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15" is here, suggestions on box finish.

1K views 31 replies 5 participants last post by  mobeer4don 
#1 ·
I read through some of the threads here but I notice that a lot are for big ass subwoofers
Nothing wrong with that, but I can't do above a 12" for now. I am in college and I live at home. That limits me in budget and I don't want max sized components for when I move. I am very handy and I have a friend who is a carpenter and the two of us combined should be able to handle a cabinet. Ideally, I would want a Rhythmik 12SE but I can't afford a $1000+ subwofer, so i was eyeing up a HSU VTF2 MK4 which would run me about $600 shipped right now. I would like to spend $400 - 500 on electronics in a DIY. Why almost the same price? Spacing out when I buy things will give me something to do that I like a lot. I want a piano black finish because it would match my speakers. I am using a 10" 100watt JBL which is simply unbearable for any HT movie right now.


OK so, I need some help in where to start. I listen to music/movies/video games in an even mix. I would prefer the subwoofer was musical over output. If I'm at too low of a price point to make it worth the effort please just tell me! If all goes well I will definitely make a second for 2 12" boxes. That's part of the reason for trying to save money in the first place. If I can get more bang for my buck going DIY, I would love advice on what driver(s) and amp. Then I need to know how to build the cabinet, apart from with MDF. The quality of $500 in electronics in a well made enclosure is comparable to what popular subwoofer?


edit:

I've dug deeper and found the FAQ and a few people asking the same questions as I. I don't know what driver choices I have in my price range and I would need a design to follow to build the box. Also want to know if it is worth the effort with my budget.
 
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#2 ·
You're saying the box has to be 12" or the driver? A VTF2 is a lot bigger then that, so I'm going to assume you mean driver. A really easy build for you would be a dual opposed sealed setup, with a boosted amp. Take two of these Infinity woofers, and wire them together for a 4 ohm load.

http://www.amazon.com/Infinity-Reference-1262w-1200-Watt-High-Performance/dp/B0028AYIXK/ref=sr_1_1?ie=UTF8&qid=1360639791&sr=8-1&keywords=infinity+1262w


You would build a box like this, the second driver would be on the opposite side of the driver shown




You would power the pair of drivers with this 500 watt 25hz boosted amp.

http://www.parts-express.com/pe/showdetl.cfm?partnumber=301-514


Under budget and very good performance

 
#3 ·
Yup, 12" Driver size. How would your suggestion sound and look?

I am still curious whether it is more effective to just pay $600 for the HSU.


Any other options on what drivers to use?
 
#4 ·

Quote:
Originally Posted by skidawgz  /t/1457681/new-to-diy-would-like-to-build-12-sub/0_80#post_22953583


I am still curious whether it is more effective to just pay $600 for the HSU.

Store bought will never be as effective, dollar for dollar, as a DIY setup. Simpler maybe, but not as effective.
 
#5 ·
That sub would cost about $400 to completely build and finish. If you do a solid job building it, it will sound like a clean, powerful sub within its limits. It will have a ton more headroom above 40hz then the HSU, that graph shows the max output under 30hz, which is where all the boost is. Output under 40hz will basically equal the HSU sub. You basically said you prefer sealed "music" subs in your OP, but that doesnt really mean anything. Building a ported sub equal to the HSU would be pretty easy, the Infinity 1260 with a $125 250 watt plate amp will do the trick, thats a $250 build



Of course a more powerful ported build could be designed, and a single driver sealed build


Sealed build

http://www.parts-express.com/pe/showdetl.cfm?partnumber=295-512


Ported build

http://www.parts-express.com/pe/showdetl.cfm?partnumber=293-650


It's all about what you really want, that's the beauty of DIY!
 
#6 ·
OK, so I've taken in that so far. What is it about the most recent links, the Dayton and TC that make them better than the Infinity?

What made you suggest a dual sub setup the first time around? I've never owned a sealed sub, but all research I've done suggested I would like sealed.

What are other amp choices?


Most importantly, I am still in the dark as to what the inside of the box needs to look like, as far as bracing and foam.


Thanks for your help thus far, I am sure you answer the same questions constantly.
 
