My first sonosub. (1 Viewer)

My dedicated HTR is 15wide by 13 deep with 8ft ceilings(opens into small hallway) and 9ft viewing distance. I've got a 4yr old Toshiba 42" that was just tuned up and until I can get a name brand 50"plasma for $1500, it isn't going anywhere. Sound is an Onkyo 602 pushing Klipsch SF1 mains, SC.5 center and SS.5 surrounds... just 5.1 in a room this small.
I've been subless for a few months while I researched DIY options and finally settled on a "basic" sonosub.

Sourced from from Parts Express:
Dayton 100 watt plate amp
Tang Band 8" W8-740C
12" diameter tube cut to 14" tall making .82cuft
2"x9" port
.75MDF plugs and caps
winISD says 31hz
It looks great with pine beauty caps stained to match the furniture and a gloss black wrap for the tube. I did a really nice job on it.

But I'm really disappointed. I've never gone into the software on my Onkyo(something to explore tomorrow), but I thought something must be wrong... I did find out I'd had the mains on "small", and when I turned them to large, they're just as loud as the sub. The sub plays a little deeper than the mains, but not loud enough to matter. I've got the gain in the middle position and the crossover around 70hz... but I was expecting more... should I have been?
Do you think an 8" 100watt sub should be able to give you a "WOW!" Maybe I was kidding myself...

Yeah, that single 8 isn't going to be much louder than the mains, if louder at all.

Have you tried moving the sub around in the room, especially in a corner? 31Hz is not really low enough for HT, 20Hz tuning and more displacement will give you that "WOW". How does the sub sound with music? I made a sub for my computer with the 6.5 Neo Tang Band tuned to around 30Hz and it sounds pretty good with music and video games.

http://www.partsexpress.com/pe/showd...number=264-854

You used this driver and fed it with 100 watts. The low sensitivity and limited power is going to prevent you from playing loud and the relatively high Fs and small displacement capability is going to prevent you from playing low. It can probably be used with great success as a computer subwoofer, but doesn't seem suited for HT use at all. I don't want to sound rude, but I can't see why you would be surprised.

Steve, you have PM.

Thanks for the alternate suggestions and it looks like to get what I want I'm going to have to go bigger. The reason for small and cheap was WAF. She really likes the look and size of what I've built and it will take a little adept maneuvering to get her to let me build something bigger. I think stepping up to 250watts and a 12" driver in a suitably sized and tuned encolosure should get me in the neighborhood I'm looking for. It's small room and already fairly full of furniture... we'll see what I can come up with. It was a really good learning experience and this site helped a lot. My next one will be awesome!

When I get home tonight, I'll try moving it around the room and play with the software in my receiver. Maybe I can squeeze out a little more.

It really didn't add all that much to the music. It would be more noticable if I was using some small bookshelfs in a 2.1 config. But the floorstanding mains have 6.5" drivers and provide plenty for what they are. Just changing the mains to large doubled their presence. I really have to read the whole owners manual now.

Sam, replied to your PM - hopefully that will clarify the misunderstanding.

If small with decent extension and output is the goal, take a look at the Dayton RS 12" HO or the RS 10" HiFi.

The 12" HO in 1.75 ft^3 tuned to 22hz models to -6db @ 20hz...good on its own, even better with a touch of room gain. With only 240 watts (SA240@110$), it's good for 102db @ 20hz and >106db above 30hz. Currently on sale for $104.

The 10" HiFi in 1.5 ft^3 tuned to 22hz is -6.5 @ 20hz. 240 watts yields 101db @ 20hz and >106db above 30hz. On sale for $96.

There are countless other combinations of drivers and cabinets, but those are a couple of ideas I've been toying around with for times when decorator space is an issue. As it is, the sims of the 12" HO are within 1db of my pair of NHT1259s from 20-25hz. Each 1259 lives in a 3 ft^3 sealed cabinet.


wbs

Brent, your advice is most helpful... now to convince the wife!!!

On this project, I used no reinforcing bars along the inside of the tube to connect the opposing encaps together as I've seen in many other sonotube projects on the internet. At only 14" tall, I wasn't worried about the stability or structural "soundness" of the enclosure. The plugs are secured in the tube by a liberal amount of standard Elmers wood glue and were a very tight fit to begin with... then I used small nails evenly spaced for a bit more security.

