I figure I will have to spend a fair bit to accomplish this. My poor piggy bank shivers in fear. muhahahaha.

I never attempted to build a speaker before and am open to suggestions.

Will these two items work together with good results? Is a 1000W @ 4 ohms overkill for a HT? The paradigm is 400W RMS 1500W peak, but I don't know the impedance of the driver. I am guessing 4 ohms. Isn't that what most powered subs are?

Looking into a few car audio shops I notice that many subs are thrown together without much thought. No Theile-Small parameters are given. Prefabricated enclosures are available for any size of driver. From what I have read so far it's not that easy. More thought has to be put into the enclosure. A program called bassbox pro looks to be really good for designing boxes. I am thinking about getting that to help with the design.

Any thought? Feedback? Suggestions? TIA.

 

[j_garcia]

It's definitely not that easy. LEAP or WinISD are what you probably want to use to figure out the box for a given driver. 20Hz range on what budget exactly? It CAN be done on a budget, and you most likely won't need 1000W to do it.

 

[xboxweasel]

It's definitely not that easy. LEAP or WinISD are what you probably want to use to figure out the box for a given driver. 20Hz range on what budget exactly? It CAN be done on a budget, and you most likely won't need 1000W to do it.

I called around. The JL Audio driver will cost me $1600CDN. The Dayton amp was around $400US. That's a lot more than I had in mind. However, the PS-1200 was $780CDN. I figure that if I spend that much (or more) I should be able to get more out of my new sub.

I have no idea what power range to start in. I just figured on going bigger than what I currently have.

I'll look into LEAP and WinISD. Thanks.

 

[j_garcia]

How big is your room? My room is pretty big at 19x20 with high vaulted ceilings and I'm using a 350w amp and a single 12" driver and it hits pretty damn hard. I don't think anything Paradigm makes compares; maybe the Servo 15. What I'm getting at is, if you do it right, you won't need to spend as much as you think to do better than the 2100. SVS and HSU make subs that cost less than the PW2200 that easily compare with, if not better it.

 

[JPW]

According to Pardigms site the specs for your sub show it going down to 23Hz. If you're only getting 30Hz. Maybe there's a problem with your sub. If so Paradigm should have a good warranty. See what they will do for you. 23Hz should be enought for all but the most demanding systems.

 

[jaxvon]

As awesome as the W7 driver is, it has an Fs of 23.5Hz. The Dayton Titanic 12" and 15" drivers have an Fs of 22.2Hz and 19.93Hz, respectively. These drivers will go lower than the JL and cost less. I think in the interests of cost effective bass, a Titanic driver would be a better investment (maybe a pair )

 

[xboxweasel]

How big is your room?

room size approximately 12'w x 22'long x 8' high.

According to Pardigms site the specs for your sub show it going down to 23Hz.

I know. Using the Rives Test CD 2, playing back 31.5Hz I still get an audible signal, and a reading on my SPL meter. Playing back the 25Hz track I see the driver moving but nothing on the SPL. Playing back the 20Hz track I get no movement. But doesn't the room have a lot to do with this? Maybe at 25Hz the sub can't build up enough air pressure to register on the SPL meter.

The Dayton Titanic 12" and 15" drivers have an Fs of 22.2Hz and 19.93Hz, respectively.

Thanks. I really like the 15" given the cost. And I think I will stick to building one for now. At this price I might just order it. I'll let you know.

 

[xboxweasel]

LEAP or WinISD are what you probably want to use to figure out the box for a given driver.

Found those programs. WinISD is freeware. Seems very crude though. LEAP costs a fortune, $800. Bassbox is a lot less money, $180. Someone also made an Excel spreadsheet to help figure out cabinet sizes. I have not tried this one yet.

 

[xboxweasel]

15" sub

I currently have one of these: http://www.soundtech.com/products/systems/c600.asp as my portable "spare" system. It also has a 15" driver for the sub. The box is huge. Kind of a neat system. It has problems playing really low/high frequencies. My HT setup is better in those respects. But it can fill a small hall. The sub is awesome. I had it playing Boomtang boys - popcorn (like butta mix) in the basement. The furnace and all the ducts were vibrating like crazy. Did I ever mention that I live in a semi? muhhahahahaahaha.

This reminds me of the movie The Master of Disguise. Were Brent Spiner, playing Devlin Bowman, laughs very evilly and then farts uncontrollably.