#7 ·
The dual 12"s get you more surface area then a 15", and they cost less then most decent 15"s. Bass is pretty basic, how much air can you move. The larger the enclosure, the "easier" it is to move air lower in frequency. A smaller enclosure requires more power to reach the same output as a larger enclosure. A sealed box limits low frequency output capability, so more cone area gives you more capability.


Both of the more expensive drivers have a lot more cone excursion, so they can do more with a lot of power by themselves. The Dayton is optimized for a sealed box, and the TC a vented box. Both drivers have advanced motor designs, with distortion reducing, inductance controlling shortening rings. They are worth the money in many situations.


If you want a plate amp, options arent very special, many amps like the one I linked with and without boost. There's only one with more power then 500 watts, and all of them have high pass filters around 20hz which limits the usefulness of a sealed sub. Outboard pro audio amps are your other real option, but they can be noisy (need to do a fan mod), and sometimes difficult to setup if you're inexperienced.
 
#8 ·
Ok you seem to be subtly suggesting that I do an open box, or did I make the wrong assumption? I read through your 15" sealed pair thread.


I was (originally) hoping to make a box that is about 2 ft^3. Single or dual drivers is fine. 12" or 15" would be fine. I am up for suggestions to maximize sound. I hope to make something that sounds accurate and not sloppy boomy. What should I do?


I won't worry about the amp for now, and certainly not an outboard amp. I was definitely planning to go plate.
 
#10 ·
3ft3? Oh My. Sorry I meant ported not "open box".


If it is a ported box can I make it slightly smaller than 3ft3 without killing the capability?


What do I do to learn about bracings and filling?
 
#11 ·
3ft3 sealed for the ultimax. I wouldnt go to much smaller. Ported would be huge.


For bracing youre simply connecting all of the panels, ideally at their weakest, in the panel centers. You could just use strips of wood and make a # that goes front/back side/side top/bottom.


For fill just get some $2 poly pillows at walmart and throw 1-2 in the back of each box.
 
#13 ·
I did more reading of other threads and I just became more curious about options. Sorry.

I've decided to loosen up on the size restriction. I still want to build a sealed box, and opposed design seems intriguing.


Do I need to increase box size for a 15" subwoofer? How much in volume?


How good is the SQ of the Dayton Ultimax that you linked? The driver "looks" top-notch but I am new to this.


Do I need to increase volume for opposed drivers? Say I want to use 2 Ultimax... I assume something must change such as enclosure volume or Amp Power.
 
#14 ·

Quote:
Originally Posted by skidawgz  /t/1457681/new-to-diy-would-like-to-build-12-sub#post_22961787


I did more reading of other threads and I just became more curious about options. Sorry.

I've decided to loosen up on the size restriction. I still want to build a sealed box, and opposed design seems intriguing.


Do I need to increase box size for a 15" subwoofer? How much in volume?


How good is the SQ of the Dayton Ultimax that you linked? The driver "looks" top-notch but I am new to this.


Do I need to increase volume for opposed drivers? Say I want to use 2 Ultimax... I assume something must change such as enclosure volume or Amp Power.

Generally, yes to everything.


A 15" with good extension in a sealed box will need to be bigger then a 12". Sure you can find 15"s that work in smaller boxes and then use a boosted amp. My original recommendation was along this line of thinking, even though the box was bigger due to dual drivers.


The Ultimax should have "top notch" SQ, because it is a very well made driver.


Yes a dual opposed will need twice the cabinet volume as a single driver to equal the response.


For examples sake here's the Dayton RS390HO in a 1.5ft3 box (blue), with the boosted 500 watt amp I linked earlier in the thread, vs the Ultimax 12 (orange) in 3ft3 with a non boosted amp.




The max output below 40hz of these two subs will actually be the same due to the much greater efficiency of the 12 in a bigger box. The boost just allows the 15 to have a decent response in the tiny box, at a certain point this will compress and output above 30-40hz will continue to rise. If you dont plan on playing the sub over 105 db this will never be an issue and the boosted 15 will perform extremely well.
 
#15 ·
OK, that settles it. I will be building a 3ft3 box for the 12" Ultimax.

I'll be saving tons as I'm trying to do a piano black finish. I am sure my buddy and I are capable.