However, my next tube is going to be much bigger. Just to clarify my understanding about what these internal rods do, are they more for the structural integrity of the tube, or are they designed to keep the caps from popping out or what?

Also, played around in the software last night and managed to squeeze some decent sound out of the little guy. Actually, I got the whole system sounding better. I think I need to go buy a microphone and utilize some of the more advance calibration features. But I played with the equalization settings (of which there are a lot of parameters to adjust) and set the speaker distances and the other usual stuff I should have done the day I bought it... but it sounds a lot better overall.
I placed the sub in various spots around the room and the front right corner is still the best choice. The left wall is the one that opens onto the hallway, and the couch runs the entire length of the back wall, so right front is where it will stay.

I'm still open to more ideas regarding speaker and enclosure combinations. I'd like to keep the speaker and amp combo under $250. I know there are plenty of options out there, anybody have any favorites similar to what Brent put out?

At that price range, this is the best I know of:

http://www.avsforum.com/avs-vb/showthread.php?t=636825

It's sealed so the size didn't get too large, yet still is solid to 20hz without EQ assuming you can get a bit of room gain. I think he did a great job on the finish too.

Dayton Quatro 15" driver and the PE 240 watt plate amp is the absolute biggest bang for the buck out there.

From the sound of it, there's no way his wife is going to go for something approaching a 3ft^3 cabinet. Although, it would really open up a ton of options for price/performance...the 15" Quattro being a leading candidate.

Sam, not sure what kind of tools you have access to. Did some quick scribbling to come up with some ideas to discuss with your wife. I haven't done the exact math, but assumed a bit of fudge factor for driver/port/bracing volume and shot for a 2 ft^3 gross to yield the 1.75 net for the Dayton 12" RS-HO I modeled.

The 12" RS-HO should fit in your 12" sonotube (barely) with an external height of 32", assuming .75" end caps. Works out perfectly to have the driver facing down and a 3"x20ish" port firing out the top...SVS style. If you go to 16" tube, you only need 18.5" tall with .75" end caps....need to elbow the port with this one.

Or, if you want a small end table/plant stand/ottoman type config. A 16"x16"x17.5" external box (16x14.5x16 internal) box should do it. Conveniently, at least at my Home Depot, you can get 16"x4'x.75" MDF boards. Now you only have to cut 16" lengths out of it for the sides panels and two 17.5" lengths for the top and bottom. The HD panel saw may be accurate enough, depending on the operator. Finish to taste. I assume you can handle the circles for driver/port since you already made a sonotube. Your port will need an elbow inside of the cabinet, unless you want to do something funky with a partially external port.

Just for fun, a 16"x28.5" sonotube will get you into that sealed Quattro 15.

These guys offer wood cylinders, including veneering options, if that helps with the wife. Shipping might be cost prohibitive.
http://www.tapeease.com/Wood%20Cylinders.htm


wbs

I love this website. You guys are awesome!!!
PE has the Quatro 15" for $75 and the 240watt amp for $110. That puts me right at $200 with shipping.
I made do last time using my Dremel circle cutting adapter and it maxes out at 12", so I'm going to have to get a router this time... and I don't really count tool purchases in the grand scheme of things since I'm a tool nut. A basic Craftsman router and circle guide should go for no more than $100.
Steve, the sealed sub in the link you provided me might be the way to go. It can double as an end table and the wife would approve of that. Plus I can design the whole thing to match the rest of the furniture in the room and it'll integrate seamlessly. I didn't even consider sealed, but that would cut down on a lot of engineering and save some money and time.
Brent, I think based on my first attempt, I'm gonna go big this time. 15" sounds like I won't have any more disappointments... and with $75 for a quality driver, the cost increase over a 12" is negligible. You're inputs were right on the money for the information I was giving, so thanks a bunch for the time spent... I'm sure with the amount of hits this thread is getting, you've inspired some others.

One question. As with the sonosub I just made, I built a separate small box to house the amp... it's stained to match the sub and furniture and sits strategically located on the bottom shelf of a corner bookshelf approx one foot from the sub. I like the idea keeping the amp separate. It will make it easier to audition other subs that I may create in the future... and it's an interesting conversation piece. Anybody have any thoughts on integrating the amp into the enclosure? I do not plan to, but my mind can be changed if you're reasoning is "sound".

I think keeping the amp seperate is a good idea. If you want any specific details on that design, feel free to ask sensibull, as I'm sure he is happy to help, or feel free to ask me, as I helped him in the designing process. If you want to change it up a bit that wouldn't be a problem either.