I guess you had to be there.

 

[droeses58]

Found those programs. WinISD is freeware. Seems very crude though. LEAP costs a fortune, $800. Bassbox is a lot less money, $180. Someone also made an Excel spreadsheet to help figure out cabinet sizes. I have not tried this one yet.

Don't sell Winisd short, it's really a pretty good program for figuring box sizes.

Just for the heck of it I figured out the Dayton Titanic 15" and it's going to take a pretty big box [actually gigantic] to get down to 19Hz, 6.5 cubic feet.

I made myself a sub using the Titanic 12", that has useable bass down to 22Hz with the box I made, and that's only 3.4 cubic feet. Mines very good for movies, but a little outta control for music.

 

[xboxweasel]

Don't sell Winisd short

Someone mentioned it is only good for designing sealed boxes. I was thinking of going with a vented design. Parts express gives out box designs for the 15" in either a sealed or vented model. Only problem with their vented design; their box measures 23" cube, but the vent is supposed to be 33.46" long. I am going to ask them about this.

Jto get down to 19Hz, 6.5 cubic feet.

Part express's design calls for a 5.75 cubic foot enclosure. But I am not sure how low it will go.

I made myself a sub using the Titanic 12"

What type of amplifier did you use? How did you end up connecting it to your HT? And how did you go about setting up your amp [low pass gain/frequency, EQ frequency/bandwidth/level]?

 

[xboxweasel]

some more questions

In the vented design schematic by Parts Express there are a few parameters that I don't know the meaning of. Fb, QL, F3. These have to do with the enclosure.

For the driver T-S parameters, where do I find the Le spec (measured in mH)?

Here is a link to the vented design for the Titanic 15" from parts express:
http://www.~~~~~/pdf/295-420vented.pdf
I guess we are not allowed to enter URLs to parts express. Just replace the ~~~~~ with partsexpress.

 

[droeses58]

Someone mentioned it is only good for designing sealed boxes. I was thinking of going with a vented design. Parts express gives out box designs for the 15" in either a sealed or vented model. Only problem with their vented design; their box measures 23" cube, but the vent is supposed to be 33.46" long. I am going to ask them about this.
Part express's design calls for a 5.75 cubic foot enclosure. But I am not sure how low it will go.
What type of amplifier did you use? How did you end up connecting it to your HT? And how did you go about setting up your amp [low pass gain/frequency, EQ frequency/bandwidth/level]?

With the example partexpress uses the f3 is 25.71Hz which is the -3db point, with the example I gave the f3 is ~21.5Hz, so you can see just from that, what a difference box size makes. With a port size of 6" x 21.6" long. Or you could use 2 tubes at 3" x 10.8" long

As far as mine, I used the 500 watt bash amp that they sell, it's not as good as their 1000 watt monster, but it works for me. As far as setting it up I just let the reciever take care of that, though I'm still screwing around with placement because I just moved it to my basement were I'm building a dedicated [more or less] home theater.

 

[WmAx]

As awesome as the W7 driver is, it has an Fs of 23.5Hz. The Dayton Titanic 12" and 15" drivers have an Fs of 22.2Hz and 19.93Hz, respectively. These drivers will go lower than the JL and cost less. I think in the interests of cost effective bass, a Titanic driver would be a better investment (maybe a pair )

The JL W7 driver is 'crazy' powerful due to it's extraordinary long linear excursion and thermal handling ability. Even with FS a few Hz higher, all one has to do is use an electronic filter to increase the extension. The W7 has gobs of excursion/power handling to spare, and would ultimately still be the winner. Besides, if the person above is serious about having the highest quality subwoofer, they will certainly add a parametric equalizer to flatten lower frequency response in the room, which will allow them to add a compensatory filter to extend response.

-Chris

 

[droeses58]

In the vented design schematic by Parts Express there are a few parameters that I don't know the meaning of. Fb, QL, F3. These have to do with the enclosure.For the driver T-S parameters, where do I find the Le spec (measured in mH)?

Fb = tuning frequency, as I said above, f3 = the -3db point and I'm not really sure about QL but I think it has to do with the overall Q of the speaker.
Edit: maybe Chris can help with this one? As I am still a novice at best, but will try to help if I can.

The Le = 3.84mh and can be found in the item description.

 

[droeses58]

Besides, if the person above is serious about having the highest quality subwoofer, they will certainly add a parametric equalizer to flatten lower frequency response in the room, which will allow them to add a compensatory filter to extend response.