What is a good amp to use?
 
#17 ·
I was doing bad math earlier (how embarrassing) and didn't realize how small 3ft3 is. What I originally planned for was about a 4 - 5ft3 enclosure. I still plan to use the Ultimax, so 12" or 15" driver what do you suggest? Same amp?


I was thinking I would do downward firing simply because a) I won't have to worry about designing a speaker grill b) The driver won't be exposed for the less careful to kick or damage. If downward firing is a bad idea let me know now please.


Thanks again.
 
#18 ·
#19 ·

Quote:
Originally Posted by Jay1  /t/1457681/new-to-diy-would-like-to-build-12-sub#post_22977085


The 15" ultimax works as well in 4 ft3 as the 12" in 3 ft 3, so it's the better option if you're okay going bigger. You could even get away with upgrading the amp to a 1000 watt version with the 15.

Are you sure about the 1,000 watt amp for the 15" at 4 cubic feet? I modeled it with those specs and it blows waaaayyyy past xmax. 500 watts seems to be perfect for 4 cubic feet as it puts it just at xmax. If he wanted to use the 1,000 watt amp then a 2.5 cubic foot box would be better to keep xmax under control. It's also a slightly better performer than the 4 cubic ft at 500w and is smaller in size.
 
#20 ·

Quote:
Originally Posted by Audiophile1178  /t/1457681/new-to-diy-would-like-to-build-12-sub#post_22977214


Are you sure about the 1,000 watt amp for the 15" at 4 cubic feet? I modeled it with those specs and it blows waaaayyyy past xmax. 500 watts seems to be perfect for 4 cubic feet as it puts it just at xmax. If he wanted to use the 1,000 watt amp then a 2.5 cubic foot box would be better to keep xmax under control. It's also a slightly better performer than the 4 cubic ft at 500w and is smaller in size.

Throw an 18hz HPF on the model, it gets to about 22mm. It's been reported that the 19mm rating is only geometric, and the actual BL rating is closer to 21-22mm
 
#21 ·

Quote:
Originally Posted by Jay1  /t/1457681/new-to-diy-would-like-to-build-12-sub#post_22977223


Throw an 18hz HPF on the model, it gets to about 22mm. It's been reported that the 19mm rating is only geometric, and the actual BL rating is closer to 21-22mm

Just did that but then it reduces output on the low end. Wouldn't it be better to put it in a slightly smaller box to keep the low end output while keep xmax under check than going with a bigger box and having to put a HPF on it which will reduce the low end output? I don't know if the OP is going with a plate amp or not then it'd be a moot point but if the op ends up with a pro amp then it wouldn't make sense to me to go with the bigger box.


BTW, Jay i'm not trying to argue with you or anything as I know that you know your stuff. I'm sorta a newb and am just trying to understand it all.
 
#23 ·
I am definitely concerned with low end, I just look at everyone's DIY subs and they were like 3 feet tall and up. I wouldn't mind that if I owned a house, but i do not yet. I was hoping to build something that is no higher than typical couch arms. (I know height is just one of the dimensions I can adjust) Part of the reason I came here to DIY is because many subs I thought I respected I've heard bottom out in movies. So my ideas have changed greatly from my original post. I am also concerned with sound quality, and I look forward to build a second sub because it sounds a bit more even to me. The only thing I am not hugely concerned with is max output.


I will probably shoot for a 4.25 to 4.5ft3 box with a 15" and the 500W amp. $20 more for a better driver is almost a no brainer. However... The more expensive amp (1000W) I will cheap out on unless you think that's what it really needs be paired with.
 
#25 ·
well that got out of hand fast now didn't it??



The difference is only $100 to go big over a 12" w/ 500W. I'll have to think it over, but I appreciate all your help!
 
#26 ·

Quote:
Originally Posted by skidawgz  /t/1457681/new-to-diy-would-like-to-build-12-sub#post_22977407


well that got out of hand fast now didn't it??



The difference is only $100 to go big over a 12" w/ 500W. I'll have to think it over, but I appreciate all your help!


It's amazing how that works around here



Just think, if we were talking commercial subs it's be like going from the $600 model (500W 12") to the $1200 model (1000W 15)
 
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