As for the router and perhaps any other tools you may need to get the project going, or any other tools you may need for future DIY projects, the guys over at htguide.com are pretty much experts. This thread mentions the preferred tools at certain price points:

http://www.htguide.com/forum/showthread.php4?t=17998

Sam, no worries...we're all here to try to help each other.

Although, since you're willing to consider a bigger cabinet I have to try to give you analysis paralysis with another idea. Take a peek at the DVC12 in 3 ft^3 tuned to 20 hz. With 240 watts, WinISD predicts 105db @ 20hz vs. 100db @ 20hz for the Quattro 15. The DVC12 maintains a decreasing advantage up to 45hz, where the Quattro pulls ahead slightly. Based on the sims, $15 more (using sale price) for the DVC12 gets you the output of two Quattros at 20hz.

And if you really want to get wild, consider a 12" RS-HiFi in 4 ft^3 tuned to 20hz...-3b point is 19hz with 107db@20 from 240 watts.

For circle cutting, from what I've read, you can't do much better than ordering the Jasper jigs from PE while you're ordering that Quattro. They're going to be in my next order. http://www.partsexpress.com/pe/showd...number=365-260

wbs

Those are great suggestions. It's gonna take me a week to make a real decision.
The thought of a 15" for that price is still tempting... but the higher performance of a smaller driver (in the same cabinet has it's appeals. I could still do a box using that size woofer without the added expense of a router. The dremel does a great job, it's just a little slower than a real router.
I also just realized I could purchase only the driver for now and get the 240watt amp in a month or so. The 100watt amp I currently have could fill in nicely. I also don't have to wait on the driver to be shipped. I could start on the box now and have it ready when the driver arrives. The DVC 12" is looking like more of a plan.

Curious, I just noticed that winISD doesn't have any Dayton products on it's driver list. I know I have the latest version. What gives?

Don't want to drag you into upgraditis before you've even begun building, but if you are going to consider the 12" DVC at $90, you may as well get the 15" DVC for $105

From the release notes, it doesn't look Linear Team added drivers to the shipping db since the 5/27/02 release. Even then, it's not clear how they arrive at what drivers to include. I'd have been just as happy if the db arrived blank so I would only have to wade through the drivers I've added myself, especially considering that most of the included drivers are probably out of production. Now there's a thought...since each driver is its own data file, I could just start deleting to clean things up. Thanks for asking the question Sam.

Unless $$$ is too tight at the moment, since you know you're going to get the 240 watt amp relatively soon, I would try to order it at the sale price. The sale prices run through 2/23. You'll give up a little more than 3db of maximum output by using the 100 watt amp instead of the 240.

Steve,
didn't want to cause a divorce by having him propose a 6+ ft^3 beast to his wife for a second project. Gotta work your way into these things. The 15" DVC in a big ported box is my next upgrade for our theater room.

wbs

Just placed my order for the DVC12", 240watt plate amp, and a set of binding posts. I've got all other materials already at home... so it's time to get working on a box.
I don't have access to winISD here at work, but getting back to my options... if I was thinking about sticking with a 3cuft enclosure, say about 20hX19wx19d using 3/4mdf, and a single panel of interior bracing should get me right at 3.0 in a sealed enclosure. I'm going to model the look after the sub Steve linked to in the AVS forum. That sub is front-firing. I wouldn't be opposed to a downfiring configuration if the sub is capable of that or if there is an advantage to it (keeps the driver safe from harm), but I couldn't find any info on mounting specs. Can or should I mount the 12DVC down? Also, is there a ported option for me in that size of cabinet? As per Brent's modeling of 105db@20hz, when considering room gain in my 13'x15' dedicated HTR, it should play plenty low and loud already. Would porting get me any significant gains vs. the slight pain of engineering the port. I might consider a port if it got me a little lower without sacrificing SPL in the 20-40hz range. Thanks for your repsonses.

I think this is the sag equation to determine if a driver is suitable for downfiring:

24849/(Xmax x (Fs x Fs))

You want the result to be less than 5%. Now I prefer ported designs, but when you limit yourself to a small enclosure, you are typically better off going sealed. There has been a lot of discussion going on at AVS regarding distortions, and not only will downfiring protect the driver, but it will basically eliminate any chance for doppler distortion as well. A drawback is that you need legs and that will increase the overall size.