-Chris

Which if he uses that monster 1000 watt sub amp, that has a built in parametric eq., though I don't know how good it would be.

 

[xboxweasel]

The Le = 3.84mh and can be found in the item description.

Thanks. I missed that. I was looking at the PDFs for the driver specs.

I've been playing with winISD a bit. I came up with a vented ~181L (6.4 cubic foot) box with a tunning frequency (Fb) of 21.19Hz. The port is ~4"OD x 8"long. Outside dimensions of enclosure are ~24" cube. This off course will increase as I will be making a seperate compartment off the back for the amp. Adding another 7"-8" in depth.

 

[xboxweasel]

The JL W7 driver is 'crazy' powerful

It also costs $1600CND. While the Dayton is only $200US. Even with the exchange rate it won't come close to $1600CND. Like I said; I can buy two Dayton 15" drivers and two Dayton 1kW amps and still come out spending less. But one is good for now.

I'm getting exited. This should be fun.

For best results I am planning on using glue first and then adding tons of screws to keep it tight. I've also seen someone add a tar like substance to the inside of their box. What is that for?

What about bracing??? Do I require any on a box this size? WinISD does not allow for that option in their box designs. I am going to use 1" MDF all the way around. Possibly doubling up the front (2") to make the mounting easier (by not having to recess the hole). If I add bracing I will have to increase the outside dimensions to keep the internal volume the same.

PS: Thanks for all the input so far. You guys (and/or girls - don't want to get into trouble here) have been really helpful so far.

 

[Buckeyefan 1]

It also costs $1600CND. While the Dayton is only $200US. Even with the exchange rate it won't come close to $1600CND. Like I said; I can buy two Dayton 15" drivers and two Dayton 1kW amps and still come out spending less. But one is good for now.

I'm getting exited. This should be fun.

For best results I am planning on using glue first and then adding tons of screws to keep it tight. I've also seen someone add a tar like substance to the inside of their box. What is that for?

What about bracing??? Do I require any on a box this size? WinISD does not allow for that option in their box designs. I am going to use 1" MDF all the way around. Possibly doubling up the front (2") to make the mounting easier (by not having to recess the hole). If I add bracing I will have to increase the outside dimensions to keep the internal volume the same.

PS: Thanks for all the input so far. You guys (and/or girls - don't want to get into trouble here) have been really helpful so far.

Xbox,

I would highly recommend adding a center brace if you are seriously considering a 15" Titanic and 1000watt amp. If you use one internal brace you'll need to increase box size approximately 1/2" all around. It depends on the flow through design of the brace. Some guys use several circular holes. Some just use slats, and some use on large hole similar to the front of the sub opening.

Just out of curiosity, why aren't you considering a sealed option? A 1000 watt amp has plenty of power to drive a sealed 15" titanic, and it's footprint will be much smaller with very low Fs.

http://www.partexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-420

For anyone wondering how to post a PE item, just remove the "s", and make it "partexpress." No $ex to upset mommy and the kiddies on this site incase they're looking over your shoulder.

 

[WmAx]

It also costs $1600CND. While the Dayton is only $200US. Even with the exchange rate it won't come close to $1600CND. Like I said; I can buy two Dayton 15" drivers and two Dayton 1kW amps and still come out spending less. But one is good for now.

I know, I was responding to Jaxvon. You can get much more output for the same money using multiple drivers of another brand/type, such as the Dayton unit you are using, at the expense of the extra room that is occupies.

I've also seen someone add a tar like substance to the inside of their box. What is that for?

This serves no purpose for a subwoofer box. Tar(in thick coats) can be used in some cases to reduce the duration of resonances in panels -- this would manifest in the midrange band, not the bass band(unless you used rediculously huge and thin walls). However, other materials can be used to accomplish this that are much more user friendly and will not have the horrible odor.

What about bracing??? Do I require any on a box this size? WinISD does not allow for that option in their box designs. I am going to use 1" MDF all the way around. Possibly doubling up the front (2") to make the mounting easier (by not having to recess the hole). If I add bracing I will have to increase the outside dimensions to keep the internal volume the same.

Listen to Buckeyefan1. There is a chance that you may not need bracing, but with this large size enclosure, I would not take the chance because it is easy to add in braces to insure no problems occur as a result of not using them.

-Chris